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SUSITNA HYDROELECTRIC PROJECT
FISH RESOURCES AND HABITATS OF THE SUSITNA BASIN
Prepared by:Timothy R.Jennings
Woodward-Clyde Consultants
701 Sesame Street
Anchorage,Alaska 99503
Submitted to:
Harza-Ebasco Susitna Joint Venture
711 H Street
Anchorage,Alaska 99501
for:
The Alaska Power Authority
327 W.5th Avenue,2nd Floor
Anchorage,Alaska 99501
November 1984
ARLIS
Alaska Resources
Library &Information ServICes
Anchorage.Alaska
PREFACE
This report represents a volume of the Instream Flow Relationships
Study technical report series prepared for the Susitna Hydroelectric
Project.The primary purpose of the Instream Flow Relationships
Report and its associated technical report series is to present
technical information and data that reflects the relative importance
of the various interactions among the primary physical and biological
components of aquatic habitats within the Talkeetna-to-Devil Canyon
reach of the Susitna River.The Instream Flow Relationships Report
and its associated technical report series are not intended to be an
impact assessment.However.these reports present a variety of
natural and with-proj ect relationships that provide a quantitative
basis to compare alternative streamflow regimes.conduct impact
analyses.and prepare mitigation plans.
The technical report series is based on the data and findings
presented in a variety of baseline data reports prepared by the Alaska
Department of Fish and Game Su Hydro Aquatic Study Team.R&M
Consultants,and E.Woody Trihey and Associates.The Instream Flow
Relationships Report and its associated technical report series
provide the methodology and appropriate technical information for use
by those deciding how best to operate the proposed Susitna
Hydroelectric Project for the benefit of both power production and
downstream fish resources.The technical report series is described
below.
Technical Report No.1.Fish Resources and Habitats of the Susitna
Basin.This report.prepared by Woodward-Clyde Consultants.
consolidates information on the fish resources and habitats in the
Talkeetna-to-Devil Canyon reach of the Susitna basin available through
June 1984 that is currently dispersed throughout numerous reports.
Technical Report No.2.Physical Processes Report.This report.
prepared by R&M Consultants.describes naturally occurring physical
processes within the Talkeetna-to-Devil Canyon river reach pertinent
to evaluating project effects on riverine fish habitat.
ii
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,Technical Report No.3.Water Quality/Limnology Report.This report,
prepared by Harza-Ebasco,consolidates existing information on water
quality in the Susitna basin and provides technical discussions of the
potential for with-project bioaccumulation of mercury,influences on
nitrogen gas supersaturation,changes in downstream nutrients and
changes in turbidity and suspended sediments.This report is based
principally on data and information that is available through June
1984.
Technical Report No.4.Reservoir and Instream Temperature.This
report,prepared by AEIDC,consists of three principal components:
(1)reservoir and instream temperature modeling;(2)selection of
temperature criteria for Susitna River fish stocks by species and life
stage;and (3)evaluation of the influences of with-project stream
temperatures on existing fish habitats and natural ice processes.
Technical Report No.5.Aquatic Habitat Report.This report,
prepared by E.Woody Trihey and Associates,describes the availability
of various types of aquatic habitat in the Talkeetna-to-Devil Canyon
river reach as a function of mainstem discharge.
iii
TABLE OF CONTENTS
Page
i~
PREFACE ii
LIST OF TABLES vi
LIST OF FIGURES viii
1.0 INTRODUCTION 1-1
2.0 BACKGROUND 2-1
3.0 INTRODUCTION TO FISH RESOURCES 3-1
3.1 OVERVIEW OF IMPORTANT SPECIES 3-1
3.2 CONTRIBUTION TO COMMERCIAL FISHERY 3-1-3.2.1 Sockeye Salmon 3-2
3.2.2 Chum Salmon 3-2
3.2.3 Coho Salmon 3-3
3.2.4 Pink Salmon 3-3
3.2.5 Chinook Salmon 3-3
3.3 SPORT FISHING 3-4
3.3.1 Arctic Grayling 3-4
3.3.2 Rainbow Trout 3-5
3.3.3 Pink Salmon 3-5
3.3.4 Coho Salmon 3-5
F"""3.3.5 Chinook Salmon 3-6
3.3.6 Chum Salmon 3-6
3.3.7 Sockeye Salmon 3-6
3.4 SUBSISTENCE FISHING 3-7
4.0 SPECIES BIOLOGY 4-1
4.1 ADULT MIGRATION 4-1
4 .1.1 Sockeye Salmon 4-1
4.1.2 Chum Salmon 4-3
4.1.3 Coho Salmon 4-5
4 .1.4 Pink Salmon 4-7
4.1.5 Chinook Salmon 4-9
4.2 SPAWNING 4-12
4.2.1 Sockeye Salmon 4-12
4.2.2 Chum Salmon 4-16
4.2.3 Coho Salmon 4-21
4.2.4 Pink Salmon 4-23
fflIJIill 4.2.5 Chinook Salmon 4-26
4.3 INCUBATION 4-29
4.3.1 Dissolved Oxygen 4-30
4.3.2 Temperature 4-31
j~4.3.3 Substrate 4-35
4.3.4 Streamflow 4-36
4.3.5 Biochemical Oxygen Demand 4-37
4.3.6 Superimposition 4-38
4.3.7 Predators 4-38
iv
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Table of Contents (Continued)
4.4 REARING
4.4.1 Sockeye Salmon
4.4.2 Chum Salmon
4.4.3 Coho Salmon
4.4.4 Pink Salmon
4.4.5 Chinook Salmon
4.5 OUTMIGRATION
4.5.1 Sockeye Salmon
4.5.2 Chum Salmon
4.5.3 Coho Salmon
4.5.4 Pink Salmon
4.5.5 Chinook Salmon
5.0 HABITAT UTILIZATION AND RELATIONSHIPS
5.1 MAINSTEM AND SIDE CHANNEL HABITAT
5.1.1 Adult Salmon
5.1.2 Juvenile Salmon
5.2 SIDE AND UPLAND SLOUGH HABITAT
5.2.1 Adult Salmon
5.2.2 Juvenile Salmon
5.3 TRIBUTARY AND TRIBUTARY MOUTH HABITAT
5.3.1 Adult Salmon
5.3.2 Juvenile Salmon
6.0 SUMMARY DESCRIPTION
6.1 FACTORS AFFECTING PRODUCTION
6.1.1 Adult Migration
6.1.2 Spawning and Incubation
6.1.3 Rearing
6.2 RELATIONSHIPS AMONG LIMITING FACTORS
ACKNOWLEDGEMENTS
LITERATURE CITED
TABLES
FIGURES
APPENDICES
APPENDIX A
v
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4-38
4-42
4-43
4-46
4-47
4-50
4-50
4-53
4-56
4-59
4-60
5-1
5-1
5-1
5-3
5-4
5-6
5-8
5-9
5-10
5-11
6-1
6-1
6-1
6-3
6-6
6-8
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LIST OF TABLES
Table 1.Common and scientific names of fish species recorded from
the Susitna Basin.
Table 2.Commercial catch of upper Cook Inlet salmon in numbers of
fish by species.
Table 3.Summary of commercial and sport harvest on Susitna River
basin adult salmon returns.
Table 4.Susitna Basin sport fish harvest and effort by fishery and
species -1978, 1979,1980,1981,1982 and 1983.
Table 5.Sport fish harvest for Southcentral Alaska and Susitna Basin
in numbers of fish by species,1978-1983.
Table 6.Susitna River annual salmon escapement by sub-basin and
species.
Table 7.Chinook salmon peak survey escapement counts of Susitna
River streams by sub-basin from 1976 to 1983.
Table 8.Second-run sockeye salmon peak survey counts in sloughs
above RM 98.6,1981-1983.
Table 9.Second-run sockeye salmon total slough escapement above
RM 98.6,1981-1983.
Table 10.Percentages of fish spawning by habitat zone in 1983 for
sloughs Moose,8A and 11.
Table 11.Sex ratios of second-run sockeye at Susitna,Yentna,
Sunshine,Talkeetna and Curry stations,1981-1983.
Table 12.Chum salmon peak index counts by habitat type above RM 98.6,
1981-1983 .
Table 13.Chum salmon peak index counts in sloughs above RM 98.6,
1981-1983.
Table 14.Chum salmon total slough escapement above RM 98.6,
1981-1983.
Table 15.Chum salmon peak index counts in streams above RM 98.6,
1981-1983.
Table 16.Chum salmon peak spawner counts and spawning observations in
mainstem habitats above RM 98.6,1981-1983.
Table 17.Sex ratios of chum salmon at Susitna,Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
vi
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List of Tables (Continued)
Table 18.Coho salmon peak index counts in streams above RM 98.6,
1981-1983.
Table 19.Sex ratios of coho salmon at Susitna,Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
Table 20.Pink salmon peak index counts in streams above RM 98.6,
1981-1983.
Table 21.Pink salmon total slough escapement above RM 98.6,
1981-1983.
Table 22.Sex ratios of pink salmon at Susitna,Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
Table 23.Chinook salmon peak index counts in streams above RM 98.6,
1981-1983.
Table 24.Sex ratios of chinook salmon at Yentna,Sunshine,Talkeetna
and Curry stations,1981-1983.
vii
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LIST OF FIGURES
Figure 1.Susitna River drainage basin.
Figure 2.General habitat categories of the Susitna River '-a
conceptual diagram.
Figure 3.Commercial catch of upper Cook Inlet salmon,1954-1983.
Figure 4.Commercial catch of upper Cook Inlet sockeye,1954-1983.
Figure 5.Commercial catch e>f upper Cook Inlet chum,1954-1983.
Figure 6.Commercial catch of upper Cook Inlet coho,1954-1983.
Figure 7.Commercial catch of upper Cook Inlet pink,1954-1983.
Figure 8.Commercial catch of upper Cook Inlet chinook,1954-1983.
Figure 9.Susitna River and major tributaries from mouth to Little
Willow Creek.
Figure 10.Susitna River and major tributaries from Montana Creek to
Devil Canyon.
Figure 11.Migrational timing of second run sockeye salmon based on
fishwheel catch per unit effort at selected locations on
the Susitna River in 1981,1982 and 1983.
Figure 12.Comparison of second-run sockeye fishwheel catch and
mainstem discharge at Sunshine Station,1981-1983.
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Figure 13.1981-1983 Susitna
utilization •
sockeye escapement and relative
Figure 14.Migrational timing of chum salmon based on fishwheel catch
per unit effort at selected locations on the Susitna River
in 1981,1982 and 1983.
Figure 15.Comparison of chum salmon fishwheel catch and mainstem
discharge at Sunshine Station,1981-1983.
Figure 16.1981-1983 Susitna chum escapement and relative utilization.
Figure 17.Migrational timing of coho salmon based on fishwheel catch
per unit effort at selected locations on the Susitna River
in 1981,1982 and 1983.
Figure 18.Comparison of coho salmon fishwheel catch and mainstem
discharge at Sunshine Station,1981-1983.
Figure 19.1981-1983 Susitna coho escapement and relative utilization.
viii
,...
List of Figures (Continued)
Figure 20.Migrational timing of pink salmon based on fishwheel catch
per unit effort at selected locations on the Susitna River
in 1981,1982 and 1983.
Figure 21.Comparison of pink salmon fishwheel catch and mainstem
discharge at Sunshine Station,1981-1983.
Figure 22.Odd-year (1981 and 1983)Susitna pink escapement and
relative utilization.
Figure 23.Migrational timing of chinook salmon based on fishwheel
catch per unit effort at selected locations on the Susitna
River in 1981,1982 and 1983.
Figure 24.Comparison of chinook salmon fishwheel catch and mainstem
discharge at Sunshine Station,1981-1983.
Figure 25.1982-1983 Susitna
utilization.
chinook escapement and relative
.-
Figure 26.Distribution of juvenile sockeye salmon by macrohabitat
type on the Susitna River between the Chulitna River
confluence and Devil Canyon,May through October 1983.
Percentages are based on mean catch per cell.
Figure 27.Distribution of juvenile chum salmon by macrohabitat type
on the Susitna River between the Chulitna River confluence
and Devil Canyon,May through October 1983.Percentages
are based on mean catch per cell.
Figure 28.Chum salmon fry daily catch per hour recorded at the
downstream migrant traps,May 18 through August 20,1983
and sockeye salmon fry daily catch per hour recorded at the
downstream migrant traps,May 18 through August 30,1983.
Figure 29.Coho salmon age 0+and age 1+or older daily catch per hour
recorded at the downstream migrant traps,May 18 through
August 30,1983.
Figure 30.Distribution of juvenile coho salmon by macrohabitat type
on the Susitna between the Chulitna River confluence and
Devil Canyon,May through November 1983.Percentages are
based on mean catch per cell.
Figure 31.Distribution of juvenile chinook salmon by macrohabitat
type on the Susitna River between the Chulitna River
confluence and Devil Canyon,May through November 1983.
Percentages are based on mean catch per cell.
Figure 32.Pink salmon fry daily catch per hour recorded at the
downstream migrant traps,May 18 through July 8,1983.
Figure 33.Chinook salmon age 0+and age 1+daily catch per hour
recorded at the downstream migrant traps,May 18 through
August 3D,1983.
ix
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1.0 INTRODUCTION
This report summarizes the available information on the fishery
resources and habitats of the Susitna River.It is based primarily on
existing reports and analyses generated by the feasibility and
licensing studies of the Susitna Hydroelectric project with a lesser
dependence on additional pertinent information in the literature.The
objective of the report is to synthesize and summarize information to
describe the biology,relative abundance and seasonal habitat
utilization of important fishery resources.As a part of the Instream
Flow Relationships (IFR)report series,information summarized here
will assist in defining the relationships between physical processes
and fishery habitat in the Susitna River basin.
Since the report series provides the important information relative to
the decisionmaking process,this report is focused on habitats and
species most likely to be affected by the proposed project.Most of
the report emphasizes the Talkeetna-Devil Canyon reach [river mile
(RM)98.6-152J of the Susitna River.This river reach extends from
the proposed Devil Canyon dam site (RM 152)downstream to the
confluence of the Susitna and Chulitna rivers (RM 98.6).
The proposed project is expected to have the greatest downstream
effects on habitats within this reach.Downstream from Talkeetna,the
inflow from the Talkeetna and Chulitna rivers is expected to reduce
the magnitude of change in physical processes under with-project
conditions.Additionally,this report emphasizes salmon species and
their habitat utilization because of their importance in commercial,
sport and subsistence fisheries and high social value.The available
project information reflects the heavy emphasis given salmon species.
Section 2.0 contains a brief description of the project and project
area and a synopsis of the studies that have been conducted to date on
fish resources of the Susitna River.In Section 3.0 the species of
1-1
the Susitna River are introduced and their commercial,recreational
and subsistence utilization and importance are discussed.Section 4.0
summarizes information on the species biology of the five Pacific
salmon found in the Susitna River.Habitat utilization and
relationships are discussed in Section 5.0.Based on studies to date,
the significance of habitat types for a species life stage is
presented.Section 6.0 summarizes some factors that affect fish
production in freshwater and discusses their possible significance in
the Susitna River drainage.
1-2
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2.0 BACKGROUND
The Susitna River flows approximately 318 miles (530 km)and drains
about 19.600 square miles (50.900 km 2 )from the terminus of the
Susitna Glacier in the Alaska Mountain Range to its mouth in Cook
Inlet (Figure 1).The study area for the Susitna hydroelectric
project fish studies includes the Susitna River mainstem.side
channels.sloughs.and mouths of major tributaries.A diagram and
description of major habitat categories of the Susitna River is
presented in Figure 2.
The Alaska Power Authority (APA)has proposed construction of two dams
on the Susitna River:Devil Canyon Dam (RM 152)and Watana Dam
(RM 184).The project would reduce streamflows during the summer and
increase them during the winter.Suspended sediment,turbidity and
water temperatures are expected to follow similar patterns (reduced
levels in summer and increased levels in winter).Details of dam
construction.operation and expected changes to aquatic habitats and
fish resources are presented by Acres (1983a.b).
Fish and aquatic habitat investigations have been conducted on the
Susitna River for about ten years to evaluate the proposed
hydroelectric project.Beginning in 1974,studies were conducted to
describe and quantify fish resources,habitat utilization and aquatic
habitats of the Susitna River.In 1980 the Susitna Hydroelectric
Aquatic Studies Program was initiated.Baseline data collection on
fish and aquatic habitat resources was divided into three groups:
Adult Anadromous Fish Studies (AA).Resident and Juvenile Anadromous
Fish Studies (RJ).and Aquatic Habitat and Instream Flow Studies (AR).
The objectives of the three sections of this continuing program are:
(1)AA determine the seasonal distribution and
abundance of adult anadromous fish populations
within the Susitna River drainage;
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relative
produced
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(2)RJ determine the seasonal distribution and relative
abundance of selected resident and juvenile anadromous fish
populations within the Susitna River drainage;and
(3)AH characterize the seasonal habitat requirements of
selected anadromous and resident fish species within the
Susitna River drainage and the relationship between the
availability of these habitat conditions and the mainstem
discharge of the Susitna River.
A summary of the significant accomplishments to date by the three
sections of ADF&G's Su Hydro Group is outlined below.
Adult Anadromous
a.Documented migrational timing of salmon runs in the Susitna
River.
b.Estimated population size and relative abundance of salmon in
sub-basins of the Susitna River.
c.Estimated total slough escapements for salmon in sloughs above
RM 98.6.
d.Estimated relative abundance of spawning salmon in tributaries
above RM 98.6•
e.Quantified selected biological characteristics for salmon stocks
in the Susitna River (i.e.sex ratio.fecundity.age and length).
Resident and Juvenile Anadromous
q.Estimated population size for Arctic grayling populations in the
proposed impoundment areas.
b.Identified importanD spawning locations for resident species.
2-2
c.Estimated the relative utilization of macrohabitat types for
juvenile salmon and selected resident species.
d.Developed habitat suitability criteria for juvenile salmon.
e.Estimated population size and survival for juvenile chum and
sockeye.
f.Defined outmigration timing and rates for juvenile salmon.
Aquatic Habitat and Instream Flow
a.Collected physical and chemical water quality data describing
macrohabitat types.
b.Identified aquatic macrohabitat types within the middle reach of
the Susitna River (RM 98.6 -152).
c.Defined seasonal timing and utilization of adult salmon in
macrohabitat types.
-d.Developed site-specific habitat responses to mainstem discharge.
e.Developed habitat criteria for adult and juvenile salmon.
eulachon.Bering cisco.and selected resident species.
f.Evaluated the access and passage of adult salmon into selected
sloughs.
g.Confirmed the importance of ground water upwelling for spawning
salmon in sloughs.
For a list of ADF&G Susitna Hydro references see Appendix A.
2-3
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3.0 INTRODUCTION TO FISH RESOURCES
3.1 OVERVIEW OF IMPORTANT SPECIES
Fishery resources in the Susitna River comprise a major portion of the
Cook Inlet commercial salmon harvest and provide sport fishing for
residents of Anchorage and the surrounding area.Anadromous species
that form the base of commercial and non-commercial fisheries include
five species of Pacific salmon:chinook,coho,chum,sockeye,and
pink.Other anadromous species include eulachon and Bering cisco.
The Susitna River is a migrational corridor,spawning area,and,.
juvenile rearing area for five species of salmon from its point of
discharge into Cook Inlet [river mile (RM)0]to Devil Canyon
(RM 152),where salmon are usually prevented from moving upstream by
the water velocity at high discharge.Sloughs and tributaries provide
most of the spawning habitat for salmon,while the mainstem,sloughs,
and tributary mouths are important habitats for juvenile salmon
rearing and overwintering (ADF&G 1984a,b).
Important resident species found in the Susitna River basin include
Arctic grayling,rainbow trout,lake trout,burbot,Dolly Varden.and
round whitefish.Scientific and common names of all fish species
identified from the Susitna River basin are listed in Table 1.
3.2 CONTRIBUTION TO COMMERCIAL FISHERY
With the exception of sockeye and chinook salmon,the majority of
upper Cook Inlet salmon production originates in the Susitna Basin
(ADF&G 1984a).The long-term average annual catch of 3.0 million fish
is ~TOrth approximately $17.9 million to the commercial fishery (K.
Florey,ADF&G,personal communication,1984).In 1982 and 1983
fishermen landed record numbers of salmon in the upper Cook Inlet
fishery (Figure 3);over 6.2 million salmon were caught in 1982 and
over 6.7 million fish were landed in 1983.The Susitna River is
considered the most important salmon-producing system in upper Cook
3-1
Inlet;however,the quantitative contribution of the Susitna River to
the commercial fishery can only be approximated because of:
o The high number of intra-drainage spawning and rearing
areas;
o The lack of data on other known and suspected salmon-
producing systems in upper Cook Inlet;
o The lack of stock separation programs (except for sockeye
salmon);and
o Overlap in migration timing of mixed stocks and species in
Cook Inlet harvest areas.
Therefore,the estimates of contribution of Susitna River salmon to
the upper Cook Inlet fishery should be viewed as preliminary.
3.2.1 Sockeye Salmon
The commercial sockeye harvest has averaged 1.31 million fish annually
in upper Cook Inlet over the last 30 years (Table 2).The estimated
contribution of Susitna River sockeye to the upper Cook Inlet fishery
is between 10 to 30 percent (ADF&G 1984a).This represents an
estimated annual Susitna River sockeye harvest of between 131,000 to
393,000 fish in the commercial harvest over the last 30 years.In
1983 the upper Cook Inlet sockeye catch was the highest in the 30
years of record (Figure 4)and Susitna River sockeye contributed
approximately 500,000 fish to the total catch of 5 million (Table 3).
3.3.2 Chum Salmon
The upper Cook Inlet chum salmon catch has averaged 658,000 fish
annually since 1954 (Table 2).The contribution of Susitna River chum
to the upper Cook Inlet fishery is about 85 percent (ADF&G 1984a).
This contribution represents an estimated average annual chum harvest
3-2
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of 559,000 Susitna River fish in the commercial harvest over the last
30 years.The Susitna harvest of chum in 1982 was about 1.22 million
fish (Table 3)when a record 1.43 million chum were caught in the
upper Cook Inlet fishery (Figure 5).
3.2.3 Coho Salmon
Since 1954,the upper Cook Inlet coho salmon commercial catch has
averaged 258,000 fish annually (Table 2).Approximately 50 percent of
the .commercial coho harvest in upper Cook Inlet is Susitna River coho
(ADF&G 1984a).This contribution represents an average annual Susitna
River coho harvest of 129,000 fish in the commercial harvest over the
last 30 years.In 1982 the estimated Susitna coho harvest was 388,500
fish (Table 3)when a record 777,000 coho were harvested in the upper
Cook Inlet fishery (Figure 6).
3.2.4 Pink Salmon
The upper Cook Inlet average,annual,odd-year harvest of pink salmon
sincle 1954 is about 120,000 fish with a range of 12,500 to 544,000
fish,while the average,annual,even-year harvest is approximately
1.64 million pink with a range of 484,000 to 3.23 million fish
(Table 2;Figure 7).The estimated contribution of Susitna River pink
salmon to the upper Cook Inlet pink fishery is 85 percent (ADF&G
1984a).This represents an average annual Susitna River contribution
of 102,000 odd-year pink and 1.39 million even-year pink to the upper
Cook Inlet fishery over the last 30 years.
3.2.5 Chinook Salmon
The commercial chinook harvest has averaged 19,600 fish annually in
the upper Cook Inlet fishery over the last 30 years (Table 2).Since
1964,the opening date of the commercial fishery has been June 25,and
the Susitna River chinook salmon run begins in late May and peaks in
mid-June.Thus,the majority of chinook have already passed through
the area subject to commercial fishing.Commercial catches for
3-3
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1964-1983 have been lower than catches before 1964 (Figure 8)because
of the change in the opening date.Catches have averaged 11 ,600
chinook annually for the 20 year period of 1964-1983.Approximately
10 p,ercent of the total chinook harvest in upper Cook Inlet is Susitna
River stock (ADF&G 1984a).This represents an average annual
contribution of 1,960 chinook to the upper Cook Inlet fishery for the
last 30 years,or 1,160 fish for 1964-1983.
3.3 SPORT FISHING
Increases in population and tourism in Alaska have resulted in a
growing demand for recreational fishing.Recreational fishing is now
considered a significant factor in total fisheries management,
especially in Cook Inlet where commercial and non-commercial user
conflicts have developed (Mills 1980).The Susitna River and its
major salmon and resident fish-producing tributary streams provide a
multi-species sport fishery easily accessible from Anchorage and other
Cook Inlet communities.Since 1978,the Susitna River and its primary
tributaries have accounted for an average of 127,100 angler days of
sport fishing effort,approximately 9 percent of the 1977-1983 average
of ll.4 million total angler days for Alaska and 13 percent of the
1977-1983 average of 1.0 million total angler days for the South-
central region (Mills 1979,1980, 1981,1982, 1983,1984).
The sport fish harvests for 1978 through 1983 from the Susitna Basin
based on mail surveys to a sample of license holders are shown in
Table 4 (Mills 1979,1980,1981,1982, 1983,1984).The estimates
represent the sport fishing harvests throughout the Susitna Basin and
includes an area that is larger than that which could be affected by
the proposed project (see Figures 9 and 10 for locations of major
tributaries listed in Table 4).
3.3.1 Arctic Grayling
The annual Arctic grayling sport harvest has averaged 18,200 fish in
the Susitna Basin and 61,500 fish in Southcentral Alaska over the last
3-4
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six years (Table 5).This represents a Susitna Basin contribution of
about 30 percent to the Southcentral Arctic grayling sport harvest for
the six year period.The largest sport harvest of Arctic grayling on
record in the Susitna Basin occurred in 1980 when an estimated 22.100
fish were caught.which represents about 32 percent of the total
Southcentral grayling harvest for that year (Mills 1981).
3.3.2 Rainbow Trout
The Susitna Basin and Southcentral Alaska rainbow trout sport harvests
have averaged 16.000 and 132.900 annually since 1978 (Table 5).
Approximately 12 percent of the annual Southcentral Alaska rainbow
trout sport harvest was caught in the Susitna Basin over the last six
years.In 1979.about 18.350 rainbow trout were harvested by anglers
in the Susitna Basin.which represents approximately 14 percent of the
1979 Southcentral region grayling sport catch (Mills 1980).
3.3.3 Pink Salmon
The annual,even-year pink salmon sport harvest has averaged 42.950
fish in the Susitna Basin and 134.400 fish in Southcentral Alaska
since 1978 (Table 5).This represents a Susitna Basin harvest of
about 32 percent of the annual.even-year pink sport catch in South-
central Alaska since 1978.The annual,odd-year pink salmon sport
catch has averaged 8.600 fish in the Susitna Basin and 58,300 fish in
Southcentral Alaska since 1979 (Table 5).Approximately 15 percent of
the odd-yearSouthcentral pink harvest was caught in the Susitna Basin
since 1979.The largest sport harvest on record of pink salmon in the
Susitna Basin occurred in 1980 when an estimated 56.600 fish were
caught (Mills 1981).In 1981.the estimated odd-year pink salmon
sport harvest of 8,700 fish represented about 6.8 percent of the
estimated Susitna escapement of 127.000 pink salmon (Table 3).
3.3.4 Coho Salmon
Since 1978.the Susitna Basin and Southcentral Alaska coho salmon
sport harvests have averaged 13,200 and 103,800 fish annually
3-5
,....
·(Table 5).This represents a Susitna Basin sport harvest of 13
percent of the Southcentral Alaska coho sport harvest for the six year
period.In 1982 about 16,664 coho were landed by anglers in the
Susitna Basin (Mills 1983),which is the largest annual catch on
record.The annual sport harvest of coho in the Susitna Basin is
significant when compared with the estimated total escapement of coho
in the basin.In 1983,almost one out of every five coho entering the
basin was caught by sport anglers (Table 3).
3.3.5 Chinook Salmon
The annual chinook salmon sport harvest has averaged 37,300 fish in
Southcentral Alaska and 7,950 fish in the Susitna Basin since 1978
(Table 5).This represents an annual Susitna Basin contribution of 21
perc,ent to the Southcentral chinook sport harvest over the six year
period.The largest Susitna Basin sport harvest of chinook salmon on
record occurred in 1983 when 12,420 fish were caught by fishennen
(Mills 1984).
3.3.6 Chum Salmon
The Susitna Basin and Southcentral Alaska chum salmon sport harvests
have averaged 6,800 and 12,150 fish annually since 1978 (Table 5).
This represents an annual Susitna Basin contribution of 56 percent to
the Southcentral chum sport harvest for the six year period.The
largest sport catch of chum salmon on record in the Susitna Basin
occurred in 1978 when 15,700 fish were landed (Mills 1979).For the
years 1981 to 1983,chum salmon sport harvests have averaged between
1.4 and 1.8 percent of the estimated Susitna Basin chum salmon
escapement (Table 3).
3.3.7 Sockeye Salmon
The annual sockeye salmon sport harvest has averaged 112,900 fish in
Southcentral Alaska and 2,100 fish in the Susitna Basin for the years
1978 through 1983 (Table 5).This represents an annual Susitna Basin
3-6
.-
contribution of less than 2 percent of the Southcentral sockeye sport
harvest for the six year period.In 1983 over 5,500 sockeye salmon
were caught by fishermen in the Susitna Basin,which is the largest
annual catch on record (Mills 1984).The sport catch of sockeye from
1981 through 1983 has averaged 3 percent or less of the estimated
Susitna Basin sockeye escapement (Table 3).
3.4 SUBSISTENCE FISHING
Subsistence harvests within the Susitna Basin are unquantified even
though salmon provide an important resource for many Susitna Basin
residents.The village of Tyonek,approximately 30 miles (50 km)
southwest of the Susitna River mouth,is supported primarily by
subsistence fishing on Susitna River chinook stocks (ADF&G 1984d).
The Tyonek subsistence fishery was reopened in 1980 after being closed
for sixteen years.The annual Tyonek subsistence harvest has averaged
2,000 chinook,250 sockeye and 80 coho for the years 1980 through 1983
(ADF&G 1984c).
3-7
4.0 SPECIES BIOLOGY
4 .1 ADULT MIGRATION
4.1.1 Sockeye Salmon
~
(i)Timing of Runs
Sockeye salmon enter the Susitna River in two distinct runs.The
first run of fish enters the river in late May to early June and peaks
at Sunshine Station (RM 80)between the first and third weeks of June
(ADF&G 1984a).The escapement of first-run sockeye at Sunshine
Station was about 5,800 fish in 1982 and 3,300 fish in 1983.First
run sockeye spawned exclusively in Papa Bear Lake and inlet stream in
the Talkeetna River drainage (RM 97.1)in 1982 and 1983 (ADF&G 1982a,
1984a).Peak spawning activity for first run sockeye in Papa Bear
Lake was between the second and fourth weeks of July in 1983 and
between the third week of July and the first week of August in 1982.
SeCCind-run sockeye enter the Susitna River about the last of June and
in 1981,1982 and 1983 passed Sunshine Station between the third week
of July and the second week of August (ADF&G 1984a).Second-run
sockeye are abundant in the Talkeetna-Devil Canyon reach (RM 98.6-152)
from about the third week of July to the fourth week of August.A
summary of second-run sockeye migration timing in the Susitna River
basin for 1981,1982,and 1983 is presented in Figure 11.
Second-run sockeye salmon migration timing may be influenced by river
disc:harge.In 1982 a discharge spike above 80,000 cfs at Sunshine
Station coincided with reduced ADF&G fishwheel catches at Sunshine
Station (Figure 12).In 1983 river discharge was below 80,000 cfs
during most of the second-run sockeye migration at Sunshine Station
and the migration passed Sunshine Station in one major peak
(Figure 12).In 1981 river discharge was declining from over 150,000
cfs at Sunshine Station when most of the second-run sockeye passed
Sunshine Station (Figure 12).Based on this analysis,it appears that
4-1
-.
-
.....
spikes in discharge over 80,000 cfs at Sunshine Station can delay
sockeye salmon migration timing.
(ii)Escapement
The total annual escapement of second-run sockeye salmon in the
Susitna River has averaged 250,000 fish for 1981,1982 and 1983
(Table 6).Total escapement is derived by the summation of population
estimates at Yentna Station [RM 28,tributary river mile (TRM)04]and
Sunshine Station (RM 80)plus an additional five percent to correct
for fish that may spawn in other portions of the basin (Barrett 1984).
The majority (94 percent)of second-run sockeye in the Susitna River
enter the Yentna sub-basin (RM 28)and the Talkeetna-Chulitna
sub-basin (RM 80-98.6),with an estimated annual escapement to these
sub-basins of 235,000 fish (Table 6).
For 1981,1982,and 1983,second-run sockeye escapements have averaged
2,800 fish annually in the Talkeetna-Devil Canyon sub-basin (Table 6),
with a range of 2,170 to 3,360.The escapements are based on
popullation estimates at Talkeetna Station (RM 103),corrected for the
esti.mated 30 percent of the fish that return downstream below
Talkeetna Station and spawn elsewhere (Barrett 1984).The annual
second-run sockeye escapement to the Talkeetna-Devil Canyon sub-basin
for 1981 through 1983 represents about 1 percent of the total annual
sockeye escapement to the Susitna Basin for 1981-1983 (Table 6,
Figure 13).
Scale patterns of sockeye returning to the Chulitna River (RM 98.6)
and Talkeetna River (RM 97.1)spawning areas and of sockeye spawning
in sloughs upstream of Talkeetna Station were examined as part of the
ADF~~G stock separation program.The analysis indicated that the
sockeye spawning in sloughs upstream of Talkeetna Station in 1982
could not be separated from Talkeetna and Chulitna stocks on the basis
of scale patterns (ADF&G 1982b).The sockeye spawning upstream of
Talkeetna Station may be strays from Chulitna River and Talkeetna
4-2
.....
""'"
"""'
""'",
River stocks,or could be a stock that originated from strays of the
Talkeetna or Chulitna stocks •
(iii)Migration Rate
Tagged,second-run sockeye salmon migrated the 23 miles between
Sunshine Station (RM 80)and Talkeetna Station (RM 103)at an average
rate of travel of 1.8 miles per day (mpd)in 1981,2.4 mpd in 1983 and
2.7 mpd in 1982 (ADF&G 1984a).The avera~gerateof travel increased ....£)0 Vii v
for tagged,second-run sockeye between unsh..ine--St~tion and Curry J'I.·1 @,;{i,~1 +~.lk""I"'''''
Station (RM 120):2.7 mpd in 1981,3.4 mpd in 1982 and 3.7 mpd in 1983
(ADF&G 1984a).It appears that sockeye migration rates increase
and/or milling decreases as sockeye approach spawning areas.
4.1.2 Chum Salmon
(i)Timing of Runs
Chum salmon enter the Susitna River in late June to early July and are
numerous in the lower river at Yentna Station (RM 28,TRM 04)by the
third week of July (ADF&G 1984a).The chum migration lasts about one
month in the lower river,with most fish passing Yentna Station by the
third week of August (ADF&G 1984a).The chum migration passes
Sunshine Station (RM 80)from the end of July to early September.In
the Talkeetna-Devil Canyon reach (RM 98.6-152),the chum migration
begins about the end of July and continues until the end of August.A
summary of chum migration timing in the Susitna River for 1981,1982,
and 1983 is presented in Figure 14.
Chum salmon migration timing may be influenced by river discharge,
commercial catches in upper Cook Inlet and stock differences (ADF&G
1984a).During chum migrations in 1981 and 1983,peak river discharge
levels greater than 80,000 cfs at Sunshine Station coincided with
reduced fishwheel catches at Sunshine Station and appeared to delay
the chum migrations (Figure 15).In contrast,during the 1982 chum
migration,river discharge levels at Sunshine Station did not exceed
4-3
.....
-
-
"'"'
-
80.000 cfs during the chum migration and the migration passed Sunshine
Station in one major peak (Figure 15).The 1982 chum migration at
Sunshine Station was approximately two weeks shorter in duration than
the 1981 and 1983 migrations.presumably because the 1982 migration
was undelayed by'high river discharge.In 1982.the chum salmon
average migration rate (see Sec.4.1.2.iii)from Sunshine Station to
Talkeetna Station (RM 103)was faster than in 1981 and 1983 (ADF&G
1984a)and indicates that the 1982 chum migration was undelayed by
high river discharge at Sunshine Station.
Commercial catch data from the upper Cook Inlet fishery for 1981.1.982
and 1983 were compared with 1981.1982 and 1983 ADF&G fishwheel
catches at Sunshine Station.A 20 day adjustment was made to allow
for migration timing between the fishery and Sunshine Station (ADF&G
1984a).Reduced fishwheel catches in 1981 and 1983 corresponded with
peak commercial catches greater than 100.000 fish.However,the 1982
peak fishwheel catch and the second peak fishwheel catch in 1983 at
Sunshine Station coincided with peak commercial catches greater than
100,000 fish in upper Cook Inlet.In some years differential
commercial fishing may take place on Susitna River chum stocks,while
in other years commercial harvests in upper Cook Inlet do not appear
to influence the migration timing of chum in the Susitna River.The
effElct of commercial catches on chum migration timing may be masked by
run strength and river discharge.
Preliminary observations by ADF&G personnel suggest that the Chum}'/1"J",J.""l)......,.1'Ll!S til ,",'-
migration in the Susitna River is not segregated by spawning habitat ,,;,II:!J,A,',t;Jcl:.I,f{-c r ",~(I',
typE!S (ADF&G 1984a).Slough spawning and stream spawning chum salmon 0:"i)i_M !)",1 7fro,'".;VI)''''M.-(I
were numerous in both habitats in late July 1983.
(iiJi Escapement
For the last three years.the annual chum salmon total escapement in
the Susltna River has averaged 356.200 fish (Table 6).Chum total
escapement is derived by the summation of population estimates at
Yentna Station (RM 28,TRM 04)and Sunshine Station (RM 80)plus an
4-4
additional five percent estimated to spawn in other portions of the
basin (Barrett 1984).The majority (83 percent)of Susitna River chum
salmon enter the Talkeetna-Chulitna sub-basin (RM 80-98.6),which has
a three-year average escapement of 295,600 fish (Table 6).
In the Talkeetna-Devil Canyon reach,the chum salmon escapement has
averaged 24,100 fish for 1981,1982 and 1983 (Table 6),with a range
of Jl2,500 fish to 30,200 fish.The escapements are derived from
population estimates at Talkeetna Station (RM 103),less 40 percent
for those fish that return downstream below Talkeetna Station and
spawn elsewhere (Barrett 1984).The Talkeetna-Devil Canyon sub-basin
chum salmon escapements for 1981 through 1983 represent about seven
percent of the total Susitna River basin escapements for those years
(Table 6,Figure 16).
(iii)Migration Rate
Tagged chum salmon migrated between Sunshine Station (RM 80)and
Talkeetna Station (RM.103)at an average rate of travel of 3.8 miles
per day (mpd)in 1983,4.1 mpd in 1981 and 4.9 mpd in 1982.Chum
salmon migrated at faster rates between Talkeetna Station and Curry
Station (RM 120):4.5 mpd in 1981,6.3 mpd in 1983,and 7.7 mpd in
1982.Migration rates appear to increase as chum salmon approach
spavming areas.
4.1.3 Coho Salmon
(i)Timing of Runs
Coho salmon enter the Susitna River in mid-July and are abundant in
the lower river at Yentna Station (RM 28,TRM 04)from the third week
of July until the third week of August (ADF&G 1984a).The majority of
the coho migration passes Sunshine Station (RM 80)between the end of
July and the end of August.Coho salmon are numerous in the
Talkeetna-Devil Canyon reach (RM 98.6-152)from the last week of July
4-5
--
....
.--
to the first week of September.A summary of coho migration timing in
the SusitnaRiver for 1981, 1982,and 1983 is presented in Figure 17.
Coho salmon migration timing may be influenced by river discharge,
comllllercial catches in upper Cook Inlet and stock differences (ADF&G
1984a).During coho migrations in 1981 and 1983 river discharge
levels greater than 80,000 cfs at Sunshine Station coincided with
reduced ADF&G fishwheel catches at Sunshine Station and appeared to
dela:y the migrations (Figure 18).In 1982 river discharge did not
exce:ed 80.000 cfs at Sunshine Station during the coho migration and
the migration passed Sunshine Station in one main peak (Figure 18).
The 1982 coho migration was approximately two weeks shorter in dura-
tiOIll than the 1981 and 1983 migrations.presumably because it was
undEllayed by high river discharge levels.The average migration rate
of eoho salmon in 1982 (see Sec 4.1.3,iii)between Sunshine Station
and Talkeetna Station (RM 103)was faster than in 1981 and 1983 (ADF&G
198~,a).The faster migration rate in 1982 adds support to the sugges-
tion that coho salmon were undelayed by high river discharge in 1982.
Commercial catch data from upper Cook Inlet in 1981.1982 and 1983
werE~compared with 1981,1982.and 1983 ADF&G fishwheel catches at
Sunshine Station (RM 80).A 24 day adjustment was made to allow for
coho migration timing between Cook Inlet and Sunshine Station.Peak
conmnercial catches coincided with peak fishwheel catches in all three
yealcs suggesting that migration timing of Susitna River coho is not
influenced by differential commercial fishing on Susitna River stocks
in Cook Inlet.However,high catches in the commercial fishery
apparently reduced the strength of the coho escapement into the
Susitna River in 1983 (Table 3).
It appears that the coho migration in the Susitna River is not
segregated by spawning habitat type (ADF&G 1984a).
(ii)Escapement
The annual coho salmon total escapement in the Susitna River basin has
averaged 86,800 fish for 1981,1982 and 1983 (Table 6).Total
4-6
-
escapement estimates of coho salmon are obtained by summation of
population estimates at Yentna Station (RM 28,TRM 04)and Sunshine
Station (RM 80)plus an additional 85 percent estimated to spawn in
other portions of the basin (Barrett 1984).Most coho salmon (97
percent)enter the lower Susitna sub-basin (below RM 80),the Yentna
sub-basin (RM 28)and the Talkeetna-Chulitna sub-basin (RM 80-98.6)
(Table 6).
The annual coho escapement in the Talkeetna-Devil Canyon reach
(RM 98.6-152)has averaged 2,200 fish for the last three years
(Table 6)with a range of 1,400 fish to 3,100 fish.The estimates are
base,d on population estimates at Talkeetna Station (RM 103),less 40
perc:ent for those fish that return downstream below Talkeetna Station
and spawn elsewhere (Barrett 1984).During 1981 through 1983,the
Talkeetna-Devil Canyon sub-basin coho escapement contributed less than
thrE!e percent to the total Susitna River basin coho escapement for
th08e years (Table 6,Figure 19).
(iii)Migration Rate
For the last three years,tagged coho salmon traveled from Sunshine
Station (RM 80)to Talkeetna Station (RM 103)at average rates of 1.4
mi1E~s per day (mpd)in 1983,4.0 mpd in 1981 and 5.3 mpd in 1982
(ADF&G 1984a).Coho salmon migrated at faster rates between Talkeetna
Station and Curry Station (RM 120):5.7 mpd in 1983,10.0 mpd in 1982
and 11.3 mpd in 1981 (ADF&G 1984a).Coho migration rates appear to
increase and/or milling decreases the further upstream they migrate.
4.1.4 Pink Salmon
(i)Timing of Runs
Piruk salmon enter the Susitna River in late June to early July and are
numerous in the lower river at Yentna Station (RM 28,TRM 04)from the
4-7
.....
.....
second week of July to the third week of August (ADF&G 1984a).The
majority of the pink migration passes Sunshine Station (RM 80)between
the third week of July and the second week of August.In the
Talkeetna-Devil Canyon sub-basin (RM 98.6-152)the pink salmon
migration lasts about 4 weeks from the fourth week of July to the
third week of August.A summary of pink migration timing in the
Susitna River for 1981,1982 and 1983 is presented in Figure 20.
The pink salmon migration at Sunshine Station in 1982 was about 2
weeks shorter in duration than the 1981 and 1983 migrations at Sun-
shine Station (Figure 20).During pink migrations in 1981 and 1983
river discharge levels greater than 80,000 cfs at Sunshine Station
coinlcided with reduced fishwheel catches at Sunshine Station and
apparently delayed the migrations (Figure 21).In 1982 river
discharge did not exceed 80,000 cfs at Sunshine Station during the
pink salmon migration and the migration passed Sunshine Station in one
main peak (Figure 21).The average migration rate of pink salmon in
1982 (see Sec.4.1.4,iii)between Sunshine Station and Talkeetna
Station (RM 103)was faster than in 1981 and 1983 (ADF&G 1984a).The
faster migration rate in 1982 adds support to the suggestion that pink
salmon were undelayed by high river discharge in 1982.Peak discharge
levels apparently delay upstream movements of pink salmon •
(ii)Escapement
Pinlt salmon have a two-year life cycle that results in two genetically
distinct stocks occurring in each stream.In the Susitna Basin,the
even-year runs are numerically dominant (ADF&G 1984a).The annual
odd'-year pink salmon total escapement in the Susitna River has
aveiraged 138,200 fish for 1981 and 1983,while the even-year pink
sabnon total escapement in the Susitna River was approximately
1,317,900 fish in 1982 (Table 6).Pink salmon total escapement is
derived by the summation of population estimates at Yentna Station (RM
28,TRM 04)and Sunshine Station (RM 80)plus an additional 48 percent
estimated to spawn in other portions of the basin (Barrett 1984).
Most pink salmon (96 percent of the even-year run,97 percent of the
4-8
-
.....
.....
-
odd-year run)are distributed in the lower Susitna sub-basin,the
Yentna sub-basin,and the Talkeetna-Chulitna sub-basin (Table 6).
For the years 1981 and 1983,odd-year pink salmon escapements have
averaged 4,400 fish annually in the Talkeetna-Devil Canyon sub-basin
(Table 6),with a range of 1,700 fish to 7,100 fish.In 1982,the
even-year pink salmon escapement in the Talkeetna-Devil Canyon
sub-basin was approximately 54,800 fish (Table 6).The escapement
estimates are derived from population estimates at Talkeetna Station
(RM 103),less 25 percent for those fish that return downstream below
Talkeetna Station and spawn elsewhere (Barrett 1984).The odd-year
average escapement for 1981 and 1983 in the Talkeetna-Devil Canyon
sub-basin represents about 3 percent of the total odd-year Susitna
Basin pink escapement,while the even-year escapement in 1982
represents about 4 percent of the total even-year Susitna Basin
esca~ement (Table 6,Figure 22).
(iii.)Migration Rate
Duri.ng 1981 through 1983,tagged pink salmon migrated from Sunshine
Station (RM 80)to Talkeetna Station (RM 103)at average rates of
spee~d of 2.6 miles per day (mpd)in 1981,5.9 mpd in 1983 and 7.4 mpd
in 1982 (ADF&G 1984a).The average rates of travel for pink salmon
increased between Talkeetna Station and Curry Station (RM 120):6.0
mpd in 1981,7.1 mpd in 1983 and 10.0 mpd in 1982 (ADF&G 1984a).Pink
sal~[on migration rates appear to increase and/or milling decreases the
further upstream they migrate (ADF&G 1984a).
4.1 ..5 Chinook Salmon
(i)Timing of Run
Chinook salmon enter the Susitna River in late May to early June.In
the lower river most chinook (over 90 percent)have migrated past
Sus:i.tna Station (RM 26)by July 1 (ADF&G 1972).Chinook salmon are
abundant at Sunshine Station (RM 80)for about one month between
4-9
.....
--
mid-June and mid-July (ADF&G 1984a).In the Talkeetna-Devil Canyon
reach (RM 98.6-152),the chinook migration lasts for about one month
from.the third week in June to the third week in July.A summary of
chin.ook migration timing in the Susitna River for the years 1981,
1982,and 1983 is presented in Figure 23.
Chin.ook migration timing may be influenced by river discharge (ADF&G
1982a).During the 1981 chinook migration and in the early part of
the 1982 chinook migration,river discharge peaked near 80,000 cfs at
Sunshine Station (RM 80).These discharge peaks coincided with
reduced fishwheel catches at Sunshine Station (Figure 24).However,
in 1983 reduced fishwheel catches during the chinook migration did not
coincide with the peak river discharges near or above 80,000 cfs
(Fi~iure 24).The correlation of high river discharge (above 80,000
cfs)with reduced fishwheel catches at Sunshine Station is not as
clear for chinook salmon as it is for sockeye,chum,coho and pink
salmon.
(11)Escapement
The minimum total escapement of chinook salmon in the Susitna River
basin for 1983 was approximately 125,600 fish (Table 6).The estimate
is based on 1983 chinook stream count surveys (ADF&G 1984a)and the
relationship that a peak chinook survey count represents at most 52
percent of the total escapement (Neilsen and Geen 1981).The
escapement estimates derived by this method should be viewed as
preliminary minimum escapements because:(1)in 1983 the surveys did
not include all known chinook spawning streams in the Susitna Basin
(ADJP&G 1984a);(2)counts may not represent peak numbers as some
strt:~ams were surveyed only once;and (3)the relationship that a peak
sU~7ey count represents at most 52 percent of the total escapement may
not apply to Susitna River chinook.
The 1983 estimate of chinook escapement by the stream count method in
the Talkeetna-Devil Canyon reach (RM 98.6-152)was about 8,500 chinook
(AD:~&G 1984a)compared to 10,800 chinook approximated by the
4-10
-
.....
mark/recapture method in 1983.The mark/recapture estimate has a
correction factor of 25 percent applied to the ADF&G population
estimate of 14.400 fish.which accounts for the estimated number of
fish that move downstream of Talkeetna Station (RM 103)and spawn
elsewhere (Barrett 1984).Figure 25 shows the chinook escapements to
the Talkeetna-Devil Canyon sub-basin and the Talkeetna-Chulitna
sub~basins based on 1983 and 1984 ADF&G population estimates.
All known and suspected chinook spawning streams in the
Talkeetna-Devil Canyon sub-basin were surveyed twice in 1983.whereas
elsewhere in the Susitna Basin stream surveys were not conducted in
all of the known and suspected chinook spawning streams and most
streams were surveyed once (ADF&G 1984a).Due to the increased
sampling effort.the chinook escapement estimated by the stream count
method in the Talkeetna-Devil Canyon sub-basin in 1983 is probably
more accurate than other sub-basin chinook escapements approximated by
the stream count method in 1983.
While chinook stream su~ey counts and escapements derived by the
stre;am count method may not accurately estimate chinook total
escapement numbers.they do provide an index of the relative
importance of chinook spawning streams in the Susitna Basin.Chinook
saln~n peak spawning counts have been conducted by ADF&G in selected
Susj.tna Basin chinook spawning streams since 1976 (Table 7).The 1983
survrey included most of the maj or chinook spawning streams in the
Susitna Basin and was completed under good to excellent survey
conditions (ADF&G 1984a).The 1983 chinook salmon count in the
Susitna drainage index streams was approximately six percent higher
than the 1976-1982 average (ADF&G 1984a).In 1983.approximately 80
percent of chinook salmon counted in the survey were observed below RM
80 in the Yentna sub-basin and the lower Susitna sub-basin (Table 7).
In the Talkeetna-Devil Canyon reach.the chinook stream count in 1983
of 4,432 was the highest recorded for 1976-1983 and represents
app1:oximately seven percent of the 1983 total Susitna Basin chinook
strl~am count (Table 7).
4-11
-
....
(iii)Migration Rate
Tagged chinook salmon migrated between Sunshine Station (RM 80)and
Talkeetna Station (RM 103)at an average rate of travel of 2.1 miles
per day (mpd)in 1982 and 1.8 mpd in 1983 (ADF&G 1984a).The average
rate of travel for tagged chinook salmon between Talkeetna Station and
Curt:y S ta tion (RM 120)was 2.2 mpd in 1982 and 2.7 mpd in 1983 (ADF&G
1984a).It appears that chinook salmon spend less time milling and/or
mig:r:'ation rates increase the further upstream they travel (ADF&G
1984a).
4.2 SPAWNING
4.2.1 Sockeye Salmon
(i)Spawning Locations
jV~rlya It of the
'Ihe-majority--Q£.second-run sockeye salmon in the Talkeetna-Devil
Canyon reach (RM 98.6-152)spawn in slough habitat.Approximately 99
pereent of the 2420 second-run sockeye counted during peak spawner
couuts were observed in sloughs (ADF&G 1984a).The remaining
second-run sockeye salmon were in mainstem and tributary stream
habitats.One main channel second-run sockeye spawning site was
identified during the 1981-1983 surveys (ADF&G 1981a,1982a,1984a).
The site (RM 138.6 -138.9)was used by eleven spawning second-run
sockeye on September 15,1983.Six second-run sockeye were observed
in streams during the 1981-1983 surveys,however all six were
considering milling fish that did not spawn in streams (ADF&G 1981a,
1982a,1984a)•During slough spawning surveys in 1981-1983.
second-run sockeye were observed in seventeen sloughs above RM 98.6
(T~ble 8).Only three of the seventeen sloughs contained significant
numbers of spawning second-run sockeye in all three years.
Sloughs 8A,11 and 21 accounted for 89 percent of the total slough
peak counts in 1981,95 percent in 1982 and 92 percent in 1983
(Table 8).
4-12
.-
The peak of spawning occurred between the last ~l1eek of August and the
end of September in all three years (ADF&G 1981a,1982a,1984a).A
portion (24-43 percent)of the second-run sockeye salmon monitored in
three sloughs in 1983 did not spawn in the slough of first recorded
entry (ADF&G l.984a).These fish suffered mort~Llity from either bear
predation or s:tranding,or departed the slough ,and presumably spawned
elsewhere.
Peak survey counts are indices of fish abundance.To estimate the
total slough escapement of second-run sockeye above RM 98.6,the total
fish days in slough habitat for sockeye salmon was divided by the
average slough life of sockeye salmon (11.8 days in 1983)(ADF&G
1984a).The 1983 total slough escapement of second-run sockeye salmon
in sloughs above RM 98.6 was an estimated 1,060 fish (Table 9).This
estimate is ~Lbout 56 percent of the 1983 CUlrry Station (RM 120)
second-run sockeye escapement of 1,900 fish and approximately 25
percent of the 1983 Talkeetna Station (RM 103)second-run sockeye
escapement of 4,200 fish.Second-run sockeye were observed spawning
almost exclusively in slough habitat above RM 98.6,therefore the
differences bE~tween the total slough escapement and the Curry Station
and Talkeetna Station population estimates are probably attributable
to:(1)milling fish that return downstream below Talkeetna Station
and spawn elsewhere;(2)the error associated with estimating the
slough escapeDlent;and (3)the error associated with approximating the
population estimates at Talkeetna and Curry Stations (ADF&G 1984a).
It was assumed that in 1981 and 1982 second-run sockeye salmon
averaged the same slough life of 11.8 days that was estimated for 1983
second-run sockeye (ADF&G 1984a).The estimated total fish days for
~second-run sockeye in sloughs in 1981 and 1982 was divided by the 1983
estimated slough life to estimate total slough escapement of
second-run sockeye in 1981 and 1982.The total slough escapement-
.-
above RM 98.6 was about 2,200 second-run sockeye in 1981 and
approximately 1,500 second-run sockeye in 1982 (Table 9).The 1981
total slough ,escapement of 2,200 fish is 79 pel:cent of the 1981 Curry
Station estimate of 2,800 second-run sockeye and 46 percent of the
1981 Talkeetna Station population estimate of 4,800 second-run
4-13
sockeye.The 1982 total slough escapement of 1,500 fish is 115
percent of the 1982 Curry Station population estimate of 1,300
second-run sockeye and 48 percent of the 1982 Talkeetna Station
population estimate of 3,100 second-run sockeye"Differences between
total slough escapements and the population estDnates at Talkeetna and
Curry stations are probably due to the same factors outlined above for
the differences in 1983.
Second-run sockeye generally spawn in the upper habitat zones of
The access and upstream passage of sockeye salmon into sloughs and
(ii)Access
,~
..,.,
-
.....
-
side channels are dependent primarily on water depth and length of the
passage reachlas that are restrictive to the upstream movement of '..ft,i1 l
salmon (ADF&G 1984d).·Hydraulic velocity barriers do not e~+6tf'1.~1\.1?A<).(;..;l-,
sloughs in the Talkeetna-Devil Canyon reach (RM 98.6-152).The
mainstem discharge level directly influences access and passage into
sloughs because of its influence on backwater at the mouth of sloughs
and breaching at the upstream (head)end of sloughs.Under low
mainstem discharge levels (unbreached conditions),the backwater at
the mouth of e;loughs and side channels may not be of sufficient depth
to allow succ:essful passage.As mainstem discharge increases,the
backwater area generally increases in depth and extends its length
upstream,which increases the depths within those critical passage
reaches affected by the backwater.The elimination of passage
restrictions within a reach by backwater inundation continues in the
upstream direction with increasing mainstem discharge,until breaching
occurs,at which point depths become adequate for passage at all
passage reachE!s in most sloughs and side channels (ADF&G 1984d).
4-14
-
.....
r
--
Mainstem discharge levels in the Susitna River at Gold Creek
(RM 136.7)commonly range between 20,000 and 30,000 cfs during June,
July and Augus1t when adult salmon are migrating upstream and 15,000 to
20,000 cfs during peak spawning periods (20 August to 20 September)
(ADF&G 1984d).Because of the diversity in the morphology of
individual sloughs,the access and passage into sloughs varies
considerably at a mainstem discharge level.Breaching of sloughs at
most sites in the Talkeetna-Devil Canyon reach (RM 98.6-152)occurs at
relatively high mainstem discharges (19,000 to 42,000 cfs)(ADF&G
1984d).During the peak spawning period (20 August to 20 Septem~~
mainstem discharge at Gold Creek equals or E~xceeds 15,000 cf s;-5'o
percent of the time (ADF&G 1984d~;;f~~"~>:>"~~"~;~;"and "p;;~;~e into
sloughs and side channels is more often controlled by the backwater at
the slough mouth and the local flow from groundwater and runoff
sources.Locall flow from groundwater appears to be correlated with
mainstem discharge (APA 1984).Therefore,aLS mainstem discharge
decreases,local flow from groundwater may also decrease.
Sloughs 8A,11 and 21 have accounted for over 90 percent of the
sockeye salmon total peak counts in slough haLbitat (Table 8).The ~
most serious passage restrictions for mainstem discharges below
breaching discharge for these three sloughs occur in Slough 21 (ADF&G
1984d).
(iii)Fecundi.ty and Sex Ratio
The fecundity of second-run sockeye salmon was e~stimated from a sample
of 25 females collected at Sunshine Station (RM 80)in 1983 (ADF&G
1984a).The mean number of eggs per female,based on this sample,.was
3,543 eggs (range:2,950 to 4,800 eggs).This i.s similar to the range
of sockeye fe(~undity (2,500 to 4,300 eggs)·reported by Morrow (1980).
Regression analyses of the number of eggs per female as a function of
length and/or weight were used to predict Susitna River second-run
sockeye fecundities.The details of the analyses are reported by
ADF&G (1984a).The mean fecundity for Susitna River second-run
sockeye is 3,350 eggs per female (ADF&G 1984a).This estimated
4-15
fecundity is derived from the regression analysis of fecundity as a
function of length and from the mean length of sockeye salmon measured
at Sunshine Station.
The egg retention of second-run sockeye salmon was estimated in 1983
from sampling 56 female sockeye carcasses from four sloughs between
river miles 98.6 and 161 (ADF&G 1984a).The average egg retention was
about 250 eggs per female.Almost 80 percent of the carcasses had
retained 25 or fewer eggs,while only seven percent of the fish
sampled had retained more than 1,000 eggs.
The sex ratio (male to female)of second-run sockeye salmon in the
Susitna River was 1.0:1 in 1981,1.2:1 in 1981 and 1.3:1 in 1983
(ADF&G 1981a,1982a,1984a).Sex ratios of sockeye salmon at specific
sampling locations varied considerably between some locations and
years (Table 11).Sex ratios of sockeye salmon by age are reported by
ADF&G (1981a,1982a,1984~).Some males matured at an earlier age
than females.Most returning adult sockeye were four and five year
fish that had gone to sea after one winter in freshwater.
4.2.2 Chum Salmon
(i)Spawning Locations
Most chum salmon above RM 98.6 spawn in either slough or tributary
stream habitat:s.About 93 percent of the 10,5"70 chum salmon counted
during peak index surveys were observed in stream or slough habitats;
the remaining 7 percent were observed at mainstem spawning sites
(Table 12).In 1983 chum salmon peak index counts in stream and
slough habitats were about equal,while in 1982 and 1981 counts were
higher in slough habitats (Table 12).
Chum salmon peak index counts in sloughs above RM 98.6 were:2,596
fish in 1981,2,244 fish in 1982 and 1,467 fish in 1983 (Table 13).
Eleven of the 33 sloughs surveyed in all three years were occupied by
spawning chum salmon in each year (Table 13).
4-16
Four of the eleven,sloughs 21,II,8A and 9,averaged more than 200
fish for 1981,1982 and 1983 and accounted for about two-thirds of the
total chum sa~mon counted in slough habitats (Table 13).
Total slough E!SCapements of chum salmon in slolJlghs above RM 98.6 was
estimated by dividing the total fish days in slough habitat by the
average slough life of chum (ADF&G 1984a).The total slough
escapement was about 2,950 chum salmon in 1983,5,100 chum salmon in
1982 and 4,500 chum salmon in 1981 (Table 14).
In 1983,some chum salmon monitored for slough life were not confirmed
spawners in the slough of first recorded entry.The percent of
non-spawning (~hum salmon ranged from 0 to 85.~7 in the five sloughs
monitored (AD}/&G 1984a).Some of the non-spawners were milling fish
that later spawned elsewhere.
Chum salmon generally spawn in the lower habitat zones of sloughs,
while second-run sockeye spawn in the upper habitat zones of sloughs
(Table 10).Although some overlap exists,spawning chum and sockeye
salmon are apparently segregated within slough habitat above RM 98.6
(ADF&G 1984a).
Chum salmon peak index counts in streams above RM 98.6 were:241 fish
in 1981,1,737 fish in 1982,and 1,500 fish ill 1983 (Table 15).In
1982 and 1983 over 95 percent of the chum salmon counted during peak
spawner surveys were observed in three streams:Indian River,Fourth
of July Creek and Portage Creek (Table 15).In 1981,Indian River,
Fourth of July Creek and Lane Creek were occupi.ed by about 85 percent
of the 241 chum salmon counted during peak surveys (Table 15).
Chum salmon peak counts at mainstem spawning sites were:16 fish in
1981,550 fish in 1982 and 219 fish in 1983 (Table 12).Eighteen chum
salmon mainstem spawning sites were identified during 1981-1983
surveys;seven sites were used in two or more of the three years
(Table 16).
4-17
-
-
""'"
The peak of chum salmon spawning occurred during the last week of
August in streams,the first week of September in sloughs.the first
two weeks of September at mainstem spawning sites in 1981,1982 and
1983 (ADF&G 1981a.1982a.1984a).
(ii)Access
Chum salmon spawn primarily in tributary or slough habitat in the
Talkeetna-Devil Canyon reach (RM 98.6-152)(Table 12).Access and
passage into selected sloughs has received preliminary investigations
by ADF&G (1983d).Trihey (1983)and R&M COltl.sultants (1982)have
examined passage conditions and streambed stability in selected
tributaries.
Small deltas are formed at the mouth of most tributaries.As the
stage in the mainstem decreases.the tributaries become perched above
the river.that is,the tributaries flow across steep deltas.If the
steep deltas ~rere to remain under low mainstem conditions,the access
and upstream passage of fish would be inhibited or eliminated.Based
on the analys:es by Trihey (1983)and R&M COIllsultants (1982),most
tributaries ill the Talkeetna-Devil Canyon sub--basin have sufficient
energy to dOWllcut the perched deltas to establ:lsh a channel at a new
gradient.Tributaries that support chum spa..ming that may remain
perched under low mainstem flows are Jack Long Creek.Sherman Creek,
Fifth of July Creek (RM 123.9).and Little Portage Creek (R&M
Consultants 1982).None of these streams appear to support
significant numbers of spawning chum salmon (Table 15).Tributaries
that have not been evaluated are Chase Creek and Lower McKenzie Creek;
however.neither of these streams appear to be important chum spa..ming
tributaries (Table 15).
The access and upstream passage of chum salmon into sloughs and side
channels are dependent primarily on water depth and length of the
passage reaches that are restrictive to the upstream movement of
salmon (ADF&G 1984d).Hydraulic velocity barriers do not exist at
sloughs in the Talkeetna-Devil Canyon reach (RM 98.6-152).
4-18
.....
-
.....
-
The mainstem discharge level directly influences access and passage
into sloughs because of its influence on backYil'ater at the mouth of
sloughs and breaching at the upstream (head)e1lld of sloughs.Under
low mainstem d.ischarge levels (unbreached conditions),the backwater
at the mouth of sloughs and side channels may not be of sufficient
depth to allow successful passage.As mainstem discharge increases,
the backwater area generally increases in depth and extends its length
upstream,which increases the depths within those critical passage
reaches affected by the backwater.The elimination of passage
restrictions within a reach by backwater inunda,tion continues in the
upstream direction with increasing mainstE~m discharge,until
controlling discharge levels occur,at which point depths become
adequate for passage at all passage reaches in most sloughs and side
channels (ADF&G 1984d).
Mainstem discharge levels in the Susitna River at Gold Creek
(RM 136.7)conmonly range between 20,000 and 30,000 cfs during June,
July and August when adult salmon are migrating upstream and 15,000 to
20,000 cfs during peak spawning periods (20 August to 20 September)
(ADF&G 1984d).Because of the diversity in the morphology of
individual sloughs,the access and passage into sloughs varies
considerably ELt a mainstem discharge level.Breaching of sloughs at
most sites in the Talkeetna-Devil Canyon reach occurs at relatively
high mainstem discharges (19,000 to 42,000 cfs)(ADF&G 1984d).During
the peak spawning period (20 August to 20 September)mainstem
discharge at Gold Creek equals or exceeds 15,000 cfs 50 percent of the
time (ADF&G 1984d).Therefore,access and passage into sloughs and
side channels are more often controlled by the backwater at the slough
mouth and the local flow from groundwater and runoff sources.Local
flow from groundwater appears to be correlated with mainstem discharge
(APA 1984).Therefore,as mainstem discharge decreases,local flow
from groundwater may also decrease.
Sloughs 8A,9,11 and 21 have accounted for about two-thirds of the ~
total peak counts of chum salmon in slough habitats during 1981,1982
and 1983 (Tcilile 13).The most serious passage restrictions for
4-19
mainstem discharges below breaching discharge for these four sloughs
occur in Sloughs 9 and 21 (ADF&G 1984d).
(iii)Fecundity and Sex Ratio
The fecundity of chum salmon was estimated from a sample of 27 females
collected at Sunshine Station (RM 80)in 1983 (ADF&G 1984a).The mean
number of eggs per female,based on this sample,was 3,189 eggs with a
range of 2.478 to 4,076 eggs (ADF&G 1984a).This is similar to the
range of chum fecundity (2.400 to 4.000 eggs)reported by Scott and
Crossman (1973).Regression analyses of the numDer of eggs per female
as a function of length and/or weight were used to estimate Susitna
River chum sellmon fecundities.The details of the analyses are
reported by ADF&G (l984a).The mean fecundity for Susitna River chum
salmon is 2.850 eggs per female.This estimated fecundity is derived
from the regression analysis of fecundity as a function of length and
from the mean length of chum salmon females sampled at Sunshine
Station.
The egg retention of chum salmon was estimated in 1983 from sampling
229 female chum salmon carcasses in 12 sloughs and One main channel
spawning site between river miles 98.6 and 161 (ADF&G 1984a).The
average egg r.etention was about 114 eggs per female.Almost 75
percent of the carcasses had retained 25 or fewer eggs.while less
than four percent of the fish sampled had retained more than 1,000
eggs.
The sex ratio (male to female)of chum salmon i~L the Susitna River was
1.0:1 in 1981.1.1:1 in 1982 and 1.3:1 in 1983 (ADF&G 1981a,1982a.
1984a).Sex ratios of chum salmon at specific sampling location
varied between locations and years (Table 17)"Sex ratios of chum
salmon by age are reported by ADF&G (1981a.1982a.1984a).Most
returning adult chum were four and five year old fish that had gone to
sea during thEdr first summer of life.
4-20
....
.....
4.2.3 Coho Salmon
(i)Spawning I ..ocations
Most coho salmon in the Talkeetna-Devil Canyon reach (RM 98.6-152)
spawn in tributary stream habitat.During spawning ground peak
surveys in 1981-1983,over 99 percent of the 1,336 coho salmon counted
were observed in streams (ADF&G 1984a).Only five coho salmon were
observed spawning in mainstem and slough habitats.In 1981,one coho
salmon was captured in the mainstem at RM 129 ..2,while in 1983 two
coho salmon lo1ere observed spawning in the mainstem at RM 131.1
(ADF&G 1981a,1984a).The only documented slough habitat that coho
salmon utilized for spawning during 1981 through 1983 was at Slough 8A
(RM 125.1),where two coho salmon were observed spawning on October 2,
1982 (ADF&G 1982a).
Coho salmon peak index counts in tributary streams above RM 98.6 were:
458 fish in 1981,633 fish in 1982 and 240 fish in 1983 (ADF&G 1984a).
Twelve tributary streams above RM 98.6 were found to contain coho
salmon during index surveys in 1981-1983 (Table 18).Peak index
counts greater than 10 fish in all three years were recorded in:
Whiskers Creek,Chase Creek,Gash Creek,Lower McKenzie Creek,Indian
River and Portage Creek.The two most important tributary streams for
coho spawning lo1ere:Gash Creek and Indian River in 1981,Whiskers
Creek and Lowlar McKenzie Creek in 1982 and Whiskers Creek and Indian
River in 1983 (Table 18).
Coho spawning activity in tributary streams above RM 98.6 peaked
between the llOlst week of August and the first week of October in 1981,
1982 and 1983 (ADF&G 1981a,1982a,1984a).
(ii)Access
Coho salmon spawn almost exclusively in tributaries in the
Talkeetna-Devil Canyon reach (RM 98.6-152).Small deltas are formed
at the mouth of most tributaries.As the stage in the mainstem
decreases,the tributaries become perched abov'e the river,that is,
4-21
....
....
....
,....
the tributaries flow across the steep deltas.If the steep deltas
were to remain under low mainstem conditions,the access and upstream
passage of fish would be inhibited or eliminated.
Trihey (1983)examined the hydraulic conditions supporting fish
passage into Indian River and Portage Creek,'while R&M Consultants
(1982)evaluated the streambed stability of numE~rous tributary mouths
between the confluence of the Susitna and Chulitna rivers (RM 98.6)
and Devil Canyon (RM 152).Based on the analyses in these studies,
most tributari.es in this reach of river have sufficient energy to
downcut the pe.rched deltas to establish a channel at a new gradient.
One tributary that supports coho spawning tha.t may remain perched
under low mainstem flows is Jack Long Creek.Tributaries that have
not been evaluated include the following coho spawning streams:Chase
Creek,Slash Greek and Lower McKenzie Creek.Of the three,Chase
Creek and LOWE,r McKenzie Creek support higher rLUmbers of coho salmon
than Slash Creek and are among the five most ~nportant coho spawning
tributaries il1L this reach of river based on three year index count
averages (Table 18).
(iii)Fecundity and Sex Ratio
Fecundity has not been estimated for coho salmon in the Susitna River,
but is expecte~d to be approximately 2,500 to 3,.000 eggs,as reported
by Morrow (1980).
The sex ratio (male to female)of coho salmon in the Susitna River was
0.9:1 in 1981"1.4:1 in 1982 and 1.3:1 in 1983 (ADF&G 1981a, 1982a,
1984a).The sex ratios of coho salmon at specific sampling locations
varied between years and sites (Table 19).Sex ratios of coho salmon
by age are reported by ADF&G (1981a,1982a,1984a).Most returning
adult coho were three and four year old fish that had gone to sea
after one or two winters in freshwater.
4-22
""'"
4.2.4 Pink Salmon
(i)Spawning l.ocations
The maj ority of pink salmon in the Talkeetna-Devil Canyon reach
(RM 98.6-152)spawned in tributary stream habitat.Peak index counts
for streams above RM 98.6 were 378 fish in 1981)2,855 fish in 1982
and 1,329 fish in 1983 (Table 20).In 1981 La.ne Creek,Chase Creek
and Fourth of July Creek had peak counts of 358 pink salmon;which
accounted for almost 95 percent of the total peak counts of 378 fish
for that year.,In 1982,when pink salmon escapement in the Susitna
River was at an even-year high,eight streams had peak index counts ·of
over 100 pink salmon each and accounted for almost 93 percent of the
total count of 2,855 fish for that year (Table 20).'Indian River,
Portage Creek and Fourth of July Creek were the most important pink
salmon spawning streams in 1983;the three streams collectively had a
peak index count of 1,249 fish which contributE!d about 94 percent of
the total stream peak count of 1,329 fish.The peak of pink salmon
spawning in streams above RM 98.6 occurred during the second and third
weeks of August in all three years (ADF&G 1981a,1982a.1984a).
Pink salmon were observed spawning in slough habitat in 1981 and 1982.
Total slough I!SCapement for pink salmon above HM 98.6 in 1981 was 38
fish in Slough 8 (Table 21).In 1982,total slough escapement above
RM 98.6 was about 297 fish in seven sloughs (Table 21).Two of the
seven sloughs"11 and 20,accounted for over 80 percent of the pink
salmon total escapement in sloughs in 1982.No pink salmon were
observed spawning in sloughs in 1983;fish counted in slough habitat
during spawning surveys in 1983 were considerE!d milling fish (ADF&G
1984a).In 1981 the peak of pink salmon spawning in Slough 8 occurred
about the last week of August,while in 1982 the peak of pink salmon
spawning in sloughs occurred during the first three weeks of August
(ADF&G 1981a,1982a).
No pink salmon were observed spawning in the mainstem of the Susitna
River above IDol 98.6 in 1981-1983 (ADF&G 1984a).
4-23
,....
....
(ii)Access
Pink salmon spawn primarily in tributaries in the Talkeetna-Devil
Canyon reach (RM 98.6-152);sloughs are used by spawning pink salmon
to a lesser eJ~tent.The highest use in both habitats occurs during
even years (Tables 20,24).
Small deltas are formed at the mouth of most tributaries.As the
stage in the mainstem decreases,the tributaries become perched above
the river,that is,the tributaries flow across steep deltas.If the
steep deltas were to remain under low mainstem con~itions,.the access'
and upstream passage of fish would be inhibited or eliminated.
Trihey (1983)examined the hydraulic conditions supporting fish
passage into Indian River and Portage Creek,while R&M Consultants
(1982)evaluated the streambed stability of numerous tributary mouths
between confluence of the Susitna and Chulitna rivers (RM 98.6)and
Devil Canyon (RM 152).Based on the analyses in these studies,most
tributaries in this reach of river have sufficient energy to downcut
the perched deltas to establish a channel at a new gradient.
Tributaries that support pink salmon spawning that may remain perched
under low mainstem flows are Little Portage CreE:k,Fifth of July Creek
(RM 123.9),Sherman Creek and Jack Long Creek (R&M Consultants (1982)•
Chase Creek a.nd Lower McKenzie Creek are pink spawning tributaries
that have not been evaluated for streambed stability or salmon
passage.These streams appear to be of moderate to low importance for
pink salmon spawning (Table 20).
The access and upstream passage of pink salmon into sloughs and side
channels are dependent primarily on water depth and length of the
passage reaches that are restrictive to the upstream movement of
salmon (ADF&G 1984d).Hydraulic velocity barriers apparently do not
exist at sloughs in the Talkeetna-Devil Canyon reach.
The mainstem discharge level directly influences access and passage
into sloughs because of its influence on backwater at the mouth of
4-24
.-
-
.-
-
""'"
sloughs and breaching at the upstream (head)end of sloughs.Under
low mainstem discharge levels (unbreached condi.tions),the backwater
at the mouth of sloughs and side channels may not be of sufficient
depth to allow successful passage.As mainstem discharge increases,
the backwater area generally increases in depth and extends its length
upstream which increases the depths within those critical passage
reaches affected by the backwater.The elimination of passage
restrictions within a reach by backwater inundClLtion continues in the
upstream dirli!ction with increasing mainstem discharge,until
controlling discharge levels occur,at which point depths become
adequate for passage at all passage reaches in most sloughs and side
channels (ADF&G 1984d).
Mainstem discharge levels in the Susitna River at Gold Creek
(RM 136.7)commonly range between 20,000 and 30,000 cfs during June,
July and August when adult salmon are migrating upstream and 15,000 to
20,000 cfs during peak spawning periods (20 August to 20 September)
(ADF&G 1984d).Because of the diversity i.n the morphology of
individual sloughs,the access and passage into sloughs va~ies
considerably at a mainstem discharge level.Breaching of sloughs at
most sites in the Talkeetna-Devil Canyon reach occurs at relatively
high mainstem discharges (19,000 to 42,000 cfs)(ADF&G 1984d).During
the peak spawning period (20 August to 20 September)mainstem
discharge at Gold Creek equals or exceeds 15,000 cfs 50 percent of the
time (ADF&G 1984d).Therefore,access and passage into sloughs and
side channels is more often controlled by the backwater at the slough
mouth and the local flow from groundwater and runoff sources.Local
flow from gro\lndwater appears to be correlated with mainstem discharge
(APA 1984).Therefore,as mainstem discharge decreases,local flow
from groundwater may also decrease.
Sloughs 11 and 20 accounted for over 80 percent of the total pink
salmon escapement in sloughs in 1982 (Table 21).Based on analyses by
ADF&G (l984d)it appears that Slough 11 will ha'iTe passage restrictions
a.t low rna.i..ns.t..e.m.diS.charge level.s,.while access aI!.d passage .!nto 1.:r....."'~,"'.;,~,..:t>tS~ugh ~~_~,.~~_~~..~e .mainta~-t.~~reaches by the loc;;.l'>.,'~5/0 '7-4.2c;
flow of Waterfall Creek.w&~"41 H til ~...J,-----,,------
4-25
-
(iii)Fecundity and Sex Ratio
iPinksalmonfecunditywas estimated from a sample of 22 females at
Sunshine Station (RM 80)in 1983 (ADF&G 1984a).,The mean number of
eggs per female was 1,475 eggs with samples ranging from 1,125 to
1,975 eggs.This is similar to the range reported for pink salmon
(800 to 2,000)by Morrow (1980).Regression analyses of fecundity as
a function of fish length and/or weight were used to predict Susitna
River pink salmon fecundities.The details of the analyses are
reported by ADF&G (1984a).The predicted fecundity for Susitna River
pink salmon is about 1,350 eggs per female,which is based on the
regression analysis of fecundity as a function of length and the mean
length of the all female pink salmon measured at Sunshine Station.
The sex ratio (male to female)of all pink salmon sampled in the
Susitna River was:0.8:1 in 1981,1.4:1 in 1982 and 0.9:1 in 1983
(ADF&G 1981a, 1982a,1984a).A summary of pink salmon sex ratios at
sampling locations in the Susitna River for 1981 through 1983 is
presented in Table 22.All pink salmon returning to the Susitna River
are two year old fish that went to sea in their first summer of life.
4.2.5 Chinook Salmon
Chinook salmon spawn exclusively in tributary stream habitat in the
Talkeetna-Devil Canyon reach (RM 98.6-152).No chinook spawning was
observed in any mainstem,side channel or slough habitats.Peak index
counts of chinook salmon in streams above RM 98.6 were:1,121 fish in
1981,2,474 fish in 1982 and 4,432 fish in 1983 (Table 23).
The total chinook salmon escapement to streams above RM 98.6 was
estimated by the relationship that a maximum survey count represents
at most 52 percent of the total escapement (Nielson and Geen 1981).
Based on this method,chinook total escapement to streams above
RM 98.6 was about 2,150 fish in 1981,4,750 fish in 1982 and 8,500
fish in 1983.These estimates of chinook total stream escapement
should be viewed as preliminary estimates because:(1)in 1981 not all
4-26
--------------------------------------------------
.-
.....
.....
chinook salmon spawning streams were surveyed above RM 98.6;and
(2)most importantly,the relationship that a peak count represents at
most 52 percent of the total escapement may not be valid for Susitna
River chinook salmon.
The 1982 total stream escapement of 4,750 chinook salmon is about 44
percent of the 1982 Talkeetna Station (RM 103)chinook escapement of
10,900 fish and approximately 42 percent of the 1982 Curry Station
(RM 120)chinook escapement of 11 ,300 fish.Differences between the
total stream E~scapement and the Talkeetna Station and Curry Station
population estimates are probably due to:(1)milling fish that
return downstr,eam below Talkeetna Station and spawn elsewhere;(2)the
error associated with estimating total stream el:3Capement;and (3)the
error associated with estimating the population size at Talkeetna and
Curry Stations (ADF&G 1984a).
The 1983 total stream escapement of 8,500 chinook salmon is about 60
percent of the 1983 Talkeetna Station (RM 103)chinook escapement of
14,400 fish and 90 percent of the 1983 Curry Station (RM 120)chinook
escapement of 9,600 fish.Differences in 1983 between total stream
escapement and the Talkeetna Station and Curry Station population
estimates are attributable to the reasons outlined above for 1982.In
1981,chinook salmon escapement was not estimated at Talkeetna and
Curry stations,therefore comparisons of the tl:ltal stream escapement
in 1981 to esc.apement estimates at Talkeetna al1d Curry Stations were
not possible.
Portage Creek and Indian River are the two most important tributary
streams for chinook salmon spawning in this reach of river.The two
streams accounted for over 90 percent of the chinook peak index counts
above RM 98.6 in 1981 through 1983 (Table 23).
Chinook spawning activity in tributary streams above RM 98.6 peaked
between the last week of July and the first week of August in 1981,
1982 and 1983 (ADF&G 1981a,1982a,1984a).
4-27
....
....
-
-
(ii)Access
Salmon are usually prevented from migrating upstream of Devil Canyon
(RM 152)bec~lse of the high water velocity at high discharge.
However,in 1982 and 1983 chinook salmon were observed in tributary
mouths and trlbutaries in upper Devil Canyon.In 1982,21 chinook
salmon were observed in two tributaries in upper Devil Canyon;34
chinook salmon were observed in three tributaries in upper Devil
Canyon in 1983 (Table 23).
Chinook salmon spawn exclusively in tributaries in the Talkeetna-Devil
Canyon reach (RM 98.6-152).Small deltas are formed at the mouth of
most tributaries.As the tributary enters the mainstem river,the
change in gradient and subsequent change in flow velocity cause the
tributary to drop transported materials if the velocity in the
mainstem is not sufficient to carry the material downstream.As the
stage in the mainstem river decreases,the tributaries become perched
above the river,that is,the tributaries flow across the steep
deltas.If the steep deltas were to remain under low mainstem flow
conditions,the access and upstream passage of fish would be inhibited
or eliminated •
Trihey (1983)examined the hydraulic condit:ions supporting fish
passage into the mouths of two tributaries,Indian River and Portage
Creek,in the Talkeetna-Devil Canyon sub-basin.Portage Creek and
Indian River are the two most important tributaries in this river
reach for chinook spawning (Table 23).The influence of mainstem
discharge on passage of salmon into these tributaries was evaluated at
mainstem discharges ranging from 8,000 to 34,500 cfs.Trihey's
analysis indicated that passage of salmon into these two tributaries
is not likely to be impeded at low mainstem discharge.It is expected
that tributary flows would provide sufficient energy to downcut the
perched tributary mouths to establish a channel at a new gradient.If
Indian River or Portage Creek does not downcut to a new streambed,
adequate tributary streamflow is expected to provide sufficient depths
for passage at the tributary mouths.
4-28
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"...
I
R&M Consultants (1982)examined the streambed stability at numerous
tributary mouths between the confluence of the Susitna and Chulitna
rivers (RM 98.6)and Devil Canyon (RM 152).Based on this study,it
is expected that most tributaries in this river reach will downcut
perched deltas at low mainstem flows and establish a channel at a new
gradient.Tributaries with chinook spawning that may have restricted
access (perched deltas)under low mainstem flows are Jack Long Creek
and Sherman Greek.Both of these creeks support low numbers of
spawning chinook salmon (Tab Ie 23).
(iii)Fecundity and Sex Ratio
Fecundity has not been estimated for chinook salmon in the Susitna
River,but is expected to be approximately 4,200 to 13,600 eggs,as
reported by Morrow (1980).
The sex ratio (male to female)of chinook salmon in the Susitna River
was 2.8:1 in 1981,1.4:1 in 1982 and 1.5:1 in 1983 (ADF&G 1981a,
1982a,1984a).A summary of chinook salmon sex ratios at sampling
locations in the Susitna River for 1981 through 1983 is presented in
Table 24.Sex ratios of chinook salmon by age are reported by ADF&G
(1981a,1982a,1984a).Most returning adult chi.nook were five and six
year old fish that had gone to sea after one wiI1lter in freshwater.
4.3 INCUBATION
Salmon embryo incubation (defined as the period between fertilization
and complete yolk absorption)in the Susitna River begins in July with
chinook spawning.This is followed by pink salmon in mid-to late
August and chum and sockeye in late August to e~lrly September.In the
middle Susitnll River,chum incubation begins slightly earlier in the
tributaries than in the sloughs.Incubation of sockeye in the middle
river sloughs begins about the same time as chun~.The last species to
spawn are the coho salmon,which spawn <3llmost exclusively in
tributaries in September.
4-29
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-
"""
,~
Successful incubation and emergence is dependent on numerous
biological,chemical,and physical factors.These factors include
dissolved oxygen,water temperature,biochemical oxygen demand (BOD),
water depth,surface water discharge,and velocity,permeability,
porosity,and intragravel flow (Reiser and Bjornn 1979).Also,
droughts,floods,freezing temperatures,superimlposition of redds,and
predators can affect successful incubation (McNeil 1969).The
following section discusses these factors.The information is derived
from studies on the Susitna River system and from studies at other
locations.
4.3.1 Dissolv,ed Oxygen
Dissolved oxygen is needed during egg incubation to facilitate
metabolic reactions.Reiser and Bjornn (1979),follOWing extensive
literature review,found that:
(1)Sac fry incubated in low and intermediate oxygen
concentrations were smaller and weaker than sac fry reared
at higher concentrations;
(2)Reduced oxygen concentrations lead to smaller newly hatched
fry and a lengthened incubation period;
(3)Low oxygen concentrations in the early stages of development
may delay hatching,increase the incidence of anomalies,or
both;and
(4)Low oxygen concentration during the latter stages of
devE~lopment may stimulate premature hcLtching.
Brannon (1965)found apparent differences in characteristics of
alevins at hatching that had been raised at different oxygen
concentrations ranging from 3.0 to 11.9 1IIlg/1.Although slowed
development was evident at low concentrations,these fish eventually
4-30
,....
attained a weight similar to those raised in higher concentrations by
the time they reached the fry stage.
In studies on four sloughs (8A~9,II,and 21)on the middle Susitna
River in Apdl and May of 1983 ~ADF&G (1983a)found that mean
concentrations of intragravel dissolved oxygen were consistently lower
than mean concentrations for overlying surface waters.Means for
intragravel concentrations ranged from 4.6 to 8.5 mg/l whereas the
surface wa telrs ranged from 9.1 to 11.2 mg/1.The lowest
concentrations occurred in Slough 8A and the highest in Slough 11.
The low concentrations in Slough 8A may have caused some delay in chum
and sockeye development although diversion of cold mainstem water
through this slough as a result of an iCE~j am may also have
contributed Olr been directly responsible.De'l'elopment at the other
three sloughs (9~11 and 21)for embryos and alevins was generally
uniform.
McNeil and Bailey (1975)recommend a dissolved oxygen threshold of at
least 6.0 mg/l~while Reiser and Bjornn (1979)recommended
concentrations at or near saturation with te:mporary reductions to
5.0 mg/l.In general~for the Susitna sloughs studied thus far,this
recommendation is usually met.The exception is the lower values
found in Slough 8A and some concentrations in Slough 9 (ADF&G 1983).
The intragraVI!l flow of water is important in .assuring that dissolved
oxygen is made available to the incubating eggs and that metabolic
wastes are r,emoved.Reiser and Bjornn (I979)recommend that the
apparent velocity through the gravel should be more than 20 cm/hour
while Bell (I980)recommends a rate of 110 cm/hour.~::."..,
4.3.2 Temperature
Temperature and salmon embryo development are strongly interrelated
with higher temperatures resulting in mOl:e rapid development.
Development is also related to species~time of egg deposition~and
the temperature regime over the period of incubation.In general~the
4-31
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--
lower and upp,er limits for successful initial incubation of salmon
embryos are 4.5 to 14.5°C (AEIDC 1984).Incubation can occur at lower
temperatures if the initial temperature is greater than approximately
4.0°C.This initial sensitivity to low temperatures is apparently
related to embryo developmental phases because once the blastopore is
closed on the developing embryo,the sensitivity is reduced (Combs and
Burrows 1957).This relationship appears to be consistent for all
Pacific salmon species except coho.In certain instances,this
species is apparently able to tolerate near oOe initial temperatures
(Dch,ADF&G,personal communication,1984).
The relationship between temperature and embryo development is
frequently measured in temperature units (TU's).These are defined as
the difference,between the average temperature ,and O°C over 24 hours.
For example,if eggs were incubated at 7°C for 5 days,the accumulated
TU's would be 35.
Studies by Wangaard and Burger (1983)have shown that the time to
emergence (complete yolk absorption)can 'lTary considerably at
different temperatures.In laboratory tests at average temperatures
between 2.1 and 4.0°C,these authors found that the time to complete
yolk absorption for Susitna chum and sockeye eggs varied between 30 to
60 days,with lower temperatures resulting in longer periods of
development.There are some compensatory mechanisms that tend to
counteract thl~se differences,otherwise salmon would not be able to
adjust to natural variations in temperatures.For example,Dong
(1981)suggested that the accumulation of one temperature unit at low
temperatures results in a greater amount of development than the
accumulation of one.temperature unit at high temperature.This,
however,does not decrease the total number of days for incubation.
For example,Wangaard and Burger (1983)found that chum and sockeye
from the Susitna River do not have the ability to regulate their
development rates to result in a similar number of days to complete
yolk absorption when average incubation temperatures vary from 2.1 to
4.0°C.This was evident from the 30 to 60 day delay in complete yolk
,absorption in their tests.Wangaard and Burger also found,however,
4-32
I··..
....
.-
that temperature compensation is noted for growth as a function of
accumulated t,emperature units (particularly below 1°C).The authors
did not find a less efficient development in cold water at hatching.
Instead,they found that alevins in colder liater temperatures had
hatched earlil!r relative to length development.
In summary,it appears that although metabolic efficiency is similar
at temperatures less than 4.0°C and that it takes more temperature
units at higher incubation temperatures to reach complete yolk
absorption,the ultimate result is that highelt:'temperatures (in the
range 0 to 4°C)results in increased growth.This increased growth
overshadows the compensation that takes place 'with growth rates as a
function of accumulated temperature units (Wangiaard and Burger 1983).
For most species on the Susitna River,the timing of egg deposition is
sufficiently early in the season to avoid ini.tial temperatures near
O°C.If an embryo has accumulated approximate~y 140 TU's (the
approximate level needed to achieve closing of the blastopore),then
it probably has passed the sensitive stage.The peak spawning for
most salmon in the Talkeetna-Devil Canyon reac~h (RM 98.6-152)occurs
prior to September 1.This is the case for chinook and pink salmon
(ADF&G 1984a).Chum and sockeye salmon overlap this period,however,
they utilize ,areas of upwelling in the mainstem and sloughs that have
temperatures throughout the winter that vary between about 2 to 4°C,
thus potentially avoiding the initial criticall stage.Coho salmon
spawn late in the season and,if they do not spawn in upwelling areas
(this is not known at the present time),embryos theoretically do not
accumulate sufficient temperature units to get them past this critical
stage.However,because coho salmon have been successfully spawned
and initially incubated at O°C,(Och,ADF&G,personal communication,
1984),perhaps this species does not have these initial temperature
requirements for successful incubation •
Of interest on temperature/time of emergence relationships are the
findings by Graybill et a1.(1979)on the Skagit River in Washington.
This river has been affected by hydropower development for at least 60
4-33
years.PreseIllt water temperature conditions year round are generally
warmer by several degrees than pre-project te:mperatures (no actual
pre-project temperatures have been recorded,however modeling has
established a possible pre-project scenario).E'or chinook salmon,the
timing for sp~lwning has not been noticeably altered,at least through
records that date back to 1948.However,it appears that emergence
timing of Skagit River chinook has been advancE~d by about one month.
Pink salmon emergence has been advanced by about 4 to 11 weeks and
chums from 0 to 5 weeks.The implications of this advancement in the
Skagit River are not clear.Numerous authors have speculated that
such an advan.cement of emergence in any rive]~system would not be
specifically patterned to natural peak abundallces in food organisms
and therefore would not be advantageous to survi~al.
One long ternl example of potential effects of an altered thermal
regime on salmon populations is provided by Envi.roriocon Ltd.(1981)as
quoted by Shepard (1984).In 1954,a hydroelectric project was
completed on the Kemano River in British Columbia,Canada.The
project diverted water from a lake into the Kemano River which
resulted in a tripling of the mean annual flow in the lower Kemano and
warmer winter temperatures.Based on emergence projections for pink
and chum salmon,advancement of emergence over pre-project conditions
may be five weeks.Correspondingly,pink and chum salmon stocks in
the Kemano have increased from 1951 through 1980 whereas other streams
nearby have not exhibited this general trend.It is unclear if
temperature is an important factor in this example because wetted
habitat has also increased and flows have become more stable.
However,Shepard (1984)concludes that prematUl:e emigration of up to
five weeks would appear to have either nil or bemeficial impact on the
Kemano runs.
Wangaard and Burger r s (1983)findings of a 30 to 60 delay in chum
emergence could mean that embryos incubated at the lower temperatures
would result in fish that are out of phase with the normal parr-smolt
transformation (the parr-smolt transformation is the salmonid life
phase where they undergo a physiological change so that they can adapt
4-34
"""
....
to a saltwatelr environment)and therefore,they would not be viable.
Wangaard and Burger state that the effect on the sockeye (that they
incubated)was unclear because they rear for one to two years in
freshwater before they outmigrate.
To simplify the predictions for chum salmon incubation from
fertilization to emergence,AEIDC (1984)has developed a nomograph
with the variables of date of fertilization,average incubation
temperature,and date of emergence.This is useful for examining and
for estimating potential changes in the Susitna incubation periods
from pre-project to with-project conditions.
4.3.3 Substrate
Salmon require certain substrate characteristics for successful
spawning and incubation.The substrate must be capable of allowing
sufficient flow to deliver dissolved oxygen to the embryos and carry
away metabolic:wastes.It also must not contain a high percentage of
fines which CCluld cut off the flow or prevent emergence of fry.Based
on a literature review,Reiser and Bjornn (l9J9)recommend that the
substrate used for incubation should contain l4ass than 25 percent by
volume of fines <6.4 mm.
Substrate also cannot be excessively large because adult salmon
generally are unable to utilize large rocks or solid substrate.
Instead they require intermediate sized gravels.The substrate size
depends to some extent on the size and spe1cies of fish and the
substrate that is available to the fish.Based on extensive field
studies on the Susitna River by ADF&G (1984e),chum salmon in sloughs
generally utilize substrates between 1 in.and 10 in.in diameter.
Sockeye in sloughs also utilize a similar size range of substrates.
Silt is not used nor is sand.Chinook that spawn in the tributaries
must often utilize rubble (3-5 in.diameter)i:md cobble (5-10 in.).
Based on literature review and extrapolation from the other river
systems,ADF&G (l984e)indicates that pink salmon utilize substrates
between approximately small gravel (1/8-1 in.in diameter)to rubble
4-35
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.....
.....
(3-5 in.)with large gravel (1-3 in.)being near the point of most
utilization.Using a similar method of analysis,ADF&G (1984e)found
that coho would mainly use small gravel (1/8 to 1 in.)with sizes up
through large gravel (1-3 in.)potentially suitable.
4.3.4 Streamflow
(i)High Streamflow
During periods of high streamflow,McNeil (1969)found that
disa.ppearance of embryos often exceeded 50 percent for chum and pink
salmon eggs and alevins in streams that he studied in southeast
Alaska.On one occasion,McNeil recorded a loss that exceeded 90
perc:ent.In another example,Wilson,et a1.,(1981)found losses for
pink salmon eggs incubating in the mainstem Terror River on Kodiak
Isll1md,Alaska as a result of storm flows.In addition,high flows
can also cause deposition of fine sediment on the redds which can
reduce permeability or entrap emerging fry (Hale 1981).
A clear definition of the flows that result in loss is ill-defined
because moderately high flows may be beneficial in assuring adequate
intE~rchange of intergravel and surface waters and improving the oxygen
supply to embryos (Reiser and Bjornn 1979).In general,velocities
should be less than those that displace spawning bed materials (Reiser
and Bjornn 1979)•
In the Susitna River and tributaries,high streamflows and scour
predominantly occur during the open water season either due to rain
events or ice/snow melting.Increases in streamflow to specific
habitats can also occur during the ice covered period.For example,
ice jams and staging can cause overflows from the mainstem into
habitats such as sloughs (Wangaard and Burger 1983).No quantitative
information is available on scouring effects in the Susitna River.
Ho~ever,it is reasonable to assume that at high flows,the potential
for scouring increases along with the potential for increased adverse
imp.act if incubating embryos are present •
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.-
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....
-
-
(ii)Low Streamflow
OncE~embryos have begun incubation,reductions in discharge can lead
to dessication of embryos,low oxygen levels,high temperatures,or,
during cold weather,freezing (Hale 1981).McNeil (1969)found that
frel~zing could be a cause of high mortality,but that its occurrence
was erratic in streams that he studied in southeast Alaska.
Responses of incubating embryos and behavioral characteristics of
alevins have been studied by Stober,et al.(1982)on the Skagit
Rivlar,Washington.Using chinook,chum,coho,and pink embryos,the
authors found that various periods of daily dewatering (with
maintenance of humidity and temperature)up to 24 hrs per day in
sevlaral substrate types resulted in a high prehatching survival for
all species and a decrease in post-hatching survival in direct
relationship to the length of daily dewaterings.Also,tolerance to
single dewatering events of various times decreased as development of
alevins progressed.Stober et al.(1982)qualified these results to
state that they should be used cautiously during extrapolation to
field conditions.Such extrapolation would probably be valid for the
sevlere conditions (particularly cold)that occur on the Susitna River.
The Skagit River studies do point out,however,that the alevins have
som,e ability to avoid severe conditions by moving through the gravel.
4.3.5 Biochemical Oxygen Demand (BOD)
Reiser and Bjornn (1979)state that excessive amounts of organic
material to a stream may result in reduced oxygen and detrimental
impacts on embryos.Based on this,it was recommended that BOD should
not diminish or deplete the dissolved oxygen content below stated
levels.
BOD levels have not been measured in the Susitna.Under existing
conditions,dissolved oxygen levels remain at or greater than
saturation in the mainstem.Therefore,it is suspected that BOD is at
low levels.This may not be apparent in habitats adjacent to the
4-37
".,.
.-
.-
mainstem due to high organic content of waters (e.g.upland sloughs),
conc,entrations of dead post-spawned salmon (e.g.,side sloughs)or
movellIlent of water through the groundwater system.
4.3.6 Superimposition
Superimposition can occur if salmon excavate existing redds that were
developed by previous spawners.In addition to mechanical injury that
can occur,existing embryos can be removed from the redd,thus
exposing them to light (which can kill incubating embryos )and
predators.Superimposition becomes more prevalent when the density of
spawning adults increases •
4.3.7 Predators
Numerous species of predators can consume eggs.McNeil (1969)
suggests that sculpins (Cottus sp.)and possibly other fish ,predators
may be involved.Apparently sculpins are capable of digging into
coarse gravel substrates and consuming embryos and alevins.Sculpins
(Cottus sp.)and other potential predators on eggs are present in the
Susitna River,but no information is available on the effects of
pred.ation by this species.
-
4.4 REARING
4.4.1 Sockeye Salmon
(i)Emergence
/
.....
The emergence of sockeye salmon in the Talkeetna-Devil Canyon reach
(RM 98.6-152)occurs primarily during the month of March (ADF&G
1983b,c).In late April most sockeye juveniles of age 0+have reached
33 111m in length and have completely absorbed their yolk sac.This
obsE!rved emergence timing is earlier than the April to June emergence
reported for sockeye by Morrow (1980)and Scott and Crossman (1973).
4-38
""",
I~
.....
.....
(ii)Seasonal Movements
After emergence sockeye usually spend one to two years in lakes and
other freshwater rearing areas before going to sea (Morrow 1980,Scott
and Crossman 1973).However,in the Talkeetna-Devil Canyon reach,
sockeye rearing lakes are not interconnected to the river.Most
juvenile sockeye leave the Talkeetna-Devil Canyon reach during their
first year of life (age 0+fish);age 1+sockeye have accounted for
only one percent of the catch in the downstream migrant traps (ADF&G
1983b,c).It is unknown if the age 0+sockeye leaving the sub-basin
go directly out to sea as smolts or move to rearing habitats in other
sub-basins of the Susitna River.
After emergence,there is a pattern of downstream movement throughout
the summer (ADF&G 1983b,c and 1984b).The peak of this downstream
move,ment for age 0+sockeye is in late June to early July.During
1983 in the Talkeetna-Devil Canyon reach catches of juvenile sockeye
were:the highest in side slough and upland slough habitats.Over 90
perc:ent of the 1,010 juvenile sockeye collected by seining and
elec:trofishing were captured in these two habitats.In 1982 the high
utilization of side and upland sloughs was similar to 1983
utilization;over 90 percent of the 1325 juvenile sockeye collected
..primarily by seining in 1982 were caught in upland and side-slough
habitat (ADF&G 1984b).
In 1983 juvenile sockeye were about equally distributed between upland
slough habitat and side slough habitat (Figure 26).The most
important upland slough for sockeye rearing in 1983 was Slough 6A.
Slough 11 was the most important side-slough habitat for juvenile
sockeye in 1983.In comparison to upland and side-slough habitats,
tributaries and side channels were relatively unimportant to rearing
sockeye in 1983.
The percent distribution of juvenile sockeye in macrohabitat type
presented in Figure 26 has been derived by dividing the total catch in
a habitat type by the number of cells sampled in that habitat type.
4-39
pea
I,
..-
.-
-
--
This value is then expressed as the percent of the total catch in all
habitats divided by the number of cells sampled in all habitats (ADF&G
1984b).This method weights the catches in each habitat type equally;
because catches are divided by the amount of sampling intensity (i.e.
the number of cells sampled)in each habitat type •
Changes in juvenile sampling techniques in 1981,1982 and 1983 and
geaI'biases may make direct comparisons of abundance and distribution
data,between years inappropriate (ADF&G 1984b).In 1981 minnow traps
werE:the primary gear,in 1982 seining was principally used and in
1983 seining and electrofishing were the primary methods (ADF&G
1984b).While catch comparisons and percent distribution differences
among years may be invalid,the trends of habitat utilization in
1981-1983 are probably valid.Most juvenile sockeye were found in
sidE~-slough and upland slough habitat in all three years (ADF&G 1981b,
1983b,1984b).
The high catches in 1983 of juvenile sockeye in Slough 11 (75 percent
of the side slough distribution)were probably due to two factors.
First.Slough 11 is an important side slough for sockeye spawning;in
1982 456 sockeye were counted in Slough 11 during peak counts and the
tot~ll slough escapement to Slough 11 was an estimated 1,199 sockeye
(ADF&G 1984a).These numbers represent over 75 percent of the peak
counts and total slough escapement for sockeye salmon in 1982.
Because Slough 11 was such an important sockeye spawning area in 1982,
it is expected that in 1983 Slough 11 would be an important sockeye
natal slough.Secondly,Slough 11 is breached only at high discharges
(ovl~r 42,000 cis)that occur about 1 percent of the time (ADF&G 1984d)
while the other two important side sloughs for sockeye spawning
(sloughs 8A and 21)breach at lower discharge levels (25,000 to
33,000 cis)(ADF&G 1984d).There has been decreased catches in natal
sidl~sloughs associated with breaching that transforms the side-slough
to side-channel habitat (ADF&G 1984b).Juvenile sockeye may leave
brea.ched side sloughs in search of more favorable rearing habitat.
Unb:reached side sloughs provide habitats with lower water velocities
4-40
..-
-
..-
-
and deeper pools,which juvenile sockeye apparently utilize more than
the swifter velocities of the mainstem and tributaries (ADF&G 1984b).
During July to August 1983 there was a redistribution of juvenile
socklaye from natal side slough habitat to upland slough habitat (ADF&G
19841b).This may have resulted from breaching discharges in early
June at sloughs 8A and 21.Slough 6A was the most important upland
slough for juvenile sockeye in 1983 and 1982 (ADF&G 1983b,1984b)•
Slough 6A has low water velocity,clear water,adequate depth and
abundant cover and is quite different from the majority of sloughs in
the 'Talkeetna-Devil Canyon sub-basin (ADF&G 1984b).
Some overwintering of juvenile sockeye occurs in the Talkeetna-Devil
Canyon sub-basin.This has been documented by winter sampling and the
downstream outmigrant trap catches of age 1+fish.However,catches
of age 1+sockeye have been low (less than 1 percent of the outmigrant
trap catches)and it appears that this reach of the river is not used
extensively for overwintering by juvenile sockeye.Age 1+sockeye
have been observed in sloughs 9,11 and 6A (ADF&G 1984b).
(iii)Food Habits
Juvenile sockeye food habits were examined in July and August 1982 at
sloughs 8A and 11 (ADF&G 1983b).Fish were found to be feeding
primarily on chironomid larvae,pupae and adults.However,dominance
is based on numbers not biomass or volume.Since chironomids are
small,their contribution may be overemphasized by the numerical
method.Electivity indices suggested a positive selection for
chironomid larvae.Cladocerans and copepods were an important food
source for juvenile sockeye in slough 11 during August.A variety of
aquatic and terrestrial insects·were also consumed.
Riisl and Friese (ADF&G 1978)also found that Susitna River juvenile
sockeye fed primarily on zooplankton and diptera larvae.Sockeye
juvEmile in lakes feed principally on plankton crustaceans,chironomid
pupae and occasionally terrestrial insects (Scott and Crossman 1973).
4-41
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.....
_.
4.4.2 Chum Salmon
(i)Emergence
Chum.salmon emergence in the Talkeetna-Devil Canyon reach
(RM 98.6-152)occurred during 1982 in late February and March (ADF&G
1983b,c).By late April most juvenile chum had reached 35 mm in
length and completely absorbed their yolk sacs.Morrow (1980)reports
that chum eggs hatch from December to February and that fry emerge
from the gravel in about 60 to 90 days after hatching.
(ii)Seasonal Movements
Afte~r emergence chum salmon may outmigrate to the estuary in a single
night if they are in systems close to the ocean (Scott and Crossman
1973).However,in situations where the chum outmigration lasts for
daye;or weeks,juvenile chum will feed actively in freshwater and grow
considerably before reaching the estuary (Morrow 1980).
Most:juvenile chum in the Talkeetna-Devil Canyon reach (RM 98.6-152)
emerge and absorb their yolk sacs by late April,however peak
outmigration (at RM 103)does not occur until early June and early
July in 1983 (ADF&G 1983b,c;1984b).This indicates that juvenile
chum from this reach of the Susitna River can spend one to three
months rearing in freshwater.All juvenile chum outmigrate as age 0+
fish.
Most juvenile chum (over 90 percent)were distributed in side slough
~nd tributary habitats in the Talkeetna-Devil Canyon reach during 1983
(Figure 27).These side sloughs and tributaries were primarily areas
of adult chum spawning in 1982.Slough 21,which had the highest
juvl~nile chum density in side sloughs in 1983,had the highest peak
COUlrlt in sloughs of adult spawners in 1982 (ADF&G 1984a,b).
Sim:ilarly,Indian River had the highest density of juvenile chum in
tributaries in 1983 and the highest peak count of adult spawners in
tr~butary habitat in 1982 (ADF&G 1984a,b).
4-42
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In E!arly June during 1983 juvenile chum densities dropped in side
slough and tributary habitats and increased at side channels,upland
sloughs and the downstream outmigrant traps at RM 103 (ADF&G 1984b).
Most juvenile chum had left the sub-basin by mid-July (Figure 28).
(iii)Food Habits
The food habits of juvenile chum have not been examined in the
Talkeetna-Devil Canyon reach (RM 98.6-152).Juvenile chum can spend
one to three months rearing in this reach of river before outmigrating
and can gain up to 27 mm in length during this period (ADF&G 1983b).
Morrow (1980)reports that juvenile chum may feed on chironomids and
cladocerans.Food habit studies of juvenile chinook,coho and sockeye
\
in the Talkeetna-Devil Canyon sub-basin indicate that chironomids
comprised a significant portion of the diet for these three species
(AD]'&G 1983b).It is expected that juvenile chum also feed on
chiI'onomids in this reach of river.Other food items may be
important.
4.4.3 Coho Salmon
(i)Emergence
Coh"emergence probably occurs before May in the Talkeetna-Devil
Canyon reach (RM 98.6-152)as age 0+juvenile coho were caught in the
downstream outmigrant traps (RM 103)in mid May 1983 (ADF&G 1984b).
HOWE!Ver,the emergence timing for coho appears to extend over a
considerable time period,based upon the lower lengths observed in
JunE!and July 1981,1982 and 1983 (ADF&G 1981b,1983b,1984b).Scott
and Crossman (1973)report that coho emergence can occur from early
Marc~h to late July,depending upon time of spawning and incubating
watl!r temperatures.
(ii)Seasonal Movements
Juv4!nile coho usually spend one to two years rearing in freshwater
(agli!1+and 2+smolts),although some coho outmigrate at the end of
4-43
"'"'
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I
their first summer (age 0+fish)and some coho remain in freshwater
thre,e or four years (Scott and Crossman 1973).Juvenile coho
appa,rently prefer pool habitat for rearing over riffle habitat,where
they establish territories and become aggressive toward other juvenile
cohcl and other salmonids (Morrow 1980).
There is a pattern of downstream movement of juvenile coho throughout
the summer in the Talkeetna-Devil Canyon river reach (RM 103-152)
(Figure 29).The low catches of juvenile coho at the downstream
outnligrant traps (RM 103)indicate that some juvenile coho of all age
groups (age 0+,1+,2+)leave the Talkeetna-Devil Canyon sub-basin
(ADF&G 1984b,1983b).Some fish (age 0+,1+may move to other
sub-~asins and continue their freshwater residence,while others (age
1+,2+fish)probably outmigrate to the sea as smolts.
Mos1:juvenile coho (96 percent)were distributed in tributary,upland
slough and side slough habitats in the Talkeetna-Devil Canyon
sub--basin during 1983 (Figure 30).This percent distribution is based
upon mean catch per cell in the different habitats;catches are
weighted equally among the macrohabitats because total catch in a
habitat type is divided by the number of cells sampled in that habitat
tYP4~(ADF&G 1984b).
Important tributaries for juvenile coho rearing in 1983 (Figure 30)
werl~spawning areas for adult coho in 1982 (ADF&G 1982a).Whiskers
Crelek,Chase Creek and Indian River had the highest coho densities,
basled upon mean catch per cell,of the tributaries in the
Talkeetna-Devil Canyon reach (RN 98.6-152)in 1983.
Sloughs 6A and 5 were important upland sloughs for juvenile coho
rea:ring,while Whiskers Creek Slough and Slough 8 were important side
sloughs for juvenile coho rearing in 1983 (ADF&G 1984b).The presence
of juvenile coho in these sloughs coupled with the infrequent catches
in side-channel habitat suggests that juvenile coho are found
4-44
primarily in low-velocity,clear water areas.Upland sloughs and side
sloughs may attract juvenile coho additionally because water
templl!ratures tend to be warmer than side channels and tributaries
(ADF,&G 1984b).Due to low catches of juvenile coho,seasonal
mov~ments of juvenile coho between macrohabitat types are not clearly
defined.
Changes in juvenile sampling techniques in 1981,1982 and 1983,and
gear biases may make direct comparisons between years of abundance and
distribution data inappropriate (ADF&G 1984b).In 1981 minnow traps
were the primary year,in 1982 seining was principally used and in
1983 seining and electrofishing were the primary methods (ADF&G
1984b).While catch comparisons and percent distribution differences·
among years may be invalid,the trends of habitat utilization in
1981-1983 are probably valid.Sampling in 1981 and 1982 indicated
that Slough 6A,Whiskers Creek Slough,Slough 8,Fourth of July Creek,
Lane Creek and Indian River were important juvenile coho rearing areas
(ADF&G 1981b,1983b).
Significant overwintering of juvenile coho in the Talkeetna-Devil
Canyon reach occurs in side sloughs and upland sloughs (ADF&G 1984b).
In 1981 through 1983 Whiskers Creek Slough (side slough)and Slough 6A
(upland slough)were important overwintering areas for age 1+and 2+
coho.Juvenile coho also use mainstem and side-channel habitats for
ovezwintering (ADF&G 1981b).
(iii.)Food Habits
JuvE:nile coho food habits were examined in August and September 1982
in the Talkeetna-Devil Canyon reach (RM 98.6-152).Juvenile coho were
caught at Indian River,Fourth of July Creek,Slough 8A,Slough 11 and
Slough 21 (ADF&G 1983b).Chironomids were the dominant food item
numE~rically in samples collected during August and September.Since
chironomids are small,their volumetric contribution is probably less
than their numeric contribution.Electivity indices suggested a
positive selection for chironomid larvae by juvenile coho.Other
4-45
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....
....
dipterans.and mayfly and stonefly nymphs were occasionally eaten.
Scott and Crossman (1983)report that juvenile pink.chum and sockeye
can be important food items for age 1+and older coho.These food
items are more likely to occur in coho diets between May and August,
whetl.juvenile pink.chum and sockeye are more numerous in the
Talkeetna-Devil Canyon sub-basin.Riis and Friese (ADF&G 1978)found
that juvenile coho in the Susitna River fed on drifting aquatic insect
larv'ae in the spring;the adult stage of aquatic insects were major
foodl items during the summer and fall.
4.4.4 Pink Salmon
(i)Emergence
The emergence of pink salmon probably occurs in March and April in the
Talkeetna-Devil Canyon reach (RM 98.6-152).Limited information
obtained in 1981 indicated that pink salmon fry appeared in Slough 11
and Indian River on March 23 and yolk sac absorption for pink fry was
about 50 percent on April 11 (ADF&G 1981b).Scott and Crossman (1973)
report that pink salmon emerge in April or May.
(ii)Seasonal Movements
Aftl!r emergence juvenile pink move almost immediately downstream to
the sea (Morrow 1980,Scott and Crossman 1973).All juvenile pink
salmon outmigrate in their first summer (age 0+fish)and little if
any freshwater rearing occurs.
It appears that most juvenile pink salmon leave the Talkeetna-Devil
Canyon reach (RM 98.6-152)in May and June.In 1983 the downstream
outmigrant traps (RM 103)caught few juvenile pink after July;the
highest catches at the outmigrant traps were recorded in late May and
early June (ADF&G 1984b).In 1982,the downstream outmigrant trap
caught only seven juvenile pink during early July;this further
suggests that most juvenile pink move downstream before July (ADF&G
1983b)•
4-46
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(iii)Food Habits
It :is uncertain if juvenile pink feed in the Susitna River.It
appears that juvenile pink spend little time in the Talkeetna-Devil
Canyon reach (RM 98.6-152)after emergence.Scott and Crossman (1973)
report that juvenile pink salmon remain in freshwater for such a short
time that many do not feed at all.However,juvenile pink that
migl:ate longer distances to the estuary,probably eat nymphal and
larval insects.Thus,it may be reasonable to expect that juvenile
pink in the Talkeetna-Devil Canyon sub-basin may feed occasionally on
chit'onomid larvae and other aquatic insects during their outmigration.
4.4.5 Chinook Salmon
(i)Emergence
Most:chinook salmon emerge from the gravel in tributaries of the
Talkeetna-Devil Canyon reach (RM 98.6-152)in March or April (ADF&G
1983d).Juvenile chinook had emerged prior to mid April in Indian
RivE~r in 1981 (ADF&G 1983c).Post-emergent chinook in Indian River
ranged.in length from 31-41 mm in April and May 1981 (mean length was
34 n~)(ADF&G 1981b).
(ii)Seasonal Movements
AftE~r emergence juvenile chinook school at first,but as they grow and
become mobile they become territorial and aggressive (Scott and
Crossman 1973).Most juvenile chinook spend one year in freshwater
residence before outmigrating to the ocean (as age 1+smolts),however
in some cases juvenile chinook outmigrate in their first summer (as
age 0+smolts)or spend two years in freshwater and outmigrate as age
2+smolts (Scott and Crossman 1973,Morrow 1980).Most juvenile
chinook in the Talkeetna-Devil Canyon sub-basin (RM 98.6-152)spend
one winter in freshwater before going to sea as age 1+smolts (ADF&G
1981a,b;1982a;1984a,b).
4-47
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One to two months after emergence there is a downstream movement of
some juvenile chinook (age 0+)from areas of high post-emergent
densities (natal tributaries)to rearing and overwintering areas
(mainstem.side channels,side sloughs,upland sloughs and tributary
mouths)(ADF&G 1981b, 1983b,1984b).The downstream redistribution of
age 0+juvenile chinook has been observed in the Deshka River
(RM 40.6)by Delaney et al.(1981),in Montana Creek (RM 77)by Riis
and Friese (ADF&G 1978)and in the Little Susitna River (eight miles
east:of the Susitna River mouth)by Delaney and Wadman (ADF&G 1979).
SomE~age 0+juvenile chinook move downstream and leave the
Talkeetna-Devil Canyon reach;the downstream outmigrant traps (RM 103)
in 1983 captured age 0+juvenile chinook throughout the season with a
major peak catch occurring in August (ADF&G 1984b).These age 0+
chinook were probably redistributing to rearing and overwintering
sitE!s below RM 103 and don 1 t represent outmigrating age 0+smolts •
The distribution of juvenile chinook iII;the Talkeetna-Devil Canyon
reach in 1983 reflects the importance of natal,rearing and
overwintering macrohabitat types (Figure 31).Tributaries are the
only natal areas of juvenile chinook in the Talkeetna-Devil Canyon
sub··basin.Indian River and Portage Creek accounted for over 90
per(~ent of the adult spawner peak counts in tributaries during
1981-1983 (ADF&G 1981a, 1982a,1984a).Thus,it is expected that
tributaries are important juvenile chinook habitats (61 percent of the
juvlmile chinook distribution for all macrohabitats in 1983)and that
Indian River and Portage Creek are the two most important tributaries
for juvenile chinook rearing (90 percent of the juvenile chinook
distribution in tributary habitat in 1983)(Figure 31).Tributaries
had the highest densities of juvenile chinook in spring and early
su~ner,while mainstem side-channel habitat increased in importance in
July and late summer (ADF&G 1984b)•
Imp,ortant summer rearing macrohabitats for juvenile chinook are side
sloughs,side channels,upland sloughs and tributary mouths (ADF&G
1981b,1983b,1984b).In 1983 juvenile chinook were widely
distributed in the Talkeetna-Devil Canyon sub-basin at numerous side
4-48
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channels,side sloughs and upland sloughs after chinook moved
downstream from natal tributaries (Figure 31).Apparently juvenile
chinook prefer areas of moderate water velocity and depth,and utilize
turbidity for cover (ADF&G 1984b).These conditions are often present
at side-channel habitats;consequently,densities of juvenile chinook
were higher in side channels than in side slough or upland slough
habitats (Figure 31).
Side sloughs,tributaries,mainstem,and side channels are used by
juvenile fish for overwintering areas (ADF&G 1981b,1983b,1984b).
However,tributaries apparently become less important after November
as low winter flows and icing occurs (ADF&G 1981d).Side sloughs may
att'ract overwintering juvenile chinook because of warmer water
temperatures associated with groundwater upwelling (ADF&G 1984b).
In 11981 juvenile chinook were captured throughout the Susitna River
from Alexander Creek (RM 10.1)upstream to Portage Creek (RM 148.8)
(ADE'&G 1981b);in 1982 fish were collected between Goose Creek
(RM 73.1)and Portage Creek (RM 148.8)(ADF&G 1983b).In both years
juvemile chinook abundance was higher downstream of the Chulitna River
(RM 98.6)and may be due to higher spawner utilization (Table 7)in
the areas below the Talkeetna-Devil Canyon reach and/or an abundance
and quality of juvenile rearing habitat.
Changes in juvenile sampling techniques in 1981,1982 and 1983 and
geal:biases may make direct comparisons of abundance and distribution
dat~L between years inappropriate (ADF&G 1984b).While catch
comparisons and percent distribution differences between years may be
inv~Llid,the trends of habitat utilization in 1981 through 1983 are
prohably valid.It is apparent from catch data that in 1982 juvenile
chinook abundance in the Talkeetna-Devil Canyon sub-basin was lower
than in 1981 and 1983 (ADF&G 1984b).
(iii)Food Habits
JuvEmile chinook food habits were examined in August and September
1982 at sloughs 8A,11,20,21 and at Indian River and Fourth of July
4-49
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....
-
-
Creek (ADF&G 1983b).Fish were found to be feeding primarily on
chironomid larvae,pupae and adults.However,dominance was based on
numbers and not biomass or volume.Since chironomids are small,their
impo,rtance may be overemphasized by the numerical method.Electivity
indi.ces indicated that juvenile chinook had a positive selection for
chiI'onomid larvae.Terrestrial and other aquatic insects were also
eatE!n by juvenile chinook (ADF&G 1983b).
Riil:I and Friese (ADF&G 1978)found that terrestrial insects were more
important than aquatic insects in the diet of Susitna River juvenile
chiILook.Apparently,Riis and Friese (ADF&G 1978)lumped adult stages
of some aquatic insects with insects that have entire life cycles on
land.Therefore,their conclusion that terrestrial insects comprised
a miajor portion of the diet of juvenile chinook may be inaccurate.
They'also concluded that juvenile chinook and coho had similar food
habjLts.However,the results of food habit studies done in 1982
indicated that juvenile chinook and coho diets were usually
significantly different (P<0.05)(ADF&G 1983b).
4.5 OUTMIGRATION
4.5,,1 Sockeye Salmon
(i)Timing
Most juvenile sockeye salmon leave the Talkeetna-Devil Canyon reach
(RM 98.6-152)during their first year of life.Over 99 percent
(12,312)of the 12,395 juvenile sockeye caught in outmigrant traps at
RM 103 in 1983 were age 0+fish,while only 83 fish were age 1+(ADF&G
198':'b)•It is unknown if the age 0+sockeye leaving this reach of
rivlar go directly out to sea as smolts or move to rearing habitats in
othlar sub-basins of the Susitna River.If they do go directly to the
oce.an their survival is low,because less than one percent of
returning adult sockeye at Curry Station (RM 120)outmigrated as age
0+smolts (ADF&G 1982a).
4-50
"%"T"iI LkiihtALXibi~~"'"""......~.....~_
I
{
(
I
i
.i
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ir
~
The peak outmigration of age 0+sockeye occurred during early July in
both 1983 (Figure 28)and 1982 (ADF&G 1984b,1983b).The outmigration
was :monitored from mid June to mid October in 1982 and from mid May to
the end of August in 1983 (ADF&G 1984b,1983b).Catches of age 0+
sockeye occurred throughout the sampling season.The outmigration of
age 1+sockeye was over by the end of June in 1983 and the end of July
in 1982.
During 1983 juvenile sockeye outmigration rates in the mainstem at
RM 103 were weakly correlated with mainstem discharge (ADF&G 1984b).
The coefficient of determination (r2 )between mainstem discharge and
juvenile sockeye outmigration rate was 0.12 for age 0+fish and 0.06
for age 1+fish,thus only 12 and 6 percent of the variation in the
outmigration rates was accounted for by correlating outmigration rates
with mainstem discharge.
Juvenile sockeye apparently outmigrate close to the river banks.A
high outmigrant trap selectivity for juvenile sockeye was observed in
1983 (ADF&G 1984b).
(ii)Size
The average size of outmigrating age 0+sockeye in 1982 at RM 103 was
42 nm in late June during peak outmigration and increased throughout
the season to 72 mm by early October (ADF&G 1983b).Age 1+sockeye
outmigrating in 1982 averaged 77 mm in early June and 87 mm in late
July.In 1983 age 0+and 1+sockeye were separated by length
analysis.In early May age 0+sockeye were less than 56 mm,while age
1+sockeye were 56 mm or greater.In late June age of sockeye were
less;than 71 Dlm,while age 1+sockeye were 71 mm or greater (ADF&G
198Q,b)•
Morrow (1980)reports that sockeye smoltification is mainly controlled
by fish size rather than age.The size at which fish smolt seems to
be determined by the genetics of the stock.
l
.~
L -~-
4-51
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(iii.)Population Estimates
In 1983 the outmigrant population of age 0+sockeye was estimated from
the Talkeetna-Devil Canyon reach (RM 98.6-152).Fry were fin clipped
and tagged with half-length coded wire tags at sloughs 8A,11 and 21
and recaptured in downstream outmigrant traps at RM 103.The
outD!1igrant population of age 0+sockeye was an estimated 560,000 fish
using the Peterson mark/recapture estimator and 575,000 fish using the
Sch~lefer estimator (ADF&G 1984b).
Survival estimates for egg to outmigrant were calculated by dividing
the outmigrant population estimate by the total potential egg
deposition.Survival from egg to outmigrant was about 40.9 percent
using the Peterson estimate of population size and 42.0 percent using
the Schaefer estimate of population size (ADF&G 1984b).
The high survival rate (41-42 percent)for egg to outmigrant for
juv4:mile sockeye in the Talkeetna-Devil Canyon reach is not comparable
to survival estimates for egg to outmigrant in other studies (ADF&G
198'4b).The study in the Susitna River covered a shorter period of
timla (egg to outmigrating age 0+sockeye at RM 103),while other
studies (Russell 1972 and Meehan 1966,cited in ADF&G 1984b)reported
su~~ival estimates of 0.6 to 8.5 percent from egg to outmigration of
age 1+or age 2+sockeye smolts.
The high survival rate for egg to outmigrant in the Talkeetna-Devil
Ca~ron river reach may be due to the productivity of sockeye spawning
are;as (ADF&G 1984b).The three major sockeye spawning areas,sloughs
8A,11 and 21,are side sloughs associated with the mainstem Susitna
Riv,er.These side sloughs may provide a more stable incubating and
rearing habitat than tributaries (ADF&G 19·84b).However,the
dewatering of eggs deposited under high water conditions along the
slough margins,may be a case when side sloughs would not provide
stable incubating habitat for all incubating embryos.
4-52
.-
A cOlmparison of data from the east bank outmigrant trap at RM 103 for
1982 and 1983 indicated that 1983 juvenile sockeye catch rates were
1.4 times higher than 1982 catch rates (ADF&G 1984b).This relative
abundance of age 0+sockeye in 1983 and 1982 did not correspond to the
parent spawner relative abundance in 1982 and 1981.The total slough
escapement of sockeye salmon above RM 98.6 in 1982 was only 68 percent
of the 1981 total slough escapement and the 1982 Curry Station
(RM 120)sockeye escapement was only 50 percent of the 1981 Curry
Station escapement.The possible explanations for lower than expected
juvenile catches in 1982 are:(1)parent spawner density was high
enough in 1981 to result in superimposition of redds,which would lead
to poor egg survival;and (2)eggs in 1981 were spawned under high
water conditions,which later could have led to dewatering of many
redds and subsequent egg mortality (ADF&G 1984b).
4.5.2 Chum Salmon
(i)Timing
All juvenile chum salmon in the Susitna River outmigrate to the ocean
in their first year of life.The outmigration was monitored by the
downstream outmigrant traps from mid May to the end of August in 1983
and from mid June to mid October in 1982 (ADF&G 1983b,1984b).In
1982,the peak outmigration of juvenile chum occurred on June 21,just
thrE~e days after the trap began fishing.Therefore,it is possible
that:the peak outmigration occurred before June 18 in 1982.By mid
July 1982 almost 90 percent of the total downstream migrant trap catch
(75~f total chum)had been caught;no juvenile chum were caught at the
downstream migrant.trap after mid August in 1982 (ADF&G 1983b).In
1983 the chum outmigration at the downstream migrant traps (RM 103)
peaked in early June and early July;by mid August all fish had left
the Talkeetna-Devil Canyon reach (RM 98.6-152)(Figure 28).
In 1983 juvenile chum outmigration rates were strongly correlated with
mainstem discharge (ADF&G 1984b).During mid May to mid July (this
period accounted for over 98 percent of the catch at the downstream
4-53
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....
"""'I
I
I
i
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~I
migrant traps)almost 80 percent of the variation in chum catch rates
was accounted for by correlating outmigration rates with mainstem
discharge.The coefficient of determination (r 2 )between mainstem
disc:harge and juvenile chum outmigration rates was 0.79;r =0.89
(ADE'&G 1984b).Thus,chum outmigration timing is strongly influenced
by i.ncreases in mainstem discharge.
Juvemile chum apparently outmigrate primarily near mid river.A low
outllligrant trap selectivity for juvenile chum was observed in 1983
(ADF&G 1984b)•
(ii)Size
The average size of juvenile chum in the Talkeetna-Devil Canyon reach
(RM 98.6-152)was about 42 mm (length range 29-55 mm)during the first
two weeks of July 1982 (ADF&G 1983b).By this time most juvenile chum
(aII[Ost 90 percent of the outmigrant trap catch)had left this reach
of 1~he river.Most juvenile chum had reached a length of 35 mm after
emelrgence by late April 1982 (ADF&G 1983b).Thus,some chum grow
considerably after emergence before outmigrating while others exhibit
litde growth.This could be due to differences in timing of
emelrgence and outmigration for juvenile chum in this reach of river,
or perhaps some juvenile chum feed less actively than others.
(iii)Population Estimates
In 1983 the outmigrant population of juvenile chum was estimated from
the Talkeetna-Devil Canyon reach (RM 98.6-152).Fry were fin clipped
and tagged with half-length coded wire tags at sloughs 8A,9,11 and
21 and at Indian River;outmigrating fry were captured at downstream
outll1ligrant traps at RM 103 and examined for marks.The outmigrant
population of juvenile chum was an estimated 3,322,000 fish using the
Peterson mark/recapture estimator and 3,037,000 fish using the
Schaefer estimator (ADF&G 1984b).
4-54
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F
,I
I I
1
i
.,
I
1
l
Survival estimates for egg to outmigrant were calculated by dividing
the outmigrant population estimate by the total potential egg
deposition.Survival from egg to outmigrant was 14.1 percent using
the Peterson estimate of population size and 12.9 percent using the
Sch8Lefer estimate of population size (ADF&G 1984b).The survival rate
(13-0 14 percent)for egg to outmigrant for chum salmon in the
Talkeetna-Devil Canyon reach is within the range (0.4-35.4 percent)of
those reported from other studies (ADF&G 1984b).
The survival rate for chum salmon egg to outmigrant may be lower than
the survival rate (41-42 percent)for egg to outmigrant for sockeye
SaltilOn because of macrohabitat differences (ADF&G 1984b).Sockeye
spallffi exclusively in side slough habitat while chum spawn in side
slough and tributary habitats.Thus chum salmon embryos are exposed
to .a wider range of habitat conditions and it can be inferred that
slough spawning and incubation may result in higher survival rates
than tributary spawning and incubation.
Daily outmigration rates,population size and recruitment rates of
juvEmile chum were estimated at Slough 11 in 1983 (ADF&G 1984b).Fish
WerE!tagged with half-length coded wire tags and marked with Bismark
Broun dye so that fish marked over a three day period could be
separated upon recapture by the particular day they were marked.This
technique made it possible to estimate population size for a given
day"daily emigration rates and daily recruitment rates.On day two
of the experiment,population size of juvenile chum in Slough 11 was
an 4!stimated 2,068 fish,the daily emigration rate was 32.7 percent of
the population,and the daily recruitment (emergence)rate was 1.84
perl~ent of the population (ADF&G 1984b).Thus,the population size
was increasing over the three day period because the emergence rate
exc4!eded the emigration rate.
A comparison of data from the east bank outmigrant trap at RM 103 for
1982 and 1983 indicates that in 1983 juvenile chum catch rates were
2.3 times higher than 1982 catch rates (ADF&G 1984b).This relative
4-55
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I
abundance of juvenile chum in 1983 and 1982 corresponded with the
parent spawner relative abundance.The 1982 chum escapement (29,400
fish)at Curry Station (RM 120)was 2.2 times higher than the 1981
chum escapement (13,100 fish)(ADF&G 1984a).Thus,downstream
outlllligrant trap catch rates can provide a comparative index of annual
differences in the relative abundance of chum outmigrants (ADF&G
198qb).
4.5.3 Coho Salmon
(i)Timing
The outmigration of juvenile coho from the Talkeetna-Devil Canyon
reach (RM 98.6":"152)was monitored by downstream migrant traps (RM 103)
during 1982 and 1983 (ADF&G 1983b,1984b).There was a pattern of
downstream movement of juvenile coho throughout the summer
(Figure 29).Age 0+coho accounted for over 90 percent of the total
trail catches of 5,646 fish;age 1+and 2+coho comprised the remaining
portion of the catch (ADF&G 1984b).The low catches of juvenile coho
at the downstream outmigrant traps (RM 103)indicate that some
juvEmile coho of all age groups (age 0+,1+,2+)leave the
Talkeetna-Devil Canyon reach (ADF&G 1984b,1983b).Some fish (age 0+,
1+)may move to other sub-basins and continue their freshwater
res:ldence,while others (age 1+,2+fish)probably outmigrate to the
sea as smolts.
Frol11 November 1980 to May 1981 age 2+coho were captured in the
Talkeetna-Devil Canyon reach (ADF&G 1981b).After May in this reach
of river and mid-June in the Cook Inlet to Talkeetna reach no age 2+
coho were caught.It appears that age 2+smolts leave the
Talkeetna-Devil Canyon sub-basin by June 1 and the lower Susitna River
by June 15.Catches of age 2+coho have been low at the outmigrant
tr~~s at RM 103,however it appears that age 2+coho catches peaked in
early June 1982 and 1983 (ADF&G 1983b,1984b).
4-56
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Therle is evidence that age 1+and older fish may not have the same
catchability as age 0+fish at the outmigrant traps (ADF&G 1984b).
The 'Outmigrant traps may be more effective in catching the younger and
smaller fish.thus the relative abundance of older fish outmigrating
from the sub-basin may be underestimated.
Analyses of scales in 1981 through 1983 from returning adult coho
salmon at Curry Station (RM 120)indicated that most coho outmigrate
from the Susitna River as age 1+or 2+smolts;in 1981 one coho adult
was sampled at Curry Station that had outmigrated in its first summer
(age 0+)(ADF&G 1984b,1983b.1981b).Thus,if the age 0+coho caught
at the downstream migrant traps (RM 103)are outmigrating to the sea
as smolts.their survival is low.In 1981 about two-thirds of the
returning coho adults sampled at Curry Station had outmigrated as age
2+smolts,in 1982 46 percent were age 2+smolts and in 1983 53
percent were age 2+smolts.
During 1983 juvenile coho outmigration rates in the mainstem at RM 103
were moderately correlated with mainstem discharge (ADF&G 1984b).The
coefficient of determination (r2 )between mainstem discharge and
juvenile coho outmigration rates was 0.17 for age 0+fish and 0.22 for
age 1+fish.thus 17 and 22 percent of the variation in the
outl1ligration rates was accounted for by correlating outmigration rates
with mainstem discharge.
The increased catch of age 0+coho in August 1983 at the downstream
outmigrant traps (Figure 29)may be a result of:(1)high discharge
levElls (about 32,000 cfs at Gold Creek on August 10)that breached
maiI1lstem rearing areas and displaced juvenile coho downstream;and
(2)increased discharge in tributaries allowed trapped juvenile coho
in side channels and pools of Indian River and Portage Creek to
outmigrate from these tributaries (ADF&G 1984b).
(ii)Size
The average size of age 0+coho in the Talkeetna-Devil Canyon
sub-~asin (RM 98.6-152)was 41 mm in late June 1982 and 56 mm in late
4-57
....
....
June 1981;age 0+coho increased in size over the summer to 65 rom in
late September 1982 and 63 mm in late September 1981 (ADF&G 1983b,
1981b).In 1983 age 0+coho were separated from age 1+and older coho
by length frequency and scale analyses;age 0+coho were less than
46 mm in early May,less than 66 mm in late June,and less than 96 rom
in late September (ADF&G 1984b).
Length frequency and scale analyses did not provide a separation
length between age 1+and 2+coho because of length overlaps (ADF&G
1983b).Therefore,age 1+and 2+fish were combined as age 1+and
older in most analyses.During February to May 1982 from Cook Inlet
to Devil Canyon,age 1+coho ranged in length from 63-116 mm,while
age 2+coho ranged in length from 89-158 mm.During early June 1982
frolIl Cook Inlet to Devil Canyon,age 1+fish ranged in length from
85-129 mm,while age 2+fish ranged in length from 117-202 DUD.(ADF&G
1983b).Most age 2+coho in the Deshka River (RM 40.6)ranged between
120-·140 mm in 1980 and had outmigrated by late July (Delaney et al.
1981).
(iii.)Population Estimates
No population estimate or survival estimate for juvenile coho has been
dOnE!in the Susitna River.Catches of juvenile coho in 1982 suggest
that:the river reach below RM 98.6 is more important to coho rearing
than above RM 98.6.About 80 percent of the juvenile coho caught in
1982 were captured below RM 98.6 (ADF&G 1983b).
A comparison of data from the east bank outmigrant trap at RM 103 for
1982 and 1983 indicates that in 1983 juvenile coho catch rates were
2.8 times higher than the 1982 catch rates (ADF&G 1984b).This
relative abundance of juvenile coho in 1983 and 1982 corresponded with
parlmt spawner relative abundance.The 1982 coho escapement
(2,IWO fish)at Curry Station (RM 120)was 2.2 times higher than the
1981 coho escapement (1,100 fish)(ADF&G 1984a).Thus,the downstream
4-58
--
-
outmigrant trap catch rates can provide a comparative index of annual
differences in the relative abundance of juvenile coho outmigrants
(ADF&G 1984b).
4.5.4 Pink Salmon
(i)Timing
All juvenile pink sa~on in the Susitna River outmigrate to the ocean
~·3'"i;:1C:-''':
in their first year of life (age 0+fish).After emergence in April
and May,juvenile·pink move almost immediately downstream to the
estuary.In 1983 juvenile pink catches were highest at the outmigrant
traps (RM 103)during late May and early June;few (eight)juvenile
pink:were caught after June (Figure 32).
In 1983 juvenile pink outmigration rates were moderately correlated
with mainstem discharge (ADF&G 1984b).During mid May to mid July
abollt 30 percent of the variation in pink catch rates was accounted
for by correlating outmigration rates with mainstem discharge.The
coefficient of determination (r2 )between mainstem discharge and
juvfmile pink outmigration rates was 0.30;r =0.55 (ADF&G 1984b).It
appE~ars that pink outmigration timing is influenced by increases in
mainstem discharge.
(ii]!Size
The average size of juvenile pink,between river mile 79 and 136,was
abmlt 36 rom (length range 29-43 mm)during late May to late July 1982
(ADF&G 1983b).No increase in size was observed for the July fish
when compared to fish measured in May,however the sample size was
small (28 fish).Thus,it appears that juvenile pink grow little if
any during their freshwater residence.
(iii)Population Estimates
No 4~stimate of population size of juvenile pink in the Talkeetna-Devil
Canyon reach (RM 98.6-152)has been done.Catches of juvenile pink
4-59
.....
r
.....
have been low;in 1983 245 fish were caught in the downstream
outmigrant traps (RM 103),while in 1982 only six juvenile pink were
captured in the outmigrant trap •
Juvenile pink abundance is undoubtedly greater in odd years than in
even years.Adult runs of pink salmon are numerically dominant in
even years in the Susitna River;even year escapement of pink salmon
is about 10 times greater than odd year escapement.Thus,the progeny
of e:ven year pink salmon emerge and outmigrate in the following odd
year.
4.5.5 Chinook Salmon
(i)Timing
Most juvenile chinook spend one year in freshwater before outmigrating
to the ocean (as age 1+smolts),however in some cases juvenile
chinook outmigrate in their first summer (as age 0+smolts)or spend
two years in freshwater and outmigrate as age 2+smolts (Scott and
Crossman 1973,Morrow 1980).Most juvenile chinook in the
Talkeetna-Devil Canyon reach (RM 98.6-152)spend one winter in
freshwater before going to sea as age 1+smolts (ADF&G 1981a,b;1982a;
1984a,b).
The downstream outmigrant traps (RM 103)in 1983 captured age 0+
chinook throughout the season (mid May to the end of August)with a
majc1r peak occurring in August (Figure 33).These age 0+chinook were
probably redistributing to rearing and overwintering areas below
RM 103 and don't represent outmigrating age 0+smolts.
The majority of the outmigration of age 1+chinook smolts from the
Talkeetna-Devil Canyon sub-basin occurred in May and June in 1981 and
1982 (ADF&G 1983b).In 1983,the outmigration of age 1+chinook at
the downstream outmigrant traps (RM 103)was over by mid July
(Figure 33).Age 1+chinook had outmigrated downstream of Goose Creek
4-60
....
(RM 73)by the end of July in 1982 (ADF&G 1983b).Most age 1+chinook
appa.rently leave the Susitna River by September as no age 1+chinook
were:captured between Cook Inlet and Talkeetna Station (RM 103)after
the end of August (ADF&G 1981b).
Duri.ng 1983 juvenile chinook outmigration rates were moderately
correlated with mainstem discharge (ADF&G 1984b).The coefficient of
detE!rmination (r2 )between mainstem discharge and juvenile chinook
outDligration rates was 0.25 (r=0.50)for age 1+fish and 0.19 (r=0.44)
for age 0+fish.Thus 25 and 19 percent of the variation in
outDligration rates was accounted for by correlating outmigration rates
with mainstem discharge.
The outmigration peak of age 0+chinook in mid August 1983 was
probably influenced by the discharge peak of 32,000 cfs at Gold Creek
on August 10 (ADF&G 1984b).The discharge peak may have breached
chinook mainstem rearing areas and caused a downstream displacement of
juvlmile chinook.In addition,tributary discharges increased during
this time period and could have allowed juvenile chinook that were
tr~?ped in side channels and pools of tributaries to outmigrate from
tributaries.
(ii)Size
Age 1+juvenile chinook averaged 90 mm in length during May and June
in 1981 and 1982 (ADF&G 1983b).This is when most age 1+chinook are
outllnigrating from the Talkeetna-Devil Canyon sub-basin (RM 98.6-152).
In this reach of the Susitna River,age 0+and age 1+chinook can be
separated by length frequency analysis (ADF&G 1984b).In early May
age 0+chinook above RM 103 are less than 56 mm,in early June age 0+
chinook are less than 71 mm,and in early July age 0+chinook are less
than 81 mm.After August 1 all chinook above RM 103 are considered
age 0+fish (ADF&G 1984b).
4-61
-
-.
"""
Below Talkeetna Station (RM 103),it is not possible to separate age
0+and age 1+chinook from length frequency data alone because of
overlapping lengths of the two age groups.After September 1 all
juvenile chinook below RM 103 are considered age 0+fish (ADF&G
1981b).
(iii)Population Estimates
No estimation of population size for juvenile chinook has been done in
the Susitna River.Moderate numbers of juvenile chinook have been
caught in the Talkeetna-Devil Canyon reach (RM 98.6-152).Analysis of
catch data for 1981 through 1983 indicates that in 1982 juvenile
chil1look abundance in the Talkeetna-Devil Canyon sub-basin was lower
than in 1981 and 1983 (ADF&G 1984b).Catch comparisons of the east
bank downs~ream migrant trap (RM 103)between 1982 and 1983 indicate
that juvenile chinook abundance was over four times greater in 1983
than for the same time period in 1982.The downstream outmigrant
traps (RM 103)apparently provide an index of relative abundance of
juvE!nile salmon between years (ADF&G 1984b).
In 11983 only 434 age 1+chinook were caught in downstream outmigrant
traps at RM 103,while 5,768 age 0+chinook were caught (ADF&G 1984b).
Correlation analysis between age 1+chinook catches and trap
velocities indicates that the relative abundance of age 1+fish may be
undE~restimated because of trap avoidance (ADF&G 1984b).
4-62
.",.
"""'I
",..
-
5.0 HABITAT UTILIZATION AND RELATIONSHIPS
5.1 MAINSTEM AND SIDE CHANNEL HABITAT
Main.stem habitat is comprised of those portions of the Susitna River
that normally convey streamflow throughout the year (Figure 2).Both
single and multiple channels are included in this habitat category.
Grou.ndwater and tributary inflow appear to be inconsequential _~+,tl'~3-
contributors to the overall characteristics of mainstem habitat:The WI""•
mainstem is typically characterized by high water velocities and well
armclred str.eambeds.Substrates generally consist of boulder and
cobble size materials with interstitial spaces filled with a
grout-like mixture of small gravels and glacial sands.Suspended
sediment concentrations and turbidity are high during summer due to
the influence of glacial melt-water.Streamflows recede in early fall
and the mainstem clears appreciably in October.An ice cover forms on
the river in late November or December and lasts until April or May
(ADF&G 1983e,Trihey 1982).
SidE!-channel habitat consists of those portions of the Susitna River
that normally convey streamflow during the open water season but
become appreciably dewatered during periods of low flow (Figure 2).
SidE~channel habitat may exist either in well defined overflow
channels,or in poorly defined water courses flowing through partially
submerged gravel bars and islands along the margins of the mainstem
rivnr.Side channel streambed elevations are typically lower than the
mean monthly water surface elevations of the mainstem Susitna River
obsf!rved during June,July and August.Side channels are
chalcacterized by shallower depths,lower velocities and smaller
strE!ambed materials than the adjacent habitat of the mainstem river
(ADF&G 1983e,Trihey 1982).
5.L 1 Adult Salmon
Fiv4a species of Pacific salmon utilize the mainstem and side channels
of the Susitna River above the Chulitna confluence (RM 98.6)primarily
5-1
....
as a migrational corridor and to a lesser extent as spawning habitat
from late spring into the fall (ADF&G 1981a. 1982a.1984a).Use
periods for adults of each species are:
....
Sockeye -July through mid-September;
Chum -mid-July through mid-September;
Coho -late-July through mid-September;
Pink -late-July through August;and
Chinook -mid-June through July
....
-
Relative abundance estimates based upon 1981.1982 and 1983 escapement
data indicate that the mainstem and side channels of the
Talkeetna-Devil Canyon reach (RM 98.6-152)serves as a migrational
corridor for less than 10 percent of the total Susitna River salmon
escapement (Table 6).During migration periods,various behayioral
--...-'
and distribution patterns are associated ~ith-certain-~~acteristics
------"_._~.__.~,~_....'-,~'"_.••_~-~,~.,••"••"~._,="'",.~~~-~,~~,••••_-~-----
of mainstem habitat.including water depth,velocity.channel
...,,,,,,,,;vO''''''~''''''''''''''-'''''''"''''~.~_....."...__.._,,,__~,,~,""""""':l".;"""'_"'~--.!'l/I1I~~...
c~~figu~~~d location or absence of obstructions (ADF&G 1981c)•
.,.-,'~""""·"""""""~~'--"~""'t:>/iy",._~·,;"",,,,,",~~..,_.~,,,,,,,~~"'~~"i>iil-"""'l'f(l;<~~~~j;ji;.,"'ilJI
Generally.passage of adult salmon during migration corresponds with
the summer high-flow season.However,peak river discharge events
above 80.000 cfs at Sunshine Station (RM 80)apparently cause upstream
move~ents of salmon to decrease and increases milling behavior until
flolirs subside following major flow events (Figures 12.15.18,21.
24).This relationship of slowed upstream migration caused by high
rivElr discharge was observed in the Talkeetna-Devil Canyon reach at
flo~rs above 40.000 cfs at the USGS gaging station Gold Creek
(RM 136.8)(ADF&G 1984d).
Mainstem and side channel spawning above RM 98.6 has been observed for
sockeye,chum and coho salmon (ADF&G 1981a.1982a.1984a).Chum
salmon apparently utilize the mainstem margins and side channels for
spa~ming more than coho or sockeye.Counts of chum salmon spawning in
mainstem and side-channel habitat were:16 fish in 1981.550 fish in
1982 and 219 fish in 1983 (Table 12).Only three coho and eleven
sockeye were observed spawning in mainstem and side-channel habitat
5-2
....,
.....
..-
during 1981-1983.Mainstem spawning is apparently restricted by the..-
lack of suitable spawning substrate and groundwater upwelling (ADF&G
1981iC)•
5.1.2 Juvenile Salmon
Juvenile salmon of all five species present in the Susitna River
utilize the mainstem and side channels above RM 98.6 primarily as a
migrational corridor.Mainstem and side channels are important
over~intering and rearing areas for some species.Periods of juvenile
salmon mainstem and side channel use and relative abundance in the
Talkeetna-Devil Canyon reach (RM 98.6-152)are outlined below.
Sockeye -During 1982 and 1983 juvenile sockeye moved out of the
Talkeetna-Devil Canyon reach primarily during June and July
(ADF&G 1983b,1984b)(Figure 28).In 1983,juvenile sockeye used
mainstem and side-channel habitat in low densities for rearing
(Figure 26).
Chum -During 1982 and 1983 juvenile chum had migrated downstream
of RM 103 by mid-July (ADF&G 1983b,1984b)(Figure 28).Juvenile
chum used mainstem and side channels for rearing in low densities
(ADF&G 1984b)(Figure 27)•
Coho -Outmigration of juvenile coho peaked during June,July and
August during 1983 and during June in 1982 (ADF&G 1983b,1984b)
(Figure 29).Coho juveniles used mainstem and side-channel
habitats for overwintering in 1981 (ADF&G 1981b).Relatively few
juvenile coho utilized mainstem and side-channel habitat for
rearing in 1983 (Figure 30).
Pink -Most juvenile pink moved downstream of RM 103 during May
and June in 1983 (Figure 32).Minimal freshwater rearing and
growth occurs for juvenile pink salmon because of their short
(one month)residence time.Mainstem and side channel use by
juvenile pink for rearing is probably low.
5-3
-
Chinook -The majority of age 1+chinook moved downstream below
RM 103 in .May and June in 1981, 1982,and 1983 (ADF&G 1981b,
1983b,1984b)(Figure 33).Age 0+chinook moved downstream
throughout the open water season in 1983.Mainstem and side
channels are important rearing and overwintering habitat for
juvenile chinook (ADF&G 1981b,1983b,1984b).
Duri.ng 1983 juvenile salmon outmigration rates were positively.....
corI'e1ated with mainstem discharge (ADF&G 1984b).The correlation
coefficient was highest for juvenile chum (r=0.89;r 2 =0.79),
indi.cating that outmigration rates for juvenile chum may be influenced
by increased river discharge levels.Correlation coefficients were
modE~rate to low for the remaining juvenile salmon and ranged from
r=0.55;r 2 =0.30 for juvenile pink to r=0.24;r 2 =0.06 for age 1+
sockeye.Peak flow events may displace some juvenile salmon (e.g.
chinook)frou;t mainste~~nd side-channel rearing areas (ADF&G 1984b).
5.2 SIDE AND UPLAND SLOUGH HABITAT
.....
-
-
The clear water in sloughs originates from local surface runoff and
ground water upwelling.Ground water upwells in the slough channels
throughout the year,thus keeping these areas relatively ice free in
the winter.Observations indicate the Susitna River is the primary
SOU1:'ce of the water in many of the sloughs.Local runoff is an
important water source for some sloughs in the summer.
The stage in the mainstem controls the water surface elevation of the
lowl~r portion of the sloughs by forming a backwater that can extend
soml~distance upstream into the slough.This backwater is divided
intc)two parts--c1ear water and turbid water.The mainstem water
creates a turbid plug at the mouth of the slough that backs up the
clear water in the slough.As the stage in the mainstem drops,.th.~_....,.--------,-......""""""-,~~.
sizl:!and character of the backwater changes.At fall flows of
app:roximately 8,000 to 10,000 cfs at Gold Creek (RM 136.7),the
bacltwater recedes.This reduces the depth of water at the entrance to
5-4
-
the sloughs.In some cases t the slough mouth and the mainstem become
separated by a gravel bar.
When high mainstem flows overtop the upstream (head)end of the
sloughs t the flows flush fine sediments that accumulate in the lower
portion of the sloughs.As peak flows in the ma:instem subside and the
stage in the mainstem drops below the head end of the slough t
discharge through the slough drops and the water in the slough begins
to clear.
Because there is much diversity in the morphology of individual
sloughs t the flows at which they overtopped vary considerably.In
general,most side sloughs are overtopped at flows between 20 ,000 to
30 t OOO cfs t although some sloughs (e.g.Slough 11)are only.overtopped
at high discharge levels (42,000 cfs).
In general slough water temperatures are warmer than mainstem
temperatures in the winter.
.....
Upland sloughs differ from side sloughs in thalt the upstream (head)>JIlII ,1'1 ,
end of the slough is not interconnected with the surface waters of the fl.l<vtr~\""-Icr~
r--;:-::--lr/~I'V'-""1
mainstem Susitna River or its side channels (Figure 2).Upland el'-t:").\C
p\';""C iii'
sloughs are characterized by the presence of beaver dams and an .
accumulation of silt covering the substrate resulting from the absence
of mainstem scouring flows.
The access and upstream passage of salmon i.nto sloughs and side
channels are dependent primarily on water depth and length of the
passage reaches that are restrictive to the upstream movement of
salmon (ADF&G 1984d).Hydraulic velocity barriers apparently do not
exist at sloughs in the Talkeetna-Devil Canyon reach (RM 98.6-152).
The mainstem discharge level directly influences access and passage
into sloughs because of its influence on backwater at the mouth of
sloughs and breaching at the upstream (head)of sloughs.Under low
mainstem discharge levels (unbreached conditions),the backwater at
the mouth of sloughs and side channels may not be of sufficient depth
5-5
-
.....
.....
to allow successful passage.As mainstem discharge increases,the
backwater area generally increases in depth and extends its length
upstream,which increases the depths within those critical passage
reaches affected by the backwater.The elimination of passage
restrictions within a reach by backwater inundation continues in the
upstream direction with increasing mainstem discharge,until the
slough is brea,ched,at which point depths beCOmE!adequate for passage
at all passage reaches in most sloughs and side channels (ADF&G
1984d).
Mainstem discharge levels in the Susitna River at Gold Creek
(RM 136.7)commonly range between 20,000 and 30,000 cfs during June,
July and August when adult salmon are migrating upstream and 15,000 to
20,000 cfs during peak spawning periods (20 August to 20 September)
(ADF&G r984d).Because of the diversity in the morphology of
individual sl'Dughs,the access and passage into sloughs varies
considerably at a mainstem discharge leve+.Breaching of important
spawning sloughs in the Talkeetna-Devil Canyon reach occurs at
relatively high mainstem discharges (19,000 1:0 42,000 cfs)(ADF&G
1984d).During the peak spawning period (20 August to 20 September)
mainstem discharge at Gold Creek equals or exceeds 15,000 cfs 50
percent of the time (ADF&G 1984d).Therefore,access and passage into
sloughs and side channels are more often controlled by the backwater
at the slough mouth and the local flow from groundwater and runoff
sources.LocaLl flow from groundwater appears to be correlated with ..J...!
mainstem discharges (APA 1984).Therefore,ias mainstem discharge r51,.(fl~4!~'
OJll.
decreases,local flow from groundwater may also decrease.The most ~.~5 .,,,,,"
serious passage restrictions for mainstem discharges below breaching .t\I'j;~~r,~
q,~\
discharge in important spawning sloughs occurs in Sloughs 9 and 21)....
(ADF&G 1984d).
5.2.1 Adult Salmon
Adults of four salmon species have been observed spawning in slough
habitat in the Talkeetna-Devil reach (RM 98,,6-152)j only chinook
salmon have not been observed using slough habitats for spawning
5-6
(ADF&G 1981a.1982a,1984a).Results of escapement and spawning
surveys in 1981 through 1983 indicated that chuul and sockeye were the
most numerous salmon in sloughs during peak spa~~ing periods,pink and
coho were less abundant (see Sec.4.2.1-4.2.5,ii:i).
Total slough escapements in sloughs above RM 98.6 were:
Chum -4,501 fish in 1981;5,057 fish in 1982,2,944 fish in 1983 j
Sockeye 2,17:6 fish "in 1981;1,488 fish in 1982;1.060 fish in 1983
Pink -38 fish in 1981;297 fish in 1982;o fish in 1983
Two coho salmon were observed spawning in Slough 8A on October 2,
1982.
.....
....
Sloughs 8A,9.11 and 21 have accounted for about two-thirds of the
total peak counts of chum salmon in slough habitats during 1981,1982
and 1983 (Table 13).Sloughs 8A,11 and 21 have accounted for over 90
percent of the sockeye salmon total peak counts in slough habitat
(Table 8).
Use periods for salmon spawning in sloughs abmre RM 98.6 were August
and September in 1981.1982 and 1983.The peak of pink salmon
spawning occurred during the first three weeks ,of August,the peak of
chum spawning was the first week of September and sockeye peak-spawning activity was from the last week of August to the end of
September (ADF&G 1981a,1982a,1984a).
Sockeye salmon above RM 98.6 spawn almost exclusively (over 99 percent
of the peak spawner counts of 2,420 for 1981-1983)in slough habitat.
Sloughs are also important spawning habitats for chum salmon as 60
percent of the peak spawner counts of 10,570 for 1981 through 1983 was
observed in slough habitat.Factors contributing to salmon spawning
in sloughs in this river reach are:(l)clear water base flows j Wr../Jo.e$..t.~'~'r!'I!,#"'-'i ~~60;'4 !"'t~"'"15
originating from ground water upwelling,local surface runoff or l'I~(y,~-Iu ~"".f'>J{~?
!"\.f<.11'\+e~'lI\i ..e e-(:-tt ....
interstitial inflow insure maintenance flows;and (2)the presence of c...~c++V~~IJ "'<'c~4""
ground water upwelling in sloughs oxygenates spclwning substrate,keeps "".\IIl,J '"(Ii i~.:>
silt from compacting the spawning gravels,and provides a stable
5-7
.-
-
-
temperature regime that maintains incubating embryos through the
winter.
5.2.2 Juvenile Salmon
Sloughs are important habitats for juvenile salmon in the
Talkeetna-Devil Canyon reach (RM 98.6-152)bE!cause they serve as
rearing and overwintering areas.The significa,nce of slough habitat
for juvenile s,almon is discussed below.
-Sockeye Most sockeye natal areas are side sloughs.Three-
important sockeye natal areas are SlClughs 8A,11 and 21
(Table 8).Some sockeye move to upland slough habitat for
rearing.Overwintering sockeye have been found in slough habitat
(ADF&G 1984b).
Chum -Many sloughs above RM 98.6 are nat.al areas for juvenile
chum (Table 13).These natal sloughs provi,de rearing habitat for
about one to three months until juvenile chum move downstream as
smolts.
Coho -Some juvenile coho move from natal tributaries to upland
and side sloughs for rearing.Juvenile (:oho apparently prefer
clear water and lower velocities found in u~land sloughs.Upland
sloughs were second in importance in 1983 for coho rearing after
natal tributaries (ADF&G 1984b).Some juvenile coho use sloughs
for overwintering.
-
Pink -The extent of slough utilization by juvenile pink is
uncertain because juvenile pink spend little time in freshwater.
Use of slough habitat by juvenile pink appears to be limited to
natal sloughs.
Chinook -Juvenile chinook used side sloughs and upland sloughs
for rearing in relatively low densities in 1983 (Figure 31).
5-8
Sloughs appear to be important overwintering habitat
chinook.
The importance of sloughs as juvenile overwin~~and rearing '..\\.:\<ll~-.,~.,~""_,,,CY""P'#''''\1"
habitats may ble related to:(1)the ice-free,C:.~ear-wat 'dfid1tions
during winter compared to lowered flow and icing n coho and chinook
natal tributaries;and (2)during summer mainst~n flow,the high stage
of the mainstem acts as a hydraulic control CiLt the slough outlet,
increasing the depth of water in the lower end of the slough.These
clear water areas promote benthic production!.which improves the
quality of the rearing habitat for juvenile salmlon.
5.3 TRIBUTARY AND TRIBUTARY MOUTH HABITAT _,..,'1/
~~
The depth of water in the mouths of tributaries in the Talkeetna-DeVi~~
Canyon reach (RM 98.6-152)is sensitive to chan.ges in mainstem flow.
At high flows,the mainstem creates a backwater at the tributary
mouth,thus i:ncreasing the water depth.The lineal extent of the
backwater in the tributary depends on the stage in the mainstem and
the gradient of the tributary.At low mainstem stages,the backwater
is eliminated,resulting in increased flow velocities at the mouth.
Small deltas form at the mouth of most of the tributaries.As the
tributary enters the mainstem river,the change in gradient and
subsequent change in flow velocity cause the tributary to drop
transported materials if the velocity in the mainstem is not
sufficient to carry the material downstream.As the stage in the
mainstem river decreases,the tributaries may become perched above the
....river,that is,the tributaries flow across steep deltas.If the
steep deltas were to remain under low mainstem flow conditions,
upstream passage of adult salmon and resident fish would be inhibited
or eliminated.However,based on studies by R,&M Consultants (1982),
the tributary flows are sufficient to cut through the deltas to
establish a channel at a new gradient.In 1982.tributaries were
observed to cut through perched deltas during low August flows;most
5-9
of the tributaries had sufficient energy to
(R&M Consultants 1982).
/Tributary mouth habitat extends from the uppermost point the tributary
influenced by mainstem Susitna River or slough backwater effects to
the downstream extent of the tributary plume which extends into the
mainstem Susitna River dr sloughs (ADF&G 1981c)"The tributary plume
is clearwater which extends downstream in the main channel before \
f4""~1!'~'
mixing with the more turbid mainstem water.This area has a mixture it,;
of characteristics associated with both mainstem and tributary.The----extent of the plume is influenced by mainstem/fLow.At higher flows,
Tributary streamflow,sediment,and thermal regimes reflect the
integration of the hydrology,geology,and clilnate of the tributary
drainage (Figure 2).The physical attributes of tributary habitat are
not dependent on mainstem conditions.
,.,..
the plume is restricted.Depths and velocities in the plume are a
function of channel morphology and mainstemstage.Water temperature
and water quality are those of the tributary.
5.3.1 Adult Salmon
Except for sockeye salmon,salmon species,present in the SusitnaRiver
were observed spawning in tributaries in the Talkeetna-Devil Canyon
reach (RM 98.6-152)during 1981,1982 and 1983 (ADF&G 1981a, 1982a,
1984a).Peak spawner counts in tributaries above RM 98.6 for chum,
coho,pink and chinook salmon are given in T,ables 15, 18,20,23.
Tributaries serve as the primary spawning habi.tat for chinook,coho
and pink salmon.Based,on peak spawner counts in all habitats,
tributaries are about equal in importance with slough habitat for chum
salmon.
Important salmon spawning tributaries include:Indian River (chinook,
pink,coho and chum),Portage Creek (chinook,coho,pink and chum),
Fourth of July Creek (pink and chum),Lane Creek (chinook and pink)
.....
5-10
-------------------~-----------,------------------,---
,...•
.....
--
~-
....
I I I
Cash Creek (coho),Whiskers Creek (coho)and Lower McKenzie Creek
(coho)(Tables 15, 18,20,23).
5.3.2 Juvenile Salmon
The significffilce of tributary and tributary mouth habitats for
juvenile salmon in the Talkeetna-Devil Canyon I:each (RM 98.6-152)is
discussed below •
Sockeye -Juvenile sockeye apparently utilize tributary habitat
incidentally;in 1983 'few juvenile SocklO!ye were captured in
tributary habitat (Figure 26).It is p]~obable that juvenile
sockeye do not overwinter in tributary habitat.No tributaries
are known sockeye natal areas.
Chum -Some tributaries above RM 98.6 are natal areas for
juvenile chum (Table 15).These natal tributaries may provide
rearing habitat for about one to three months until juvenile chum
move downstream as smolts.
Coho -Some juvenile coho use tributaries for rearing throughout
the summer (ADF&G 1984b).Some coho redistribute downstream from
areas of emergence in tributaries to more favorable rearing
habitat,including tributary mouths.This redistribution occurs
throughout the summer as fish become more mobile.Tributary
mouths apparently provide important milling and rearing areas for
age 0+coho (ADF&G 1981b,1983b).It appears that ma1nstem side
channels,side sloughs and upland sloughs are more important
overwintering habitat for juvenile coho thBLO tributaries.
Pink Some tributaries above RM 98.6 are natal areas for
juvenile pink (Table 20).The extent of tributary utilization by
juvenile pink is uncertain because juvenile pink spend little
time in freshwater •
5-11
---------------_._-----------..----------------------"._---
.....
Chinook -Tributaries had the highest densities of juvenile
chinook in spring and early summer in 1983 (ADF&G 1984b).
Redistribution of juveniles from areas of emergence in
tributaries to more favorable rearing habitat,including
tributary mouths,occurs throughout the summer as fish become
more mobile.Tributary mouths apparently provide important
milling and rearing areas for juvenile chinook.Tributaries may
be utilized by juvenile chinook for overwj.ntering,however most
fish apparently leave tributaries after November when low winter
flows and icing occurs (ADF&G 1981b).
,llIl!IIII!II
-
5-12
I I
-------------------..............--.......-.------_._--_._----~~------------------
i I
-6.0 SUMMARY DESCRIPTION
"""
.-
-i
6.1 FACTORS AFFECTING PRODUCTION
Each life stage of salmon has factors that may limit production.Some
of these factors are complex and the mechanisms are not easily
understood such as the relationships among food availability,growth,
and survival.In contrast,other factors are readily defined,like
freezing of redds which'cause direct mortality"Although biological
organisms do have the ability to adjust and adapt to various
environmental conditions,overall they may not be highly successful.
For example,survival of salmon eggs from deposition to fry emergence
may only be 5 percent or less under natural conditions.In contrast,
survival rates'of 95 percent or greater oc:cur frequently under
artificially controlled conditions (e.g.,hatchery on laboratory
conditions)that exclude many of the limiting factors.Following is a
summary of the major limiting factors that affect the freshwater
phases of anadromous salmonids in the Susi.tna River.Although
specific studies may not have identified some ()f these as factors in
the Susitna River,they have been described as factors in other
similar river systems and therefore it is assumed that similar factors
may be important in the Susitna River •
6.1.1 Adult Migration
A discussion on limiting factors in salt water is not included in this
discussion,however,factors such as predation,environmental
conditions (e.g.water quality),predator-prey relationships and
commercial and sport fishing must be considered in relation to
production.Once adult salmon enter the Susitna River,several
potential situations can exclude or prevent them from successful
spawning.These are briefly listed and described as follows:
-
a.Sport Fishing -sportfish harvests remove fish from the system.
The primary effort in the Susitna River is the taking of chinook
salmon followed by coho.The effect of sport fishing on Susitna
6-1
--------------............_-""""''''''''''-----------_._-----------------_.,-
.....
b.
c.
River salmon is most evident on coho salmon (Table 3).In 1983,
almost one of every five coho entering the Susitna River was
caught by an angler.The extent of harvest is governed by
regulation,fishing and water conditions,access by people to
sites,etc.
Predation -in areas where salmon are avai.lable,predators such
as bears and seals can remove adults prior to spawning.ADF&G
personnel (l984a)have noted predation by bears,as well as
otter,weasels and eagles in the Susitna River,but this removal
of fish is unquantified.Predation by animals is probably less
significant than the effects of sport fishing •
Access harriers to upstream migration such as impassable
reaches in sloughs under low flow can prev4:mt fish from reaching
spawning areas.Whether or not this precludes successful
~~oor"';;''Ql._""~~~.,,,,,,,,~~~~,,~~~
spawning elsewhere is unknown,but exposure to bear predation and
~=v.v""""""';:~;lt'~"";:;.\'f,!flC~~"'~~~$1fl.~."I"!\1'~.d><-:I'l"~'
lack of success in passing these reaches can result in mortality.
Salmon strandings in passage reaches of sloughs have been noted
(ADF&G 1984a).
Additional factors such as high or low temperature extremes,low
dissolved oxygen,and turbid waters have been implicated as potential
factors limiting upstream migration (Reiser and Bj ornn 1979).
However,these have not been shown to prevent successful migration in
the Susitna River,probably because the adults are exposed to ranges
in these factors that are within their range of tolerance.Other
factors such as high flows have been shown to result in cessation of
upstream movement (ADF&G 1984a)(Figures 12,15,18,21,24),but
movement does resume following these events and fish do successfully
move to their spawning sites.Therefore,the fish are not removed
from production and mortality associated with high flow events is not
a significant factor.
6-2
I I I
6.1.2 Spawning and Incubation
Each species within the Susitna Basin tends to utilize specific areas
for spawning (see Section 4.2).In this regard,the lack of a specific
type of area can limit production for a specific species.Spawning
and incubation habitat may be limited in the Talkeetna-Devil Canyon
reach (RM 98.6-152).
Specific factors which would limit the availability of spawning are:
in
..,f
\,.."A,IfV ",....,A ,iF'Y!/"t.(/'J'''''r v ','Ii
I
Water Depth -Theoretically,depth is only a factor when it is /
too shallow.However,salmon tend to prefer certain depths which I
/
can vary from species to species and stock to stock.Depth may I
II'
be limiting in some side-slough habitats in the Susitna River.---I
Substrate -Lack of useable substrate within the range utilized
by a specific species limits the amount of area available for
spawning and incubation.Substrate such as sand or silt is
unusable as are extremely large substrate and bedrock.
Additionally,even though the correct range of gravel may be --present,the substrate may be cemented together by silts and
therefore fish are unable to effectively dig a redd.This may be
one of the reasons for the small use of mainstem and side channel
habitats by salmon for spawning in the Susitna River.
Water Velocity -Although velocity requirements vary amongst
species,areas with high velocities (in excess of sustained
swimming speeds)will preclude spawning activity.High velocity-may limit utilization of mainstem and side-channel habitats..-
the Susitna River.
c.
b.
a.
-
d.Water Temperature -Various species seek areas and spawning
periods that have favorable water temperatures for spawning and
incubation.If these temperatures are not within tOlerance.I.
range,mortality can result.Low temperatures can de~~
act~~Temperature also affects development rate{Cold w~ter
~~I
temperatures may limit us'e of mainstem and side-channel habitats~~J;riJ)pd U'"
6-3
VJ \c.,.\f}~••}\ti.w,,\
U',<;:~,~q 'I '1,,"'>\~~;1~1\.
--------------------_......_--------------------_.="-
Predation -Sculpins'and other fish species have been implicated
Upwelling -Certain species,particularly chum salmon,seek areas
of groundwater upwelling for spawning and incubation (ADF&G
1984e).These areas offer potential temperature and flow
benefits.Because these areas often support major spawning,it
is assumed that the lack of such areas is potentially limiting to
spawning and incubation for chum and sockeye salmon in the
Talkeetna-Devil Canyon reach (RM 98.6-152).
-
e.
f.
g.
'1j:Jv ~f1r~as taking significant numbers of salmon eggs.Hunter (1959)......./"f'J
found that,with pink and chum fry,the mortality could range J1'1.'f.',jrr,,/.l:::,,-!:_\J:~...\j').,AM"vnq·
from 23 to 86 percent.
Low Streamflow -Extremely low water can dewater spawning areas
and expose incubating eggs and alevins (McNeil 1969).Reduced
winter flows may cause significant mortality,if adult fish
spawned under high water conditions and redds were located along
the margins.This may have occurred during 1982 spawning and
1982-1983 incubation periods (ADF&G 1984b).The dependence on
upwelling may limit mortalities associated with flow fluctuations
in the Susitna River.
h.High Streamflow -Extremely high flows can scour redds and
destroy eggs and alevins.High scouring flows (greater than
30,000 cfs at Gold Creek)are uncommon in fall and winter in the
Susitna River.Thus,scouring is probably not an important
limiting factor.
i.Freezing -If redds are frozen,the eggs will be destroyed and
lost.Alevins may be able to move through the gravel to avoid
adverse conditions.Freezing of redds is associated with low
streamflows and sub-freezing temperatures;these conditions occur
yearly in the Susitna River.The reduction in production due to
frozen redds is unquantified in the Susitna River,however,
dependence on upwelling by spawners may reduce losses due to
freezing.
6-4
areas.
habitat.
Sedimentation -An influx of fine sediments can shut off the
-
j •
b~J'Y'l~9-J
water flow through substrate and result in unsuitable spawning ~l'I>I
h C;I'1"'1}Sedimentation of spawning areas in sloug s and side vr
channels by high mainstem discharge and ice processes occurs in /
the Susitna River.In spring 1982,Slough 9 suffered a heavy _:/[,.AyOifJ..,
influx of silts and sands reducing the amount of usable spawning ~k,II'L"":It~~''
fl1,~Jt
,.;;;,"'"I
Intraspecific Competition -The number of eggs and resulting fry
can increase proportionally up to a certain point.However,
beyond this point,competition for redd sites and superimposition
of redps on previous redds results in lower survival.Based on
Dissolved Oxygen -If sufficient dissolved oxygen is not present,
growth of embryos can be retarded and mortality may occur.(IJ'\k
Dissolved oxygen is strongly tied to permeability of gravels and-~~
f'
intragravel flow.Density of salmon eggs can also be a
significant factor.If only a few eggs are present,a given
level of dissolved oxygen,flow,and substrate permeability may
be sufficient.However,at higher egg densities,this level
might be totally insufficient and therefore would limit
production by causing poorly developed fry or in severe cases,
mortality.Studies by ADF&G (1983a)have indicated that
dissolved oxygen levels in the Susitna River are generally not a
problem for incubating embryos.
lfic redd sites
spawning habitats in
(e.g.chum and sockeye may
middle river sloughs).This
those for intraspecificsimilarto
tition -Spawners from two or more species may
coblems
~n studies,ADFYG (1984a)concluded that spawner
t:oo high for chum salmon in 1983 in sloughdenr
egg
hs'
compel.,
1.
m.
k.
--
-
....
]
"""
n.Ice Processes -In certain instances,staging resulting from ice
cover can raise the stage of the river diverting cold winter
mainstem water (O°C)into sloughs that are predominantly supplied
by warmer upwelling water (e.g.Slough 8A in 1983;ADF&G 1983a).
Cold mainstem water can reduce intragravel temperatures causing
mortalities or delays in emergence that affect production.
I '
I '
6.1.3 Rearing
Factors that limit the rearing phase of salmonids are complex and vary
with species,size,and time of year.They may affect species for
only a short period of time (e.g.,pink salmon fry may only be in
freshwater for a few days before they outmigrate)or for more than a
year (e.g.chinook,coho or sockeye juveniles).Following is a brief
summary of the major factors that affect rearing fish:
a.Primary and secondary production -The amount of food available
qatspecifictimesoftheyearcanbecriticaltoassuringthat&l-'\),'"j",
!J£/'I
production continues.In the Susitna River the highly turbid "~~oJ :nQ,ff'K "l.J~'
water in the ice-free season p~:_vents __S~g~~~-~~~S<.t"t;"Ir,f-cl
penetration and primary production~inter primary a:aa seeeileaj('y::\:§','~,)Vl'i1
production may be severely restricted by the ice cover and low Se ,--tv
().A.'I
levels of light.These,in turn.can severely reduce secondary 2J4-""
production and potential fish food sources from within the system
(autochthonous food production).The extent of either
autochthonous or allochthonous (food sources from outside the
system such as insects that fall into the water)food production
tCi/"'YintheSusitnaRiverispresentlyunknown.although a study is Wv'.J lIi'eM".AI
currently underway to understand primary ~
relationships.Nutrients that support primary production may not
be limiting in the Susitna River because extensive blooms of
algae have been noted during brief clear-water periods that occur
prior to freeze-up.
b.Water Velocity -This factor is important both for allowing
production of food organisms and for optimization of energy
6-6
_.
-
c.
d.
e.
f.
expenditures by fish.For example,fish will seek areas in which
they do not have to needlessly expend energy.Low to moderate
stream gradients and water velocities generally are considered
productive juvenile rearing habitat (Canada Fisheries and Oceans
1980).Peak flow events that affect mainstem rearing areas may
cause a downstream displacement of juvenile chinook (ADF&G
1984b).
Water Depth -Small fish appear to utilize shallower areas with
greater frequency.Unless too shallow to allow free movement,
depth is not thought to limit fish production in the Susitna
River.
Substrate The number of benthic invertebrates generally
decreases in the progression of rubble to bedrock to gravel to
sand (Reiser and Bjornn 1979).This affects fish food
production.Substrate also provides cover for juveniles and
areas of decreased velocity.Cementing of interstitial spaces in
mainstem and side-channel substrates reduces their utility to
rearing juveniles.
Water Quality -Temperature,dissolved oxygen,turbidity,pH and
other water quality parameters can all limit production if they
,
are not within a specific range.Even within this range,an
optimum may not be available under natural conditions (e.g.an
optimum temperature for growth of salmonids may be around 15°C.
However,temperatures do not reach this level in the Susitna).
Cover -Juvenile salmonids require microhabitats that provide
protection or escape opportunities from predators.Cover can
include turbid water,vegetation,substrate and depth.Large
substrate and turbidity commonly provide cover in mainstem and
side-channel habitats.Vegetation and organic debris provide
cover in upland and side-slough habitats.
6-7
-
I ~
6.2 RELATIONSHIPS AMONG LIMITING FACTORS
Limiting factors prevent all organisms from unrestricted expansion.
Each factor has a certain degree of importance,but existing
populations are the result of exposure to the composite of these
factors.In the Susitna River,a precise definition of the exact
level of importance of each of the factors described for each species
and life stage is nearly impossible.
Factors that cause direct mortality are most easily defined (e.g,if
flood flows scour out redds,the eggs are·most likely lost from
production)•Factors such as primary and secondary productivity are
not as easy to define because fish will attempt to find alternate
habi.tats or food sources if one particular combination of these is not \~
avai.lable.For impact prediction,the best analysis possible is to ~(/l~5~
dete:rmine whether or not a factor will ch!:~~~aud cau~~f
an increase or decrease in production /~der with-project conditions.
For example,large annual variations in streamflow can affect
....
spa'ioming,incubation,and rearing.A more stable flow regime may,in
fact,have a very ~positive impact on production (Canada Fisheries
and Oceans 1980).The actual degree of positive impact may be
difficult to quantify,but at least the change may be in a positive
dirE!ction rather than negative.Thus,production could be
to be maintained or increased.
A'general statement regarding the relative importance of limiting
factors affecting various life stages can be made.Spawning habitat ../,
for all species of salmon appears to be limited in this reach of the ~J~.,at1V~l$~V!Jj
Sus:ltna River.The lack of .suitable substrates and upwelling areas ~AI:jJ.t-v.II'
are the predominant factors in low utilization of mainstem and Q'-
sidl~-channel areas.Low winter water temperatures may be a--significant factor affecting incubation.These can be caused by
dewatering and freezing or ice processes in the Susitna River.
Survival of embryos in slough habitats appear to be quite high.
Rea:ring habitat is probably not an important limiting factor for chum,
chinook,pink or coho production in the Talkeetna-Devil Canyon reach
6-8
-
(RM 98.6-152).Rearing habitat for sockeye salmon is limited in this
reach.Sockeye rear in a few sloughs which support plankton
production.Physical characteristics of other sloughs and other
habitat types are not conducive to sockeye rearing.
The end result of exposure to limiting factors in any system is the
number of fish that are able to survive and reproduce.The on-going
studies to document the fish resources and habitats of the Susitna
River are designed to establish these numbers.If the project is
built~with-project monitoring will be used to determine if the
composite of factors resulting from project operation has increased or
decreased production.
6-9
-
.....
.....
....
ACKNOWLEDGEMENTS
The assistance of D.Beyer,Harza-Ebasco Susitna Joint Venture,in preparing
the sections on incubation and factors affecting production is greatly ap-
preciatled •
ACRES.1983b.FERC license application for major project:Susitna
Hydroelectric Proj ect ~Exhibit E.Prepared for Alaska Power
Authority~Anchorage,AK.Volume 6A:Chapter 3.603 pp.
I~
.-
-
LITERATURE CITED
ACRES.1983a.FERC application
Susitna Hydroelectric Project~
and D.Prepared for Alaska
Volume 1:189 pp.
for license for major project:
Initial Statement -Exhibit A~C~
Power Authority~Anchorage,AK.
Alasl~Department of Fish and Game.1978.Preliminary environmental
assessment of hydreoectric development on the Susitna River.
Prepared for the U.S.Fish and Wildlife Service.Anchorage,AK.
207 pp .
....
....
Alaska Department of Fish and Game.1972.
Status Report.Alaska Department of
Alaska •
Cook Inlet King Salmon
Fish and Game.Juneau ~
....
Alaska Department of Fish and Game.1979.Little Susitna River
juvenile chinook and coho salmon study.Prepared by Kevin
Delaney and Roger Wadman,Division of Sport Fish.Anchorage,AK.
Alaska Department of Fish and Game.1981a.Susitna Hydro Aquatic
Studies -Phase I Final Draft Report:Adult anadromous fisheries
proejct.Prepared for Acres American~Inc.Buffalo,NY.
Alask.a Department of Fish and Game.1981b.Susitna Hydro Aquatic
Studies Phase I Final Draft Report:Resident fish
investigation on the lower Susitna River.Prepared for Acres
American,Inc.Buffalo,NY.166pp.
Alaska Department of Fish and Game.1981c.Susitna Hydro Aquatic
Studies -Phase I Report (Vol.1):Aquatic habitat and instream
flow proj ect.Prepared for Acres American,Inc.Buffalo,NY.
260 pp.
Alaska Department of Fish and Game.1982a.Susitna Hydro Aquatic
Studies Phase II Final Data Report:Volume 2.Adult
anadromous fish studies.Anchorage.AK.239 pp.
Alaska Department of Fish and -Game.1982b.Susitna Hydro Aquatic
Studies -Phase II Final Report:Volume 2.Adult Anadromous
Fish Studies,Part B:Appendices A-H.Anchorage,AK 318 pp.
Alaska Department of Fish and Game.1983a.Susitna Hydro Aquatic
Studies -Phase II Data Report:Winter aquatic studies (October,
1982 -May,1983),Anchorage,AK.137 pp.
Alaska Department of Fish and Game.1983b.Susitna Hydro Aquatic
Studies.Phase II Basic Data Report.Volume 3:Resident and
juvenile anadromous fish studies below Devil Canyon,1982.177
pp.
Tyonek subsistence salmon
Browning,Division of
-
-
--
,....
Alaska Department of Fish and Game.1983c.Susitna Hydro Aquatic
Studies -Phase II Report:Summarization of Volumes 2,3,4;
Parts I and II,and 5 -Su Hydro Basic Data Reports,1982.
Prepared for Alaska Power Authority,Anchorage,AK.126 pp.
Alaska Department of Fish and Game.1983d.Susitna Hydro Aquatic
Studies,Phase II Report:Synopsis of the 1982 aquatic studies
and analysis of fish and habitat relationships.Anchorage,AK.
152 pp.
Alaska Department of Fish and Game.1983e.Susi tna Hydro Aqua tic
Studies:Phase II Basic Data Report.Volume 4:Aquatic habitat
and instream flow studies,1982.Part I and II.367 pp.
Alaska Department of Fish and Game.1984a.Susitna Hydro Aquatic
Studies,Report No.1:Adult anadromous fish investigations,May
-October 1983.Prepared for Alaska Power Authority,Anchorage,
AK.380 pp.
Alaska Department of Fish and Game.1984b.Susitna Hydro Aquatic
Studies,Report No.2:Resident and juvenile anadromous fish
investigations,May -October 1983.Dana C.Schmidt,Stephen S.
Hale,Drew L.Crawford,Paul M.Suchanek (eds.),Prepared for:
Alaska Power Authority,Anchorage,AK.395 pp.
Alaska Department of Fish and Game.1984c.
fishery,1983.Prepared by James
Commercial Fisheries.Soldotna,Alaska.
Alaska Department of Fish and Game.1984d.Susistna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Review Draft).Chapter 6:
An evaluation of passage conditions for adult salmon in sloughs
and side channels of the middle Susitna River.Prepared for
Alaska Power Authority,Anchorage,AK.178 pp.
Alaska Department of Fish and Game.1984e.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Draft).Part II,Chapter 7:
An evaluation of chum and sockeye salmon spawning habitat in
sloughs and side channels of the middle Susitna River.Prepared
for Alaska Power Authority,Anchorage,AK.178 pp.
Alaska Power Authority.1984.Comments on the FERC Draft
Environmental Impact Statement of May 1984.Volume 9,Appendix
VII -Slough Geohydrology Studies.Anchroage,AK.
Arctic Environmental Information and Data Center.1984.Assessment of
the effects of the proposed Susitna hydroelectric proj ect on
instream temperature and fishery resources in the Watana to
Talkeetna reach,Alaska Power Authority.
Barrett,B.1984.
Presentation.
ADF&G Su Hydro.February 15 Workshop
!'
....Bell,M.C.1973.Fisheries Handbook of Engineering
Biological Criteria (Revised 1980).
Fisheries-Engineering Research Program,Corps of
Pacific Division.Portland,Oregon.
Requiretnents and
Prepared for
Engineers,North
I"""
!
!
Brannon,E.L.1965.The influence of physical factors on the
development and weight of sockeye salmon embryos and alevins.
Int.Pac.Salmon Fish Comm.Prog.Rep.No.12.26 pp.
Combs,B.D.and It.E.Burrows.1957.Threshold temperatures for the
normal development of chinook salmon eggs.Prog.Fish Cult.
19 (l):3-6.
-
Canada Fisheries and Oceans.
Vancouver,B.C.82 pp.
1980.Stream Enhancement Guide.
-
Delaney,K.,K.Hepler,K.Roth.1981.Deshka River Chinook and Coho
Salmon Study.ADF&G Federal Aid in Fish Restoration.Volume 22.
AFS 49 - 1 &2.
Flor,ey,K.1984.ADF&G Commercial Fisheries.Anchorage,Alaska.
Personal Communication.
Gray'bill,J.P.,R.L.Burgner,J.C.Gislason,P.E.Huffman,K.H.Wyman,
R.G.Gibbons,K.W.Kurko,Q.J.Stober,T.W.Fagnan,A.P.Stayman
and D.M.Eggers.1979.Assessment of the reservoir-related
effects of the Skagit project on downstream fishery resources of
the Skagit River,Washington.University of Washington,College
of Fisheries,Cont.No.FRI-UW-7905.
Hale,S.S.1981.Freshwater habitat relationships
(Oncorhynchus keta).Alaska Dept.of Fish &
Division,Anchorage,AK.
-chum salmon
Game,Habitat
Hunter,J.G.1959.
in a coastal
835-886.
Survival and production of pink and chum salmon
stream.Journal Fish.Res.Bd.Can.16(6):
McNeil,W.J.1969.Survival of pink and chum salmon eggs and alevins.
In:Symposium on Salmon and Trout in Stream.Edited by T.G.
Northcote,Institute of Fisheries,University of British
Columbia,Canada.pp.101-116.
McNeil,W.J.and J.E.Bailey.1975.Salmon rancher's manual.National
Marine Fisheries Service,Auke Bay Alaska Fisheries Laboratory.
National Oceanic and Atmospheric Administration.
Mills,M.J.1979.Alaska Statewide Sport Fish Harvest Studies.
ADF&G Federal Aid in Fish Restoration.Volume 20.F-9-11,SW-I.
Mills,M.J.1980.Alaska Statewide Aport Fish Harvest Studies 1980.
Alaska Department of Fish and Game.Federal Aid in Fish
Restoration.Volume 21.F-9-12,SW-I.65 p.
Mills,M.J.1981.
Data.ADF&G
F-9-13,SW-I.
Alaska Statewide Sport Fish Harvest Studies -1980
Federal Aid in Fish Restoration.Volume 22.
Mills,M.J.1982.Alaska Statewide Aport Fish Harvest Studies.
ADF&G Federal Aid in Fish Restoration.Volume 23.F-9-14,SW-I.
Mills,M.J.1983.Alaska Statewide Sport Fish Harvest Studies:
ADF&G Federal Aid in Fish Restoration.Volume 24.SW-I.
Mills,M.J.1984.Alaska Statewide Harvest Studies.ADF&G Federal
Aid in Fish Restoration.Volume 25.SW-IA.
MOrrl)W,J .E.1980.The Freshwater Fishes of Alaska.
Northwest Publishing Company.Alaska
Alaska
jli'il!bI,
Neilson,J.D.and G.H.Geen.1981.Enumeration of spawning salmon
from spawner residence time and aerial counts.Transactions of
the American Fisheries Society.110(4).
Och,R.1984.Manager -Crooked Creek Hatchery,Kasilof,Alaska.-
Personal Communication.
R&M Consultants,Inc.1982.Susitna Hydorelectric Project:
Stability Analysis.Prepared for Acres American Inc.
NY.q pp.
Tributary
Buffalo,
.....Reis1er,D.W.and T.C.Bjornn.1979.Influence of forest and range
land management on anadromous fish habitat in the western United
States and Canada.1.Habitat requirements of anadromous
salmonids.USDA Forest Service Gen.Tech.Rept.PNW-96.54 pp.
Scott,W.B.and E.J.Crossman.1973.Freshwater Fishes of Can~da.
Volume 19.Fisheries Research Board of Canada Ottawa,Canada.
Shepard,B.G.1984.Predicted impacts of altered water temperature
regime on Glendale Creek pink (Oncorhynchus gorbuscha)fry.Can.
MS Rep.Fish.Aquat.Sci 1782:v+55 p.
Stober,Q.J.,S.C.Crumley,D.E.Fast and E.S.Killebrew.1982.
Effects of hydroelectric discharge fluctuation on salmon and
steelhead in the Skagit River,Washington.University of
Washington,College of Fisheries Conts.No.FRI-UW-8218.
Trihey,E.W.1982.Preliminary assessment of access by spawning
salmon to side slough habitat above Talkeetna.Prepared for
Acres American,Inc.Buffalo,NY.26 pp.
-----------------------------------------'"----
....,
,~
,....
Trihey,E.W.1983.Preliminary assessment of access by spawning
salmon into Portage Creek and Indian River.Prepared for Alaska
Power Authority,Anchorage,AK 31 pp.
Wangaard,D.and C.Burger.1983.Effects of various water
temperature regimes on the egg and alevin incubation of Susitna
River chum and sockeye salmon.U.S.Fish and Wildlife Service,
National Fishery Research Center,Anchorage,Alaska.
Wilson,W.J.,E.W.Trihey,J.E.Baldrige,C.D.Evans,J.G.Thiele,and
D.E.Trudgen.1981.An assessment of environmental effects of
construction and operation of the proposed Terror Lake
hydroelectric facility,Kodiak Island,Alaska.Prepared for the
Kodiak Electric Association by the Arctic Environmental
Information and Data Center.419 pp •
!I
-
Tabll~1.Common and scientific names of fish species recorded from
the Susitna Basin.
-
Scientific Name
Petromyzontidae
Lampetra japonica
Salml:midae
Coregonus laurettae
Coregonus pidschian
Oncorhynchus gorbuscha
Oncorhynchus keta
Oncorhynchus kisutch
Oncorhynchus nerka
Oncorhynchus tshawytscha
Prosopium cylindraceum
Salmo gairdneri
Salvelinus malma
Salvelinus namaycush
Thymallus arcticus
Osmeridae
Thaleichthys pacificus
Esocidae
Esox lucius
Catostomidae
Catostomus catostomus
Gadidae
Lota Iota
Gasterosteidae
Gasterosteus aculeatus
Cottidae
Cottus sp.
Common Name
Arctic lamprey
Bering cisco
humpback whitefish
pink salmon
chum salmon
coho salmon
sockeye salmon
chinook salmon
round whitefish
rainbow trout
Dolly Varden
lake trout
Arctic grayling
eulachon
northern pike
longnose sucker
burbot
threespine stickleback
sculpin
,.,.
Table 2.Commercial catch of upper Cook Inlet salmon in numbers of fish by
species,1954 -1983.
Year Chinook Sockeye Coho Pink Chum Total
1954 63,780 1,207,046 321,525 2,189,307 510,068 4,291,726
1955 45,926 1,027,528 170,777 101,680 248,343 1,594,254
1956 64,977 1,258,789 198,189 1,595,375 782,051 3,899,381
1957 42,158 643,712 125,434 21,228 1,001,470 1,834,022
1958 22,727 477,392 239,765 1,648,548 471,697 2,860,129
1959 32,651 612,676 106,312 12,527 300,319 1,064,485
1960 27,512 923,314 311,461 1,411,605 659,997 3,333,889
~]l961 19,210 1,162,303 117,778 34,017 349,628 1,683,463
1962 20,210 1,147,573 350,324 2.711,689 970.582 5,200,378
1963 17,536 942,980 197,140 30,436 387,027 1,575,119
1964 4,531 970,055 452,654 3.231,961 1,079,084 5,738,285
1965 9,741 1,412,350 153,619 23,963 316,444 1,916,117
1966 9,541 1,851,990 289,690 2,006,580 531,825 4.689,626
1967 7,859 1,380,062 177,729 32,229 296,037 1,894,716
1968 4,536 1,104,904 470,450 2,278,197 1,119,114 4,977,201
1969 12,398 692,254 100.952 33,422 269,855 1,108.881
1970 8,348 731,214 275,296 813,895 775,167 2,603.920
1971 19,765 636,303 100,636 35,624 327,029 1,119,357
1972 16,086 879,824 80,9~33 628,580 630,148 2,235,571
1973 5.194 670,025 104,420 326.184 667,573 1,773,396
1974 6,596 497,185 200,125 483.730 396,840 1,584,476
1975 4,780 684.818 227,372 336,359 951.796 2,205,135
1976 10,867 1,664.150 208,710 1,256,744 469,807 3,610.278
1977 14,792 2,054.020 192,975 544,184 1,233.733 1,049,704-1978 17,303 2,622.487 219,234 1,687.092 571.925 5,118,041
1979 13,738 924.415 265,166 72.982 650,357 ~,926,658
1980 12,497 1,584.392 283,623 1,871,058 387,078 4,138,648
1981 11,548 1,443,294 494,073 127,857 842,849 2,919,621
1982(1)20,636 3,237,376 777,132 788,972 1,428.621 6.252,737
1983 20,396 5,003.070 520,831 ·73,555 1,124,421 6,742,273
Average 19,595 1,314,917 257 811'even-1,640,222 658,363 3,031.382,odd -120,416
(1)ADF&G Preliminary Data
'I i 1 ~J ]J J j 1 ]I J J J I j I
Table 3.Summary of commercial and sport harvest on Susitna River basin adult salmon returns.
Commercial Harvest Sport Harvest
Susitna
TTnno'r Estimated Estimated Estimated Basin~l"'l"'--
Cook Inlyt Estimated 2 Susitna Susitna 3 Total Sport 4 Percent of
Species Harvest Percent Susitna Harvest Escapement Run Harvest Escapement
-
Sockeye Mean Range
81 1,443,000 20 (10-30)288,600 287,000 575,600 1,283 0.4
82 3,237,0005 20 (10-30)647,400 279,000 926,400 2,205 5 0.8
83 5,003,000 10 (l0-30)500,300 185,000 685,300 5,537 3.0
Pink
81 128,000 85 108,800 127,000 235,800 8,660 6.8
82 789,0005 85 670,650 1,318,000 1,988,650 16,8225 1.3
83 74,000 85 62,900 150,000 212,900 4,656 3.1
Chum
81 843,000 85 716,550 297,000 1,013,550 4,207 1.4
82 1,429,0005 85 1,214,650 481,000 1,695,650 6,8435 1.4
83 1,124,000 85 955,400 290,000 1,245,400 5,233 1.8
Coho
81 494,000 50 247,000 68,000 315,000 9,391 13.8
82 777 ,0005 50 388,500 148,000 536,500 16,6645 11.3
83 521,000 50 260,500 45,000 305,500 8,425 18.7
Chinook
81 11,500 10 1,150 ------7,576
82 20,6005 10 2,060 ------10,521 58320,400 10 2,040 ------12,420
~Source:ADF&G Commercial Fisheries Division
3 B.Barrett,ADF&G Su Hydro,February 15,1984 Workshop
Yentna Station +Sunshine Station estimated escapement
~Mills 1982,1983,1984 preliminary data
Preliminary data
Presentation 2
+5%for sockzye
+48%for pink2+5%for chum 2+85%for coho
-)J I i I )1 1 )I )!J }j I
Table 4.Susitna Basin sport fish harvest and effort by fishery and species -1978,1979, 1980, 1981,1982 and 1983.
Days Chinook Coho Sockeye Pink Chum Rainbow Dolly Lake Arctic
Locations Fished Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Grayling Burbot
.!1?!!
Willow Creek 22,682 47 905 56 18,901 2,458 913 280 0 208 9
Caswell Creek ---
Montana Creek 25,762 408 2,451 85 15,619 4,429 1,193 633 0 958 9
Sunshine Creek ---
Clear (Chunilna)Creek 5,040 12 2,200 28 2,074 1,912 1,501 1,817 0 859 27
Sheep Creek 11,869 256 478 14 6,981 1,697 470 108 0 461 18
Little Willow Creek 5,687 0*151 28 3,142 1,015 334 63 0 334 0
Deshka River 9,111 850*1,798 0 697 0 3,634 0 0 579 0
Lake Creek 8,767 326*2,212 254 2,833 1,015 2,721 154 36 2,115 45
Alexander Creek 6,914 769*2,401 183 1,146 215 2,640 136 0 1,871 0
Talachulitna River 732 12 88 141 31 234 0 235 0 99 0
Lake Louise,Lake
Susitna,Tyone River 13,161 0 0 0 0 0 0 0 2,522 2,278 2,947
Others 14,970 163 2,388 56 3,994 2,692 1,519 2,739 877 3,770 208
1978 Total 124,695 2,843 15,072 845 55,418 15,667 14,925 6,165 3,435 13,532 3,263
1979
Willow Creek 18,911 459 462 94 3,445 582 1,500 618 0 1,654 18
Caswell Creek 3,710 156 624 0 100 9 282 91 0 354 0
Montana Creek 22,621 312*1,735 346 2,472 745 1,536 527 0 791 9
Sunshine Creek 3,317 10 774 157 700 55 382 264 0 0 45
Clear (Chunilna)Creek 5,125 312 1,248 31 645 355 1,373 827 0 1,045 9
Sheep Creek 6,728 10 462 31 2,418 682 573 127 0 645 64
Little Willow Creek 5,171 0 262 141 745 118 345 336 0 1,091 0
Deshka River 13,236 2,811 973 0 109 0 3,182 0 0 1,463 82
Lake Creek 13,881 1,796 2,671 440 882 136 4,527 164 9 1,963 109
Alexander Creek 8,284 712 1,560 79 236 45 1,182 182 0 745 145
Talachulitna River 2,185 293 125 47 100 55 0 155 0 664 45
Lake Louise,Lake
Susitna,Tyone River 12,199 0 0 0 0 0 0 0 2,618 2,936 2,363
Others 12,639 39 1,997 220 664 1,245 3,472 909 472 4,918 282
1979 Total 128,007 6,910 12,893 1,586 12,516 4,072 18,354 4,200 3,099 13,342 3,171
1 J 1 I 1 1 J i J J 1 J I J ]j
Table 4.(Continued)
Days Chinook Coho Sockeye Pink Chum Rainbow Doll v Lake Arctic
Locations Fished Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Crayling Burbot
1980
Wi 11 ow Creek 29,011 289 1,207 83 23,638 989 1,168 636 0 1,868 0
Caswe 11 Creek 4,963 215 1,124 77 1,663 19 154 83 0 353 26
Montana Creek 19,287 559 2,684 257 8,230 571 854 167 0 655 13
Sunshine Creek '5,208 132 1,534 116 2,408 225 193 39 0 0 39
Clear (Chunilna)Creek 4,388 172*661 6 622 385 950 751 0 1,348 32
Sheep Creek 8,041 45*430 9 6,362 648 385 83 0 725 45
Little Willow Creek 8,190 32 494 77 6,420 270 353 122 0 1,156 0
Deshka River 19,364 3,685 2,290 0 689 0 4,305 0 0 1,817 224
Lake Creek 8,325 775 2,351 267 2,101 69 2,144 121 9 1,972 0
Al exander Creek 6,812 1,438 999 52 809 121 1,945 353 0 1,145 0
Talachulitna River 2,542 121 491 112 276 17 379 982 0 1,713 0
Lake Louise,Lake
Susitna,Tyone River 10,539 0 0 0 0 0 0 0 2,609 4,477 6,612
Others 12,216 45*2,234 257 3,403 1,445 2,658 790 267 4,854 212
1980 Total 138,886 7,389 16,499 1,304 56,621 4,759 15,488 4,127 2,876 22,083 7,203
Days Chinooi Chinook Coho Sockeye Pink Chum Rainbow Dolly Lake Arctic
Locations Fished Salmon Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Crayling Burbot
1981
Willow Creek 14,060 144 441 747 77 2,797 1,533 1,475 249 0 1,188 48
Caswell Creek 3,860 77 172 901 38 335 0 326 38 0 144 0
Montana Creek 16,657 239 422 2,261 182 1,782 805 1 ,111 240 0 891 0
Sunshine Creek 3,062 57 0 968 220 958 125 249 10 0 57 115
Clear (Chunilna)Creek 3,584 86 287 422 29 19 57 1,226 1,418 0 996 0
Sheep Creek 6,936 0 0 326 105 1,236 987 201 57 0 872 0
Little Willow Creek 3,845 0 0 29 67 604 192 374 48 0 623 0
Deshka River 13,248 738 2,031 632 0 19 0 3,631 10 0 1,255 96
Lake Creek 6,471 163 632 1,035 211 412 48 2,874 67 19 1,600 29
Alexander Creek 6,892 278 843 891 67 57 10 2,290 287 0 1,130 29
Talachulitna River 1,378 57 0 240 172 29 0 0 0 0 479 0
Lake Louise,Lake
Susitna,Tyone River 14,397 115 0 0 0 0 0 0 0 4,093 4,892 5,292
Others 7,850 277 0 939 115 412 450 3,851 814 287 7,089 57
1981 Total 102,240 2,748 4,828 9,391 1,283 8,660 4,207 13,757 3,238 4,399 21,216 5,666
]J I 1 .--,1 I 1 I j J J i -I J J i ]
Table 4.(Continued)
Days Chinoo~Chinook Coho Sockeye Pink Chum Rainbow Dolly Lake Arctic
Locations Fished Salmon Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Grayling Burbot
1982
Willow Creek 19,704 220 409 1,069 94 4,789 2,086 891 262 0 1,520 63
Caswell Creek 5,101 178 293 776 52 1,092 0 189 73 0 252 0
Montana Creek 23,645 126 115 3,060 514 3,595 1,708 2,243 356 0 849 0
Sunshine Creek 3,787 52 0 1,719 189 1,132 231 545 42 0 42 73
Clear (Chunilna)Creek 3.,856 52 398 996 115 220 31 608 1,069 0 943 0
Sheep Creek 9,093 0 0 367 88 2,599 1,750 325 409 0 723 0
Little Willow Creek 5,579 0 0 398 105 1,520 199 335 189 0 377 0
Deshka River 18,391 1,142 3,165 2,463 0 377 0 3,804 0 0 1,457 252
Lake Creek 8,649 356 1,289 1,603 252 398 199 3,134 482 0 1,955 0
Alexander Creek 10,748 681 1,825 1,907 335 482 0 2,505 42 0 1,582 84
Talachulitna River 1,911 0 0 524 63 220 0 0 31 0 587 0
Lake Louise,Lake
Susitna,Tyone River 14,024 0 0 0 0 0 0 0 0 4,056 3,532 5,565
Others 9,980 220 0 1,782 398 398 639 2,400 1,666 335 5,041 .63
1982 Total 134,468 3,027 7,494 16,664 2,205 16,822 6,843 16,979 4,621 4,391 18,860 6,100
**1983
Willow Creek 13,405 136 398 576 425 1,647 1,490 1,689 336 0 1,794 21
Caswell Creek 5,048 10 262 408 151 126 0 231 157 0 315 31
Montana Creek 17,109 199 305 1,402 534 902 1,311 1,332 325 0 336 0
Sunshine Creek 3,429 105 0 722 685 241 42 178 84 0 31 367
Clear (Chunilna)Creek 7,564 252 682 836 534 73 650 1.836 1,962 0 1,553 84
Sheep Creek 6,237 0 0 596 370 682 902 409 52 0 839 10
Little Willow Creek 2,791 0 0 52 110 157 147 514 73 0 84 0
Deshka River 23,174 934 3,955 1,036 0 21 0 2.434 0 0 1,280 126
Lake Creek 14,749 535 1,888 1,392 726 430 52 2,287 262 0 2,224 283
Alexander Creek 9,425 672 1,039 408 69 126 0 608 136 0 483 0
Talachulitna River 4,566 63 273 84 41 0 0 0 105 0 3,178 0
Kashwitna River 1,344 231 0 52 0 0 0 357 304 0 514 0
Lake Louise,Lake
Susitna,Tyone River 12,948 0 0 0 0 0 0 0 0 3,210 4,217 4,070
Others 12,367 303 178 861 1,892 251 639 4,625 1,067 287 3,387 534
1983 Total 134,156 3,440 8,980 8,425 5,537 4,656 5,233 16,500 4,863 3,497 20,235 5,526
*Chinook less than 20 inches**Source:Mills 1984 (Preliminary data)
Source:Mills (1979-1983)
]i I I )1 ]I 1 )1 i J
Table 5.Sport fish harvest for Southcentral Alaska and Susitna Basin in numbers of fish by species,1978-1983.
Arctic Grayling Ra i nbow Trout Pink Salmon Coho Salmon Chinook Salmon Chum Salmon Sockeye Salmon
South-SusHna South-Susitna South-Susitna South-Susitna South-Susitna South-Susitna South-Susitna
Year central Basin central Basin central Basi n central Basin centra 1 Basin central Basin central Basin
1978 47,866 13,532 107,243 14,925 143,483 55,418 81,990 15,072 26,415 2,843 23,755 15,667 118,299 845
1979 70,316 13,342 129,815 18,354 63,366 12,516 93,234 12,893 34,009 6,910 8,126 4,072 77,655 1,586
1980 69,462 22,083 126,686 15,488 153,794 56,621 127,958 16,499 24,155 7,389 8,660 4,759 105,914 1,304
1981 63,695 21,216 149,460 13,757 64,163 8,660 95,376 9,391 35,822 7,576 7,810 4,207 76,533 1,283
1982 60,972 18,860 142,579 16,979 105,961 16,822 136,153 16,664 46,266 10,521 13,497 6,843 128,015 2,205
1983 1 56,896 20,235 141,663 16,500 47,264 4,656 87,935 8,425 57,094 12,420 11,043 5,233 170,799 5,537
Average 61,535 18,211 132,908 16,000 134,413 42,954 103,774 13,157 37,294 7,943 12,149 6,797 112,869 2,128
(even)(even)
58,264 8,611
(odd) (odd)
Mills 1984,Preliminary Data
Source:Mills (1979-1983)
1 ]J )1 j I .]1 I 1 i ]I 1
9
8
5
6
7
Table 6.Susitna River annual salmon escapement by sub-basin and species.
Sub-basin Sockeye 1 Chum 2 2 Pink3 4CohoChinook Total
Lower Susitna River (RM 11 ,900 17,000 39,900 Even 427,400 56,300 Even 552,500
o to 80)exclgding Yentna Odd 44,800 Odd 169,900
River (RM 28)
Yentna River (RM 28)6 119,200 19,500 20,000 Even 447,300 44,700 Even 650,700
Odd 48,400 Odd 251,800
Talkeetna (RM 97.1)and 116,000 295,600 24,700 Even 388,400 16,100 (62,000)Even 840,800
Chulitna (RM 98.6)rivers Odd 40,600 Odd 493,000
including Susitna ~iver
from RM 80 to 98.6
Talkeetna Station to 8 2,800 24,100 2,200 Even 54,800 8,500 (9,500)Even 92,400
Devil Canyon (RM 98.6 to 152)Odd 4,400 Odd 42,000
Total Susitna basin9 249,900 356,200 86 800 Even 1,317,900 125,600 Even 2,136,400
,Odd 138,200 Odd 956,700
12 1981-83 average of ADF&G second-run sockeye escapements
3 1981-83 average of ADF&G escapement estimates
4 Even year 1982 only;odd year 1981 and 1983 average;from ADF&G escapement·estimates
Minimum estimates of escapement from ADF&G 1983 survey counts and conversion factor of 52%(Nielson and
Geen 1981);numbers in parenthesis are 1982-83 average of ADF&G escapement estimates
Lower Susitna sub-basin equals total Susitna basin escapement minus Yentna and Sunshine escapements
Yentna sub-basin escapement from ADF&G estimates at Yentna Station (TRM 04)
Talkeetna-Chulitna sub-basin escapement equals Sunshine Station (RM 80)escapement minus Talkeetna-Devil
Canyon sub-basin escapement
Talkeetna Station-Devil Canyon sub-basin escapement equals Talkeetna Station (RM 103)escapement minus
milling fish that return downstream.Milling rates:sockeye 30%,chum 40%,pink 25%,chinook 25%,coho 40%
(Barrett 1984)
Total Susitna basin escapement equals Yentna Station (TRM 04)escapement plus Sunshine Station (RM 80)
escapement plus:5%for sockeye,48%for pink,5%for chum,85%for coho (Barrett 1984)
--1 I J 1 I )J )i 1 J 1 1
Table 7.Chinook salmon peak survey escapement counts of Susitna River streams by sub-basin from
1976 to 1983.
Sub-basin 1976 1977 1978 1979 1980 1981 1982 1983
1LowerSusitnasub-basin
Alexander Creek 5,412 9,246 5,854 6,215 a a 2,546 3,755
Deshka River 21,693 39,642 24,639 27,385 e 19,237a a 16,OOOd
Goose Creek 160 133 283 b a 262 140 d 477
Kashwitna River (North Fork)203 336 362 457 a 557 156 d 297
Little Willow Creek 833 598 436 324 c a 459 316 d 1,042
Montana Creek 1,445 1,443 881 l,094c a 814 887 d 1,641
Sheep Creek 455 630 1,209 778 a 1,013 527 945
Sucker Creek (Alexander Creek)b b b b b b b 597
Willow Creek 1,660 1,065 1,661 1,086 a 1,357 592 d 777 .
Wolverine Creek (Alexander Creek)b b b b b b b 491
Subtotal 31,861 53,093 35,325 37,339 ---4,462 21,164 29,259
Yentna sub-basin2
Camp Creek (Lake Creek)b b b b b b b 1,050
Canyon Creek 44 135 b b b 84 b 575
Lake Creek 3,735 7,391 8,931 4,196 a a 3,577 7,075
Peters Creek 2,280 4,102 1,335 a a a a 2,272
Quartz Creek b 8 b b b 8 b b
Red Creek b 1,511 385 b b 749 b b
Sunflower Creek (Lake Creek)b b b b b b b 2,250
Talachulitna River 1,319 1,856 1,375 1,648 a 2,129 3,101 10,014
Subtotal 7,378 15,003 12,026 5,844 ---2,970 6,678 23,236
Talkeetna-Chulitna sub-basin3
Bunco Creek 112 136 a 58 a a 198d 523
Byers Creek 53 69 a 28 a a 7 b
Chulitna River 124 229 62 a a a 100 d b
Chulitna River (East Fork)112 168 59 a a a 119 d b
1 »J J ]I I jJ 1 1 1 1 1 1 )
Table 7.(Continued)
Sub-basin 1976 1977 1978 1979 1980 1981 1982 1983
.t
Chulitna River (Middle Fork)1;870 1,782 900 a a a 644~3,846
Clear Creek (Chunilna)1,237 769 997 864 c a a
982 d 806
Honolulu Creek 24 36 13 37 a a 27 b
Prairie Creek 6,513 5,790 5,154 a a 1,900 3,844d 3,200 c
Troublesome Creek 92 95 a a a a 36 b
Subtotal 10,137 9,074 7,185 987 ---1,900 5,957 8,375
Talkeetna-Devil Canyon sub-basin4
Chase Creek 5 b b b b b b 15 15
Cheechako Cre~k b b b b b b 16 25
Chinook Cre~k b b b b b b 5 8
Devil Creek b b b b b b b 1
Fourth of July Creek b b b b b b 56 6
Gold Creek b b b b b b 21 23
Indian River 537 393 114 285 a 422 1;053 1,193
Jack Long Creek b b b b b b
2 6
Lane Creek b b b b b 40 47 12
Portage Creek 702 374 140 190 a 659 1,253 3,140
Whiskers Creek b b b b b b b 3
Subtotal 1;239 767 254 475 ---1,121 2,474 4;432
TOTAL 50,615 77,937 54,790 44,645 10,453 36,273 65;302
ab No total count due to high turbid water
Not counted
~Poor counting conditions
Counts conducted after peak spawninge.Estimated peak spawning count
Source:ADF&G 1984a
~RM 0-80,excluding the Yentna sub-basin
3 RM 28,Yentna River drainage
4 RM 80-98.6
5 RM 98.6-152
Above RM 152
Table 8.Second-run sockeye salmon peak survey counts in sloughs
above RM 98.6,1981-1983.
3-Year
Slough River Mile 1981 1982 1983 Average
3B 101.4 1 0 5'2
3A 101.9 7 0 0 2
6A 112.3 1 0 0 0
8e 121.9 0 2 0 1
8B 122.2 0 5 0 2
Moose 123.5 0 8 22 10
8A 125.1 177 68 66 104
B 126.3 0 8 2 3
9 128.3 10 5 2 6
9B 129.2 81 1 0 27
9A 133.8 2 1 1 1
10 133.8 0 0 1 0
11 135.3 893 456 248 532
17 138.9 6 0 6 4
19 139.7 23 0 5 9
20 140.1 2 0 0 1
21 141.1 38 53 197 96
..-
Total 1,241 607 555 801 1
Source:ADF&G 1981a,1982a,1984a,
1 Three-year average of totals
Table 9.Second-run sockeye salmon total slough escapement above
RM 98.6,1981-1983.
River 3-Year
Slough Mile 1981 1982 1983 Average
3E 101.4 0 0 10 3
3A 101.9 13 0 0 4
8G 121.9 0 5 0 2
8E 122.2 0 13 0 4
Moose 123.5 0 20 31 17
8A 125.1 195 131 130 152
E 126.3 0 20 10 10
9'128.3 18 13 0 10
9B 129.2 212 0 0 71
9A 133.8 4 0 0 1
11 135.3 1,620 1,199 564 1,128
17 138.9 11 0 11 7
19'139.7 42 0 10 17
21 141.1 63 87 294 148
Total 2,178 1,488 1,060 1,575 1
F
Source:ADF&G 1984a
.-1 Three-year average of totals
,.....
-.
table 10.Percentages of fish spawning by habitat zone in 1983 for sloughs
Moose.8A and 11.
Spawning Locatio~Percent
Sloygh/by Habitat Zones Non-
S . 3RMSpeciesn1234 5 6 7 pawnJ.ng
Moose Sockeye 7 50.0 50.0 42.9
RM 123.5 Chum 7 100.0 0.0 85.7
8A Sockeye 16 8.3 0.0 91.7 25.0
RM 125.1 Chum 5 20.0 80.0 0.0 0.0
~
11 Sockeye 55 7.1 7.1 0.0 45.3 0.0 28.6 11.9 23.6
RM 135.3 Chum 29 39.1 52.2 0.0 8.7 0.0 0.0 0.0 20.7
Source:ADF&G 1984a
--
1 RM =River Mile
;Habitat Zones are defined in ADF&G 1984a
Includes milling fish.bear killed fish and other non-spawning mortalities
,~
....Table 11.Sex ratios of second-run sockeye at Susitna.Yentna.
Sunshine,Talkeetna and Curry stations,1981-1983 .
....
Sex ratio (M:F)1
Location 1981 1982 1983
Susitna Station 0.9:1 1.0:1
RM 26
Yentna Station 1.2:1 2.1:1 1.5:1
RM 2:8,TRM 04
Sunshine Station 1.0:1 0.9:1 0.9:1
Rm 80
Talkeetna Station 0.6:1 1.3:1 1.6:1
RM 103
Curry Station 0.8:1 2.1:1 1.6:1
RM 120
Source:ADF&G 1981a, 1982a,1984a
.....
1 Jncludes all aged and non-aged fish
Table 12.Chum salmon peak index counts by habitat type above
RM 98.6,1981-1983.
3-Year
Habitat Type 1981 1982 1983
Total
''''''1 16 219 785Mainstem550
Streams 241 1,737 1,500 3,478
2 2,596 2,244 1,467 6,307Sloughs
Total 2,853 4,531 3,186 10,570
Source:ADF&G 1981a,1982a,1984a
....
1
2
Includes main channel and side channel habitats
Includes upland slough and side slough habitats
Table 13.Chum salmon peak index counts in sloughs above RM 98.6.
1981-83.
River 3-Year
Slough Mile 1981 1982 1983 Average
1 99.6 6 0 0 2
2 100.2 27 0 49 25
3H 101.4 a a 3 1
311.101.9 a a 0 0
4 105.2 a a a 0
5 107.6 a 2 1 1
6 108.2 a a a a
611.112.3 11 2 6 6
7 113.2 a a a a
8 113.7 302 a a 101
8D 121.8 0 23 1 8
8e:121.9 0 48 4 17
8B 122.2 1 80 104 62
Moose 123.5 167 23 68 86
AI 124.6 140 0 77 72
A 124.7 34 0 2 12
8A 125.1 620 336 37 331
EI 126.3 58 7
9 128.3 260 300 169 243
~9E1 129.2 90 5 0 32
9il.133.8 182 118 105 135
101 133.8 0 2 1 1
11 135.3 411 459 238 369
12 135.4 a 0 a a
1'1 135.9 4 0 4 3-'14,135.9 a a 0 a
15 137.2 1 1 2 1
16 137.3 3 0 0 1
17 138.9 38 21 90 50
18 139.1 0 0 a a
19 139.7 3 0 3 2
20 140.0 14 30 63 36
21 141.1 274 736 319 443
""'"22:144.5 114
21A 144.3 8 0 0 3
r-Tota:l 2.596 2.244 1.467 2.102 1
SouI'ce:ADF&G 1981a. 1982a.1984a
1 Three-year average of totals
.....
..-
r
Table 14.Chum salmon total slough escapement above RM 98.6.
1981-1983.
River 3-Year
Slough Mile 1981 1982 1983 Average
~
1 99.6 10 0 0 3
2 100.2 43 0 96 46
6A 112.3 19 5 0 8
8 113.7 695 0 0 232
8D 121.8 0 53 0 18
l!ifi'llllli 8C 121.9 0 108 8 39
8B 122.2 0 99 261 120
Moose 123.5 222 59 86 122
A'124.6 200 0 155 118
A 124.7 81 0 4 28
8A 125.1 480 1.062 112 551
B 126.3 0 104 14 39
9 128.3 368 603 430 467
9B 129.2 277 12 0 96
9A 133.8 140 86 231 152
11 135.3 1.119 1.078 674 957
13 135.9 7 0 8 5
15 137.2 0 0 4 1
16 137.3 5 0 0 2
17 138.9 135 23 166 108
19 139.7 5 0 6 4
20 140.0 24 28 103 52
21 141.1 657 1.737 481 958
21A 144.3 14 0 0 5
22 144.5 0 0 105 35
Total 4.501 5.057 2.944 4.167 1
Source:ADF&G 1984a
1 Three-year average of totals
r
Table 15.Chum salmon peak index counts in streams above RM 98.6,
1981-83.
"
Table 16.Chum salmon peak spawner counts and spawning observations
in mainstem habitats above RM 98.6,1981-1983.
River Spawning
Mile 1981 1982 1983 Observation
Dates
100.5 2/
m..,114.6 10 3/9/2/82
115.1 20 9/12/83
118.9 17 9/19/83
128.6 10 9/5/82
~9/7 /82
129.2 2 9/8/81
129.8 3/5 9/12/82
130.5 3 9/8/81
131.0 3/3/
131.1 3 3/9/7 /81
131.3 12 4 9/4/82
10/1/83
136.1 6 50 110 9/6/81
9/4/82
9/9/83
136.8 12 9/9/83
137.4 25 8/19/82
9/5/82
138.3 2/
139.0 16 56 9/4/82
9/15/83
143.3 22 9/4/82
148.2 400 8/18/82
Tota.l 16 550 219
,~
1/River miles of spawning locations from ADF&G were standardized by
EWT&A to R&M blue line maps.
2/No spawning observed.Redds observed and/or live eggs sampled.
3/Spawning areas designated by spawning maps in ADF&G appendices.
Source:ADF&G 1984a
Table 17.Sex ratios of chum salmon at Susitn.a,Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
Location/Sex Ratio (M:F)l
River Mile 1981 1982 1983
Susitna Station 0.6:.1 0.7:1
RM 26
Yentna Station 1.0:1 1.3:1 1.3:1
RM 28,TRM 04
Sunshine Station 0.8:1 1.0:1 1.0:1
RM 80
Talkeetna Station 1.3:1 1.9:1 1.5:1
RM 103
Curry Station 1.1:1 1.1:1 1.9:1
RM 120
Source:ADF&G 1981a,1982a,1984a
1 Includes all aged and non-aged fish
Table 18.1Cohosalmonpeakindexcounts in streams above RM 98.6,
1981-1983.
River 3-Year
Stream.Mile 1981 1982 1983 Average
Whiskers Creek 101.4 70 176 115 120
Chase Creek 106.9 80 36 12 43
Slash Creek 111.2 0 6 2 3
Gash Creek 111.6 141 74 19 78
Lane Creek 113.6 3 5 2 3
Lower McKenzie Creek ·116.2 56 133 18 69
Little Portage Creek 117.7 0 8 0 3
Fourth of July Creek 131.1 1 ,4 3 3
Gold Creek 136.7 0 1 0 0
Indian River 138.6 85 101 53 80
Jack Long Creek 144.5 0 1 1 1
~Portage Creek 148.9 22 88 15 42
..-Total 458 633 240 444 2
Source:ADF&G 1981a,1982a,1984a
~1 Counts done by helicopter and/or foot surveys
2 Three-year average of totals~~
.-
Table 19.S,ex ratios of coho salmon at Susitna,Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
Location!Sex Ratio (M:F)1
River Mile 1981 1982 1983
-Susitna Station 0.8:1 0.6:1
RM 26
Yentna Station 0.9:1 2.4:1 2.3:1
RM 28,TRM 04
.-
Sunshine Stati,on 0.7:1 1.4:1 1.2:1
RM 80
Talkeetna Station 1.5:1 1.5:1 1.7:1
RM 103
Curry Station 2.0:1 1.3:1 2.0:1
~RM 120
Source:ADF&G 1981a, 1982a,1984a
1 Includes all aged and non-aged fish
Three-year average of totals
Table 20.P:lnk salmon peak index counts in st:reams above RM 98.6,
1981-1983.
River 3-Year
Stream Mile 1981 198.2 1983 Average
Whiskers Creek 101.4 1 138 0 46
Chase Creek 106.9 38 107 6 50
Lane Creek 113.6 291 640 28 320-Lower McKenzie Creek 116.2 0 23 17 13
McKenzie Creek 116.7 0 17 0 6
Little Portage Creek 117.7 0 140 7 49
Fifth of July Creek 123.7 2 113 9 41....Skull Creek 124.7 8 12 1 7
Sherman Creek 130.8 6 2·4 0 10
Fourth of July Creek 131.1 29 702 78 270
Gold Creek 136.7 0 11 7 6
Indian River 138.6 2 738 886 542
Jack Long Creek 144.5 1 21 5 9
Portage Creek 148.9 0 169 285 151
~...
Total 378 2,855 1,329 1,521 1
Source:ADF&G 1984a
1
....
....
Table 21.Pink salmon total slough escapement above RM 98.6.
1981-1983.
River 3-Year
Slough Mile 1981 1982 1983 Average
8 113.7 38 0 0 13
Moose 123.5 0 2 0 1
8A 1125.1 0 5 0 2
B 126.3 0 18 0 6
9 1128.3 0 18 0 6
11 135.3 0 170 0 57
20 140.0 0 75 0 25
21 1141.1 0 9 0 3
Total 38 297 o
-
"""
Source:ADF&G 1984a
1 Three-year average of totals
Table 22.Sex ratios of pink salmon at Susitn,a,Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
Table 23.Chinook salmon peak index counts in streams above RM 98.6.
1981-1983.
River 3-Year
Stream Mile 1981 1982 1983 Average
Whiskers Creek 101.4 0 3
Chase Creek 106.9 15 15-Lane Creek 113.6 40 47 12 33
Fifth of July Creek 123.7 3
Sherman Creek 130.8 3 0
Fourth of July Creek 131.0 56 6
Gold Creek 136.7 21 23
Indian River 138.6 422 1.053 1.193 889
Jack Long Creek 144.5 2 6
Portage Creek 148.9 659 1.253 3.140 1.684
Cheechako Creek 152.5 16 25
Chinook Creek 156.8 5 8
,....Devil Creek 161.0 0 1
Total 1.121 2.474 4.432
Source:ADF&G 1981a,1982a.1984a
-
'i~
1 Three-year average of totals
Includes all aged and non-aged fish
Table 24.Sex ratios of chinook salmon at Yentna,Sunshine,
Talkeetna and Curry stations,1981-1983.
"....
Location!Sex Ratio (M:F)1
River Mile 1981 1982 1983
Yentna Station 6.4:1 2.3:1
RM 28,TRM 04
Sunshine Statil:>n 3.5:1 L 2:1 L 2:1
~RM 80
*~Talkeetna Station 2.7:1 2.3:1 2.4:1
RM 103
,~Curry Station 1.9:1 1.5:1 1.4:1
RM 120
Source:ADF&G 1984a
1
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ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 1
HARZA""EBASCO
WoocIwar&awM ConeuIbmta ~I SUSITNA JOINT VENTURE
»-))I j J j )I J J ]J
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21
3)
4)
5)
6)
11
CEIlEllAL HABITA!CATEGORIES Of THE SUSITNA RIVER
Hain5te18 Habitat clInsi,h of those portions of the SusHna River that
nOl"lllll1Yconve,y-slrellmflo.lhroL4ghout the year.80th stngle and multiple
"hanne'reaches are included in this habHat category.Groundwater and
tributary Inflow appear tp.be Inconsl!quenttil contributors.to the overall
characteristics of IIItn5te.habit,lot.Matoste.habilat 15 typtcatly
chlrlcterhed by Mgt!",ater ve-Iodtie~and ...ell aJ1llOred '3otrearrbeds.
Substrates generally consist 01 boulder Ind cobble size materhls...Hh
tntlrsUUai Spaces filled ",Uh ill grout-hke mb-ture of 5J11i1111 graveh and
g",(I.1 unds.Suspended sedlnml concentrations and turbidHy are hlgb
during 1......'due to the infl"ence of 91ilclll ..elt-w.ter.StrelmOMols
recede In e.rl,t fall imd the aainste_cleilrs apprechbly in Dctober.An
1(e cover fonllS Cln the rher tn lite "ovedJer or Decetrber.
Side Ch,Rnei HaMiat consists of tiUise jjur-th;;;$,uf the SlJsttn;l:fth'~r that
Mrally conn)'streamflow durlng the open water season but bel:ame
.ppreclabl~df'llitered during ."rlods 0'10.flow.Side channel hal:dlat
..y eJ.h:t eUher tn ",ell deft ned overflw chlnneh.or In poorly defined
.der C014r$li/:1i flowing through pirtilll)'sublllerged gravel bus and is hnds
Ilong the .,ryln$of the IIItnst81 rher.Side channel streadled ele-
Vlttons are typJcllJlI)'lower than the ••n IJOnthl~~ter surface ele-
vilttons of the mtnsteM Susttna River observed durtng JUrle.July and
A.iguU.Side (hannel h4bltats are characterized by shallower depths..
lower 'feloclties.and suller streafltted llitertals than the adjacent
habitat of the Niostem river.
Side Slough Habitat Is located In spdng hd overllo",chillnneh betwet'n
fhe edge of t~e hoodpl.-.ln .nd the Nt.'le.a~d side channeh of the
Susltna Itlver and 15 u$ually separated fr..,the matnstem and side
r;h.nrleh by well vegetaud ban.An exposed alluvial bt'nIl often
sepllrdes the bead of the s'o14gh frOll Nlnstetll or side chann~l flollis-.
the confrolHng strcambed/stre.flttank elevatfons at t~e upstream end of
the side sfoughS are slightly len lhan the water surface ell'vatlons of
the ..ea.II10llthly 1I000S 0'the ..fnstem Sltsllna Rtver observed for June.
July ••nd Aug14st.At tntel1lledlate and 10.-fll*periods,the 'Stele 'iloughs
(unvey clear wate~fr,-$lNiIll tributaries and/or Ilpw(!lIlng '1l'"Ound",ater
(MUG 1981c,19BZb).these clear water Inflows .re (!ssent1a'CQn-
trlhutor$.to the eJIjstence or tilts ~abttat type.The flrlater surface
elevation of the SUS Una Aher gen.r.n~Cliuses a badwder to utend
well up into the $lough fl1lll Its lower end (ADF&1i llJ8lc,1982b).Even
though this subslaotlal back.ater e.llhh.the slOf.lghs function hydrau-
lically very Illch like sNll strea.systems and seve"a)hundred feet of
the slough channel often conve~s water Independent of mlnstem b.dwaler
effects.At high flows the ".ter surface elevation of the hla1nsteJll river
ts suffh:hmt to overtnp the upper end of fhe sloulJh (ADF&1i 19tHc.
1982b).Surhce w.ter temperatures 'fl the stde slough~dudnn sUlflller
IIOnths are prlndpall)'•functton of Iltr ti!lllperatlire.s-ohr ....diation.
and the tellperature of the 'ocal runoff.
~C::~:a;1:~to:a;Jeta:,ot~~fersS n~~~n~:~c~~~:ctS~du;tthha:h'etasturlf~c~h~~t~~~
0'the IlIilns.tem Susltna Rher or Its side chlinnels.Thes.t'!Slollghs are
charactertzed by the presence of bener diAlS and an acclll'lIuhtion of !itlt
covering the su1lstrate r,.suiting from ihe abselice of matnstem ~coudilg
flws.
~~~~i~~icHa:~~tt~~~stt~~~~cu~ht!1nfUtlh~~~t~~:'~~s.or T~~t.au~:~50~~~
streamflow,sediment,and thel"llldl regtllll!s :dlect the integraUon of the
hydroI09~,qeo109~.and elllllte of tbe tributary drainage.the physical
dblbutes of trtbutiJl'"j'h.blt.t are not dependent on mainstem conditions.
lrtootary Mouth HabU.t eKtends frollll the uppermost pOint io th~lributary
::~:~~~::::t::~n~:~lheSU:::~:t:~;·:lu:~~~th t'!~~:.~~~tei:t~f~h~t~la~~s.~:~
SusHna River or slo"gh (ADF&G 1901c t 1982bl.
lake;H,bit.t consists of various 1enllc environments thal OCt;;ur l'IlHhtn
l"fie1UiTin'lRlver drainage.lhe~e habitats ran9f from 'imall.shallow,
Isolated la..es pert;;h~d on thl'"hndra (0 larger.deeper 1411.l'S llihlch
COnnect to the plo)inUtom SLlsltfla Ittver throuyh well defined trihutdry
sy5tlllls.lht:'lIies receive their .ater from sprin9s.s-urface rUl\off
.nd/or tributaries.
ALASKA POWER AUTHORITY
BUBITNA HYDROELECTRIC PROJECTGENERALHABITATCATEGORIESOFTHESUSITNARIVER
A CONCEPTUAL DIAGRAM (SOURCE:ADFAG 1982 e).
FIGURE 2
Woodw....a,de coneultanbl6 HARZA-EBASCO
SUSITNA JOINT VENTURE
,~
Ifil~
-•"-'0
0
0 .'0
0
0-4-Z--Z
0.....
0
1950
.-
I
1955
,
1980
I
1985
'tEAR
1
1970 1980 1985
....
ALASKA "OWER AUTHORITY
au.IT..A HYDROELECTRIC PROJECT
~HARZA-EBASCO.............cCl..,..••CC••_••IIl••d......'V
•SUSITNA JOINT VENTURE
-~•0
0
0.
19-'l\lil 0
0
0...
z--z
(,).r..•0
--1860 1985
ALASKA ~OWER AUTHORITY
aUSITNA HYO"OELECTAIC PRO.lECT
~HARZA-EBASCO•Ia••".0•.1 •lit 'C:7.,SUSITNA .I0lNT VENTURE
....
2'_-----------------------------,
-!'
0
0
0.
0
0
0.-z--zu..
C ,r0-
198518801875117019801955
Ol+----...---.,..---.,..---.,..--__,.---...,,.----t
1.50
.CO••1EIIaM.CATCIt OF ..'D COOl(I&ET CHUM.1154-1183.
ALA3KA POWER AUTHORITY
aUalTNA HYDROELECTRIc:PROJECT
~HARZA-EBASCO•'$.ilCIJr*C......~
W SUSITNA JOINT VENTURE
,.....-•0
0
r0-O
0..
a---z
0
II'-
4..-0
-
,...1985
ca_EllCIAL CATCH C)Ir WI '0 COOK -..r COMO,1.54-1 ••3.
ALA,KA POWER!AUTHORITY
SU8I11IA H·YDROELECTRIC PROJECT
P18UM •
~HARZA-EBASCO"·*-"au.c_.....~
SUSITNA JOINT VENTURE
1985U80117511701MI,...,...
zu
~
C
Q
z--
-•.,
oo-ooo--
-
-I
.ALASKA ItOWER AUTHORITY
aUa'TNA HYDROELECTRIC PRO.lECT
.~HARZA-E8ASCO..............Ha...Zill•••4Cl:tl._.......,.'\;J
SUSITNA JOINT VENTURE
-------------
-•0-0
0 ...
~-z
0t-."C
'0
.-
.-
i,...I,••5 i
1870 1985
COIIMnCIAL CATat OF .,EII COOK -.aT CHINOOK,1854-1983.
ALAaKA POWER AUTHORITY
aualT.."HYDROELECTRIC PROJECT
"I'..Qs ..c ........6 HARZA-EBASCO
Ft8UJItE •SUSITNA JOINT VENTURE
..._~-.....
.,.-'ANCHORAGE
COOK INLET
15 Kilometers
_..lr---....,o Miles
o 5 10
.-
-
SUSITNA RIVER AND MAJOR TRIBUTARIES FROM
MOUTH TO LITTLE WILLOW CREEK
FIGURE 9
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
~HARZA-EBASCO~CanMIII8nta SUSITNA JOINT VENTURE
_.
-
.-
o 5 10 Miles
....~~J
o S 10 1S KilomelEfS
SUSITNA RIVER AND MAJOR TRIBUTARIES
FROM MONTANA CREEK TO DEVIL,CAVON
ALASKA POWER AUTHORITY
SUSITNJ'HYDROELECTRIC PROJECT
FIGURE 10
~HARZA-EBASCO
WDocM.do CoMuItanIa 'C7CIvde SUSITNA JOINT VENTURE
I I J I ]]1 r )l )1 .)1 1 I
!
CURRY
STATION -
I I ..;;<;8;"1 ;,.;;.f"·':;r ''I I. '.9..8.::";_,,.:.,_-,:~.l./.L ,..·,.;.d:.·.·.·•..J :-..;'......,.8 J
,~·:ry:3'7'<'):·::--:'·'...,'1982.,..'..:},;-,,..•-',-
1---1"-:;:>:"·i;"·f:,:;;:;q:Zd;t;./;1 I 1981---------------_.._-------------------- -----
I 1:·t:"ttllt"}"·1~;'7~3tu':;t.t;;J I •88;\I ".....',",;,.......:~~.:~~".~....,*,,4 ,·-"i·'··;."'.·.<!·.u~:-:.:-..~,.,,:.;''.'..,.-..-.-.'"".I'
TALKEETNA I I EEi:I;i·,.;:';;;:;t::~:;;·;;;1 11982
STATION 1
I F;;i '1;;,<:;;:·t·,;,",:;.,.:,::I I 19 81
~-~-------------~~----~---------------------
SUNSHINE
STATION -
~----~----------~~---~~~----~~-~---------
::::.~~~18.21~i I ~1;,trJ:j_;;_;P~_i::;_J '
..'..~p,x,LL;L I
I 9 I.1r----JI··;;..··':;·lt,;;.:it;:;.;;;:t1 I
...dioll PUll
RORO'\Cal,,,~p'";"'"I~"~::~··:··-···..·..·>·:···:1·!·~·:1:-<-;';;,..=,..:..\
/\
SDID Cumuiativi SllDJgCumulativ.ICal,,,'If lUorl Calch i
•••••• •••••••6/12 6/26 7110 7/24 8/7 8/21 9/4
T I
9/18
DATE
MIGRATIONAL TIMING OF SECOND-RUN SOCKEYE SALMON BASED ON FISH WHEEL CATCH PER UNIT EFFORT
AT SELECTED LOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:ADF&G 1984 8).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 11
Wood....CIvde Conaultang 61 HARZA-EBASCO
SUSITNA JOINT VENTURE
COMPARISON OF SECOND-RUN SOCKEYE FISHWHEEL CATCH AND
MAINSTEM DISCHARGE AT SUNSHINE STATION,1981-1983•
flSIiWH£El CATCH 'fe)
DISCHARGE 101
i1
,-,·',,,',
1983 ::·',·,, i
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AlLY "'UG.UP1.
"FIGURE 12
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
HARZA-EBASCO
Woodwanl-CIvde Consullana.e91 SUSITNA JOINT VENTURE
DEVIL CANYON (FISH BARRIER)•
MAINSTEM 1,~
I
TRIBUT ARIES O~6 - --.........:SLOUGHS 99~
"I
!~
11,800
COOK INLET
•
'TALKEETNA -DEVIL
CANYON SUB-BASIN
~TALKEETNA -CHULITNA
~SUB-BASIN
YENTNA SUB-BASIN
O LOWER SUSITNA
SUB-BASIN
TOTAL ESCAPEMENT 248,900
.....11981 -1983 SUSITNA SOCKEYE ESCAPEMENT
AND RELAnvE UTLIZAnON
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
.,.,.FIGURE 13 :
.~HARZA-EBASCO........ltih_-...IIoClClfl•••«c..:......III.IIlII....'J
SUSITNA JOINT VENTURE
1 j J ]l I j j 1 1 I 1 ])I
I
CURRY
STATION-
I CHUM SALMON I
.1.'1 1~&lM;Ma~ill),*I:ml:;!VMJig f •"','I'.,....n....C"IlIi•
•••21 EDi h'$,i;fK.;,ly:t.[:I I ~t'it~::'H
/\
"'"BI·.BUiltlnSl!1 I .""......If."%C-ul"If."'.•>•.'••••..•••.".•.•.•C.tell ,.,llloft Calcll,or £"ort
TALkEETN~
STATION
SUNSHINE.
STATION
.,~--------~------------~------------~----~--.1.'"_~#~>;~_i'fi'~li*:r~[;>;.I."-.-'0.'-··:·-i·u>;;;;iiiL:-:V;»;,,';;;"jj:;
"'21 .-"£2$:;g ,
••••t-IIli!!!'~."I
~~-----------~----------------~--------~-I ~al'7:%I·/'t;;UL~;';:!I;.atRt'Fil.'.1.1
I 1:,eiYtlllirf!iiliE1B .I.I.Z
I Ii¥fUi;:!;!!:?Xf j1r1 t ';J):'S'M;:;1g I '1"
~------~~--~---------~--------~---~---------
I .'.lilff.1;i,;;11IaJRliMiiL'.I •I"
:r~~1::~H:i:11tEE'.IBn '.1.1
I ,IEm 1;Ht1IBdllli$1:til '.1 ••
r-,-~,--.,,-,,I I I I I
1/21 7/1 7111 112 "I'"10 "'1
DATE
I
"Zl
MIGRATIONAL TIMING OF CHUM SALMON BASED ON FISHWHEEL CATCH PER UNIT EFFORT AT SELECTED
LOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:ADF&G 19848)
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 14 Woodward-Clyde ConauIlanta E9 HARZA-EBASCO
SUSITNA JOINT VENTURE
11
I
1
IEPl.
1
~,
"~,
I I ',., I
..I.,,'I ,V I,,,,,
\
\
\,
'..•......
1983
J
n
,lUG.
j
A
;1
II
I I,,
I '
,,,,.,
I ,
I,I"
I ~,,\,\.,
I ,,,f',,\',I I
, I ',,\,.\
V
•,~22 ::19
.lJLY
i
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
III
~
o
I
f\
;;,..',oJ'J
CI I
CI •p \,
\....,,
V
. I HARZA-EBASCO
WDodwarcf.CIrde Consultanbl E9 SUS ITN A JO INT VE NTUR EFIGURE16
f1SHWH£EL CATCH (FCt
DISCHARGE 10)--------
COMPARISON OF CHUM SALMON FISHWHEEL CATCH AND
MAINSTEM DISCHARGE AT SUNSHINE STATION,1981-1983.
I I J »
-~[4-"",
I 1
t~••
~..
III
III:r
S
II<x,
:r
III
t.......,
.D
IEPl.
....,.
I ,•
I '"I •
, I
"-',\'~
'J \.../
1982
\{'
I',~,,,,
'....
)
1981
l~
AUG.
AUG.
I,,,
I,
\
\,,",,
~\r
V
"IJI,y
.AlLY
lI,'I, I
I ,
I I.,:,,.
I I ,
I 'III ,I
,'I:~
I,
I ,,'
III ..I \,I ,
ti I :\/V~\I, I
I ,\:','
~e
,.
~
.0
tot,
S:-+o1DO
:;
III
'":r
S,
II:
%
i ••
III..-'DU...
1 j 1 J
~Tu,l
It,.
.J~1\,\
!,,i,a,II
110
,"
~
,I,..,, I
'"'"•,,,
:r ~,I ,
!Cl t"--,I ,
CI •\..to p
~I ,
:r ..,
II>...,
....!:!
0
u '....,,,,,,
50 \','V
DEVIL CANYON (FISH BARRIER)
I
I
MAINSTEM I 7,.
YENTNA SUB-BASIN
~TALKEETNA -CHULITNA
~SUB-BASIN
•
TALKEETNA -DEVIL
CANYON SUB-SASIN
17.000
..~~",,_...,.SLOUGHS 80"
-
-
.....
I
-
COOK INLET
D LOWER SUSIT.NA SUB-BASIN
TOTAL ESCAPEMENT 358.200
--
1981 -1983 SUSITNA CHUM ESCAPEMENT
;AND RELATIVE UTLIZATION
FIGURE 18
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
".d-~~6 HARZA-EBASCO
SUSITNA JOINT VENTURE
J I J J ---I 1 J j B j J i 1
COHO SALMON
CURRY
STATION
I I .1i;';n,W'*tpnii'••iiiM-;"8'
1-li!;;Fi;;~""2
iiiiiiM 11111
Me.I.."..II.......'ct.'..~'IiW i
/\
1%C:-ul.tl",1%Cu.ul.t1"
Co'ell ,,,,EII.,I Golell pet E'!o,1
-----_-......_---...-_...._---------------_...
TALKEETNA
STATION
I 1iiMi".UisfS'5WmSll-l "I'Hi&iI--1"82
f--MG;UPiti;I&B 1"81
---~---~--.--~~~--_-._~---~~----------~
SUNSHINE
STATION
YENTNA
STATION -
I liiiiiii'i$iiiUiilfiiiM I "1'
I Ef.W$iiilil 1"12
I M.llii;''-I "8'
~---------~...~---_-._~-----~~------~---~
~1I_iiII 1"8'
I---Jiiliijililttli&iJi'ijipp;g I "12
I liiiul:@ta;:;;;w I "8 I
1/28'/10
I
8/47/2.1/1 8/18
DATE
MIGRATIONAL TIMING OF COHO SALMON BASED ON FISHWHEEL CATCH PER UNIT EFFORT AT SELECTED
LOCATIONS ON THE SUSITNA RIVER IN 1981,-1982 AND 1983.(SOURCE:ADF&G 1984 a).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 17
HARZA-EBASCO
Woodward-Clyde Consultants e91 SU SIT NA JO INT VENT UR E
j i J J 1 )j 1 j
---'50
\
,
MI'T."
,~~",:\,'J '",\J \,,,,,
\
\,,....
1983
""IlUG •
~
1\
Ap
I 'I \•f •,,,,"
I .',,,
12 If
.allY
p
I
I•2 t,
o,,,,--·J'v-""",,
40
HARZA-EBASCO
Wood.-ClvdeCaneuItarU E!:7ISUSITNA JOINT VENTURE
,r
'10
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Co)..
-........
%•...
Ii
!
%•5
FIGURE ~8
FlSHWHEEL CATCH IFC)
DISCHARGE CO)
COMPARISON OF COHO SALMON FISHWHEEL CATCH AND
MAINSTEM DISCHARGE AT SUNSHINE STATION,1981';'1983.
I
,,,
\,
\,,
"-\\",""\,
1981
UPT.
'\,,
'\.,, ,,,..,,
\1 \..
"-wi
1982
1\
, 1
'J •
"1,
1,
\"
AUQ.
.AlLY
1 ~,I
.\I~
1\'I• ,• I,I
"-.\, I
1"\.,, \
,"/I
\..".'l Iv''\ I "Ii,,\,, I ' ,,,,
"'""....
.M-Y
Pi
~
I
III...
2
o
~
"1\
I ', I,'• ' I,I ..,''\•,I
, I I I;;_,\'1
§•J ~..,\
I • ,
III 'I~\/\I '
-...'"Io\
2-+-7.
3+00
10
$1-
130
-'..
".......llt
••
n--....-'O
IJ...
I,)...
:t;
co:
%..
%
III...
:;...
1M
%'.,...,.
i:..
-......
1M
:I:a
":a:
:I:
%
III
DEVIL CANYON (FISH BARRIIER)
I
MAINSTEMlc1 ..
TRIBt.lT ARIES 98.............
2.200
----SLOUGHS c 1..
38,900
-
....
.....
.....COOK INLET
_TALKEETNA.-D.EVIL
CANYON SUB-BASIN
~TALKEETNA -CHULITNA
~SUB-BASIN
YENTNA SUB-BASIN
D LOWER SUSITNA SUB-BASIN
TOTAL ESCAPEMENT 88,800
1981 -1983 SUSITNA COHO ESCAPEMENT
.AND RELAnvE UTLIZATJON
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 18
~HARZA-EBASCO".~da,deCofl••lUiur...III....'CJ SUSITNA JOINT VENTURE
i .J 1 )--]j 1 1 ]~J I j j
-~I PI NK SALMON
M,dl..,.....;::,':"*,,:1,,.,~w~:~:I
S~::I~YN ~:~~::::tl'::::~I:'
C,'e"pIf (Uor'Ce'c"p.r Ellor.
t---fIiH:iiii·tiBMm.,..III1I
I .,..-.1"12
I li_ie••i;WiSa III1I
TALKEETNA
STATION •
SUNSHINE •STATION
~~------~-~---~----~---------------~--------
I -t·;;;_·III1I
I .-d 1"12
l--f.iil..:I••'J'8E1tiiBI "I II1I
It-- - _..- - - _..--.....- - - -~- - - ----....- -..- -.......- - - - ---- ----
I r=iiRt:k'I,=':liIDIII1 1.1111
1 ••1111 11182
I DiIiJiI:ili:iiWiltiilit1 III1I
~---------------~------------------~-------_...
YENTNA .
STATION
I 1;;@••tw;i;;_'I(.;'I.;.it~W;j;)t:a III1I
I Mr:lifit1RIEII 11.12.,.....$::-:......it:''~~...,ii..••••:;g.:.
I Fiht;r;;O;!jtrftN:8;wilt'.ilii&Jlif;fMtr;Wi'tH 16 11o.:)f:~·;,··~tJ";~"'..~;::-..'."i."~'••'..,.•••••}~.•,..~!F,,"'.;-lo i'"~. .;;:-.:.,1.(;,·;·l?:..--:·..¥::~",->;.-.,:_~,N~:.:.
I'•••I I I I I I I I I I •
8/21 711 7118 7/21 1/7 1/17 1/21 III
DATE
MIGRATIONAL TIMING OF PINK SALMON BASED ON FISH WHEEL CATCH PER UNIT EFFORT AT SELECTED
LOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:ADF&G 1984 a).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 20
HARZA-EBASCO
WOodward-a,deConsultanla E31 SUSITNA JOINT VENTURE
AUG..JUL'"
flSHWHEEL tATCH (Fe)
DISCHAfIG£CO)
COMPARISON OF PINK SALMON FISHWHEEL CATCH AND
MAINSTEM DISCHARGE AT SUNSHINE STATION,1981-1983.
IfPT.
1982
AUG.
~
I'.,'
I
I
I
I
I
"
I,,,\r'\I
\f\.,:\ •
V I,I
\"'-'.I \ ,- v \...r
I,
\
\,
,~
"I I
I '
I 'l
I \J
I 'II~
,1\I~\,,,'";\I v..,'I \',,.-..
2
o
........
~
!
iii
~z•£
u...
J I j ]]J J j ])I j »J i I j J )
•
T I
44-100 ..
l.I'II~1981 'I 1983r,I I
I I"I I1\I I.....,I'1'0 I I
V.
!iI ,")
l'It'I ,
I I ,,t ,I I I ,.,"I..I I I I :;,,"V \I...\r,--,\...•I J I ...\...~I ,,I ....0 ..\/'z ",...,z t \l 0 I '--....~I \"r,~g \
,,..\I I \ I
....\\,,Ii 0 'vJ ',,',IE 2 -\Vv',\I \z I I \1 './'z I \'....I I ....Vz..,z ..II.I!r!4 ~\,......,""-..E 40 ~-o \,,
0uI\..,,\U,
\..
'0 V 1\,--,......
..........I ""0
.0
~
.........AUG.I£PT.
FIGURE 21
ALASKA POWER AUTHORIlY
SUSITNA HYDROELECTRIC PROJECT
Woodvnrd-ClvdeConauitanle 61 HARZA-EBASCO
SUSITNA JOINT VENTURE
DEVIL CANYON (FISH BARRIER)
MAINSTEMI O~r __-.TRIBUTARIES 95,...__....;:,:.-SLOUGHS 5,.
....,
,
....
~YI:NYEAR
(19fl2)RUNS
X10
".400
44.800
•
TALKEETNA -DEVIL
CANYON SUB-BASIN
~TALKEETNA -'CHULITNA
~SUB-BASIN
<""";,,.":.YENTNA SUB-BASIN
D LOWER SUSITNA
SUB-BASIN
TOTAL ESCAPEMENT 138,200
COOK INLET
ODD-YEAR (1981 a.1983)SUSITNA PINK ESCAPEMENT
AND RELATIVE UTLIZATION
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 22
'.Ll2:l HARZA-EBASCO
.....llMdi.._.........CllCI......eo-uII8I...r:;::::l SUSITNA JOINT VENTURE
l'J ]1 1 ])~
CHI NOOK SALMON
Mdl..,..,
.......\Ca'clt
,Lj·,,,·w.·!f!·····',',:1 m,,wi'*"i iInHhd;!:!:J:,·:~;:):~:;PA;:A::~~.::
/\
50/.CuMutatlv.'50/0CulIllllall".
COtcr.p.r Effort Cotch p.r EHortJ-IIHI I I.~~'::::;::::::;:;::.:..~~...,..::t1fl.ri:;:$$:J;;@11ttirriJilL>:irIJ!i:rJ$I.1981
11--~I¥1tl!i*:~i;;ii:I¥,mt1.!1 '.982
~_:::j:;M~#1:;WI;~:!;:i:nn:5i:i:1 11983
CURRY
STATION·
t-'------------ ------------- - _......--------......
TALKEETNA
STATION -
I li£1iWn~'I.·~1I1I.IwtXi.,i.3;.pA.l,$;;.:.z;&:iiuy j;;::1983
I IMlIS!tlI8i1flt 11982
I "'.11II1'11 '1981.~:..':~jiZci%£§:·g·Cr-t;;;;,f-----------------------....------__-----_- _..-
~-_t,·····"!!;Tmr",.•j··'?t'('."{'Wt::W(1 11982'I"t·;,!m<5·"··:'!I>fli··t+:'·E~·~
H'!i'I"\@'1,··,··,·(··'··'·rj.,l·;">·A ..d.,.....~ISUNSHINE.·;;~,H·,·,;;.."·,;:"··#,,·i,,d,,J,J;+.!h>iM..983
STATION -
• I I I I I I I I '.• I
6/15 6/19 7/3 7/17 7/31 8/14 8/28
DATE
MIGRATIONAL TIMING OF CHINOOK SA~MON BASED ON FISH WHEEL CATCH PER UNIT EFFORT AT SELECTED
LOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:ADF&G 1984 8).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 23
HARZA-EBASCO
Woodw.....ClwdeConeuIIante E91 SUSITNA JOiNT VENTURE
i]
\
j
".I.lly
I
1983
••
l\.../\,..I "
.'"V \
\,,
'.-1\\,
\",...,'y"""\I
'"~
,.II
.&JHE
flSl'fWHE£L CATCH CFC)
DISCHARGE CO)
COMPARISON OF CHINOOK SALMON FISHWHEEL CATCH AND
MAINSTEM DISCHARGE AT SUNSHINE STATION,1981..1983.
,.20u
.,IlLy
III,
, I
I ,,,
I ,
, I,I'J,
I'I...,....',r".-\,,
1982
,.3)".....£
,'.~
'-,J\I'J'I \ , \
, \ I \'\I 'I "_/,'\I"\~,1 \I \8,""I
0'V "'~I (,I ...,,
...'
2
o
_0
lOt
.0
..
u...
~
It:r,
%...
::;
III...:r
~,
i i j ---]1 i j -1 1 I j
;
T l I T1\1\1&81
I \
I \
""I ,•10 ••"J I i
1 ,"\"I ,
::;.\,r....._-'\::;)\
I \,...'...,'\III ..III ...a ;;,
%or.I \z
~0 I !0 '...••~0,
I "Ii 2 \a:I \:r ~I ~J:\,
:r v-I :t ..
~..f !!...o •2 a ~...~,II.-o "
I -0
0
\.....1"",.,,/
,u...II.
"'""1 ,I I..!-~a
'"
.lJLY
FIGURE 24
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT. I HARZA-EBASCO
WlNYlward.a,deConaultante E!9 SUSITNA JOINT VENTURE
TOTAL ESCAPEMENT UNKNOWN
~TALKEETNA -CHtlt.ITNA
~SUB-BASIN
O LOWER SUSITNA
SUB-BASIN
•
'TALKEETNA -DEVIL
CANYON SUB-BASIN
8.500
UNKNOWN ESCAPEMENT
DEVIL CANYON (FISH BARRIER)
I
I
MAINSTEM:0..
I ~SLOUGH 0 ..,.""".....1IIi..8,
TRIBUT AFl:IES 100...-.......-.
,~
-I
COOK INLET
1982.-1983·SUSITNA CHINOOK ESCAPEMENT
AND 'RELATIVE.UTILIZAnON
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 25
..D....cIoCIJdIIc:a........~HARZA-EBASCO
SUSITNA JOINT VENTURE
1 J -,J j ]1 i J 1 i
MolRIlam II
UPLAND SLOUGHS
Saun Malnllam
~Sit ..Combined
/ \19.~·1.'\
~Whillla,.C,..11
MAINSTEM SiDE
CHANNELS
~
SIDE SLOUGHS
TRIBUTARI ES
N!ne S!!!!!et!@ -
Combined
COMBINED MACROHABITAT
TYPES
DISTRIBUTION OF JUVENILE SOCKEYE SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER
BETWEEN THE CHULITNA RIVER CONFLUENCE AND DEVIL CANYON.MAY THROUGH OCTOBER 1983.
PERCENTAGES ARE BASED ON MEAN CATCH PER CELL.(SOURCE:ADF&G 1984 b).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 26
Woodward-Clvde Consultants e11 HARZA-EBASCO
SUSITNA JOiNT VENTURE
J 1 ]]I i j 1 I I i j i j ~I
I
MAINSTEM SIDE CHANNEL
UPLAND SLOUGHS
Ellven
Mo;ns"m
S itea Combined
~5".
Whlsk.rs eruk
Slough
Slough 22
COMBINED
M ACROHABITAT
TYPES
TR IBUTARIES
SI DE SLOUGHS
Cha ..Cre.k
DISTRIBUTION OF JUVENILE CHUM SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER BETWEEN THE
CHULITNA RIVER CONFLUENCE AND DEVIL CANYON.MAY THROUGH OCTOBER 1983.PERCENTAGES ARE BASED
ON MEAN CATCH PER CELL.(SOURCE:ADF&G 1984 b)..
ALASKA POWER AUTHORITY
SUSITNA HYDROelECTRIC PROJECT
FIGURE 21
. I HARZA-EBASCO
WoocIward-ClvdeConsult8nla e9 SUSITNA JOINT VENTURE
10
9
-
II
a:1
~S
a:
~5
0+--r-~--,~.,....-r---r'--,~,....-r---r'--'--':~::;::=9''''''-==:;:::~~,--r---.,
III Z3 Z8 1 1 It 11 1Z Z7 1 7 11 17 U aT 6 II 16 11 16
I--MA"-.,.I---JUN£I JULY----+__AUGUST~
DATE
-CffUV SALIlfOM FRY OAtt.Y CATCH "Eft HOUR RECORDED AT THE
DOWNSTREAM MIGRANT TRAPS.MAY 18 THROUGH AUGUST 20.1983.
(SOURCE:ADFIG 1184 b).
~
16.5
15.0
13.5
lZoO
~10:1
0:9.0-a:....1.5Q"
::60U
~.cu
z:s ze Z 1 12 17 U 27 1 U Z7 6 II 16 21 16 ~
I--"'A"JUN(----+---JUl.Y--__-!-AUGUST -----l
DATE
SOCKEYE SALMON FRY DAILY CATCH PER HOUR RECORDED AT
THE DOWNSTREAM MIGRANT TRAPS.MAY 18 THROUGH AUGUST 30.
1983.(SOURCE:ADFIG 1884 b).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 28
~HARZA-EBASCO"Dd_6C1rde~'C/
SUSITNA JOINT VENTURE
J I J ]1 J I 1 I J »-j
26 31
o ~.'..I I ..I'i'"I I ~T""r'-''''j''''''l .r-"-r·"y""y··''j'·'',I I ,
18 23 28 Z 7 12 17 22 27 2 7 12 17 2 2 27 I 6 II 16 21
t-MAY "1.JUNE ..,..JULY ",.AUGUST ",
10 ••-COHO.AGE to
••.•COHO.AGE t I9 •
8
ll:
:::>70
J:
6
ll:
W
Q..5
J:4u
I-
<t 3u
Z
DATE
COHO SALMON AGE 0+AND AGE 1·OR OLDER DAILY CATCH PER HOUR RECORDED AT
THE DOWNSTREAM MIGRANT TRAPS.MAY 18 THROUGH AUGUST 3D,1883.(SOURCE:
ADF&G 1 &84 b).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 29
HARZA-EBASCO
WDodwerd-ClJdeConsulblnta 81 SUSITNA JOINT VENTURE
J 1 ]i 1 J I I --1
Whl,keu
C,ull ,
Slough
W hialle,.Crull
Slough ,
I .I
Slough 184·'.
~UPLAND SLDUGHS
SiDE SLOUGHS MAINSTEM SIDE
"'"
~CHANNEL
I"if.4.0·'.fou,Trlbuto,l....I /
Combined 3.2.".
Cho ..
Crull ~
TRIBUTARIES .....----
Whi.lIe,.
Crull
COM BIN ED M ACROHAB I TAT
TYPES
DISTRIBUTION OF JUVENILE COHO SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER BETWEEN THE CHULITNA
RIVER CONFLUENCE AND DEVIL CANYON,MAY THROUGH NOVEMBER 1983.PERCENTAGES ARE BASED ON MEAN CATCH
,PER CELL.(SOURCE:ADF&G 1984 b).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 30
HARZA-EBASCO
Woodward-ClydeConsult-u E11 SUSITNA JOiNT VENTURE
6.~UPLAND SLOUGHS
COMBINED MACROHABITAT
TYPES
J ,)I J J ~~..J ~I )I )I ])D
I
S.2 °'0 Siouah 22 va"".vn.I.."".1
,-...6 ,-.......•...66 ....
SlouOh 22
I ...."a:W/17 70/_\
Whittlen Creek
Slough 'c:32.6°4 7 S 26.so'.V-SIOugh 9Side\:
Side Channel 10
SIDE SLOUGHS SiDE~CHANNELS
Five Trlbutorles
Combined 10,4°'.
DISTRIBUTION OF JUVENILE CHINOOK SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER BETWEEN
THE CHWTNA RIVERCONFUENCE AND DEVIL CANYON,MAY THROUGH NOVEMBER 1883.PERCENTAGES ARE
BASED ON MEAN CATCH PER ~.ELL.(SOURCE:ADFIG 1884 b).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 31
Woodward-ctvde Consultanla E9 I HA RZ A-EB AS CO
SUSITNA JOINT VENTURE
1 !]
1.0
J I I I ]J j J 1 I j -I j
0.8
a::
::>
0
%:0.6
a:
w
Q.
0.4
:J:
0...
c;(
U
0 ,I
19 24 29 3 8 13 18 23 28 3 8
I'MAY -,.JUNE I I,JULY-...j
DATE
PINK SALMON FRY DAILY CATCH PER HOUR RECORDED AT THE DOWNSTREAM MIGRANT TRAPS,
MAY 18 THROUGH JULY 8.1883.(SOURCE:ADF&G 1884 b).
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 32 ~CotwuItMIae9 HARZA-EBASCO
SUSITNA JOINT VENTURE
))J J I 1 I J I )1 1
150 ....,~,..L1I ...nnll-ar.1:till
I=CHiNOOK:AGE t'l
12.5-
302252119II326132.29 6 14
J.-MAY -I.JUNE -I-JULY ..I.AUGUST -I
t \0 .(~..,--,-",;,r~.•....."~Op'-r I'n iCc'Ii)I I I f l I i I
18
10.0a::
:>
0
:I:
a:7.5
w
Q..
:I:
U
I-5.0c(
u
2.5
DATE
CHINOOK SALMON AGE 0+AND AGE 1+DAILY CATCH PER HOUR RECORDED AT THE DOWNSTREAM
MIGRANT TRAPS,MAY 18 THROUGH AUGUST 30,1983.(SOURCE:ADF&G 1984 b);
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
FIGURE 33
WoodwarcJ.Clvde Conaultanta E3 I HA RZA -E BAS CO
SUSITNA JOINT VENTURE
APPENDICES
APPENDIX A -ADF&G Susitna Specific Reference List
Alaska Department of Fish and Game.1978.Preliminary
environmental assessment of hydroelectric development on the
Susitna River.Prepared for the U.S.Fish and Wildlife
Service.Anchorage.AK.207 pp.
-I
I
2.
Alaska Department of Fish and Game.1977.
Susitna River Hydroelectric Project:
study (l July 1976 -30 September 1976).
Department of the Interior.Fish and
Anchorage.AK.91 pp.
Corps of Engineers
Baseline inventory
Prepared for U.S.
Wildlife Service.
3.Alaska Department of Fish and Game.1979.Little Susitna River
juvenile chinook and coho salmon study.Prepared by Kevin
Delaney and Roger Wadman.Division of Sport Fish.Anchorage.AK.
4.Alaska Department of Fish and Game.1981.Susitna Hydro Aquatic
Studies -Phase I Final Draft Report:Adult anadromous
fisheries project.Prepared for Acres American.Inc.
Buffalo.NY.
5.Alaska Department of Fish and Game.1981.Susitna Hydro Aquatic
Studies -Phase I Report:Resident fish investigation on the
Upper Susitna River.Prepared for Acres American.Inc.Buffalo.
NY.137 pp.
6.Alaska Department of Fish and Game.1981.Susitna Hydro Aquatic
Studies Phase I Final Draft Report:Resident fish
investigation on the Lower Susitna River.Prepared for Acres
American.Inc.Buffalo.NY.166 pp.
7.Alaska Department of Fish and
Studies -Phase I Report:
the Lower Susitna River.
Buffalo.NY.121 pp.
Game.1981.Susitna Hydro Aquatic
Juvenile anadromous fish study on
Prepared for Acres American,Inc.
8.Alaska Department of Fish and Game.1981.
Studies -Phase I Report (Vol.1):
instream flow proj ect.Prepared for
Buffalo.NY.260 pp •.
Susitna Hydro Aquatic
Aquatic habitat and
Acres American.Inc.
9.Alaska Department of Fish and Game.1981.Susitna Hydro Aquatic
Studies -Phase I Report (Vol.2 Pt.1):Aquatic habitat and
instream flow project.Prepared for Acres American.Inc.
Buffalo.NY.305 pp.
10.Alaska Department of Fish and Game.1981.Susitna Hydro Aquatic
Studies -Phase I Report (Vol.2 Pt.2):Aquatic habitat and
Instream Flow Proj ect.Prepared for Acres American.Inc.
Buffalo.NY.541 pp.
11.Alaska Department of Fish and Game.1982.Susitna Hydro Aquatic
Studies -Phase I Report:Aquatic Studies Program.Prepared
for ACRES American Incorporated,Buffalo,NY.137 pp.
12.Alaska Department of Fish and Game.1982.Susitna Hydro Aquatic
Studies -Phase II Final Data Report:Volume 2.Adult
Anadromous Fish Studies.Anchorage,AK 239 pp.
13.Alaska'Department of Fish and Game.1982.Susitna Hydro Aquatic
Studies -Phase II Final Report:Volume 2.Adult Anadromous
Fish Studies,Part B:Appendices A-H.Anchorage,AK 318 pp.
14.Alaska Department ofFish and Game.1983.Susitna Hydro Aquatic
Studies -Phase II Report:Summarization of Volumes 2,3,4;
Parts I and II,and 5 -Su Hydro Basic Data Reports,1982.
Prepared for Alaska Power Authority,Anchorage,AK.126 pp.
15.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies -Phase II Data Report:Winter aquatic studies
(October,1982 -May,1983),Anchorage,AK.137 pp.
16.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies,Phase II Report:Synopsis of the 1982 aquatic
studies and analysis of fish and habitat relationships.
Anchorage,AK.152 pp.
17.Alaska Department ofFish and Game.1983.Susitna Hydro Aquatic
Studies -Phase II Report:Synopsis of the 1982 aquatic
studies and analysis of fish and habitat relationships.
Appendices A-K.Anchorage,AK.357 pp.
18.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies.Phase II Basic Data Report.Volume 3:Resident
and juvenile anadromous fish studies below Devil Canyon,
1982.277 pp.
·19-.Alaska Depa.-rtment of Fish -and Game.1983.Susitna Hydro Aquatic
Studies.Phase II Basic Data Report.Volume 3:Resident
and juvenile anadromous fish studies below Devil Canyon,1982
(Appendices).
20.~.llaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies:Phase II Basic Data Report.Volume 4:Aquatic
habitat and instream flow studies,1982,Part I and II.367
pp.
21.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies.Phase II Basic Data Report.Volume 4:Aquatic
habitat and instream flow studies,1982,Appendix A (Draft).
Anchorage,AK.182 pp.
22.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies:Phase II Basic Data Report.Volume 4:Aquatic
habitat and instream flow studies,1982,Appendix B (Draft).
Anchorage,AK.99 pp.
23.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studie:s:Phase II Basic Data Report.Volume 4:Aquatic
habitat and instream flow studies,1982,Appendix C (Draft).
Anchor'age,AK.221 pp.
24.Alaska Department of Fish and Game.1983.Susitna Hydro
Studies:Phase II Basic Data Report.Volume 4:
habitat and instream flow studies,1982,Appendices
(Draft).Anchorage,AK •.168 pp.
Aquatic
Aquatic
D and E
.....
,~
25.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studies:Phase II Basic Data Report.Volume 4:Aquatic
habitat and instreamflow studies,1982,Appendices F-J
(Draft).Anchorage,AK.236 pp .
26.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic
Studie:s -Phase II Basic Data Report.Volume 5:Upper
Susitna River impoundment studies,1982.Anchorage,AK.150
pp.
27.Alaska Dep~lrtment of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.1:Adult Anadromous Fish Investigations,
May -October 1983.Prepared for Alaska Power Authority,
Anchor'age,AK.380 pp.
28.Alaska Dep~lrtment of Fish and Game.1984.Susitna Hydro Aquatic
Studie-s,Report No.2:Resident and juvenile anadromous fish
investigations,May -October 1983.Dana C.Schmidt,Stephen S.
Hale,Drew L.Crawford,Paul M.Suchanek (eds.),Prepared for:
Alaska Power Authority,Anchorage,AK.395 pp.
29.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983.Chapter 1:Stage and
Discharge Investigations.Prepared for Alaska Power Authority,
Anchorage,AK.136 pp.
30.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investiga tions,May -October 1983..Chapter 2:Channel geometry
investigations of the Susitna River Basi.n.Prepared for Alaska
Power Authority,Anchorage,AK.212 pp.
31.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studie.s,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983.Chapter 3:Continuous water
temperature investigations.Prepared for Alaska Power Authority,
Anchorage,AK.145 pp.
.....
I
32.Alaska Department of Fish and Game.1984.Susitna
Studies,Report No.3:Aquatic Habitat and
Investigations (May-October 1983)-Chapter 4:
Investigations (+Appendix).Prepared for
Authority,Anchorage,AK.30 pp.
Hydro Aquatic
Instream Flow
Water Quality
Alaska Power
.-
.-
i
33.Alaska Depll.rtment of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations (May-October 1983)-Chapter 5:Eulachon Spawning
Habitat in the Lower Susitna River (+Appendix).Prepared for
Alaska Power Authority,Anchorage,AK.32 pp.
34.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Review Draft).Chapter 6:An
evalu8ltion of passage conditions for adult salmon in sloughs and
side c:hannels of the Middle Susitna RivE!r.Prepared for Alaska
Power Authority,Anchorage,AK.178 pp.
35.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Draft).Part II,Chapter 7:
An Evaluation of Chum and Sockeye Salmon Spawning Habitat in
Sloughs and Side Channels of the Middle Susitna River.Prepared
for Alaska Power Authority,Anchorage,1~.178 pp.
36.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studies,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Draft).Part II,Chapter 8:
An Evaluation of Salmon Spawning Habitat in Selected Tributary
Mouth Habitats of the Middle Susitna River.Prepared for Alaska
Power Authority,Anchorage,AK.70 pp.
37.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
StudiE!S,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Draft).Part II,Chapter 9:
Habit8lt Suitability Criteria for Chinook,Coho,and Pink Salmon
Spawning.Prepared for Alaska Power Authority,Anchorage,AK.
61 pp.
38.Alaska Dep.artment of Fish and Game.1984.Susitna Hydro Aquatic
StudiE!s,Report No.3:Aquatic Habitat and Instream Flow
Investigations,May -October 1983 (Draft).Part II,Chapter 10:
The Effectiveness of Infrared Thermal Imagery Techniques for
Detecting Upwelling Groundwater.Prepared for Alaska Power
Authority,Anchorage,AK.61 pp.
39.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
StudiE!S,Report No.4:Access and Transmission Corridor
Aquatic Investigations,July -October 1983.Prepared for
Alaska Power Authority,Anchorage,AK.
40.Alaska Department of Fish and Game.1984.Susitna Hydro Aquatic
Studies:Procedures Manual,May 1983 -June 1984.Prepared
for Alaska Power Authority,Anchorage,AK.255 pp.
.....41.Alaska Department of Fish and Game.
StudiE~s:Procedures Manual,
(Appendices).Prepared for
Anchorage,AK.119 pp.
1984.Susitna Hydro Aquatic
May 1983 June 1984.
Alaska Power Authority,
.....
42.Barrett,JB.M.1974.An assessment of the anadromous fish
populations in the Upper Susitna RbTer watershed between
Devil Canyon and the Chulitna River.Division of Commercial
Fisheries,Alaska Department of Fish and Game,Anchorage,
AK.57 pp.
43.Barrick,L.,B.Kepshire and G.Cunningham.1983.Upper Susitna
RbTer Salmon Enhancement Study·(Draft).Division of
Fisheries Rehabilitation,Enhancement and Development,Alaska
Department of Fish &Game.Anchorage,AlC 15 pp •
44.Friese,N.V.1975.Preauthorization assessment of anadromous fish
popul~ltions of the upper Susitna River watershed in the
vicinllty of the proposed De,ril Canyon Hydroelectric Proj ect.
Divisllon of Commercial Fisheries,Alaska Department of Fish
and Game.Anchorage,AK.108 pp.
45.Riis.J.C.1977.Preauthorization Assessment of the Susitna River
Hydroelectric Project:Preliminary investigations of water
quality and aquatic species composition.Sport Fish Division,
Alaska Department of Fish and Game.Anchorage,AK.50 pp.