HomeMy WebLinkAboutAPA316Subtask 7.1 0
Phase 1 Final Draft Report
Resident Fisb Investigation
on tbe Upper Susllna River
ADF&G I 1981
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Subtask 7.10
Pbase 1 Final Draft Report
Resident Fisb Investigation
on tba Upper Susllna River
ADF&G I 1981
by
Alaska Department of Fish and Game
Susitna Hydro ~atic Studi~$ 2207 Spenard Road____ ·-------
Anchorage, M_aska 99503
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for
Acres American Incorporated
liberty Bank Bui ld i ng, Main at Court
Buffalo, New York 14202
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ARLIS
Alaska Resources
Library & Information Services
Anchorage. AJ~ska.
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TABLE OF CONTENTS
Title Page
LIST OF FIGURES.................................................. i v
LIST OF TABLES ........•.......••..............•...•........... ·... vi
LIST OF PLATES................................................... ix
LIST OF APPENDIX TABLES.......................................... x
1. SlJ~1MARY .............•.•••..........................•........ E-1-1
2. INTRODUCTION ..••....•....••.........•......... ;............. E-2-1
2.1 Objectives ........•.•...•..................•..•.... ~··· E-2-1
2.2 Methods................................................ E-2-11
3. SPECIES REPORTS -RESIDENT FISH............................. E-3-1
3.1 ARCTIC GRAYLING ..................... ~.................. E-3-1
3.1.1 Abstract........................................ E-3-2
3.1.2 Introduction.................................... E-3-3
3 .1. 3 Methods.. . . . . . . . . . . • • . . . . . . . . . . . . . . . . . . • . . • . . . . . £..:3-5
3.1.4 Results ~nd Discussion ....• :.................... E-3-5
3.1.4.1 Distribution and
Relative Abundance ................•.....
3.1.4.2 Age, Length and Sex
Composition ......•..•.............•.....
3. 1. 4. 3 Spawning ....•.•..••......................
3.1.4.4 Tagging and Recapture .................. ..
3.1.4.4.1 Introduction .......•..•.....•.....
3.1.4.4.2 Population Estimation ....•........
3.1.4.4.3 Migration ........................ .
3.2 BURBOT .•.•...........•.................•.............•.
3.2.1 Abstract ••.•.••.................................
3.2.2 Introduction •....•........•••.•. ~ ...........•...
3.2.3 Methods ••..••.....•....................•........
3.2.4 Results and Discussion ..........••.....•........
3.2.4.1 Distribution and
E-3-5
E-3-21
E-3-33
E-3-34
E-3-34
E-3-38
E-3-41
E-3-67
E-3-67
E-3-67
E-3-69
E-3-69
Relative Abundance...................... E-3-69
3.2.4.2 Age, Length and Sex
Composition............................. E-3-72
3.2.4.3 Tagging and Recapture.................... E-3-77
i
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3. 3 ROUND WHITEFISH ............•...........................
3.3.1 Abstract ....................................... .
3.3.2 Introduction ................................... .
3.3.3 Methods ........................................ .
3.3.4 Results and Discussion .................•........
3.3.4.1 Distribution and
E-3-79
E-3-79
E-3-79
E-3-80
E-3-81
Relative Abundance...................... E-3-81
3.3.4.2 Age, Length and Sex
Composition............................. E-3-81
3.3.4.3 Tagging and Recapture.................... E-3-85
3.4 LONGNOSE SUCKER .................... ~ .................. .
3.4.1 Abstract ....•..............•................. · .. .
3.4.2 Introduction ................................... .
3.4.3 Results and Discussion ......•...................
· 3.4.3.1 Distribution and
E-3-87
E-3-87
E-3-87
E-3-88
Relative Abundance...................... E-3-88
3.4.3.2 Age, Length and Sex
Composition............................. £-3-91
3.4.3.3 Tagging and Recapture .... ~ ......... ~..... E-3-91
3.5 COTTIDS.. •• • . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . ... . . . . E-3-94
3.5.1 Abstract ....................................... .
3.5.2 Introduction ....•.................•.............
3. 5 . 3 Methods .....•.............•.....................
3.5.4 Results and Discussion ....•....••...............
·3.5.4.1 Distribution and
E-3-94
E-3-94
E-3-95
E-3-95
Relative Abundance .................. ;... E-3-95
3.5.4.2 Age, Length and Sex
Composition............................. E-3-97
3. 6 LAKE TROUT .....•.. .' .....................•.. · ............ .
3.6.1 Abstract .................. ; .........•.•. · .•....••
3.6.2 Introduction ................................... .
3.6.3 Results and Discussion ......................... .
3.6.3.1 Distribution and
E-3-98
E-3-98
E-3-98
E-3-99
Re 1 at i ve Abundance ................... ~. . E-3-99
3.6.3~2 Age, length and Sex
Composition ......••..... ~............... E-3-99
3.6.3.3 Tagging and Recapture.................... E-3-101
3.7 MISCELLANEOUS SPECIES ......•........... :............... E-3-102
i i
.4. RECOMMENDATIONS............................................. E-4-1
~~. ACKNOWLEDGEMENTS............................................ E-5-1
6. LITERATURE CITED............................................ -E-6 .. 1
APPENDIX TABLES
i i i
F i g u re E. 2 . 1
Figure E.2.2
Figure E.2.3
,Figure E.2.4
Figure E.2.5
Figure E.2 .6
Figure E.2.7
Figure E.2.8
Figure E.2.9
Figure E. 2 .10
F i g u re E • 2 • 11
Figure E.2.12
Figure E.2.13
Figure E. 2.14
Figure E.3.1.1
Figure E.3.1 2
LIST OF FIGURES
Map of the upper Susitna River basin
from.the proposed Devil Canyon damsite
to the Denali Highway.
Map of Fog Creek
Map of Tsusena Creek
Map of Deadman Creek
Map of·Watana Creek
Map of Kosina Creek
Map of Jay Creek
Map of Goose Creek
Map of Oshetna· River·
Map of typical tributary habitat
location in the upper Susitna
River basin with sampling sites
defined.
E-2-2
E-2-3
E-2-4
E-2-5
E-2-6
E-2-7
E-2-8
E-2-9
E-2-10
E-2-13
Resident and Juvenile anadromous E-2-19
study, catch and effort form, mobile
gear, 1980~1981.
Resident and Juvenile anadromous E-2-20
study, catch and effort form, fixed
gear, 1980-1981.
Resident and Juvenile anadromous E-2-21
study, biological data form, 1980-1981
Resident and Juvenile anadromous study, E-2-22
tag and recapture form, 1980-1981.
Arctic grayling hook and line catch per E-3-10
hour. Upper Susitna River habitat location
sites by month, 1981.
Arctic grayling hook and line catch per E-3-11
hour by month for selected fish habitat
sites upstream of stream mile one to the
proposed impoundment elevation, 1981.
iv
Figure E.3.1.3
Figure E. 3.1.4
F i g u re E . 3 . 1. 5
Figure E.3.1.6
Figure E.3.2.1
Figure E.3.2.2
Figure E.3.2.3
Figure E.3.3.1
Figure E.3.4.1
Arctic grayling percent age frequency,
upper Susitna River, 1981.
Arctic grayling age-length relation-
ship, upper Susitna River, 1981.
Arctic grayling length frequency compo-
sition, upper Susitna River, 1981.
Arctic grayling age-length distribution.
Upper Susitna River tributary habitat
locations, May to September, 1981.
Percent incidence of burbot at habitat
locations, upper Susitna River, 1981.
Burbot age-length relationship, upper
Susitna River, 1981.
Length frequency composition of burbot,
captured at habitat location sites on
the upper Susitna River May -September,
1981.
Percent incidence of round whitefish
at habitat locations, upper Susitna
River, 1981.
. Percent incidence of longnose sucker
at habitat locations, upper Susitna
River May to September, 1981.
v
E-3-23
E-3-25
E-3-26
E-3-28
E-3-70
E-3-75
E-3-76
E-3-83
E-3-90
Table E.2.1
Table E.2.2
Table E.3.1.1
Table E.3.1.2
Table L3.1.3
Table E.3.1.4
Table E.3.1.5
Table E.3.1.6
Table E.3.1.7
Table E.3.1.8
Table E.3.1.9
Table E.3.1.10
LIST OF TABLES
Tributary habitat location streams and
their proposed impoundment elevation,
river mile, and elevation at their mouth.
Upper Susitna River tributary habitat
location sites and geographic locations.
Arctic grayling total catch by tributary
by month, upper Susitna River, 1981.
Arctic grayling catch and effort by
gear type, upper· Sus itna River habitat
location sites, 1981.
Arctic grayling hook and line catch and
effort for selected fish habitat sites
by tributary, 1981.
Arctic grayling hook and line catch and
effort for habitat 1 ocati on sites by
tributary and month, 1981.
Arctic grayling hook and line catch and
effort for habitat location sites (1) by
tributary and month, 1981.
Page
E-2-12
E-2-15
E-3-6
E-3-8
E-3-9
E-3-12
E-3-13
Arctic grayling hook and line catch and E-3-14
effort for selected fish habitat sites above
mile 1 to PEI by tributary and month~
1981.
Arctic grayling hook and line catch and
effort by tributary for stream reach to
be i~pounded and month, 1981.
E-3-15
Arctic grayling actual versus expected hook E-3-17
and line catches for habitat locations.
Arctic grayling actual versus expected hook E-3-18
and line catches compared for tributary study
sites 1-5 and tributary habitat locations
1-!i. May to SPptrl1llll'r, 1981.
Arctic grayling actual versus expected hook E-3-19
and 1 ine catches compared for tributary study
sites 1-5 and upstream selected habitat
locations within the proposed impoundment,
1981..
vi
Table E.3.1.11
Table E.3.1.12
Table E.3.1.13
Table E.3.1.14
Table E.3.1.15
Table E.3.1.16
Table E.3.1.17
Table E.3.1.18
Table E.3.1.19
Table E.3.2.1
Table E.3.2.2
Table E.3.2.3
Table E.3.2.4
Table E.3.3.1
Table E.3.3.2
Arctic grayling actual versus expected hook E-3-22
and line catches by month for habitat
location sites, 1981.
Arctic grayling, age-length frequency E-3-24
composition at habitat location sites
on the upper Susitna River, May to
September, 1981.
Arctic grayling sex composition by month, E-3~30
upper Susitna River habitat locations, May
to September, 1981.
Grayling sex compos it ion, upper E-3-32.
Susitna River, May to September, 1981.
Arctic grayling tagged by month and E-3-35
tributary, upper Susitna River, 1981.
Arctic grayling recaptures by tributary of E-3-36
tagging and month, upper Susitna River,
June to September, 1981.
Arctic grayling population estimates, upper E-3-39
Susitna River tributaries, 1981.
Arctic grayling movement as demonstrated E-3-42
by tagged fish recovered within stream of
tagging by month of tagging.
Arctic grayling movement from initial E-3-45
tributary of tagging as indicated by tag
recoveries, 1981.
Burbot captured by month and tributary E-3-71
upper Susitna River, 1981.
Burbot catch per trotline day fished E-3-73
and by tributary, upper Susitna River,
1981.
Age, length and sex frequency composition E-3-74
of burbot, upper Susitna River basin,
1981.
Burbot tagged by month and tributary, E-3-78
upper Stsitna River, 1981.
Ro,md whitefish catch per gillnet day, E-3-82
upper Susitna River, 1981.
· Ro1md whitefish age-length-sex frequency E-3-84
co11position, upper Susitna River, 1981.
vii
Table E.3.3.3
Table E.3.4.1
. Table E.3.4.2
Table E.3.4.3
Table E.3.5.1
Table E.3.6.1
Round whitefish summary of tagging data,
upper Susitna River, 1981.
Longnose sucker catch by gillnet day and
tributary, upper Susitna River, 1981.
Longnose sucker age-length~sex frequency
composition ·at habitat location sites,
upper Susitna River, 1981.
Longnose sucker tagged by month and
tributary, upper Susitna River, 1981.
Cottid catch per minnow trap day at
fish habitat location sites on the
upper Susitna River, May to September,
1981.
Lake trout catch and. effort, upper
Susitna River basin lakes, May to
September, 1981.
viii
E-3-86
E-3-89
E-3-92
E-3-93
E-3-96
E-3-100
Plate E-2-1
. Plate E-3-1
Plate E-3-2
Plate E-3-3
LIST OF PLATES
Rafts used for transportation in the
impoundment study reach, 1981 •
High catches for angler hours fished
were recorded in Kosina Creek pools such
as the one pictured, stream mile 1 to 2.
Sampling for juvenile fish, Jay Creek
habitat location, 1981.
A large Arctic grayling with Floy anchor
tag in place, upper Susitna River, 1981 ..
ix
E-2-17
E-3-20
E-3-31
E-3-37
Appendix Table EA-1
Appendix Table EA-2
. Appendix Table EA-3
Appendix Table EA-4
Appendix Table EA-5
Appendix Table EA-6
Appendix Table EA-7
Appendix Table EA-8
LIST OF APPENDIX TABLES EA
Arctic grayling fork length comparisons by tributary
for~1ay, 1981 (95% C.I.)
Arctic grayling fork length comparisons by tributary
for June, 1981 (95% C.I.)
Arctic grayling fork length comparisons by tributary
for July.
Arctic grayling fork length comparisons by tributary
for August, 1981 (95% C~I.)
Arctic grayling fork length comparisons by tributary
for September, 1981 (95% C.I.).
Juvenile fish species captured by date, location,
and size groupings, upper Susitna River, 1981.
Model of upper .Susitna River population estimation
for Arctic grayling.
Arctic
tagging
grayling recaptured within tributary
by tributary of tagging and month
recapture, upper Susitna River, June to September,
X
of
of
SUMMARY
1. Upper Susitna River studies had as its objectives for 1981 operations:
Determine the seasonal distribution and relative abundance of selected
resident and juvenile anadromous fish populations within the study area.
Identify spawning and rearing locations of the resident species and the
rearing locations of juvenile anadromous species to estimate their
comparative importance.
Record descriptive information on captured fish (species, location of
capture site, age class), and discuss seasonal migration patterns ·of
selected adult resident species .
. 2. A four man crew was utilized in the upper Susitna River basin fis~eries
studies. Transportation into the study area was provided by fixed wing
aircraft, after which both helicopter and river rafts were used to reach
the various habitat locations. On site operations began May 20 and
extended through September 28.
3. For each stream habitat location within the confluence portion of site
.number 1, the following sampling gear was fished for two consecutive time
periods ranging from 18 to 24 hours: five minnow traps, two trotlines,
and one 30 foot variable mesh gillnet (panels of 1-1/2 to 2-1/2 inch bar
mesh). At sites 1 through 5, hook and line, beach seines and backpack
E-1-1
electrofishing units were used to collect fish as stream conditions
permitted. Selective fish habitat sites were sampled exclusively by rod
and reel with the exception of Sally Lake where gillnets and minnow traps
were alsq used.
4. Arctic grayling, burbot, round whitefish, and longnose suckers over
150 mm in length and in good condition after capture were tagged using
Floy anchor tags inserted well above the lateral line just posterior of
the dorsal fin.
5. Ei~ht fish species were taken during 1981 sampling and included: Arctic
grayling, burbot, cottid, Dolly Varden, Lake trout, longnose sucker,
humpback whitefish, and round whitefish. No juvenile or adult salmon
were either captured or observed iri the upper river.
6. During upper Susitna River studies of 1981, a total of 3,303 Arctic
grayling Thymallus arcticus greater than 135 mm of length were captured.
Adult grayling were captured from all habitat location sites in the eight
tributaries. Two hundred three angler hours fished within habitat
locations produced 1,326 grayling for a catch per unit effort of 6.4.
Highly significant differences were found in catch per unit effort by
tributary of sampling.
Young of the year and juvenile grayling were captured through the summer
in shallow, clearwater sloughs along the main Susitna and from quiet
pools and side channels off Goose and Jay creeks.
E-1-2
The total number of grayling tagged during the season was 2,511. Recap-
tures amounted to 11% (268) of the total tagged.
Schnabel population estimates, based on the tag and recapture program,
were generated by tributary and for the upper Susitna as a whole. The
estimate for the upper Susitna was 10,279 (95% confidence limits 9,194 -
11,654). This population level would give an average of approximately
501 adult grayling per clearwater tributary mile or 121 per river mile
including the main Susitna, to. be inundated. Tagged grayling demon-
st.rated ·interchange between tributaries using the main Susitna as a
migratory corridor.
Age determination was made by scales taken from 381 grayling collected
from the eight tributaries throughout the season. Fish age IV averaged
270 mm, age V averaged 303 mm, age VI averaged 329 mm and age VII
averaged 352 mm (all length fork length).
Observations during May of 1981 indicate that grayling spawning takes in
late April or early May under the ice or in early May flood waters
immediately following ice out.
7. Eighty-eight adult burbot, Lota lota, were captured in the upper Susitna
River. Catches were distributed over all tributary habitat 1 ocati ons.
The catch per trotline day fished averaged 0.68 for all locations. One
juvenile burbot of 15 mm FL was captured from lower Jay Creek on June 20.
E-1-3
The majority of the burbot aged were in the age classes IV, V, and VI.
The mean lengths of burbot for these respective age classes were 357 mm,
382 mm, and 409 mm.
8 .. Thirty three adult round whitefish Prosopium cylindraceum were captured
during 43 gillnet days fished at upper Susitna habitat locations. Six
habitat location sites were productive for this species. Fish aged were
VI to.VIII with age VII fish the most numerous.
9. One hundred forty four longnose sucker, Catostomus catostomus, were
captured during 43 gillnet days fished at upper Susitna habitat
locations. Six of the eight habitat locations fished produced this
species. Ninety longnose suckers were used for age determinations, Age
VII suckers averaged 355 mm while Age VIII averaged 381 mm and Jl.ge IX
averaged 405 mm.
10. Thirty eight slimy sculpin, Cottus cognatus, were collected at seven of·
eight habitat locations ·in the upper Susitna River.
11. Lake trout, Salvelinus namaycush,. were taken from Sally and Deadman
I akes. No 1 ake trout were captured . from the Sus itna River or from the
eight tributary stream habitat locations.
12. ·During 1981 operations, minnow traps produced minimal catches considering
man hours expended in their use. The general use of this gear shall be
discontinued in future upper main river and tributary sampling.
E-1-4
2. INTRODUCTION
The upper Susitna River basin is drained by the Susitna River from the pro-
posed Devil Canyon dam site, River Mile (RM) 152, to the Susitna Glaciers
(Figure E.2.1). the study area for summer 1981 field work was limited to
those reaches of eight streams tributary to the upper Susitna River, beginning
with fog Creek (R.M. 173.9) and extending to the Oshetna River (R.M. 226.9),
which will be permanently or seasonally inundated by the proposed Susitna dam
impoundments (Figures E.2.2-E.2.9). The Denali Highway currently provides
access to a portion of the upper Susitna Basin; however, the study area lies
in a true wi 1 derness setting where access is 1 imited to foot trave 1 , 1 i ght
aircraft, boat, snowmachine or helicopter.
Prior to initiation of the 1981 Susitna Hydroelectric Aquatic Studies,
fisheries data pertaining to species composition, seasonal distribution·,
relative abundance, migrational movements and aspects of species life history
. '
within the upper Susitna River basin consisted of various preliminary environ~
mental assessments (Andrews 1952, 1954, 1958, 1960, 1961, 1965; Riis and
Friese 1978; Williams 1978). These studies define species composition. and
highlight habitat locations and issues of particular concern, but because of
their limited scope were unable to quantitatively examine resident fish
populations and their relationship to the aquatic environments.
2.1 ·Objectives
Determ·lne the seasonal distribution and relative· abundance of selected resi-
dent and juvenile anadromous fish populations within the study area.
fTl
I
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Figu r e £.2.1 . Map of the upper
Dena li Hi gl11vay.
from
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n
0)>
r m
l / I / L/
Figure E.2·2 · Map of Fog Creek.
E-2-3
1----:-/-:::,-:--.,...,_-.___-'-----·-', -----,-------·--·--~-------,---
/ ·----I
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Fi~ure £.2.3. Map of Tsusena Creek.
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\
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I mile
E-2-4
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\ ("-
", "" \ """·· r-\ '~ ~)
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SCALE
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Fioure E. 2. 4. Map of Deadman Creek.
__ ,
1mile
E-2-5
SCALE
0
(
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( J .... ,/ ' y //
; I I !}_)
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,-....... .i ,...., "\__. ·-'
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1 mile SCALE
\ .. ---~::c:::::::10 ====~ -----
E-2-6
r-...-1:" ' r ........ ,...,,
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Fi9ure E.2.6. Map of Kosina Creek.
l~..r--.......
C'rl"'"' -..... ,..,"\...-r
I ._-../
J
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1 mile
E-2-7
SCALE
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SCALE
Wtlo/] /, ~= L) ' =====::::3
Figure E.2.7. Map of Jay Creek.
E-2-8
~·--------------------.:......... __ _
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Fi~ure E.2.8. Map of Goose Creek.
SCALE
1 mHe 0
E-2-9
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Fic:lUre £.2. 9.
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Map of Oshetna R' lVer.
/
Q 1mile
I
E-2-10
SCALE
0
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Task 2.1
Task 2.2
Identify spawning and rearing locations of the resident species
and the rearing locations of juvenile anadromous species to
estimate their comparative importance.
Record descriptive information on captured fish (species,
location of capture site, age class), and discuss seasonal
migration patterns of selected adult resident species.
2.2 Methods
Based on preliminary reconnaissance of the upper Susitna River basin, eight
I
major tributaries were selected for in-depth indigenous fisheries and aquatic
habitat studies. These streams are characterized by steep gradients, clear,
cold, rapid flowing water, variously sized gravel substrates, and extreme
fluctuations in discharge and turbidity.
Substantial resident fish populations are present in all eight tributary study
streams. These streams, with their locations, proposed impoundment ele-
vations, and miles which may be inundated, are listed in Table E.2.1. For the
purpose of this ~tudy, the first mile of these streams from their confluence
with the Susitna ~iver are designated as the habitat locations.
A typical tributary stream habitat location with .sampling sites defined is
shown in Figure E.2.10. Preliminary ground and aerial surveys conducted in
May 1981 indicated that pri~e represehtative fish habitat occurs in the lower
one mile reach of each ~ributary stream. A sampling scheme was devised
E-2-11
Table E.2.1 Tributary habitat location streams and their proposed
impoundment elevations, river miles, and elevation at
their mouth.
Operational Level
Susitna Proposed Elevation
River Mile Impoundment at
Tributary (above mouth} ·Elevation (Ft.) ~1outh
Fog 173.9 1477 1380
Tsusena 178.9 1477 1460
Deadman 183.4 2185 1510
Watana 190.4 2185 1590
Kosina 202.4 2185 1690
Say 203.9 2185 1710
Goose 224.9 2185 2030
Oshetna 226.9 2185 2050
Upper Susitna River tributary tagging locations (study sites)
in river miles above confluence with the Susitna River.
Habitat Location Feet Upstream Average Feet
Site Number From Confluence Above Mouth
1 0-500 250
2 1,000-1,500 1,250
3 2,000-2,500 2,250
4 2,500-3,000 2,750
5 4,000-4,500 4,250
E-2-12
l'liles in
Impoundment
0.7
Mouth Only
2.3
9.0
4.0
3.0
1.5
2.0
~1il es
0.0
0.2
0.4
0.5
0.8
I
I
/
I
/
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Xn-Sampling Site
----Proposed Impoundment Elevation
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Fiqure E.2.10. A typical habitat location in the upper Susitna River basin
with samplino sites defined.
E-2-13
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involving systematic sampling of the first mile of the tributary. Five
sampling sites, each 500 feet in length, separated from each other by a 500
foot interval, were marked off. The first 500 feet of the tributary upstream
from its confluence with the Susitna was designated sampling site No. 1. Site
No. 1 included the clear ta i lwaters, normally extending 300 ·feet downstream
along the Susitna from the tributary confluence, and the turbid waters for 300
feet upstream. Table E.2.2 lists the tributary habitat locations with habitat
sites and geographic location.
Selected fish habitat sites were chosen fro~ Site No. 5 upstream to the high
flood level of the proposed impoundment. Additional selected fish habitat
sites were chosen from the 500 foot interval between study sites and form
reaches of Kosina and Deadman creeks above the proposed impoundment elevation.
The largest lake located within the proposed impoundment, known locally as
Sally Lake, was also designated a selected, fish habitat site. Criteria used
for the selection of selected fish habitat sites included uniqueness, visual
sightings of fish, large pools, cut banks, and relatively low water
velocities.
Study sites were measured with a 100 foot length of rope and boundaries were
blazed, spray painted and flagged on trees, rocks or other permanent· 1 and
markers.
Although efforts to systematically sample each habitat location were made, it
was not always possible because of geographical and impoundment 1 imi ts and
legal ramifications. Steep canyon walls on Deadman Creek limited access to
habitat location sites 1 and 2 only. Tsusena Creek, located at the extreme
E-2-14
Table E.2.2. Upper Susitna River tributary habitat location sites
and geographic locations.
HABITAT LOCATION SITE DESCRIPTION RM GEOGRAPHIC LOCATION
Fog Creek 1 Confluence 173.9 31N 04E 16DBB
2 31N 04E 16DBB
3IN 04E 16DAD
Tsusena Creek 1 Confluence 178.9 32N 04E 36ADB
Deadman Creek 1 Confluence 183.4 32N 05E 26CDB
2 32N 05E 26CAA
Watana Creek 1 Confluence 190.4 32N 06E 25CCA
2 32N 06E 25CAB
3 32N 06E 25BDC
4 32N 06E 25ACB
5 32N 06E 25ABC
Kosina Creek 1 Confluence 202.4 3iN OBE 15BAB
2 31N OBE 15BAC
3 31N OBE 15BCA
4 31N 08E 15CBA
5 31N OBE 15CCA
Jay Creek 1 Confluence 203.9 31N 08E 13BCC
2 JIN 08E 13BCA
3 31N OBE 13BAC
4 31N 08E 13B/\A
5 31N OBE 12DCB
Goose Creek 1 Confluence 224.9 30N liE 320BC
2 30N liE 32COA
3 JON liE 32CDC
4 29N liE 05BBC
5 29N 11 E 05BCB
Oshetna River 1 Confluence 226.9 JON liE 34CCD
2 29N liE OJBAB
3 29N liE 03BAC,
4 29N liE 03ACB
5 29N liE 03ACC
E-2-15
upstream end of the proposed Devil Canyon dam impoundment, wi 11 not be i nun-
dated upstream of it • s confluence with the Susitna . River so only habitat
location number 1 was sampled. Fog Creek study sites upstream of number 3
fell within private Native Corporation lands and pennission to trespass was
denied.
Sampling in the upper Susitna basin was conducted on a monthly basis with each
of the eight habitat locations sampled for two days each month. Selected fish
habitat sites were sampled as work load and transportation availability
permitted.
For each stream habitat location within the confluence portion of site number
1. the. following sampling gear was fished for two consecutive time periods
ranging from 18 to 24 hours: five minnow traps. two trotl ines. and one 30
foot variable mesh gillnet (panels of 1-1/2 to 2-l/2 inch bar mesh). At sites
1 through 5, hook and line, beach seines and backpack electrofishing units
were used to collect fish as stream conditions permitted. Selective fish
habitat sites were sampled exclusively by rod and reel with the exception of
Sally Lake where gillnets and minnow traps were also used.
A four man crew was utilized in the upper Susitna River basin fisheries
studies. Transportation into the study area was provided by ·fixed-wing
aircraft. after wh~ch both helicopter and river rafts (Plate £.2.1) were used
to reach the various habitat locations. Sampling trips lasted from 14 to 18
days during which time the crew established spike camps at each of the habitat
locations. Radio communications were accomplished with a Spilsbury Tindall
E-2-16
Plate E.2.1. Rafts used for transportation in the Impoundment study reach.
SX-11 mobile unit which a 11 owed for a phone patch through an Anchorage based
dispatch system.
Resident and Juvenile Anadromous field forms for collecting catch, effort and
biological data are presented as Figures E.2.11, E.2.12, and E.2.13. The
location, date, number of units of each specific sampling gear type, duration
of effort, and catch by species was recorded for each day sampling was con-
ducted. The biological data form was used for the collection of length, age,
and sex data, where applicable, and provided a cross reference for fish scales
taken and subsequently stored in scale envelopes. A more detailed discussion
of methodology of biological data collection and sampling techniques is
available in the procedures manual.
Tagging and recapture methods were used to study the seasonal migrations of
selected resident fish species in the upper Susitna basin. All Arctic gray-
ling, burbot, round whitefish, and longnose suckers over 200 mm in length and
in good condition· after capture were tagged using Fl oy anchor tags inserted
well above the lateral line just posterior of the dorsal fin.
The· data collected at the time of tagging included: tag number, date,
species, fork length, method of capture and location. Information recorded at
the time of tagged fish recovery included: tag number, date, method of
capture, location recaptured and the fate. of the fish. The standard tag and
recaptured form is presented in Figure E.2.14.
E-2-18
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1.0
FUa No. 03-81-7.10-2.74 Page 1 of __
SUSITNA HYDRO RESIDENT & JUVENILE ANADRO.MOUS STUDY
MOBilE GEAR CATCH OAT A RJ 81-04
Habitat Sampling Rlwer
Location Site Mile ___ _ _. _ __/ __ _} _ _) __ _/-
DATE: Clear Set ______ Clear Pulled ______ Collactor(e) _____________________ _
... "i I "'//i~ T I M E CATCH-SPECIES CODE NO. ~.t; ;-.; -R E M A R K s <lu ••• pulled ........ /;I •
--
--
--
--
--· -~---· -----------~---·~---
-·-
• total lima lor beec It aalna haul. electroahock and hook & line
GEAR TYP£ COO£ SPECIES CODE . BAIT TYPE CODE
drill glllnal ta burbol 680 ~whltelloh 682 artlllclal t
eleclroahocl< I chlnooll o+· · 410 lake lrout IiilO lloh 2
beach ..... :a chlnoclk 1 + 411 ..,._. . ...., .... 1120 eooe :a
hook & ... • chum aalmon 4150 ........ -.... 440 other 4
other (a~r) 0 coho Ot 430 ................ 1141
coho 1+ 431 r--•Nsh 1588
coho 2+ 432 ...alautechon 1511
coltld 810 aoclleye Ot 420
doRy varden 530 -·ye 1+ 421
grayling 610 alk:ldebeck 8110
figure E.2.11. Resident and Juvenile Anadromous study, catch and effort form, mobile gear, 1980-1981.
ITT
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Flle'No. 03-81-'"7.10-2.71 Page 1 of ___ .
. SUSITNA HYDRO RESIDENT & JUVENILE ANADROMOUS STUDY
FIXED GEAR CATCH DATA RJ 81-01
Habitat Sampling River _j _j _j _j Location---------SJie Mile _____ __ __ __ __ __ __ __ __
DATE: Gear Set------Gear Pulled ______ Collectorh) ----------------------
TIME CATCH-SPECIES CODE NO. REMARKS
oat pullad total
I 1
A'!;
I 5
~-~·-~"'
110
OEA!'I TYPE CODE
glllnel
llllnnow trap
trot Ina
bowbol oat
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10
10a
SPECIES CODE
burbot litO
clllnool! 0+ 410
cblnoal! 1+ 4 t1
ciiUID nlnoon 410
coho 0+ .CSO
coho 1+ 431
coho 2 • 432
coUld 810
dollr verden 630
orarlnQ eto
llumpbacl!
whltellah 682
lalla trout 6110
longnooo ouc:l!er 1120
pink .. lmon 440
rainbow trout 141
round whiteHall 1181
omellleulachon 6t1
oocl!eye o.. 420
oockere I+ 421
otloklabock 180
BAIT CODE
artificial I
""" 2 811111 3
other 4
(apocllr In rernarkol
Figure E. 2 .. 12. Resident and Juvenile Anadromous study, catch and effort form, fixed gear, 1980-1981.
Figure E.2.13. Resident and Juvenile Anadromous study, biological data
form, 1980-1981 .
File No. __ o.,3.,-.-e ... 1 ... -.-7 ....... 1 o-.-.-2 ..... 7 ... 2..__ Pape_of_
SUSITNA HYDRO RESIDENT & JUVENILE ANADROMOUS STUDY
BIOLOGICAL DATA RJ 81-02
Habitat
l.ocation -----
Sampling Rl¥er Site -----M .. e _____ _;;_ _ _/ _ _! __ _;_
Date(s) Collacted -----------
CoRectoria) ____________________________ __
•Qc,o. of!~ : •
1
2i
3; I
4 i
5
6 I
71
8
9 !
~0
11
~2
~3
~· ~5
rae
~7
~e
~~~
20
~1
Fz2
!Za
j2.c
[2!
IIEAR TYP! CODE
beodlootlne II
1111rbot "' tlla
"""~ ,.
••olroeliOOII z
9-1
""" & .... • mlnn-1ra11 I
1n111no tO
,..·~· ""-" <~'c.• tt~.o .. , ... ., " .. .!' •• • ... •"'«~· tlt.• 'f
.~ . ~~ ... ,.
28
27
28 ~
29
ac
!1
tJ2 l
!3
141 :
!~
at
31
31!
Bli
14-C
lt1
~~
~
~
"E
4tl
~1
•e
~~~
~c
SP!CI£8 COOl!
burloot 810 lunpbedl whlto!IU Sat
dllr>ook o+ 410 lAke trout 550
chlnoak 1+ 411 lonv"ooo oud<or 820
chlft ••lrllon 4110 pink NlrriOft 440
oahO 0+ 430 rolrobDWttoul &41
aohO 1+ d1 roundwMollloh , ..
aollo I+ dtl omeftlo•o'-511
CDftld 810 •oak•r• O+ 410
dol,. .arden 530 •oOII.,• 1 + 421
gro)lllnlr eto oticlo:le,_lllk eeo
E-2-21
m
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1\)
••o no~
File No. OS-81-7,10-2.73
SUSITNA HYDRO RESIDENT 6 JUVENILE ANADROMOUS STUDY
TAG AND RECAPTURE DATA RJ 81-03
TAGG.NG 0 A. T A RECAPTURE DATA
g••• ode dele aP~•'I•ath code _, tfabllal location dale '':.C:.':.P::2~ 'c"::&J" Habllal Location
'
SPECIES COD!& GEAR TYPE CODE RECAPTURE CODE
burbol 180 beach eelne a SY Hrdro elall I
dolly urdan 130 burbol ael to a ADFlG (other) 2
urarDn11 DtO drill glllnel h Sporl Fleherman 3
humpbaok whllellah 1182 electroshock 2
rainbow trout Ul gmne• I
round whitefish 1118 flooll & llna II
lake trout 550 minnow trap • lrot Une 10
figure E.2.14. Resident and Juvenile Anadromous study, tag and recapture form, 1980-1981.
releaeed
3.1 ARCTIC GRAYLING
3.1.1 Abstract
During upper Susitna River studies of 1981, 3,303 Arctic Grayling (Thymallus
arcticus) greater than 135 mm fork length were captured. Adult grayling were
captured from all habitat location sites sampled in eight major tributaries
including the Oshetna River~ Goose, Jay, Kosina, Watana, Deadman, Tsusena, and
Fog creeks. Highly significant differences were found in catch per unit
effort by tributary of sampling. Kosina Creek was the most productive of the
tributaries with a total habitat location site catch of 315 and a catch per
unit effort of 8.6 grayling per angler hour fished. The total catch for this
stream within the reach proposed to be impounded was 799.
Eighty-seven percent of adult grayling captured within habitat locations were
taken by hook and 1 ine; 12%. were taken by gill net. Two-hundred and three
angler hours fished at habitat locations produced 1,306 grayling for a ~atch
rate of •6.4 grayling per angler hour. Forty:-three gillnet days fished
produced 120 grayling for a catch rate of 12.7 grayling per gillnet day
fished.
Highly significant differences were found in the catch per angler hour fished
by month~ July was the most productive month with a total catch of 363 and a
catch rate of 8.1 grayling per angler hour fished. The seasonal average
·catch rate for all eight streams was 6.4 grayling per angler hour.
E-3-1
Young of the year and juvenile grayling were captured through the summer in
shallow, clearwater sloughs along the main Susitna and from quiet pools and
side channels off Goose and Jay creeks.
The total number of grayling tagged during the season was 2,511. Recaptures
amounted. to 11% (268) of the total tagged. All but 6 tagged grayling
recaptured, were recaptured by project personnel.
Schnabel population estimates, based on the tag and recapture program, were
generated by tributary and for the upper Susitna as a whole. The estimate for
the upper Susitna was 10,279 (95% confidence limits 9,194-11,654). This
population level would give an average of approximately 501 adult grayling per
clearwater tributary mile or 121 per river mile, including the main Susitna,
to .be inundated.
Tagged grayling demonstrated interchange between tributaries using the main
Susitna as a migratory corridor. Interstream movement was documented for 9%
of tagged fish recaptured. These recaptures were made at the mouth or within
a tributary other than the tributary of initial tag and release.
Age determination was made by scales taken from 381 grayling collected from
the eight tributaries throughout the season. Fish age IV averaged 270 mm
(range 210-313), age V averaged 303 mm {range 260-335), age VI averaged 329 mm
(range 275-385} and age Vll averaged 352 mm {range 320-395 -a 11 1 ength fork
1 ength).
E-3-2
Lengths were taken for 2,673 Arctic grayling collected from the upper Susitna
River from May through September 1981. Arctic grayling from 260 mm to 340 mm,
age V, occurred most frequently in the catches. The mean fork length of
Arctic grayling captured by hook and line and gillnet·was 304 mm and the range
was from 235 mm to 420 mm. Significant differences were found for fish
lengths between streams.
3.1.2 Introduction
The distribution of the Arctic Grayling _I!l.1m~_!_!_':l2_ ~!'.f_1j_c~ (Pallas) is
holarctic, encompassing much of northwestern North American and northeast~rn
Siberia (Scott and Crossman, 1972). In 1\laska, native populations of Arctic
grayling are found in freshwater drainages throughout interior and Arctic
Alaska and on the Alaska Peninsula south to approximately Port Heiden (Mcle~n
and Delaney, 1978).
Adult Arctic grayling have a strikingly· large dorsal fin which is low
anteriorly and disproportionately high posteriorly. The dorsal fin has
irregular but distinct rows of dark spots and is often tinged with pink or
white on the upper edge. The tail, pectoral and anal fins are usually a
dusky, yellowish-~reen; the pelvics commonly have lengthwise stripes of pink
and black which can be more or less obscure. The mouth is small and there are
small teeth on both Jaws. Juveniles are distinguished by the presence of
narrow, vertically elongated parr .marks.
Grayling are found in clear, cold, streams and lakes (Scott and Crossman,
1973). Silt laden glacial systems, such as the Susitna River, are believed to·
E-3-3
support fewer grayling throughout their life histories; however, such systems
are believed to provide essential migratory pathways and overwintering habitat
(ADF&G et al., 1978). Grayling inhabit nearly all tributaries of the Susitna
River; the greatest numbers are found in clearwater tributary systems such as
the Deshka River, Indian River, Portage Creek, Ko-si na Creek and the Oshetna
River.
Arctic grayling reach sexual maturity in Alaska at Age II to VII (Mclean and
Delaney, 1978) and are capable of spa.wning several times during their life.
The Arcti.c grayling is characterized by Reed (1964) as a migratory species.
During spring break up, from April to June, adults migrate from ice-covered
lakes and large rivers, such as the Susitna, into clear gravel-bottomed
tributaries to spawn (Morrow, 1980). Pearse (1974) found Arctic grayling less
than 200 mm fork length entering the Delta clearwater rivers in early April.
After spawning, the adults move away from the spawning areas into pools where
they spend the rest of the summer feeding on aquatic and terrestrial insects·
taken from the drift (Vascotte, 1970). A downstream migration occurs in late
August and mid-September back into overwintering areas in large rivers and
deep lakes (Pearse, 1974).
The Arctic grayling is described by McClane (1965) as a fish highly prized for
its beauty. The Arctic grayling is one of the most important sport fishes of
Alaska and northern Canada .. The grayling readily takes dry flies and is a
favorite of the fly fisherman and are also taken on spi.nning tackle. Grayling
E-3-4
are excellent food fish and may be prepared in a variety of ways. Grayling
are also utilized by subsistence fisherman in some areas for dog food and
personal consumption.
3 .1. 3 Methods
Arctic grayling were collected at upper Susitna River habitat locations from
Fog Creek (R.M. 173.9) to the Oshetna River (R.M. 226.9) from May to September
1981. Additional grayling were captured at selected fish habitat sites
including the Tyone River and both Sally and Deadman Lakes.
Five types of sampling gear, variable mesh (1-1/2 to 2-1/2 inch bar mesh)
gillnets, hook and line, beach seines, electrofishing and minnow traps were
utilized to capture Arctic grayling. Fork length in millimeters (mm) of all
fish collected was recorded and scales were taken from a representative
subsample for age determination. Fish which were killed by collection gear
were autopsied to determine sex composition and maturity.
Viable fish were tagged with Floy anchor tags and released.
3.1.4 Results and Discussion
3.1.4.1 Distribution and Relative Abundance
Three thousand three-hundred and thirteen adult Arctic grayling over 135 mm
fork length were captured during 1981 studies of the upper Susitna River.
Table E.3.1.1 lists grayling catch by tributary and month. This total
E-3-5
Table E.3.1.1. Arctic grayling total catch by tributary by month
upper Susitna River, 1981.
TRIBUTARY MAY JUNE JULY AUGUST SEPTEMBER -
Fog Creek 30 17 38 5 5
Tsusena Creek 35 75 133 53 9
Deadman Creek 53 86 110 23 15
~Jatana Creek 4 52 18 184 55
Kosina Creek 139 263 238 73 187
Jay Creek 84 181 74 21 68
Goose Creek 128 163 82 41 13
Oshetna River 24 93 157 73 167
Sally Lake 13 4 26
Deadman Lake 1
TOTAL 510 934 850 499 520
E-3-6
TOTAL --
95
305
287 .
313
900
428
427
514
43
1
3,313.
includes all catches by all gear from sampling within stream reaches proposed
to be inundated and catches from limited hook and line sampling conducted
upstream of proposed impoundment elevations.
The total catch to from within stream reaches proposed to be inundated was
2,667. With a total of 344 angler hours fished the catch per unit effort was
7.7 for angl~r hour of fishi~g.
Arctic grayling were collected at 100% of the habitat locations in the upper
Susitna River during the 1981 season. Grayling catches and catch rates are
listed in Tables E.3.1.2 and E.3.1.3 by tributary habitat location, selected
fish habitat site and gear type. This data is illustrated in Figures E.3.1.1
and E.3.1.2. The total catch for habitat location sites was 1,501 of which
eighty-seven percent were taken by hook and 1 ine and 12.7 percent by gill net.
Gillnets accounted for a substantial portion of catches in Watana and Jay
creeks. Two hundred and three angler hours fished at habitat locations
produced 1,306 grayling for a catch rate of 6.4 (Table E.3.1.4). Forty-three
gillnet days fished produced 190 grayling for a catch rate of 12.7 grayling
per gillnet day fished.
Chi square tests were run to determine significant differences in actual hook
and 1 ine catch rates between tributary habitat locations and also between
habitat locations and selected fish habitat sites within each individua)
tributary. These tests utilize hook and line catch and effort data for
habitat locations and selected fish habitat sites by tributary by month,
illust~ated in Tables E.3.1.2, E.3.1.3, E.3.1.4, E.3.1.5, E.3.1.6 and E.3.1.7.
E-3-7
Table E.3.1.2. Arctic grayling catch and effort by gear type, upper Susitna
River habitat location sites~ 1981.
Minnow
Tributary Hook & Line Gi 11 net Trap Trotline
Catch/hour Catch/day Catch/day Catch/day
Fog Creek No. Caught 51 0 0 0 51
Effort 12.4 4 36 12
CPUE 4.0 0 0 0
Tsusena Creek No. Caught 135 2 0 0 137
Effort 22.6 4 40 5
CPUE 6.0 0.5 0 0
Deadman Creek No. Caught 153 0 0 0 153
Effort 23.6 3 29 10
CPUE 6.5 0 0 0
Watana Creek No. Caught 59 31 0 1 92
Effort 18.1 6 45 22
CPUE 3.3 5.2 0 0.0
Kosina Creek No. Caught 315 30 2 0 347
Effort 36.4 8 50 20
CPUE 8.6 3.75 0.0 0
' Jay Creek No. Caught 176 110 2 0 288
Effort 23.3 8 50 28
CPUE 7.5 13.7 0.0 0
Goose Creek No. Caught 267 11 0 0 278
Effort 42.9 6 50 20
CPUE 6.2 L8 0 0
c'
Oshetna River c No. Caught 150 6 1 0 157
Effort 23.2 4 50 12
CPUE 6.4 1.5 0.0 0
Total No .. Caught 1,306 190 5 1 1 ,501
Effort 202.7 43 348 129
· CPUE 6.4 442 0.0
X Total 87.0 12.7 0.3 0 100
a Additional juvenile fish specimens were taken by various methods including
seine, electrofish. and dipping (Appendix Table 6).
E-3-8
Table E.3.1.3 Arctic grayling hook and line catch and effort for
selected fish habitat sites by tributary.
Tributar_y
Fog Total Catch
Man Hours
CPUE
Tsusena Total Catch
Man Hours
CPUE
Deadman Total Catch
Man Hours
CPUE
Wat,ana Total Catch
Man Hours
CPUE
Kosina Total Catch
Man Hours
CPUE
Jay Total Catch
Man Hours
CPUE
Goose Total Catch
Man Hours
CPUE
Oshetna Total Catch
Man Hours
CPUE
Total Total Catch
Man Hours
CPLIE
* Proposed impoundment elevation.
a not fished.
1981
E-3-g
Selected Fish Habitat Sites
Above Mile
1st Mile 1 to PIE*
21 a
4.2
5.0
a
37' a
5.1
7.3
21 186
4.5 19.6
5.2 9.5
57 427
11.5 38.5
4.9 11.1
60 81
6.5 7.4
9.5 10.9
64 51
8.9 6.2
7.5 8.3
59 297
7.91 22.1
7.46 14.0
.. 319 1042
47.5 93.7
6.7 11.1
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I
TRIB CPUE TRIB CPUE
20 20
OSHETNA WATANA
o~-ll~
20 20l
GOOSE DEADMAN _
o~-trTr'r--~ ~ o~ -JJ ~-miG SEr-
20 20
JAY TSUSENR
O _...___~MA=-:!Y -JJ-ll_gG Qp-O _.__~of---+.U..,.,..,N JJ-~G-w--
20
KOSINF\o
20
FOG
Figure E.).l.l. Arctic grayling hook and line catch per hour. Upper Susitna River habitat
location sites by month, 1981.
.I
fT1
I
w
I ...... .......
TRIB CPUE
20
OSHETNR
GOOSE 0 ----1---..,-MAY-D Il-®C--SEP-
o-LMRY DN ful-RuG &lp--
20-l
KOSINA .
o-L_MRY
TRIB CPUE
20
WRTRNR
Figure E.3.1.2. Arctic grayling hook and line catch per hour by month for selected fish habitat
sites upstre~n of stream mile one to the proposed impoundment elevation, 1981.
Table E.3.1.4. Arctic grayling hook and line catch and effort for habitat
location sites by tributary and month, 1981.
Tributary
Habitat Location Ma~ June Jul,l August Se~t. Total
Fog Catch Total 14 17 11 4 5 51
Man Hours 1.8 3.9 2.6 1.8 2.5 12.5
CPUE 8.0 4.4 4.3 2.3 2.0 4.1
Tsusena Catch Total 23 19 74 18 1 135
Man Hours 5.0 3.4 8.3 5.5 0.5 22.6
CPLIE. 4.6 5.6 8.9 3.3 2.0 6.0
Deadman Catch Total 53 69 27 4 0 153
Man Hours 7.5 9.0 3. 5 2.2 1.4 23.6
CPUE 7.1 7.7 7.7 1.8 0 6.5
Watana Catch Total 1 29 14 5 10 59
Man Hours 3.3 5.4 4.3 2.0 3.1 18.1
CPUE 0.3 5.4 3.3 2.5 3.3 3.3
Kosi na Catch Total 119 79 87 17 13 315
Man Hours 16.6 7.3 6.8 3.0 2.8 36.5
CPUE 7.2 10.8 12.8 5.7 4.6 8.6
Jay Catch Total 3 49 64 13 47 176
Man Hours 2.4 5.4 7.3 2.9 5.5 23.4
CPUE 1.3 9.1 8.8 4.6 8.6 7.5
Goose Catch Total 121 76 36 32 2 267 ..
Man Hours 16.3 12.3 4.5 7.4 2.4 42.9
CPUE 7.4 6.2 8.0 4.3 0.8 6.2
Oshetna Catch Total 4 43 50 46 7 150
Man Hours 2.2 4.8 7.7 5.1 3.4 23.2
CPUE 1.8 9. 1 6.5 9.0 2.1 6.5
TOTAL Catch Total 338 381 363 134 85 1,306
Man Hours 55.1 51.3 45.0 29.9 21.6 202.8
CPUE 6.1 7.4 8.1 4.5 4.0 6.4
Man
E-3-12
Tahle E.3.1.5. Arctic graylin9 hook and line catch and effort for habitat
location site (1) by tributary and month, 1981.
Tributary
Habitat location Ma~ June Jul~ August SeEt.
Fog Catch Total 14 13 3 3 5
Man Hours 1.2 3.1 1.3 0.9 2.5
CPUE 11.2 4.3 2.4 3.2 2.0
Tsusena Catch Total 23 19 14 18 1
Man Hours 5.0 3.4 8.3 5.5 0.5
CPUE 4.6 5.6 9.0 3.3 2.0
Deadman Catch Total 38 52 7 3 0
Man Hours 6.0 7.0 1.5 1.4 1.1
CPUE 6.3 7.4 4.7 2.1 0.0
Watana Catch Total 0 8 1 2 10
Man Hours 2.0 2.0 1.5 0.9 2.8
CPUE 0.0 4.0 0.7 2.3 3.6
Kosina Catch Total 30 38 79 15 11
Man Hours 7.7 3.6 5.9 2.5 1.9
CPUE 3.9 10.6 13.4 6.0 5. a
Jay Catch Total 3 23 50 10 46
Man Hours 2.0 2.5 5.1 2.0 4.4
CPUE 1.5 9.2 9.9 5.0 10.5
Goose Catch Total 121 34 20 27 1
Man Hours 15.0 6.5 1.6 5.4 0.3
CPUE 8.1 5.2 12.7 5.0 4.0
Oshetna Catch Total 0 3 9 8 1
Man Hours 1.0 1.0 1.0 1.0 0.8
CPUE 0.0 3.0 9.4 8.0 1.3
E-3-13
Table E.3.1.6. Arctic grayling hook and line catch and effort for selected
fish habitat sites above mile 1 to PEl by tributary and month,
1981.
Tributary
Habitat Location May June July August Sept.
Fog Catch Total
Man Hours
CPUE
Tsusena Catch Total
Han Hours
CPUE
Deadman Catch Total
Man Hours
CPUE
Watana Catch Total 2 167 17
Man Hours 0.5 16.1 3.0
CPUE 4.0 10.4 5.7
Kosina Catch Total 142 92 50 143
~1an Hours 12.9 9.0 4.4 12.2
CPUE 11.0 10.2 11.5 11.7
Jay Catch Total 75 3 3
Man Hours 6.2 0.6 0.6
CPUE 12.0 . 5.2 5.2
Goose Catch Total 0 9 36 4 2
t>'lan Hours 0.3 0.8 3.0 1.2 0.8
CPUE 0.0 11.5 12.2 3.2 2.4
'
Oshetna Catch Total 3 33 93 8 160
Man Hours 0.5 4.5 7.0 0.8 9.3
CPUE 6.0 7.3 13.3 10.7 17.2
E-3-14
Table E.3.1.7.
Tributary
Arctic grayling hook and line catch and effort by tributary
to be impounded for stream reach and month. 1981.
Habitat Location f.'lay June July August Sept.
Fog Catch Total 22 17 23 5 5
Man Hours 3.3 4.4 3.4 3.1 2.5
CPUE 6.8 3.9 6.7 1.6 2.0
Tsusena Catch Total 23 19 74 18 1
Man Hours 5.0 3.4 8.3 5.5 0.5
CPUE 4.6 5.6 9.0 3.3 2.0
Deadman Catch Total 53 86 42 6 3
Man Hours 7.5 10.5 5.8 2.5 2.3
CPUE 7.1 8.2 7.2 2.4 1.3
Watana Catch Total 1 49 16 172 28
Man Hours 3.3 8.1 5.3 18.4 6.6
CPUE 0.3 6.1 3.0 9.3 4.2
Kosina Catch Total 136 246 143 67 187
Man Hours 18.9 56.5 17.7 7.5 15.8
CPUE 7.2 9.3 10.9 8.9 11.8
Jay Catch Total 3 178 70 16 50
Man Hours 5.4 16.2 8. 7 3.6 6.3
CPU£ 1.3 11.0 8.0 4.4 8.0
Goose Catch Total 121 136 82 37 6
t~an Hours 16.2 18.3 7.8 10.0 4.8
CPUE 7.3 7.4 10.6 3.7 1.2
Oshetna Catch Tota 1 19 92 155 72 167
f1an Hours 4.2 10.8 16.6 7.7 13.8
CPU£ 4.5 8.5 9.4 9.4 12.1
E-3-15
In Table E.3.1.8 actual versus expected hook and line catch based on effort
expended for the habitat locations is compared. A highly significant dif-
ference in catch rate is found in the comparison. Kosina Creek with an
average actual catch rate of 8.6 grayling per hour and Jay Creek with 7.5
grayling per hour both had higher actual catches than were expected while both
Watana and Fog Creek catches were lower than expected.
Actual versus expected catches were compared between habitat locations and the
selected fish habitat sites within the first mile of each tributary (Table
E.3.1.9). Kosina Creek habitat location sites with a catch rate of 8.6
grayling per angler hour were found to have signifitantly higher catches than
the selected fish habitat sites located within the first stream mile (5.0 per
hour). This was the only tributary for which a difference was identified.
Actual versus expected catches for habitat location sites were compared to the
selected fish habitat sites upstream from mile one to the proposed impoundment
elevation for each tributary (Table E.3.1.10). The upstream selected fish
habitat sites from Kosina, Watana, and Jay creeks and the Oshetna River proved
more productive than the respective habitat location sites. Plate E.3.1 shows
one of the very productive Kosina Creek pools located between stream mile 1
and 2 which was sampled by hook and line. Goose Creek selected fish habitat
sites catch rates were similar to the habitat location catch rates. Tribu-
taries not included in this test and rea$ons for their exclusion are: Fog
Creek, access to the stream beyond one mile upstream from the mouth was denied
by private landowners; Deadman Creek, waterfalls impassable to fish are
located one-half mile upstream from the confluence; Tsusena Creek, only" th.e ·
mouth of the stream is proposed to be inundated.
E-3-16
Tributary_
Fog
Tsusena
Deadman
Watana
Kosina
Jay
Goose
Oshetna
Total
Table E.3.1.8 Arctic Grayling actual versus
expected hook and line catches for habitat locations
Actua 1" Catch Ex~ected Catch
51 81
135 146
153 152
59 116
315 235
176 . 151
267 276
150 149
1,306 1,306
Chi Square Value = 71.5b with 7df
a Expected catch ~ased on man hours of effort exerted (See Table 4).
b Highly significant differences at 99% level.
E-3-17
Difference
-30
-11
+1
-57
80
+25
-9
+1
0
Table E.3.1.9. Arctic Grayling actual versus expected hook and line catches
compared for tributary study sites 1-5 and tribu£ary habitat locations
1-5, May to September, 1981
Study Sites Habitat Locations
Actual Expected Actual Expected Valu~
Tributart Catch Catch Catch Catch ~
Fogb 51 54 21 18 0.67
Tsusenac
Deadmand 153 156 37 34 0.32
Watana 59 65 21 15 2.95
Kosina 335 293 57 99 15.10e
Jay 176 185 60 51 .2.0
Goose 267 275 64 54 2.13
Oshetna 150 156 59 53 0.91
a. Expected catches based on catch per hour of combined study site and habitat
location sampling.
b For Fog comparison is for study sites 1-3 and habitat loca~ions 1 and 2.
c For Tsusena only study site 1 was fished. No comparison was applicable.
d For Deadman only study sites 1 and 2 were fished.
e Significant value.
E-3-18
Table E.3.1.10. Arctic Grayling actual versus expected hook and line catches
compared for tributary study sites 1-5 and upstream selec£ed habitat
locations within the proposed impoundment, 1981
StUd,l Sites 1-5 Tributar~ U~stream Chi Square
Actual Expected Actual Expected Value
Tributary Catch Catch Catch Catch ( 1df) --
Watana 59 116 186 128 54.30b
Kosina 335 361 427 381 6.4b
Jay 176 195 81 62 7.67b
Goose 267 278 51 40 3.47
Oshetna 150 229 297 218 44.47b
a Tributaries not included were sampled for fewer than 5 study sites.
b Chi Square Value of 6.64 is highly significant. ·
E-3-19
Plate E.3.1. High catches for angler hour fished were recorded in Kosina Creek pools such as
the one pictured, Stream mile 1 to 2.
The actual versus expected Arctic grayling eaten for tributary habitat loca-
tions was also compared by month {Table E.3.1.11). June and July had catches
significantly higher than expected whi 1 e August and September catches were
lower than ~xpected. The actual catch made during May was similar to what was
expected. This test indicates that the catch rate for grayling varies by
month and that the highest success rate was recorded in June and July.
An· overall average of 6.4 grayling per hour was recorded for the tributary
habitat location sites in· the Upper Susitna River during 1981 sampling.
Kosina Creek had the highest average cat~h rate at 8.6 grayling per hour while
Watana was low with 3.3. The grayling catch rate observed in the Chena River,
a heavily fished stream near Fairbanks, Alaska, has varied from 0.6 to 0.8
grayling per hour in recent years (Hallberg, 1981). Grayling catch rat'es' of
up to 4.0 fish per hour have been recorded at the Jims River, a lightly
exploited stream along the Alaska Pipeline (Hallberg, pt>rsonal communication).
3.1.4.2 Age, Length and Sex Composition
Three hundred eighty-one upper Susitna River Arctic grayling taken from hook
and line, gillnet, and dipnet catches were aged using scale analysis. These
fish ranged from Age I to Age VIII; age V and age VI were dominant, compri~ing
33.9% and 31.5% 6f the· sample respectively (Table E.3.1.12 and Figure
E.3.L3).
Length determination was made for a total of 2,673 Arctic grayling collected
from the upper Susitna River from May through September 1981. Figure E.3.1.4
E-3-21
Month
May
June
July
August
September
Total
Table E.3.1.11. Arctic Grayling actual versus
expected hook and line catches by month
for habitat location sites, 1981.
Actual Catch Ex~ected Catch
338 355 .
381 330
139 289
139 193
85 134
1,306 1,306
Chi Square Value = 63.8 with 4dfb
. Difference
-17
+51
+72
-54
-54
0
a Expected catch based on man hours of effort exerted (See Table 5). Average
catch per man hour for all study sites = 6.44.
b Highly significant differences at 99% level.
E-3-22
rr1
I
w
I
N
w
I
l!O--~
.! . -~ f"' I
E .....,
R I
c 30-. .;
·. :
E l
N j T
-') ') ; r .:..L --,
.ii -i ,--i t. ' Q ~ u -1
E 10--l
N _J
c i
-1
y I
--1
v ~} 1~ ~I
, I
I I I : . I i I I ' . I
II I 1
i
ow ~
0 2 l! 6
AGE IN YEARS
Q
8
r
10
1 ··-·1
12
figure E.3.l.J. Arctic grayling percent age-frequency, upper Susitna River, 1981.
I
I
I
I
I
I
I
I
I
I
I
I
I
l
!
i
J
'
illustrates the age-length distribution for upper Susitna River Arctic
grayling. Of the Arctic grayling used for age determination age IV averaged
270 mm (range 210-313), age V averaged 303 mm (range 260-335), age VI averaged
329 mm (range 275-385) and age VI I averaged 352 mm (range 320-395). Arctic
grayling from 260 mm to 340 mm occurred most frequently in the catches. The
mean fork length of Arctic grayling captured by hook and line and gillnet was
304 mm and the range was from 135 mm to 420 mm (Figure E.3.1.5). An Arctic
grayling of 410 mm FL was taken in each Tsusena, Deadman and Jay creeks during
the course of 1981 studies.
Table E.3.1.12 Arctic grayling, age-length frequency composition at habitat,.
location sites on the upper Susitna River May to September,
1981.
TOTAL NO.
OF FISH ~1EAN LENGTH RANGE OF LENGTHS % OF
AGE SAMPLED (MM) (M~1) _____ SM1PLE
0
I 1 140 0.3
II 2 138 115-160 0.5
III 13 229 200-260 3.0
IV 57 270 210-313 15.0
v 129 303 260-335 33.9
VI 120 329 275-385 31.5
VII 45 352 320-395 11.8
VIII 14 375 350-400 4.0
TOTAL 381 115-400 100
E-3-24
A v
G
L
E
rT1 N
I G w
I T N
Ul H
I
N
M
M
Figure E.3.1 A
500
400
300
200
100
0
4 6 8 10 12
AGE (YEARSl
Arctic grayling age-length relationship upper Susitna River, 1981.
lengths and mean length illustrated for each age encountered.
Range of
rn.
I w
I
N
O'l
25
20 >-u z w 15
_)
0
~
10 ~ Ct::
LL I
I ~
5
0
0 45 90 1 35 1 80 225 270 3 1 5 360 405 450
LENGTH Cmm)
Figure E.3.l. 5 Arctic grayling length frequency composition upper Susitna River study, 1981.
Non-parametric one-way analysis of variance tests (Kruskal-Wallis test) were
made comparing median lengths of grayling collected from each of the eight
streams for each month (Appendix Tables EA-1 through EA-5). For each month,
test were run and significant differences were found for fish lengths betwren
streams. The high-median lengths by stream and month were; May ,Jay -34J,
,lune Tsusena -· 341; July Tsusena -325, August Tsusena -329, . September
Tsusena -356. Figure E.3.1.6 gives the age-length distribution by tributary.
Pearse (1974) found an average fork length of 355 mm for 422 grayling measured
in the Delta Clearwater and 280 mm for 85 grayling measured in the Richardson
Clearwater. These fish were captured by seine and electroshocker. Chcnr
River studies by Hallberg (1979) showed an average fork length of 181 mm for
1,111 grayling captured by electrofishing. Fish <'5. small as 100 mrn wr>r!'
included in this sample.
In general fish of less than 150 mm fork length were not readily taken by hook
and line sampling utilized in the upper Susitna. Fish of a smaller size than
this could not easily take the metal type lures or flies used in much of the
si1nlpling. Durinq Sdi!iplinq of upper· Wati\na Cn•ek (abov(· 111ilr• 6) Auqu~.l 10-11,
approximately 80 Arctic grayling of less than 150 run fork length were takt~n
using fly fishing gear.
?. large school of young of the year and age I juvenile Arctic grayling were
located in a slough near the mouth of Jay Creek ·in ,June and cluly 1981.
Juvenile grayling were also taken from Goose Creek, the Oshetna River, Kosina
Crf'ek, Tsusena Crr.ek and Watana CrPek arPas. Subsamples of these fish were
measuFed to determine 1 ength. Age 0 ranged from 20 to 22 mm in JunP, from 24
E-3-27
I"T1
I
w
I
~~ 5 00~--WRTANA --------------.. ·------------
1
~ l!OO-§ . t
~ -t ) ¥ 300 t t .
H 200
~ 100
M 0 T-l-I I I Tl
M 0 1 2 3 li 5 6 7 8 9
AGE IN IEARS
DEADMAN ~ i ~ ~~~]
I T 300]
-t.· .. t ~·
I H ~
I I 200-§
1· N 1ooJ
=l ~ 0 _,.T.__l..--l_l_IT __ I __ I -I I
.. f
--f
-soo
1
---· -TS-USENR------~--------------------l
~ ijQQ I t t l 1 ¥ 3oo ~ , I
H 2ooJ I ~ 100~ · I
M -o~~-T-rTTTTl !
M 0123li56789 I
AGE IN YEARS
k 5001 FOG
N l!OO G ~ T • t
H. 300--:1 t
I 200~ l
;
10 ~4-rr i -r rTTn j
0 1 2 3 li 5 6 7 8 9
AGE IN I EARS •
--· ·---------
0 1 2 3 li 5 6 7 8 9 _j
___,.....~--~----R-G:: IN YEARS __ -.
FigureE.3.1.6. Arctic grayling age-length distribution. Upper Susitna River tributary habitat
locations May to September, 1981. ·
r------------------. -------------------------~--------------· ----------------~----------~-----------------
: l_ 500) OSHETNA
E l!OO
N t r
¥ 300 t : t
H 200~
tl lOOj
M 0 4--T--1 ---~--[ ---T--l--11
M 0 1 2 3 l! 5 6 7 8 9
AGE IN YEARS
r,!
I
w ~-L 500 GOOSE
I.D E !
N L!OO
G
T 300
H
_ I 200
N l 00--
t1
M
Figure E.3.1.6. (cont.)
• t t
t t
L soo:J JAY
E l!OO _j ~ 300 ~ ~ ! -! t t
H l .t ~
200---:t -t
~ 100_j - . .
M o4-rrTT 1-rl--n
M 0 1 2 3 l! 5 6 7 8 9 ·
-AGE IN I EARS
L 500 -KOSINA
H ~00~
t .t + T 300-3 . 1 t
1 t H j
T 200 ~ t t
.l
N 100
to 45 mm in July, and from 47 to 60 mm in September. Age I juvenile Arctic
grayling measured ranged from 54 mm in May, from 75-95 mm in June, and from
84-98 mm in July. Two Arctic grayling 54 mm and 115 mm FL were taken 3 miles
up Goose Creek May 23. ( Plate E.3.2 shows project staff in the pursuit of
juvenile fish species. See Appendix Table EA-6 for a listing of juvenile
grayling captured).
Two hundred and sixteen grayling were examined for sex composition. 59.7%
were males and 40.3% were females for a ratio of 1.48 males:l.OO female. The
sex ratio varied from 0.85 males:1.00 female in May to 2.45 males:1.0 female
in June then remained at ·or near the 1.48 average for July, August and
September (Table E.3.1.13). No explanation for this variance in sex ratio
over time was determined by this study.
Table E.3.1.13 Arctic grayling sex composition by month upper Susitna River,
habitat locations, May to September 1981.
NO. MALE NO. FEMALE MALE: FE~1ALE
~1ay 17 20 0.85:1
June 27 11 2.45:1
July 41 26 1.58:1
August 18 12 1. 50: 1
September 26 18 1. 44: 1
TOTAL. 129 87 1.48:1
E-3-30
Plate E.3.2. Sampling for juvenile fish, Jay Creek habitat location, 1981.
The ratio of males to females was highly variable by stream (Table E.3.14).
Only Fog Creek with a 1 imited 14 fish sample had a plurality of females over
males.
Table E.3.14. Grayling sex composition, upper Susitna River tributaries, May
to September 1981.
Male % Fema 1 e % Sample Size
Oshetna 36 !:19 25 41 61
Goose 18 62 11 38 29
Jay 21 66 11 34 32
Kosina 29 62 18 38 47
Watana 5 56 4 44 9
Deadman 7 78 2 22 9
Tsusena 10 67 5 33 15
Fog ·3 21 11 79 14
TOTAL 129 60 87 40 216
T6tal sample size was small for some months and tributaries to regard sample
sex ratios as a true representation of population s.ex ratios. There is,
however, an indication of changing sex ratios by season and differences
between streams which may be real and due to differences in survival rates and
migratory behavior of the sexes. Sampling of the Delta Clearwater in 1972-73
showed that of 57 grayling autopsied 44% were male and 56% were female .
. E-3-32
3.1.4.3 Spawntng
Based on known spawning behavior fo~ other areas, project personnel believed
th~t spawning in the upper Susitna River tributaries would occur after ice out
following the peak of the spring breakup flood in late May. Aerial surveys of
the tributaries were conducted by project personnel on May 11, 1981 ·for
purposes of reconnaissance. Breakup had just occurred, streams were in high
flood, and were extremely turbid. Personnel were on site by May 20 but this
proved to be too late to document spawning. Arctic grayling examined during
May and early June exhibited spent gonads and frayed dorsal and caudal fins
indicating that they had already spawned. Fish in this condition were col-
lected at the mouths of tributaries. Two ripe males were taken at the mouth
of Goose Creek ~1ay 22. It is now believed that 1981 spawning in the upper
Susitna River tributaries took place from late April through early May likely
under the ice or durin~ mid-May spring flood when documentation would, have
been most difficult. 11 the Yukon and Alaska North Slope regions, grayling
have been known to spawn in turbid waters during spring flood periods (TES,
1981).
Young of the year and juvenile Arctic grayling were taken through the summer
in shallow, clearwater pools off the main Susitna. These clearwater 'areas
were formed by the isolation of clearwater runoff from tributaries such as
Kosina and Jay Creeks in main river side channels and sloughs. Such areas
generally had little current and were only connected to the main river at
their outlet. Additional juvenile Arctic grayling were taken in quiet pools
and side channe 1 s of Goose and Jay creeks. Spawning is be 1 i eved to have
occurred in nearby tributaries but may have occurred in these slough areas.
E-3-33
The preferred type of gravel spawning substrate occurs in pools throughout the
various tributaries. The amount of such habitat is extremely variable with
extensive occurrence in Oshetna, Kosina and Tsusena creeks; moderate
occurrence in Goose, ,lay, and Watana creeks and limited occurrence in areas
surveyed in Deadman and Fog creeks.
3.1.4.4 Tagging
3.1.4.4.1 Introduction
A total of 2,511 Arctic grayling were tagged and released during 1981
operations. The numbers of Arctic grayling tagged by month for each tributary
stream or lake within the confines of the proposed impoundment elevation are
listed in Table E.3.1.15. Those Arctic grayling surviving recapture were
subsequently released with tag intact.
Two hundred sixty-eight of the tagged Arctic grayling were recaptured. Table
E.3.1.16 lists recaptures of Arctic grayling by tributary of tagging and
month. · Twenty;.. six fish were recaptured twice and two grayling were taken
three times. Only recaptures which occurred in subsequent months or from
different tributaries during the same month were included in the totals.
All tagging was with Flay Tagging Mark li tagging guns utilizing 2-5/8 11 inter-
national orange anchor tags. Plate E.3.3 shows an Arctic grayling with Flay·
tag ln place. Tagged grayling were held upright in the current unti 1 ·res-
piratory function appeared normaL Fish deeply hooked or bleeding were not
'tagged and were sacrifi¢ed for biological sampling. A number of tagged
~-3-34
Table E.3.1.15. Arctic grayl!ng tagged by month and tributary, upper Susitna
River, 1981.
MONTH
TRIBUTARY MAY JUNE JULY AUG. SEPT. TOTAL --
Fog 19 15 32 3 5 74
Tsusena 34 68 110 49 8 269
Deadman 50 68 32 6 4 160
Watana 2 48 12 105 42 209
Kosina 97 121 211 61 158 648
Jay 80 153 56 17 64 370
Goose 97 142 71 34 9 353
Oshetna 14 83 130 65 136 428
TOTAL 393 698 654 340 426 2,511
a 108 additional grayling were tagged during the field season outside the area
proposed to be impounded.
upper Deadman
upper Kosina
Sally Lake
Deadman Lake
Numbers tagged by tributary were:
60 17
10
E-3~35
10
10
1
Table E.3.1.16. Arctic grayling recaptures by tributary of tagging and
month of recapture, upper Susitna River, June to September,
1981.
MONTH
TRIBUTARY MAY JUNE JULY AUGUST SEPTEfi1BER TOTAL
Fog 0 3 7 2 0 12
Tsusena 0 3 15 15 2 35
Deadman 0 4 11 4 3 22
Watana 0 0 2 0 2 4
Kosina 0 21 12 15 17 65
Jay 0 11 17 12 13 53
Goose 0 10 13 11 2 36
Oshetna 1 0 19 12 9 41
TOTAL 1 52 96 71 48 268
E-3-36
Plate E.3.3. Arctic Grayling with Floy anchor tag in place, Upper Susitna River, 1981.
grayling were marked by clipping the adipose fin. Recaptures of fish so
marked should give an indication of tag shedding. Through the September ·
sampling recaptures from fish so marked are too few in number for meaningful
conclusions. With a relatively high overall recovery rate of 11% (273
recovered for ·2 ,511 tagge<;l), it would appear unlikely that there was much
shedding of tags or mortality due to tagging. The bulk of grayling tagged--
96%--were captured for tagging by rod and reel.
Of one group of 86 gillnet captured grayling tagged off the mouth of Jay Creek
May 25-26, 14 or 16.3% were eventually recaptured. Thus there is no evidence
of disproportionate mortality due to gillnet capture as compared to rod and
reel. Gillnet tagged fish taken were tagged within 15 minutes following
entrapment in the net. Fish gil led resulting in gi 11 injury were not tagged.
Almost all tagged grayling recaptures were made by Fish and Game project
personnel. A total of 6 tagged grayling were recaptured by non-project
personnel: 4 at the mo.uth of Kosi na Creek, and two in Goose Creek 12 mi 1 es
upstream from its mouth.
3.1.4.4.2 Population Estimation
Arctic grayling population estimates were made for the upper Susit.na River
study .area and the proposed inundated reach of each tributary. These
estimates are based on tagging . conducted from May through August and
recoveries of tags from June through September and were produced using· the
Schnabel method (See Appendix Table EA-7 for formula and Appendix Table EA-8
E-3-3B
for recaptures used in computations). The population estimate for Arctic
grayling in the upper Susitna river study area calculated at the 95%
confidence level (4df), is 10,279 with a range of 9,194 to 11,654. Kosina
Creek has the highest estimate for an individual tributary at 2.787 (range
2,228 -3,720) followed by the Oshetna River at 2,017 {range 1,525 -2,976).
Fog Creek had the lowest estimate at 176 (range 115-369), (Table E.3.1.17).
No estimate is listed for Watana Creek, although Watana is included in the
study area total estimate, because the low nurnber of tagged fish recovered
would have resulted in an estimate with an unacceptably wide range of values.
Table E.3.1.17 Arctic grayling population estimates, upper Susitna River
tributaries, 1981. l/
POPULATION CONFIDENCE y
STREAM ESTIMATION INTERVAL
Oshetna 2,017 1,525 -2,976
Goose 1,327 1,016 -1,913
Jay 1,089. 868 -1,462
Kosin1 2,787 2,228 - 3 '720
Deadmm 979 604 -2,575
Tsusera 1,000 743 -1,530
Fog 176 115 -369
ll Watana Cr£ek estimate is not included because too few recaptures
were made.
~/ Based on June through September recoveries df = 4 at 95% level.
E-3-39
As illustrated in the discussion of tag return data, grayling interchange
freely between tributaries using the main Susitna as a migratory corridor.
Seasonal movement into and out of the clearwater tributaries has been demon-
strated. Population estimates for a tributary with the emmigration of fish
tagged or immigration of numbers of untagged fish would in effect result in a
lower ratio of tagged to untagged fish. Population estimation resulting would
be high. The upper Susitna study area would best be regarded as a whole with
the total population estimation the most valid.
On numerous occasions during 1981 sampling tagged grayling were recaptured
repeatedly during the same day of sampling frorn the pool of release. In many
instances a fish captured initially on a spinner was recaptured on a fly;
frequently, a fish captured on one lure type was recaptured on that same' lure
type. It appears that grayling do not easily learn to avoid lures making hook
and line sampling a legitimate recovery method. Problems were experienced in·
covering west bank pools when encamped on the east bank or east bank pools
when operating from the west. In the larger tributaries such as the Oshetna
River, Kosina, Deadman, and Tsusena creeks sampling was 1 imited to casting
distance from the bank of helicopter dropoff. Monthly sampling on the Oshetna
River alternated between the west and east banks.
The impoundment population estimation of 10,279 grayling over 150 mm fork
length is for approximately 20.5 miles of clearwater tributar·'es and 85 miles
of the main Susitna. This would give an average of approximately 501 adult
grayling per clearwater tributary mile or 121 per river mile including the
matn·s~sitna to be inundated. Hallberg (1979) gave a population estimation of
E-3-40
495 grayling per mile for the upper Chena River Dam Site for a 1978 study for
fish 150 mm or greater in len~th. Four sections of the Chena combined gave an
estimation of 320 grayling per mile. Earlier studies of this system had given
total population estimations as high as 1,824 per mile (including fish Under
150 mm fl). In a 1974 study Pearse (1974) gave population estimations for the
Delta Clearwater River as from 142 to 182 per mile.
3.1.4.4.3 Migration
Different patterns of movement and utilization by grayling in a drainage
system may become apparent as a particular region is studied (T.E.S., 1981).
Some tributaries may serve as spawning streams and rearing areas for fry~
whearas other tributaries, mainstream regions, or lakes may be used by both
immature and mature adult grayling as summer feeding grounds. The time of
migration out of the spawning stream depends in part on size of the system
with mature individuals carrying over after spawning in large systems until
mid-summer or autumn.
Table E.3.1.18 summarizes grayling intrastream migration patterns as shown by-
tagging and tag recovery. A total of 243 tag returns are included in this
data. Fifty tagged grayling rPcovered moved upstream, 69 moved downstream and
124· were recaptured at. their point of release. The distance of movement
recorded ranged from 2 miles downstream to 12 mi 1 es upstream within the
various tributaries. The average length of time at large for within stream
tags recovered was 39.6 days.
E-3-41
Table E.3.1.18. Arctic Grayling movement as demonstrated by tagged fish
recovered within stream of tagging by month of tagging
Number Movement Miles Days at
Taggin~ Different No. No. No. Traveled Large
Stream -onth Reca~tures u~ Down 0 Range Range
Oshetna June 23 10 9 4 -0.4 29-54
+0.2
July 12 0 7 5 -1.1 30-54
0
Sept. 4 0 0 4 -1.1
0
Totc1l 39 10 16 ]3 -0.4 29-59
+0.2
Goose May 17 5 0 12 0.0 27-85
+12.0
June 14 2 2 10 -0.3 27-81 .
+1.2
July 3 0 1 2 -0.3
0.0
Aug. 1 0 1 0 -0.1
Total 35 7 4 24 -0.3 27~85
+12.0
Jay May 10 4 0 6 -0.5 26~55
+1.4
June 24 1 8 15 -1.3 27-93
+1.7
July 8 0 0 8 0 31-64
Aug. 6 0 1 5 -0.1 31-34
Total 48 5 9 34 -0.5 26-93
+1.7
kosina May ?3 5 6 12 -0.2 37-JlO
+2.9
June 13 0 5 8 -0.5 27-93
July 17 6 5 6 -1.0 27.:.60
+2.3
E-3-42
Table E. 3 .1.18. (Continued)
Number Movement Miles Days at
Tagging Different ~0. No. No. Traveled Large
Stream Month Reca~tures u~ Down 0 Range Range
Aug. 3 0 3 0 -0.3 33-34
Sept. 3 0 3 0 -2.0 1-?
-1.5
Total 59 11 22 26 -2.0 27-93
+2.9
Watana June 1 0 1 0 -0.6 92
July 1 0 1 0 -0.2 1
August 1 1 0 0 +1.0 42
Total 3 1 2 0 -0,6 1-92
+1.0
Deadman May 6 1 0 5 0 2-85
+0.2
June 3 2 0 1 0 26-27
+0.1
July 4 0 0 4 0 1-63
Aug. 1 0 1 0 -.3 30
Total 14 3 1 10 -1.3 1-63
+0.2
Tsusena June 17 3 4 10 +-0.3 27-119
-1.0
July 16 8 6 2 -0.2 1-29
+0.3
Total 33 11 10 12 -1.0 1-119
+0.3
Fog June 11 2 4 5 -0.9 27-56
+0.4
July 1 0 1 0 +0.3 26
Total 12 2 5 5 -0.9 26-56
+0.4
[-3 -43
Interstream movem1·nt was significant for tagged grayling recaptured (Table
E.3.1.19). Twenty-five or 9% of tagged fish recaptured were recaptured at the
mouth of or in a stream other than the stream of initial tagging. The number
of grayling moving upstream in the main Susitna was 2, downstream 19, and
downstream in the main Susitna then upstream in a tributary was 4. The
average days at large was 44.2 with a range of 3-117. The average distance
moved was 8.3 miles (range 0.5-34.5 miles). The maximum rate of documented
movement was 4.7 miles/day.
r~igration patterns as shown by tag returns and/or catch rates will be dis-
cussed by tributary. Catch success was greatly affected in some tributaries
for some months by extremely turbid water conditions resulting from heavy
rains, runoff and by land slides. Under such conditions, grayling could not
feed readily by sight and did not readily take lures.
Oshetna River
May:
No grayling were taken by hook and line and only 3 were captured by gillnet at
the mouth of the Oshetna River (habitat 1 ocation site 1) during the ~1ay
sampling, however, a catch rate of 1.8 grayling per angler hour was recofded
for habitat location sites 1-5 combined. In contrast, a catch rate of 8.0 per
angler hour was recorded for the selected fish habitat sites in the lower mile
of the Oshetna River. More pools and fishable water were found between the
habitat location sites than within them. The grayling catch rate for selected
E-3-44
Table E.3.1.19. Arctic grayling movement from initial tributary of tagging
as indicated by tag recoveries, 1981.
Tributary Tributary Total
Mile of Date Days Recovery Mile of Miles
Tributart Tagging Tag No. Tagged at Large Location Reca~ture Traveled
Oshetna 0.9 3012 5/24 3 Goose o.o -2.9
Oshetna 0.6 3496 6/17 29 Goose 0.1 -2.7
Goose 0.0 3025 5/22 33 Watana 0.0 -34,5
<lay 0.0 3193 5/26 57 Kosina Slough 201. 9a -2.0
. ,Jay 1.5 3802 6/21 36 Fog 0.0 -31.5
Jay 0.1 3741 6/21 2 Kosina 0.7 2.3
(-1.6-+0.7)
Jay 0.1 3716 6/20 93 Kosina 0.7 2.3
( -1~ 6-+0. 7)
Jay 0.0 3742 6/25 4 Watana 0.0 -13.6
Kosina 0.2 3240 6/29 33 Tsusena 0.0 -23.5
Kosina 0.2 3963 6/22 4 Watana 0.0 -12.0
Kosina 0.0 3299 5/26 27 Jay 0.0 +1.5
Kosina 0.0 3214 5/26 117 Jay 0.0 +1.5
Kosina 0.1 3283 5/27 55 Kosina Slough 201. 9a '.· -0.5
Kosiila 0.0 3258 : 5/27 5 Tsusena 0.0 -23.5
Watana 0.5 2234 6/25 28 Deadman 0.2 -T. 7
Deadman 0.0 . 3339 '· 5/30 85 Tsusena 1.8 -6.3
Deadman 0.2 3348 5/30 56 Tsusena 0.8 +5.5
(-4.9-+0.8)
Deadman 0.0 3331 5/30 57 Tsusena 0.0 4.5
Deadman 0.0 3357 5/30 56 Tsusena 0.0 -4.5
Deadman 0.0 3373 5/30 55 Tsusena 0.0 -4.5
Deadman 0.2 3351 ·-5/30 56 Tsusena 1.5 6.2
(.;.4,7:-+1.5)
Deadman 0.0 3361 5/30 56 Tsusena 0.0 -4.5
Deadman 0.0 3366 5/30 56 Tsusena 0.0 -4.5
Tsusena 0.0 3385 6/l 56 Crk. 178.4a -0.5
Tsusena 0.0 3397 . 6/l 56 Fog 0. 1 -5.1
a Susitna River mile upstream of mouth.
E-3-45
fish habitat sites above mile one to approximately mile 2 during May was 6.0
grayling per hour. Limited hook and line sampling above Mile 2 produced no
grayling. The stream total catch rate for May was 6.0 grayling per angler
hour. A single grayling tagged at Oshetna River mile 0.9 May 24 moved down-
stream 3.6 miles to be recovered at Goose Creek mouth 3 days later on May 27.
June:
The numbers of grayling found at the mouth and in the other habitat location
sites increased from the May sampling as evidenced by catch rates of 3.0 and
9.1 grayling per angler hour for habitat location site 1 and sites 1-5
combined respectively. The catch rate recorded for selected fish habitat
sites i~ the lower mile increased to 10.6 as did the catch rate for select~d
sites above mile one to the proposed impoundment elevation (7.3). Grayling
appeared to be moving into the Oshetna River from the Susitna River and
actively migrating upstream.
Twenty-three grayling tagged during June in the Oshetna River were later
recaptured. Twenty five of these fish were subsequently recaptured in the
Oshetna within one half mile of their release point. One grayling was
recaptured 29 days later at 0.1 mile up Goose Creek.
July:
Large numbers of grayling were again found at the mouth, in the lower mile and
above mile one to the proposed impoundment elevation with catch rates of 9.4,
6.5 and 13.3 respectively. The greatest increase was ob~erved in that reach
E-3-46
of Oshetna from mile one to the proposed impoundment elevation where the catch
rate during July was 13.3 grayling per angler hour. The highest stream total
catch rate, 9.4 grayling per angler hour was also recorded during July.
Twelve grayling tagged during. July in .the Oshetna were recaptured. Of the 12
fish recaptured in the Oshetna 7 moved downstream from their point of release
and 7 remained at or near their point of release.
August:
Relatively large numbers of grayling remained present at the mouth, in the
lower mile and above mile one to the proposed impoundment elevation. A catch
rage of 9.0 grayling per angler hour was recorded in the habitat location
sites and a stream catch rate for August of 9.4 grayling per hour. No gray-
1 ing tagged in the Oshetna River during August were· recaptured in the Septem-
ber sampling. One hundred sixty-seven fish were captured in upriver sampling.
The lack of tagged fish would seem to indicate that earlier tagged fish had
moved out of the study area and were no longer available in the lower Oshetna
River for recovery.
September:
Grayling catch rates in the Oshetna ·River habitat ·locations decreased to 2.1
fish per angler hour in September, with only 1.3 grayling per hour being
captured at the mouth. With the exception of one relatively deep pool locbt~d
approximately 2.0 miles up the Oshetna, catch rates throughout the stream were
E-3-47
consistently low. This single cobble botto~ pool, 3 to 5 feet deep, 125 feet
long and lying along the outside of a bend, was fished extensively to
determine the presence of any tagged grayling. A catch rage of 17.2 grayling
per angler hour was recorded. None of the 167 grayling collected from this
pool carried tags. It appears that this pool provides potential wintering
habitat for grayling and that those fish occupying it in September were likely
to have moved downstream from areas not previously sampled.
Goose Creek
May:
Grayling were present at the mouth and in the 1 ower one mi 1 e of Goose Creek
during May as a catch rate of 7.4 grayling per angler hour was recorded i~ th~
habitat location sites. All of these grayling were collected at the mouth of
\
Goose Creek. No grayling were captured from Goose Creek above stream mile
one; one adult was observed in a pool three miles upstream. A single juvenile
grayling 54 mm total length was collected in a shallow side channel. Although
grayling were p~esent at the mouth and in the lower mile of Goose Creek the
extent of their upstream distribution appears very limited.
Five grayling tagged in the lower mile of Goose Creek were subseqw•ntly
recaptured upstream. Two of these fish were captured by sport fishermen
approximately 12 miles up Goose Creek. These sport fishermen reported
observing 10 additional ta!:j!:jed grayling in the same area. Fourteen grayling'
tagged during May in the lower mile of Goose Creek were captured 27 to 85 dajs
E-3-48
later in that same area. One grayling tagged May 22 at the mouth of Goose
Creek was recaptured 33 days later, 34.5 miles down the Susitna.River at the
mouth of Watana Creek.
June:
Grayling were present at the mouth and in the lower mile of Goose Creek where
the habitat location catch rate during June was 6.2 grayling per angler hour.
A significant increase was observed in the numbers of grayling above stream
mile one. The catch rate at selected fish habitat sites from mile one to the
proposed impoundment elevation was 11.5 grayling per angler hour. Grayling
previously schooled at the mouth Goose Creek had distributed in an upstream
direction.
Fourteen of the fish tagged at Goose Creek in June were later recovered in
Goose Creek within 1.2 miles of their release point. It appears that by
the end of June the general upstream movement of grayling has ceased and
random movements by individual fish predominates.
July:
Relatively large numbers of grayling were collected over the entire reach of
Goose Creek sampled. The habitat location catch rate was 8.0 graylinq pPr
ilnql<'r hour whil(' t.he catch r·at0 for the' self'clc'rl fi•;h h,Jidlat <,il<·~; n•ach wa•.
12~l grayling per hour.
E-3-49
Three grayling tagged during July were subsequently recaptured near their
release point.
August:
Fewer grayling were taken af the Goose Creek habitat 1 ocati on and at the
selected fish habitat sites during August. The habitat location catch rate
was 4.3 grayling per angler hour. Sampling efforts upstream from mile one to
the proposed impoundment elevation resulted in a grayling catch rate of
only 3.2 per angler hour. Grayling appear to have begun to move out of Goose
Creek by the August sampling.
Only one fish tagged a Goose Creek in August was later recaptured, that in
September one tenth of a mile downstream from its point of release.
September:
A majority of the grayling present in Goose Creek through the summer months
had moved out of the habitat location and upstream selected fish habitat sites
by September. The habitat location catch rate was 0.8 grayling per angler
hour; the selected fish habitat site catch above mile 1 was 2.4. ·
No tagged grayling were recaptured in September.
E-3-50
Jay Creek
May:
Small numbers of grayling were collected by hook and line in the Jay Creek
habitat location or in selected fish habitat sites because of high an~ turbid
water conditions; however, 125 grayling were captured by gillnet at the Jay
Creek Susitna River confluence.
Four grayling tagged at the mouth of Jay Creek in May were 1 ater recaptured
upstream in Jay Creek, and six were recaptured at their point of release and
one was captured 57 days later two miles downstream in a slough off the
mainstem Susitna River.
June:
Relatively large numbers of grayling were present at the mouth, in the lower
mile and upstream from mile one to the proposed impoundment elevation. The
habitat location catch rate was 6.2 grayling per angler hour while the stream
total catch rate was 7.4 per hour .. Grayling appear to hcve moved into Jay
Creek and distributed themselves within the system.
A total of twenty-eight grayling tagged during June in lJay CrN•k were later
recaptured; 15 at their point of release, 8 · upstream in Jay Creek, 1
downstream in Jay Creek and 4 in downstream tributaries. Of the latter
recoveries two were in Kosina Creek, one was in Watana Creek and one was in
Fog Creek.
E-3-51
July:
Relatively high catch rates were recorded in the Jay Creek habitat location
and in selected fish habitat sites during July. The habitat location catch
rate was 8.8 grayling per angler hour while, the stream total catch rate was
10.9 per hour.
Eight grayling tagged during July in Jay Creek were later recovered near their
point of release.
August:
High turbid water conditions prevailed during August in Jay Creek precluding
any hook and line sampling above mile one. The habitat location catch rate
was 4.1 grayling per angler hour, and a gillnet place at the Susitna River Jay
Creek confluence captured only five additional grayling.
Six August tagged grayling were later recaptured in Jay Creek near their pofnt
of release.
September:
Relatively large numbers of grayling were captured in the habitat location
particularly at the mouth of Jay Creek. The grayling catch rate at the mouth
(habitat location site No. ·1) was 10.5 per hour while the habitat location
overall had a catch rate of 8.6 per hour. It appeared that the grayling were
E-3-52
moving downstream in Jay Creek toward the mouth. however fish were still
present in the lower reach of Jay Creek .
. Kosina Creek
May:
Catch rates for habitat lC!cation site 1 and sites 1-5 combined were 3.9 and
7.2 grayling per angler hour respectively. Due to high water, that section of
Kosina Creek above habitat location site 3 was not sampled. The stream total
catch rate for May was 7.2 grayling per angler hour.
Twenty-three grayling tagged during May in Kos ina Creek were 1 ater recaptured
at or near their point of release, six downstream and twelve (were recovered)
upstream from their point of release. Two grayling tagged May 26 at the mouth
of Kosina Creek were recaptured 27 and 117 days later at the mouth of Jay
Creek, a distance of 1.5 miles up stream in the Susitna. Two grayling tagged
May 27 at 0.0 and 0.1 mile Kosina Creek was recaptured 5 and 55 days later in
Tsusena and Kosina Slough, distances of 23.5 and 0.5 miles down the Susitna
respectively.
June:
The numbers of grayling found at the habitat 1 ocation sites increased during
June as evidenced by a catch rate of 10.8 grayling per angler hour. The catch
rates for selected fish habitat sites in the lower mile and above mile one t6
the proposed impoundment level, sampled for the first time in June, were 3.97
and 11.0 grayling per angler hour respectively. With the exception of a small
pool located between habitat location sites 1 and 2, all the fishable water
was found within the habitat location sites in the lower mile of Kosina Creek.
The stretch of Kosina Creek between mile 1 and 3 was found to contain some
very large, deep pools. These pools averaged 150 to 300 feet in length, 20 to
40 feet in width, and 4 to 8 feet in depth. All were located below very
turbulent rapids. It is very possible that these pools provide an in stream
over wintering habitat area for Kosina Creek grayling as evidenced by the
continuous presence of large numbers of grayling. The stream total catch
rate for June was 9.3 grayling per angler hour, with the majority of the 246
grayling captured coming form the selected fish habitat sites between mile 1
and 3.
Thirteen grayling tagged during June in Kosina Creek were later recaptured,
eight at or near their release point and five within 0.5 miles downstream.
One fish tagged June 22 was recaptured 4 days 1 ater at the mouth of Watana
Creek, a distance of 12.0 miles; and another tagged at mile 0.2 of Kosina
Creek onJune 19 was recaptured at the mouth of Tsusena Creek, a distance of
23.7 miles.
July:
A large increase in the numbers of grayling found at the mouth of Kosina Creek
occurred 'during July, with ·the catch rate reaching 13.4 grayling per angler
hour. The formation of a large pool at the confluence with the Susitna caused
by extremely high water conditions resulted in an incr~ase in desirable
habitat greater numbers of grayling and increased CPUE. The catch rate at the
E-3-54
habitat location increased to 12.8 grayling per angler hour. Selective fish
habitat sites between mile 1 and 3 continued to have a high catch rate of 10.2
grayling per angler hour. High water conditions during July seemed to have
1 ittle effect on the sampling conducted. The highest stream monthly total
catch rate, 10.9 grayling per angler hour, was recorded in July.
Seventeen grayling tagged during July in. Kosina Creek were recaptured. All 17
of these fisr were recaptured in Kosina Creek. Six were recaptured at or near
their point of release, six moved upstream and five moved downstream.
August:
A large decrease in the numbers of grayling and in the catch rate at the
habitat location of Kosina Creek occurred in August. The catch rate was 5:7
grayling per angler hour. The catch rate in the selected fish habitat sites
between mile 1 and 3 remained high at 11.5 grayling per angler hour. High
water and turbid conditions occurred in the lower mile of Kosina C~~ek
probably hampering success rates. The stream total catch rate was 8.9 gray-
ling per angler hour for August.
Three grayling tagged in Kosina Creek during August were recaptured. All
three of these fish were recaptured in Kosina Creek and all had moved down-
stream 0.3 miles from their point of release.
E-3-55
September:
Grayling catch rates in the habitat location of Kosina Creek dropped 4. 7
grayling per angler hour. A total of only 13 grayling were captured during
September in this area. With the exception of the large pool selective fish
habitat sites between mile 1 and 3. grayling had migrated out of Kosina Creek.
The large pools in upper Kosina Creek produced the highest catch and catch
rates recorded during the season running 143 grayling and 11.7 grayling per
angler hour respectively. This would indicate migration of grayling into
these pools from surroundirg areas, possibly for overwintering.
Three grayling tagged in Kosina Creek during September were later recaptured.
All three of these grayling were recaptured in Kosina Creek 1.5 to 2.0 miles
downstream one day after being tagged~
Watana Creek
May:
Watana Creek was high and turbid during May making sampling efforts particu-
larly inefficient. A catch rate of only 0.3 grayling per. angler hour was
recorded at the habitat location. No sampling was conducted upstream of mile
one. No grayling tagged in Watana Creek in May were later recovered.
E-3-56
June:
Increased numbers of grayling appeared to be present in the Watana Creek
habitat location where the catch rate was 5.4 grayling per angler hour. Water
condition had improved from the May sarnpl ing and hook and 1 ine sampling was
effective throughout the stream.
Two grayling tagged during June in Watana Creek were later recaptured, one 92
days later only 0.2 miles from its release and the other 28 days later at the
mouth of Deadman Creek.
July:
Watana Creek catch rates for July were relatively low. The habitat location
catch rate was 3.3 grayling per hour while the stream total was 3.1 per hour.
A total of only 16 grayling were captured during the two day period although
water condition was moderately clear. The lower mile of Watana Creek does not
appear to provide high quality habitat for summer feeding grayling.
Approximately eight miles of Watana Creek will be inundated by the proposed
Susitna Dams; and through July, sampling efforts had been limited to the
lowest two miles of this reach.
A single grayling tagged in Watana during July was later recaptured a short
distance downstream in Watana.
E-3-57
August:
Catch rat~ remained relatively low at the habitat location and in the lower
mile of Watana Creek in August. Hook and line sampling was conducted at the
confluence of east and west forks of Watana Creek approximately six stream
miles from the mouth. The east fork, similar to lower Watana was turbid much
of the summer of 1981; in contrast, the west fork was clear a majority of the
·time. This west fork of Watana is excellent grayl·ing habitat with numerous
cobble bottomed pools 5-10 feet deep and up to 100 feet in length and 60 feet
in width. The catch rate in the west fork and confluence west fork-east fork
area was 10.4 grayling per angler hour. A high percentage of the grayling
collected by hook and line were 1~0 to 150 mm fork length or predominately
Age I I and II I.
Although 95 of these small grayling were tagged, none were recaptured at
downstream locations in the September sampling. One grayling tagged during
August in the 1 ower mi 1 e of Watana Creek was recaptured in September in the
upper reach of Watana Creek.
September:
The Watana Creek habitat location catch rate remained relatively low but
consistent with· July and August staying at 3.3 grayling per angler hour.
Sampling in upper Watana yielded a catch rate of 5.7 grayling per angler hour.
E,.-3-58
It is important to determine in 1982 the relationship of upper Watana Creek to
lower Watana, other nearby Susitna tributaries and to the upland lakes
draining into this system.
Deadman Creek
May:
Grayling were fourid at the mouth and immediately upstream during May. Only
the first 2000 feet up from the mouth of that section of Deadman Creek below
the 100-150 foot waterfall was accessible for sampling purposes. The s~ction
of Deadman Creek below the falls is an extremely torrential with boulder
strewn rapids containing very poor spawning and juvenile rearing habitat. The
majority of the grayling captured and observed were at the mouth. The catch
rate for the habitat location was 7.1 grayling per angler hour.
Fourteen grayling tagged at Deadman Creek in May were later recaptured, six in
Deadman Creek with one moving upstream and 5 remaining at the point of
release. Eight grayling tagged at Deadman Creek mouth on May 30 were
recaptured at Tsusena Cr~ek Mile 0.0 to 1.8 56 to 85 days later.
June:
The numbers of grayling found at Deadman Creek increased from the May levels.
The highest catch rate for the season was recorded at the habitat location
during June, 7.7 grayling per angler hour. Large numbers of grayling do not
E-3-59
appear to enter Deadman Creek to feed during the summer; however, schools of
grayling are occasionally present off the mouth and in the lower one half
mi 1 e.
Three grayling tagged at Deadman Creek in June were later recaptured .. All
three of these fish were recaptured in Deadman Creek one moving 0.1 mile
upstream and two remaining at or near the point of release.
July:
Seven grayling were captured at the mouth, with a catch rate of 4. 7 grayling
per angler hour. A slight increase in catch rate was observed upstream of the
mouth with a catch of 35 grayling. The stream total catch rate for July was
7.2 grayling per angler hour.
Sixty-eight grayling were captured in upper Deadman approximately 2 miles
upstream from the falls. The majority of these fish were tagged and released.
Upper Deadman from Deadman Lake to approximately a mile a~ove the falls
impassible to downstream, fish has many pools and extensive productive fish
habitat.
Four grayling ·tagged at 1 ower Deadman Creek in July were 1 ater recaptured.
All· four of these fish were recaptured in Deadman Creek at or· near the point
of release.
E-3-60
August:
Small numbers of grayling were present in Deadman Creek during August. A
catch rate of 1.82 grayling per angler hour was recorded at the habitat
location and the total stream catch and catch rate was 6 grayling and 2.4
grayling per angler hour, respectively. High and turbid water conditions
slightly hampered sampling success; but, as evidenced by the drop in catch and
catch rates, large numbers of grayling were not present in Deadman Creek.
A single grayling tagged during August was later recaptured in Deadman Creek
having moved downstream.
September:
With only three grayling taken, grayling catch rates in lower Deadman Creek
habitat location decreased to 0.0 grayling per angler hour.
Recovery efforts in upper Deadman selected fish habitat sites 2 miles above
the falls from which 68 grayling had been captured in July produced only 8
fish. The fish had either ceased to feed or emmigration had occurred out of
the upper stream possibly into Deadman Lake for the winter.
E-3-61
Tsusena Creek
May:
The catch rate for the mouth of Tsusena Creek, the only portion of Tsusena
Creek proposed to be inundated was 4.6 grayling per angler hour. The fish
that were present were at the confluence with the Susitna River. Limited
sampling was conducted upstream; bu~ during May, few grayling had moved into
the available habitat.
None of the grayling tagged in Tsusena Creek during May were later recaptured.
June:
The catch rate for,June increased slightly to 5.6 grayling per angler hour.
Limited sampling upstream evidenced that grayling had migrated up into the
available habitat.
Nineteen grayling tagged in Tsusena Creek during June were later recaptured.
Seventeen of these fish were recaptured in Tsusena Creek, ten at or near the
point of release, four upstream, and three downstream from the point of
release. ,Two, tagged grayling were recaptured June 1: one at the mouth of a
small creek at RM 178.4 and the other 0.1 mile up Fog Creek.
E-3-62
July:
The total catch and catch rates for the mouth were the highest recorded during
the season, 74 grayling and 9.0 grayling per angler hour respectively. High
water conditions created a long, clear water pool extending approximately 1000
yards down the Susitna River. A relatively large number of grayling occupied
this entire area of good habitat.
Sixteen grayling tagged at Tsusena Creek during July were later recaptured.
All sixteen of these were recaptured in Tsusena Creek, two at or near the
point of release, eight moved upstream and six moved downstream.
August:
The numbers of grayling at the mouth decreased substantially compared to the
preceding months with a catch rate of 3.3 grayling per angler hour. Catches
upstream also declined as the grayling started migrating out of Tsusena Creek~
No grayling tagged at Tsusena Creek in August have been recaptured.
September:
The grayling catch rate in Tsusena Creek dropped to 2.0 grayling per angler
hour with a catch of only one grayling at the mouth. Limited upstream sam-
pling indicated the majority of grayling had outmigrated.
No grayling tagged at Tsusena Creek in September have been recaptured.
Fog Creek
May:
Fourteen grayling were taken at the mouth, the only area within the habitat
location that grayling were collected. Water was high and discolored during
much of May sampling. Catch rates for the mouth and habitat location sites
1-3 combined were 11.2 and 8.0 grayling per angler hour respectively.
No grayling tagged at Fog Creek in May have been recaptured.
June:
The highest numbers of grayling were again found at the mouth, with a catch of
13 and rate of 4.3 grayling per angler hour. Upstream sampling showed no real
increas~ with 4 grayling caught. The stream total catch rate was 3.9 gray1i~g
per angler hour ..
Eleven grayling tagged at Fog Creek were later recaptured in Fog Creek, five
at or near their point of release, two moved upstream as rnuch as 0.4 mile and
four moved downstream a maximum of 0.9 mile.
The total stream catch rate was 6.8 grayling per angler hour.
E-3-64
July:
Only three grayling were captured at the mouth with a catch rate of 2.4
grayling per angler hour. The highest total number of grayling captured
during the season of 20 was recorded in July. The total stream catch rate was
6.8 grayling per angler hour. Lower Fog Creek has a 1 imited amount of
grayling habitat.
A single grayling tagged at Fog Creek in July was recaptured 0.3 miles down-
stream from its point of release 26 days later.
August:
The number of grayling in Fog Creek habitat location apparently decreased as
evidenced by a catch rate of 1.6 grayling per angler hour. Small, shallow
side channels were found to contain young of the year grayling proving some
grayling use Fog Creek as a spawning stream.
No fish tagged at Fog Creek in August have been recaptured.
September:
Five grayling were captured at the mouth of Fog Creek for a catch rate of 2.0
grayling per angler hour. No other areas of Fog Creek were sampled because of
freezing conditions.
No grayling tagged at Fog Creek during September have been recaptured.
E-3-65
Generally, it is believed that by the time of arrival of project personnel on
site, May 20, the upstream spawning run and following downstream migration was
essentially over. Sampling in June found grayling had moved back upstream
into the tributaries where relatively high numbers remained through July and
early August. Late August and September catch rates <:nd tag return data
suggests that large numbers of grayling had moved out of the tributaries,
particularly the upstream reaches. Large numbers of untagged fish were
captured in habitat locations sampled which were likely moving through from
upstream unsampled areas. Many tributary fish appear to move into the main
Susitna for wintering. The lower reaches of some tributaries such as Kosina
and Tsusena have large deep pool habitat where overwintering wou~d be
possible.
E-3-66
3.2 BURBOT
3.2.1 Abstract
Eighty-eight adult burbot, Lota lota, were captured in the upper Susitna
River. Catches were distributed over all tributary habitat locations with Jay
and Watana Creek showing the most consistent catches and highest catch rates
for the season of 1.14 and 1.09 burbot per trotline day fished respectively.
The catch rate for all tributaries for the season was 0.68 burbot per trotline
day fished. One juvenile burbot of 15 mm TL was captured from 1 ower Jay Creek
on June 20; one young of the year burbot of 102 mm TL was taken from Jay Creek
slough on August 19.
Otoliths were collected from 54 burbot and used for age determination. The
majority of the burbot aged were in the age classes IV, V, and VI. The mean
lengths of burbot for these respective age classes were 3~J7 rnm, 382 mm, ·arid
409 mm. Of the 54 burbot examined. for sex 44 percent ~~ere males and 56
percent were females.
A total of 23 burbot were tagged and released; to date none have been
recaptured.
3.2.2 Introduction
Burbot, Lata lota L i nnaeus, known as 1 awyer, ling cod, lush, and mud shark,
is the only species of the cod family (Gadfdae) that lives in fresh water.
Their distribution is circumpolar in the northern hemisphere being found in
E-3-67
all suitable fresh water habitats in continental Eurasia and North America
sduthward to approximately 40° N (Scott and Crossman, 1973). In Alaska,
burbot are found in the Copper and Susitna Rivers, Bristol Bay drainages and
throughout the Interior, and the Arctic (Mclean and Delaney, 1978).
Burbot are elongate, robust and nearly rounded anteriorly while tapering
posteriorly with the caudal fin flared out and rounded. The mouth is terminal
with the upper jaw reaching to just below the eye. A single barbel hangs from
the chin.· Coloration on the dorsal side ranges from a blotchy yellow to dark
olive green while the ventral parts are pale yellow or white (Chen, 1969,
Morrow, 1980).
In Alaska, burbot mature between Age III and VI and may live a total of 15 to
20 years of age. Spawning occurs as early as mid December and may extend
through April, taking place at night under the ice in moderately shallow water
over a substrate of sand or gravel. Female burbot can deposit up to 1 million
eggs. Depending on the temperature, .incubation time ranges from 30 to 70 days
{Morrow, 1980) .
Little is known concerning the movements or migration of burbot, although
burbot have been observed migrating during spawning and feeding periods
(1'1acCrimmon, 1959). Burbot arr i1 nocturnal bottom fP!~dinq fish. Young burbot
(Age I-IT) prefer insect 1.1rvae (Hensen & Qu'dri, 1979), while adults will feed
ori whatever is available but prefer small fish (Hewson, 1955).
Burbot support a substantial sport fishery in the lakes of the upper Susitna
River drainages, particularly the Lake Louise,· Lake Susitna and Lake Tyone
E-3-68
chain of lakes where 6,612 burbot were estimated take in 1980 (Mills, 1980).
The burbot population in the study area is subject to very little exploitation
at the present time.
3.2.3 Methods
Burbot were collected from May to September, 1981 on trotl ines baited with
strips of round whitefish, grayling and longnose sucker.
All burbot captured were measured for total length. Otoliths were extracted
from a representative sample of captured burbot for age determination. Sex
was determined by necropsy.
All burbot uninjured by the sampling gear were tagged with Floy anchor tags.
3.2.4 Results and Discussion
3.2.4.1 Distribution and Relative Abundance
Burbot were collected at all eight Upper Susitna River habitat locat1on·s
during May to September, 1981 for a total catch of 88. The percent incidence
in sampling catches ranged from 50% of the locations sampled in May to 6 out .
of 7 sampled in July and 5 out of 5 sampled in September (Figure E.3.2.1).
Catch rates for all streams .combined varied from 0.53 in May to 0.95 in
September. The second highest catch rate, 0.73 burbot per trotline day, was
recorded in July (Table £.3.2.1).
E-3-69
..-----~---,--------------------------------------------~-------·-------
100 -----------
-
-p
E -
R 75 c
-r--
-
E -
N -
T -
-
I 50 -
N -
IT! c I -
w I I
~ -
0 0 -
E 25 -
N -c -
E -
-
0 ~~~~-MA_Y~J-~~-~-L~R-UG~S_E_P_--~---~~-~--~~~-j I I I I I
Figure E.3.2.1. Pe.r:cent inci~ence of burbot at habitat locations, upper Susitna River, 1981.
Table E.3.2.1. Burbot captured by month and tributary upper Susitna River, 1981.
Tributary May June ~ ~ Sept. Total
Fog 2 0 0 2
Tsusena 0 2 2
Deadman 1 0 1 2
Watana 5 6 6 4 3 24
Kosina 0 1 2 1 2 6
llay 10 5 4 4 9 32
Goose 0 3 5 3 7 18
Oshetna 0 0 1 0 1 2
TOTAL 18 17 19 12 22 BS
Trotl ine Days 27 32 26 22 22 129
Catch/
trotline day 0.62 0.53 0.73 0.54 0.95 0.68
E-3-71
All burbot catches were made immediately up or downstream from the tributary
confluence with the Susitna. Jay Creek, with a May to September average catch
rate of 1.14 burbot per trot line day, and total catch of 32 burbot was the
most consistently productive habitat 1 ocation followed closely by Watana and
Goose creeks (Table £.3.2.2).
3.2.4.2 Age, Length and Sex Composition
Otoliths were removed and analyzed from 54 burbot for age determination. Age
classes IV, V, and VI made up the majority of burbot, comprising 24%, 20%, and
35% respectively (Table E.3~2.3}.
Of the dominant age classes found, Age IV averaged 357 mm (range 300-398), Age
V averaged 382 mm (range 345-420 mm), and Age VI averaged 409 mm (range
325-500 rnm). The age-length relationship for burbot is shown in Figure
E.3.2.2.
Length determinations were made for a total of 88 burbot. Lengths ranged from
260 mm to 740 mm with a mean of 406 mm (Figure E.3.2.3). Of the 54 burbot
examined for sex composition, 24 (44%) were males and 30 (56%) were females.'
Males·cornprised 38% of the Age IV burbot and 73% and 37% of the Age V and VI
fish respectively.
fl single burbot of 15 mm TL was taken in Jay Creek tlune 20. Jt is believed
that this f·i sh had hePn hatched for no more thiin a few days. Assurnin~1 <l 70
day incubation time for spawned eggs given in the 1 iterature for ,,laska
E-3-72.
Table E.3.2.2. Burbot catch per trotline day fiahed and by tributary,
upper Susitna River, 1981.
Catch per
No. Trotline Trotline
No. Burbot Days Day_ Fi~~ed
Fog Creek 2 12 0.17
Tsusena Creek 2 5 0.40
Deadman Creek 2 10 0.20
Watana Creek 24 22 1.09
Kosina Creek 6 20 . 25
Jay Creek 32 28 1.14
Goose Creek 18 20 .90
Oshetna River 2 12 0.17
TOTAL 88 129 0.68
a One additional burbot was taken at the mouth of Kosina Creek by gillnet;
one young of the year burbot 15 mm TL was taken in Jay Creek by minnow trap.
E-3-73
Table E.3.2.3. Age, length and sex frequency composition of burbot, upper Susitna River basin, 1981.
Total No.
of Fish Mean Range of Male Female
Age Sampled Length (mm) Lengths No/% No/% Total --
I
II
III 2 295 260-330 1 1 2
IV 13 357 300-398 5 8 13
v 11 382 345-420 8 3 11
IT1
~ VI 19 409 325-500 7 12 19
I
-...,J
.j:::.VI I 4 445 385-490 1 3 4
VIII 3 528 510-540 1 2 3
IX
X 2 667 595-740 1/50 l/50 2
XI
TOTAL 54 406 260-740 24 30 54
,..,
I w
I
-.1 ,_n
,----· -----------------------------. -·. ---------... ----------------·-· -------_-·---------------..... -·--...... ------------·--------------.. ---1
L l!OO
E
N
G
T
H 200
I
N
M
M
L___
j
•
t t
•
t
AGE IN YEARS
t
+
t
t
Figure E.3.2.2. Burbot age-length relationship, upper Susitna River, 1981.
25
20. >-u z w 15 =>
0 w
~ 10
lL
0 n ~A nn n~n
r I I I I I I I I I
0 90 180 270 360 450 540 630 720 810 900
LENGTH Cmm)
Figure E.3.2.3. Length frequency composition of burbot captured at habitat location sites
on the upper Susitna River, May -September~ 1981.
temperature regimes, this would put spawning time about mid to late March.
All specimens captured during late May field work were spent or s~xually
immature. Observations by sport anglers for burbot in Paxson Lake are that
both ripe and spent burbot have been taken in mid-March (Stratton, 1981
personal communication). On the basis of the foregoing it is likely that
spawning for this species in the upper Susitna occurs during March. A b~rbot
of 102 mm was taken from Jay Creek Slough on August 19.
3.2.4.3 Tagging and Recapture
A total of 23 burbot were tagged {Table E.3.2.4). To date no tagged burbot
have been recovered.
E-3-77
Fog
Tsusena
Deadman
Watana
Kosina
Jay
Goose
Oshetna
TOTAL
Table E.3.2.4. Burbot tagged by month and tributary,
upper Susitna River, May -September, 1981.
~ June ~ ~ Sept.
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
2 0 3 4 1
0 0 1 1 2
2 0 0 2 1
1 0 0 3 0
0 0 0 0 0
5 0 4 10 4
E-3-:-78
Total
0
0
0
10
4
5
4
0
23
3. 3 R'OUND HH ITEF ISH
3.3.1 Abstract
Thirty-three adult round whitefish, Prosopium cyl i ndraceum, were captured
during 43 gillnet days fished at upper Susitna habitat locations. This
species was captured from the Oshetna River, Jay, Kos·ina, Watana, and Tsusena
creeks. Jay and Kosina creeks were the most productive with total catches of
13 and 9 respectively. Twenty-two whitefish were aged by scale analysis.
Ages ranged from VI to VI II with age VII fish the most numerous. The fork
1 ength of age VI round whitefish averaged 323 mm (range 315-370 mm) age VII
averaged 364 mm (range 340-440 mm) and age VIII averaged 414 mm (range
387-440 mm).
3.3.2 Introduction
Round whitefish, Prosopium cylindraceum Pallus, are distributed across all of
the Aictic and Interior Alaska. Rivers of occurrence in southcentral Alaska
include the Copper, Kenai and the Susitna. This species also occur in the
large fivers draining into southeast Alaska from Britis-h Columbia. Round
~1hitefi sh are abundant in clearwater streams with gravel-cobb 1 e substrate but
the species is also found in large glacial rivers and lakes. Round whitefish
prefer freshwater and are not normally found in an estuarine environment.
Round whitefish are identifiable by their ·round, cigar-shaped body and small
mouth. Adults may reach a 1 ength of up to 20 inches and weigh up to four
pounds. There are no obvious external differences between the sexes.
E-3-79
Spawning occurs in late September through October over gravel substrate in the
shallows of rivers and the inshore areas of lakes (Furniss, 1974). For
Alaskan round whitefish~ consecutive year spawning appears to be the rule even
in Arctic populations (McCart et al., 1972). Upstream migrations associated
with spawning were also observed by McCart and are probably characteristic.
Alaskan subsistence fishermen harvest round whitefish with gill nets for human
consumption and as dog food. Round whitefish also support limited hook and
line and spear sport fisheries in the Tanana River drainage.
· 3.3.3 Methods
Round whitefish were collected from upper Susitna River habitat locations
during May to September 1981 with. variable mesh gill nets. Catches were
1 imited to the area immediately up or downstream of the tributary confluence
with the Susitna.
All fish captured were measured for fork length in millimeters (mm) and, Where·
survival was likely, the fish were tagged with Floy anchor tags and released.
Age determinations were made using scale analysis. Sex was determined by
necropsy and by abdominal. manipulation to obtain the discharge of eggs or
milt.
E-3-80
3.3.4 Results and Discussion
3.3.4.1 Distribution and Relative Abundance
Round whitefish were captured at all habitat locations in the upper Susitna
River except Fog, Deadman and Goose Creeks. Catches of round whitefish per
gill net day fished by habitat location are given in Table E.3.3.1. Jay and
Kosina Creeks were the most productive with total catches of 13 and 9
respectively. The percent incidence of round whitefish at habitat locations
ranged from 33% in July to 75% in September (Figure E.3.3.1).
Forty-seven juvenile round whitefish (18-52 mm) were captured using seines and
electroshockers at Jay Creek.
3.3.4.2 Age, Length and Sex Composition
Twenty-two upper Susitna River round whitefish from gill net catches were aged
by scale analysis. Table E~3.3.2 illustrates that ages ranged from VI to ~III
with age VII being encountered most frequently.
The fork 1 ength of age VI round whitefish averaged 323 mm (range 315-370 mm)
age VII averaged 364 mm (range 340-440 mrn) and age VIII averaged 414 mm (range
387~440 mm). Age VII fish dominated the sample.
All round whitefish captured were measured for fork length in.millimeters.
Lengths for adults ranged from 315 mm to 440 mm and the mean was 366 mm.
E-3-81
Table E.3.3.1. Round whitefish catch per gillnet day at habitat location sites,
upper Susitna River, May to September, 1981.
Catch per
Tributary Number Caught Gi 11 net Da12_ Gillnet ~
Fog Creek 0 4 0
Tsusena Creek 3 4 0.75
Deadman Creek 0 3 0
Watana Creek 5 6 0.83
Kosina Creek 9 8 1.13
Jay Creeka 13 8 1.63
Goose Creek 0 6 0
Oshetna River 3 4 0.75
Total 33 43 0. 77
a A total of 47 juvenile round whitefish 18-52 mm were taken by seine and electro-
shocker.
E-3-82
[T]
I
w
I :c
"...,)
-
r-------
lr r l I I
tv1A'( JUN JUL RUG SEP
Figure_.E.3.3.1. Percent incidence of round whitefish at habitat locations, upper Susitna River, 1981. . . . .
Table E.3.3.2. Round whitefish, age-length-sex frequen~y composition at
habitat location sites, upper Susitna River,
May to September, 1981.
Length Sex
Total No. Mean
Fish Length Range of Male Female
Age Sameled {mm) Lengths No No Total
1
2
3
4
5
6 4 323 315-370 2 1 3
7 14 364 340-410 4 1 . 5
8 4 414 387-440 3 3
9
10
11
22 366 315-370 9 2 11
E-3 -84
Eleven round whitefish examined for sex composition, 9 (82%) were male and 2
(18%) were female, for a male to female ratio of 4.5:1.
A total of 63 juvenile whitefish were taken during 1981 operations. Young of
the year whitefish taken in June ranged from 18-37 mm, in July from 38-52 mm
and in August from 49-77 mm.
3.3.4.3 Tagging and Recapture
A total of 17 round whitefish were tagged during May to September 1981 in the
upper Susitna River {Tabln E.3.3.3). No recaptures have been recorded.
E-3-85
Table E.3.3.3. Round whitefish~ summary of tagging data, upper Susitna River,
May to September, 1981.
Tributary May June ~ ~ Sept._ Total
Fog 0 0 0 0 0 0
Tsusena 0 0 0 0 0 0
Deadman 0 0 0 0 0 0
Watana 0 0 0 0 2 2
Kosina 0 0 0 0 5 5
Jay 0 1 0 6 0 7
Goose 0 0 0 0 0 0
Oshetna 0 0 0 3 0 3
Total 0 1 0 9 7 17
E-3-86
3.4 LONGNOSE SUCKER
3.4.1 Ab$tract
One hundred forty-four adult 1 ongnose sucker, Catostomus catostomus, were
captured during 43 gillnet days fished at upper Susitna habitat locations.
This species was collected from the Oshetna River, Goose, Jay, Kosina, Watana,
and Deadman creeks. Gillnet sets at Watana Creek mouth produced 52 percent of
suckers caught.
Scales were removed and analyzed from 90 upper Susitna River longnose suckers.
Age classes VII, VIII, and IX made up the majority of longnose suckers
comprising 27%, 36%, and 20% respectively. Of the longnose suckers used for
age determinations, Age VII suckers averaged 355 mm (range 325-405 mm) while
Age VIII averaged 381 mm (range 340-430 mm) and Age IX averaged 405 mm (range
380 -485 mm) .
Ninety-seven longnose suckers were tagged. One tagged at the mouth of Watana
Creek May 26 was recaptured at the same location on June 24.
3.4.2 Introduction
The· longnose sucker, Catostomus catostomus Forster, is widely distributed from
Alaska to Labrador and extends south into the Mississippi-Missouri River
systems. It is ubiquitous throughout most of the drainages of mai~larid
Alaska; it is not found on the islands along the Pacific, Bering and Arctic
coasts (Morrow, 1980).
E-3-87
The longnose sucker is the only representative species of the sucker family
found in Alaska. It can be easily distinguished from other Alaskan fishes by
its ventrally located sucking mouth and large papillose lips. There are no
obvious external differences between the sexes except during spawning periods
when breeding males have well-developed tubercles on the head, anal and caudal
fins. and are more vividly colored than the female. Sexual maturity occurs
between the ages of V and VII. Spawning usually takes place in spring shortly
after ice out in shallow gravel-bottomed portions of streams. Post spawning
mortality of between 10-30 percent may occur. Many fish spawn consecutively
for two or three years while others may skip years between spawning (Green, et
al., 1966). The eggs hatch in about two weeks, depending on temperature, and
the fry remain in the gravel an additional 1-2 weeks after hatching.
3.4.3 Results and Discussion
3.4.3.1 Distribution and Relative Abundance
Longnose suckers were found in all habitat locations except Fog and Tsusena
creeks (Table E.3.4.1). All adult suckers were captured in gill nets set
immediately upstream or downstream of the confluence of the tributary streams.
A tota 1 of 144 suckers were captured during May-September. The mouth of
Watana Creek produced consistent catches of suckers with a total of 75.
The percent incidence of longnose sucker at tributary habitat locations is
shmvn in Figure E.3.4.1. For July all locations fished produced suckers
E-3-88
Table E.3.4.1. Longnose sucker catch per gill net day fished by tributary, 1981a
Catch per
Tributary No. Caught Effort Gillnet Day
Fog Creek 0 4 0
Tsusena Creek 0 4 0
Deadman Creek 3 3 1.0
vlatana Creek 75 6 1.0
Kosina Creek 8 8 1.0
Jay Creek 28 8 3.5,
Goose Creek 14 6 2.3
Oshetna River 16 4 4.0
Total 144 43 3.45
a A. total of 24 juvenile longnose suckers 24~84 mm age I+ were captured by seine,
electric shocker. and minnow trap.
E-3-89
,...,
I
w
I
1.0
0
..---------,----·------·-·····-····--· ----------------
100
p
E
R 75 c
E
N
T
I 50
N c
I
0
E 25
N c \
E
-r 1
MAY JUN JUL AUG SEP
1-----------------'----------------------. ------------···-·-------
Figure E.3._4.1. Percent incidence of longnos~ sucker at habitat locations, upper Susitna River,
-. May to September, 1981.
(Kosina and Fog were not fished). Twenty-five percent of habitat locations
fished in May and in September produced this species.
Twenty-seven juvenile 1 ongnose suckers ranging from 28-105 mm were captured by
seine, electroshocker, and minnow traps in slough~ and backwater areas of the
Susitna River at Jay, Kosina, and Watana creeks.
3.4.3.2 Age, Length and Sex Composition
Scales were removed and analyzed from 90 upper Susitna River longnose suckers.
Age classes VII, VIII, and IX made up the majority of longnose suckers com-
pri~ing 27%, 36%, and 20% respectively.
Of the longnose suckers used for age determinations, Age VII suckers averaged
355 mm (range 325-405 mm) while Age VI II averaged 381 mm (range 340-430 mm)
and Age IX averaged 405 mm (range 380-485 mm). Gi 11 net captured l ongnose
sucker lengths ranged from 320-505 mm with a mean of 384 mm (Table E.3.4.2).
Eight suckers were examined for sex composition. Three (38%) were males and 5
(62%) were females.
3.4.3.3 Tagging and Recapture
A total of 97 longnose suckers were tagged (Table E.3.4.3). One recapture of
a tagged sucker occurred June 24 at the mouth of Watana Creek also its tagging
location on May 26.
E-3-91
Table E.3.4.2. Longnose sucker, age-length-sex frequency composition at
habitat location sites, upper Susitna River,
May to September, 1981.
Length Sex
.Total No. Mean
Fish Length Range of Male Female
Age Same led (mm) Lengths No No Total
1 1 105 105
2
3
4.
5
6 2 340 320-360
7 24 355 325-405 1 3 4
8 32 381 340-430 1 1
9 18 405 380-485 2 1 3
10 8 440 405-4-75
11 5 468 407-505
90 384 105-505 3 5 8
E-3-92
Table E.3.4.3. Longnose Sucker tagged by month and tributary,
upper Susitna River, May to September, 1981.
Tributary May June ~ ~ Sept.
Fog 0 0 0 0 0
Tsusena 0 0 0 0 0
Deadman 0 0 3 0 0
Watana 13 25 0 4 1
Kosina 0 0 0 1 0
Jay 0 7 1 17 0
Goose 0 9 0 3 0
Oshetna 0 0 1 12 0
Total 13 41 5 37 1
E-3-93
Total
0
0
3
43
1
25
3
13
97
3.5 COTTIDS
3.5.1 Abstract
Slimy sculpins, Cottus cognatus, were collected at seven of eight habitat
locations in .the upper Susitna River. A total of 38 cottids were captured
giving an overall catch per minnow trap day of 0.11. Oshetna River, Fog, and
Tsusena Creek showed the highest catch per unit of effort of 0.20, 0.22, and
0.23 respectively. The length range for the season catch was 37-95 mm.
3.5.2 Introduction
The slimy sculpin, Cottus cognatus Richardson, ranges over all of Alaska, most
of Canada, and is found as far south as Virginia. It also extends to the
extreme northeast of Siberia (Scott and Crossman, 1978).
Slimy sculpin are a small bottom-dwelling fish. They are tadpole shaped with
a rounded caudal fin, and they very in color from solid brown to a mottled
gray...:green (Morrow, 1980). Two distinguishing species cha racteri sti cs are
double chinpores and a short lateral line ending midway under the second
dorsal fin.
Slimysculpin· mature between Age II and IV and can live to Age VII (Craig and
Wells, 1976). Spawning occurs in spring at breakup. The male picks the nest
site which is usually in shallow water with a sandy substrate. The female
lays an average of 150 to 600 eggs. More than one fema 1 e may 1 ay her eggs in
E-3-94
a nest but only one male will fertilize the eggs (Koster 1936; Van Vliet,
1964). Incubation time requires about 30 days.
Sculpin feed mostly on insect larvae, nymphs, and fish larvae. The sculpin
may serve as a forage species for lake trout, burbot and grayling (Morrow,
1980).
3.5.3 Methods
Cottids were collected in the upper Susitna River with baited minnow traps.
All cottids captured were measured for total length in millimeters (mm).
3.5.4 Results and Discussion
3.5.4.1 Distribution and Relative Abundance
Thirty-eight cottids were taken during 352 minnow trap days from upper Susitna
River habitat locations and selected fish habitat sites (Table E.3.5.1). The
catch rate during May to September, 1981 fbr habitat locations was 0.11/trap
day. The high cottid catches were recorded for Fog Creek, Tsusena Creek' and·
the Oshetna River with total catches of 8, 9 and 10 respectively. Tsusena
Creek had the highest catch rate at 0.23, while no cottids were captured at
Jay Creek during this study. Sally lake, a selected fish habitat site. was
minnow trapped only during May resulting in 4 cottids collected.
E-3-95
Table E.3.5.1. Cottid catch per minnow trap day at
fish habitat location sites on the upper Susitna River,
May to September, 1981.
Minnow Trap
Habitat Location Site No. Caught Days
Fog Creek 8 36
Tsusena Creek 9 40
Deadman Creek 2 29
Watana Creek 6 45
Kosina Creek 1 50
Jay Creek 0 50
Goose Creek 2 50
Oshetna River 10 50
Sally Lake 4 2
38 350
a Total does not include Sally Lake.
E-3-96
Catch/
Trap Day
0.22
0.23
0.07
0.13
0.02
0
0.04
0.20
2.0
0.11
3.5.4.2 Age, Length, and Sex Composition
Thirty-eight cottids were measured for total lengths. Lengths ranged from
37-95 mm. No data for age determination or sex composition was recorded.
E-3-97
3.6 LAKE TROUT
3.6.1 Abstract
Lake trout, Salvelinus namaycush were taken from Sally and Deadman Lakes.
Seventeen days of gillnet effort in Sally Lake produced 30 lake trout.
Limited hook and line sampling in Sally and Deadman lakes produced 2 and 3
trout respectively. Fork 1 engths of 1 ake trout captured ranged from 305 to
505 mm. No lake trout were captured from the Susitna River or from the eight
tributary stream habitat locations.
3.6.2 Introduction
The lake trout, Salvelinus namaycush, is also known as lakr char, grey trout,
and togue. Distribution ranges from the Alaska Peninsula e1st to Nova Scotia,
south to New York, Pennsylvania, andthe Great Lakes, and north to the islands
of the Canadian arctic (Morrow, 1980). It almost always inhabits deep, clear
lakes, although stream-dwelling populations sometimes occur where the rivers
are connected to lakes; the latter situation is most common in Labrador,
northern· Quebec, and Alaska. There is considerable variation in color for
this species, but the body is generally blue-gray or bronze-green, with pale
spots on sides and back and with pale spots on the dorsal, adipose, and caudal
fins (Mclain, 1965).
Spawning occurs in the fall from early August to December. Virtually all la~e
trout spawn in lakes over clean, rocky bottoms at depths of five feet or less.
E-3-98
Sexua 1 maturity usually occurs between age V and VI I. Young emerge between
early February and late March usually preceding breakup. Studies of Alaskan
lake trout have been conducted by Roguski and Spetz, 1968, Van Wyhe and Pelk,
1969, and Furniss, 1974. The Alaska state record lake trout came from
Clarence Lake in the Kosina Creek drainage and weighed 44 pounds.
3.6.3 Results and Discussion
3.6.3.1 Distribution and Relative Abundance
Lake trout were found in Sally Lake and Deadman Lake, two selected fish
habitat sites in the upper Susitna River basin. Of these two sites, only
Sally Lake will be inundated by the proposed Watana Dam. Sally Lake sampling
was by gillnet and hook and line fished at various depths of up to ·40 feet.
All ·lake trout caught were within 100 feet of the shoreline in less than 6
feet of water. A total of.32 trout .were captured in this lake, thirty were
captured by gill net and 2 by hook and 1 ine. Three Deadman Lake trout were
captured all by hook and line. Catch per rod and reel hour was highest in
Deadman Lake where it ran 0.75/hour (Table E.3.6.1). A limited sport fishery
exists on Deadman and Sally Lakes for lake trout and grayling.
3;6.3.2 Age, Length and Sex Composition
Scales were taken from 19 lake trout collected in Sally Lake. Only seven
sc~les were readable, and all of these were Age V.
E-3-99
Table E.3.6.1. Lake trout catch and effort, upper Susitna River basin lakes
May to September, 1981.
Sally Lake
May -September 1981
Catch
Gear No. Caught Effort Unit effort No. Tagged
Gill Net 30 17 Days 1. 74/Day 10
Rod & Reel 2 12 Hours 0.17 /Hour 2
TOTAL 32 12
Deadman Lake
September 1981
Catch
Gear No. Caught Effort Onit effort No. Tagged
Rod & Reel 3 4 Hours 0.75/Hour 0
E-3-100
Lengths were recorded from 32 Sally Lake lake trout. Lengths ranged from 305
to 508 mm and the mean was 410 mm.
Sixteen lake trout were examined for sex composition. Equal numbers (8) of
each sex were found.
During mid-August, both prespawning and post spawning lake trout were captured
in Sally Lake.
3.6.3.3 Tagging and Recapture
A total of twelve lake trout were tagged at Sally lake. No recaptures have
been recorded.
E-3-101
3.7 MISCELLANEOUS SPECIES
During the course of 1981 field studies, a single specimen each of humpback
whitefish and Dolly Varden was captured. The 1 ife history and background for
these species has been presented in the RJ report submitted on the lower
Susitna River and will not be reviewed in detail here.
The humpback whitefish taken was a male 347 mm fork length taken at the mouth
of Kosina Creek on September 24. This whitefish has been documented by Fish
and Game personnel to occur in lakes Susitna and Louise.
The single Dolly Varden was taken at the mouth of Fog Creek August 25. This
fish was a male, 235 mm in fork length. ' The only prior known occurrence of
this species in the upper Susitna system was from Lake Louise.
No juvenile· or adult salmon were captured or observed in the upper River
during 1981 field ope~ations. It is believed that effort exerted was adequate
to detect salmon species if present in any numbers. A total of 348 minnow
trap days were fished in possible juvenile salmon habitat. Electrofishing and
s·eine hauls were also carried out in prime habitat. Most of the 22.5 miles of
clearwater tributary to be impounded were surveyed by foot and from hel i-
copters monthly.
E-3-102
4. RECOMMENDATIONS
During 1981 operations, gillnets, minnow traps and seines produced minimal
catches considering man hours expended in their use. The torrential water and
boulder strewn channels of the tributary streams minimized the successful
utilization of seines and gillnets. Minnow trap production was largely
limited to sculpin, and their use confirmed the absence of juvenile salmon
species. It is recommended that the general use of this gear should be
discontinued in future main river and tributary studies.
Operations in 1982 should be planned to emphasize the recovery of grayling
tagged in 1981. Sampling will be largely by hook and line. Further testing
of portable electroshocking units in select habitat sites is recommended. It
would· be desirable to use an electroshocking equipped boat to sample at
tributary mouths, side sloughs and channels, and main river habitat locations
below Vee Canyon.
Investigations shoJld endeavor to reach key streams prior to and immediately
following ice-out to determine timing and location of spawning. Such determi-
nation will be accomplished largely by catching spawning speCimens with rod
and reel.
The upper reaches of streams and lakes into which grayling now move seasonally
and will move following impoundment should be investigated by helicopter.
Specimens caught should be tagged to evaluate interchange with lower reath~s
of· tributaries and the mainstem Susitna River.
E-4-1
It may be desirable to initiate a population study of lake trout in· Sally
lake. Trout could be captured for tagging through the use of Fyke type nets.
Subsequently recovery would give an indication of population numbers.
E-4-2
5. ACKNOWLEDGEMENTS
This study was funded by the State of Alaska, Alaska Power Authority.
conducted by the following Alaska Department of Fish and Game
biologists:.
Kevin Delaney, Project Leader
Resident and Juvenile Anadromous Fisheries Studies
Drew Crawford
Larry Dugan
Stephen Hale
Karl Kuntz
Bob Marshall
James Mauney
James Quinn
Kent Roth
Paul Suchanek
Richard Sundet
Mike Stratton
E-5-1
It was
staff
6. LITERATURE CITED
Alaska Department of Fish and Game. 1978. Preliminary environmental assess-
ment of hydroelectric development on the Susitna River. Anchorage. 172
pp.
/ Andrews, R.E. 1952. A preliminary report on fish and wildlife resources in
relation to the Susitna Basin Plan. Alaska Fish and Wildlife Service.
United States Department of the Interior. _pp.
1954. A progress report on the· fishery resources of the Susitna
River Basin. Fish and Wildlife Service. United States Department of the
Interior. _pp.
,_/ 1858. Field Investigations, Denali and Vee Canyon dam site and
/
reservoir areas, Susitna River Basin. Fish and Wildlife Service. United
States Departnent of the Interior. _pp.
__ 1960. A detailed report on fish and wildlife resources affected by
the Devil Canyon Project, Alaska. Fish and Wildlife Service. United
States Department of the Interior. _pp.
____ 1961. Inventory, cataloging and population sampling of the sport
fish waters cf the Cook Inlet drainage. Alaska Department of Fish and
Game. Federal Aid in Fish Restoration, Annual Report of Progress, 1961
Project F-5-R-3, Vol. 3:175-206.
E-6-1
~· 1965. A detailed report on fish and wildlife resources affected by
Vee Project, Susitna River, Alaska. Fish and wildlife Service. United
States Department of the Interior. ___ pp.
Chen, L.C. 1969. The biology and taxonomy of the burbot, Lata lata. leptura,
in interior Alaska, Bio1. Pap., Dept. of Wildlife Manag. Univ. of Alaska,
11:1-51.
Craig, P.C., and J. Wells. 1976. Life history notes for a population of
slimy sculpin (Cottus. cognatus) in an Alaskan arctic stream. J. Fish.
Re. Bd. Canada. 33(7):1639-1642.
Furniss,· R.A. 1974. Inventory and cataloging of arctic area waters. Alaska
Department of Fish and Game. Fed. Aid Fish Restor., Ann. Performance
R~pt., Project F-9-6, JOB G-1-J. 15:1-45.
Hallberg, J.E. 1979. Distribution, abundance and natural history of the
Arctic grayling ·in the Tanana Drainage. Alaska Department of Fish and
Game. Federdl Aid in Fish Restoration, Annual Report of Progress,
1978-1979, Project F-9-11. 16 pp.
Hanson, ~1. and S.U. Quadri. 1979. Morphology and diet of young-of-the-year
burbot, Lata lata_ in the Ottawa River, Dept. of Bio., Univ. of Ottawa,
Ottawa, Ontario. Vol. 94:311-314.
Hewson, L.C. 1955. Age, maturity, spawning, and food of burbot, Lota lota,
in Lake Winnipeg. J. Fish. Res. Bd. Canada. 12(6):930-940.
E_:6-2
McCart, P., P. Craig, and H. Bain. 1972. Report on fisheries investigations
in the Sagavanirktok River and neighboring drainages. Alyeska Pipeline
Service Co. 165 pp.
McClane, A.J. 1965. McClane's standard fishing encyclopedia and inter-
national angling guide. Holt, Rinehart and Wintson. New York. __ pp.
McCrimmon, H.R. 1959. Observations on spawning of burbot in Lake Simcoe,
Ontario. J. Wildl. Mgmt. 23(4):447-449.
McLean, R.F., and K.J. Delaney. 1978. Alaska's fisheries atlas. Vol. 2.
Alaska Department of Fish and Game. 43 pp + 153 maps.
Mills, M.J. 1980. Alaska statewide harvest study-1980 data. Alaska Depart-
ment of Fish arid Game. Fed. Aid Fish. Restor. and Anad. Fish Studies,
Ann. Perf. Rept. Study No. SW-I Job No. SW-I-A, Vol. 22:1-34.
Morrow, J.E. 1980. The freshwater fisl1es of Alaska. Alaska Northwest
Publishing Company, Anchorage 248 pp.
Pearse, G.A. 1974. A study of a typical spring fed stream of interior
Alaska. Alaska Department of Fish and Game. Annual Performance Report.
Project F-9-6, Joh G-Ill-G. 15:1-?9.
E-6-3
Reed, R.J. 1964. Life history and migration patterns of Arctic grayling,
Thymallus arcticus (Pallas). in the Tanana River drainage of Alaska.
Alaska Department of Fish and Game. Res. Rept. 2:1-30.
Ricker, W.E. 1975. Computation and interpretation of biological statistics
of fish populations. Fisheries Research Board of Canada, Ottawa. _pp.
Roguski, E.A., and C.E. Spetz. 1968. Inventory and cataloging of sport fish
and sport fish waters in the interior of Alaska. Alaska Department of
Fish ancf Game. Fed. Aid Fish Restor .• Ann. Dept. Progress, Project
F-5-R-9. 9:265-285.
Scott, W.B., and E.J. Crossmann. 1973. Freshwater fishes of Canada.
Fisheries Research Board of Canada. Bull. 184. 966 pp.
Terrestrial Environmental Specialists, Inc. 1981. Life history and ecology
of selected fishes that occur in the Susitna River. Phoenix, New York.
_pp.
Van Whye, G.L., and J.W. Peck. 1969.
Summit Lakes in inter-lor Alaska.
Info. Leaflet. 124:1-40.
A limnological survey of Pasxonand
Alaska Department of Fish and Game.
Vascotto, G.L. 1970. Summer ecology and behavior of the grayling of l'kManus
Creek, Alaska .. M.S. Thesis, University of Alaska, Fairbanks. 132 pp.
E-6-4
Weast, R.C., S.M. Selby, and C.D. Hodgman. (editors). C.R.C. Standard
mathematical tables, thirteenth edition.
Cleveland, Ohio. _pp.
The Chemical Rubber Co.
/ Williams, F.T. 1967. Inventory and cataloging of sport fish waters of the
Copper River and Prince William Sound drainages, and the upper Susitna
River. Alaska Department of Fish and Game. Fed. Aid Fish Restor. Annual
Report of Progress. 1966-1967, 8:217-230.
Williams, F.T. 1976. Diary of upper Susitna River float trip. Unpublished.
Alaska Department of Fish and Game. Div. Sport Fish. Glenallen.
E-6-5
Appendix Table EA-1. Arct1c grayling fork length comparisons by tributary
for May, 1981 (95% C.I.)
Number of
Tributaries Observations Mean l. L. U.L. Median
Oshetna 19 319 302 335 325
Goose 107 297 288 306 290
Jay 88 343 336 349 340
Kosina 97 309 301 316 310
Vlatana 3 278 250
Deadman 51 301 289 311 300
Tsusena 34 334 324 344 331
Fog 30 319 308 330 323
Combined 429 315 311 319 320
Kruskal-Wallis Test
H0 : All medians the same
H1 : At least one median different
Test statistic = H = 81 140 c .
Critical table value a X2 .025,7 = 16.013
Reject H0
Appendix Table EA-2. Arctic grayling fork length comparisons by
tributary for June, 1981 (95% C.I.)
Number of
Tributaries Observations Mean L.L. U.L.
Oshetna 85 301 293 309
Goose 144 296 289 302
Jay 179 294 286 303
Kosina 246 305 299 311
Watana 48 303 290 316
Deadman 71 283 274 293
Tsusena 72 341 333 349
Fog 17 325 309 340
Combined 862 302 299 306
Kruskal-Wallis Test
H0 : All medians the same
H1 : At least one median different
Test statistic = He = 84.599
Critical table value = x2 .025,7 = 16.013
Reject H0
Median
295
300
300
310
310
290
345
320
305
'Appendix Table EA-3. Arctic grayling fork length comparisons by
tributary for July, 1981 (95% C. I.)
Number of
Tributaries Observations Mean
Oshetna 150 295
Goose 81 294
Jay 67 287
Kosina 130 290
Watana 14 302
Deadman 38 287
Tsusena 125 325
Fog 33 303
Combined 638 299
Kruskal-Wallis Test
H0 : All medians the same
H1 : At least one median different
Test statistic = He = 58.610
Critical table value = x 2 .02~,7 = 16.013
Reject H 0
L.L. U.L.
289 302
285 304
276 299
283 298
281 323
272 303
317 332
289 316
296 303
Median
299
300
290
295
298
293
325
305
300
Appendix Table EA-4. Arctic grayling fork length comparisons by
tributary for August, 1981 (95% C.I.)
Number of
Tributaries Observations Mean
Oshetna 73 301
Goose 40 307
Jay 19 314
Kosina 72 314
Wata.na 15 340
Deadroan 6 245
Tsusena 50 330
Fog 4 276
Combined 279 307
Kruskal-Wallis Test
H0 : All medians the same
H1: At least one median different
Test statistic = H = 35.253 c
Critical table value= x2 .025,7 = 16.013
Reject H0
L.L. u. L.
292 311
299 315
298 329
293 311
290 339
321 338
303 312
Median
300
305
315
305
323
233
325
315
315
Appendix Table EA-5. Arctic grayling fork length compraisons by
tributary for September, 1981
Number of
Tri buta ri es Observations Mean
Oshetna 161 331
Goose 15 306
Jay 69 301
Kosina 176 327
Watana 19 350
Deadman 7 317
Tsusena 8 356
Fog 5 355
Combined 460 325
Kruskal-Wallis Test
H0 : All medians the same
Hl.: At least one median different
Test statistic = He = 83.1920
2 Critical table value = X .025,7 = 16.013
Reject H0
L.L. U.L.
327 335
277 335
292 308
324 331
338 362
323 328
Median
330
318
300
325
355
315
355
352
325
Appendix Table EA-6. Juvenile fish species captured by date,
location, and size groupings, upper Susitna
River, 1981.
Date
5/23
6/17
6/22
6/24
7/18
7/19
7/25
8/19
8/24
9/25
6/20
8/19
6/22
6/25
7/18
7/19
Location Captured
ARCTIC GRAYLING
Goose Creek; shallow side channel 3
miles upstream from mouth
Oshetna River
Susitna River 1/2 mile below
confluence with Jay Creek
Kosina Creek
Jay Creek lower mile
Susitna River Slough upstream of
confluence with ,Jay Creek
Tsusena Creek
Jay Creek Slough
Fog Creek habitat location 2
Watana Pond
BUR BOT
Jay Creek Lower
Jay Creek Slough
ROUND WHITEFISH
Susitna River 1/2 mile below Jay
Creek
Watana Creek Mouth
Jay Creek lower one mile
Slough above Jay Creek
Number
Captured
2
1
5
3
1
9
3
1
1
2
1
21
10
1
1
1
16
20
1
10
a Length measurement in mm for total length unless stilted otherwise.
Length
Size Range
54-115
64
20-22
75-95
37
24-48
84-95
114
51
47-68
12.5.
50-150
47-60
100
15
10?
27-:32 fl
45
38-52
Appendix Table EA-6. (Continued)
Number
Date Location Ca~tured Ca[!ture Size Range
8/19 Jay Creek S ough 4 120-l!JO
8/24 Fog Creek habitat location site 2 3 49-77
. 9/25 Watana Pond 8 5?-68
LONGNOSE SUCKER
6/22 Jay Creek isolated poo 1 , north bank 15 35-55
4 60-84
6/24 , Kos ina Creek 1 28
6/25 Watana Pond 7 35-80
SLIMY SCULPIN
6/22 Jay Creek isolated pool north bank 2 30-46
a Length in millimeters for total length unless stated otherwise.
Appendix Table EA-7. Model of Upper Susitna River population
estimation for Arctic Grayling.
Schnabel method for Multiple Census
Mt the total marked fish at large at the start of the
th day (or other interval), i.e .• the number
previously marked less any accidentally killed at
previous recaptures.
M :!.Mt, the tota 1 number marked.
Ct the total sampl~ taken o·n day t.
Rt the number of recaptures in the sample Ct.
R =t;Rt, the total recaptures during the experiment.
N the population present throughout the experiment.
Population estimation
Confidence limits V(l/~) = !:Rt
----=----=
[E\CtMt) ]2
1
"N-1.96 1. 96
df = 4
Appendix Table EA-8. Arctic grayling within tributary recaptures by tributary
of tagging and month of rec~pture. upper Susitna River,
June to September, 1981.
MONTH
TRIBUTARY JUNE JULY AUGUST SEPTEfVIBER TOTAL
Fog 4 7 3 0 14
Tsusena 3 12 15 2 32
Deadman 4 3 2 0 9
Watana 0 0 0 2 2
Kosina 17 13 15 20 65
Jay 9 19 15 16 59
Goose 10 12 17 2 41
Oshetna 0 18 14 5 37
Total 47 84 81 47 259