HomeMy WebLinkAboutAPA3223D,ANIEL M. BISHOP ~nvironaid
•,
ON THE BLACK BEAR CREEK SYSTEM
NEAR ~~~LA WOCK, ALASKA
AUGUST 1982 CHECK FOR I M.=o.'¥-V---
IN Prx ... ket
DANIEL M. BISHOP ~nvironaid
12175 Mendenhall Loop Road
JUNEAU, ALASKA 99801
907 789-9305 ~~
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135'33 •
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BIOLOGICAL -ECOLOGICAL INVESTIGATIONS
on the
BLACK BEAR CREEK SYSTEM
_ AJU.!S August, 1982
Alaska Resources Library & Information Services
Libr.trv BuiiJing, Suite 111
· 321 i Providence Drive
Anchorage,AK 99508-4614
TABLE OF CONTENTS
INTRODUCTION
OBJECTIVES AND SCOPE OF WORK
CHARACTERISTICS OF UPPER BLACK BEAR CREEK DRAINAGE
Physical
Climate, weather
Configuration of area •
Streamflow characteristics
Groundwater emergence •
Stream sediment characteristics
Stream temperatures •
Lake profile information
Black Bear Lake •
Black Lake
Water chemistry data
Biological -Fisheries
Black Bear Lake -lack of data
Adult escapements
Outmigration of fry and smolt
Black Lake
Resident population
Productivity
Rearing population above Black Lake
Habitat mapping •
Summary •
Biological -Wildlife
Methods of observation
Specific observations
Black bear
Beaver
Deer
Wolf
Mustelids
General observations
Black bear
Beaver
Deer
Wolf
•'
ii
1
2
3
3
3
4
4
12
14
14
21
21
30
31
36
36
37
46
79
79
81:
87
92
110
114
114
115
115
11:8
121
123
124
126
126
127
128
129
EFFECTS OF PROPOSED HYDROELECTRIC PROJECT ON
FISHES AND THEIR HABLTATS • • • • • • • • •
Black Bear Lake Habitat
Spawning Habitats above Black Lake •
Rearing Habitats above Black Lake
Black Lake as a Rearing Habitat and
Migrating Route for Salmonids
Below Black Lake • • • • • •
EFFECTS OF PROPOSED HYDROELECTRIC PROJECT ON
WILDLIFE AND THEIR HABITATS • • • • •
Bear •
Beaver
Deer ••
Wolf, Mustelids
APPENDIX . . .
CITATIONS . .
iii
. .. . . 130
130
. . . . 130
147
156
158
. . . 160
.-. 160
160
161
161
• • 162
180
TABLES, FIGURES, PLATES AND MAP
TABLE 1: Craig Climatic Information ..•..........••.....•••.. Page 4
2: Change in profile temperatures, Lower Black Lake .•.....• 30
3: Water Chemistry Data. . . . . . • . . • • • • • • . • . . • . . • . • • . . • . • . • • . . • 32
4: Pink Salmon Peak. Escapement Sur~eys,
Black Be~t Creek, 1960-81 •.•.••.•..••.•...........••.•• 37
5a,b,c,d,: No's of Spawning Sockeye, Pink, Chum,
Coho Salmon, 1981 •.••.• ~ •.•••••.•.••••••.•.•••..•••• 40 43
6: Morphoedaphic index of 22 lakes in S.E. Alaska ••...•.... 82
7: Chemical data for Black Lake at spring turnover ••......• 84
8: Total Phosphorous in May for other lakes---............. 84
9: Zooplankton abupdance and average size in Black Lake,
Summer, 1981 and Spring, 1982 ••.••......••.•...•.•••••••. 85
10: Zooplankton abundance and average size in Black Bear
Lake, Summer, 1981 .•.••••..••.••.••...•••..•.•••••••••...
11: Population estimates of resident rearing juvenile
salmonids in Black Lake and stream system above the lake. 88
12: Speculative derivation of Natural and Regulated water
temperature in stream at groundwater emergence
into spring fork .••...••.•.•••......•••.•.•..••..••.••••• 142
13: Assumed Black Lake outflows ---used to derive
corresponding lake levels •••••..••.•.•..•.•.•••••.••..•. 156
FIGURE 1: Black Bear Lake Project Area ••••.•••....•.•••••.••.••..•• 6
2: Black Lake Height-Outlet discharge relation .... ~ ...•.... 7
3: Chronological records of Black Lake levels and of
rainfalls, Summer-Fall 1981, and Spring 1982 •.•....•.. 8
4: Relation of daily flow from Black Bear Lake to observed
level -flow from Black Lake . • • • • • . . . . • • . • • . . • . • • • • . . • . . 11
5: General location and features of groundwater systems
of Black Bear Creek above Black Lake ..•........•..•...••• 13
6: Mean daily water temperature for Four Stations on Black
Bear Creek, August, 1980 through July, 1981 ..•..•..••.•. 15
iv
.
FIGURE 7: Mean daily water temperature for Five Stations Page
on Black Bear Creek; August 1981 through May 1982 ...... 16
8a,b,c,: Hourly fluctuations in stream temperature,
Black Bear Creek •.••.••.•••..•...•...••...••..••..•. -18--20
9a: Temperature Unit (C 0
) Accumulation Curve for the
Four Black Bear Cr. Stations, 1980 -81................ 22
lOa,b,c: Profiles of Gonductivity, Dissolved Oxygen, and
Temperature in Lower Black Bear Lake ..•...••.••..•... 24 -26
lla,b,c: Profiles of Conductivity, Dissolved Oxygen, and
Temperature in Black Lake •.•...•.•.•••..•..••.••..••• 27-29
12a,b,c: Graphical Presentation of Water Chemistry at Five
Stations in Black Bear Watershed ..••..••.••..••..••.. 33-35
13a,b: Sockeye fry outmigrating into Black Lake, with
associated temperature and discharge information ••.•.. 51,52
14a,b,c,d,e: Pink fry outmigration at three locations
on Black Bear Creek with associated temperature
and discharge information 54-57,59
15a,b,c,d,e: Chum fry outmigration at three locations on
Black Bear Creek, with associated temperature and
discharge information ..•.•..••..•••..•.•....••..••.. 61-65
16a,b: Coho fry outmigrating into Black Lake, with
associated temperature and discharge information •.. 66, 67
17a,b,c,d,: Sockeye smolt leaving Black Lake, with
associated temperature and discharge information 69-71
18a,b,c,d,e,: Coho smolt leaving Black Bear Creek (two
stations) with associated temperature and
discharge information .••..••..•..•.•.•....••.•..•.• 74-78
19a,b,c: Length-weight regression plots for coho in
three location of upper Black Bear Cr. system •...•.. 89-91
20a,b,c,d,e: Detailed Habitat Mapping of Sections A,
B,C,&D with Key shown as Figure 20e •..•..•.•.•...... 98-102
21: Beaver pond areas above inlet to Black Lake ..•.•..... 108
22: Black Bear Habitat. . . • • . . . • • . . . . • . • . . . . . . . . • • . . . • • . . . . 116
23: Beaver Habitat 119
FIGURE 24: Deer /Wolf Habitats. . . . . . . . . . . . . • . . . . . . . . . . . • • • Page 122
PLATE
25 : Small Mammal Habitats . • • . . • • . . . . • . . • . . . . . . • . • . . • . • . . • • . 125
26: Habitat X-sections 12 & 13 (immediately below
confluence of south fork . . . • • • • • • • . . • • • • . . • . . • • . . . . • . . 133
27: Habitat X-sections 14 & 15 (at confluence, south fork
with lake-fed system) • . • . • • • • • . • • • • . • . . • • . • • . . . . • • . . . . . 134
28: Habitat X-sectibns 16 & 17 (Lake fed system above
south foik). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
29: Habitat X-sections 18 & 19 (Lake fed system above
south fork) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 136
30: Habitat X-sections 20,21,22 (Spring fork) ......•......• 138
31: Habitat X sections 23 (spring fork) and 24(lake fork).. 139
32: Habitat X-sections 25 & 26 (lake fork) ••.•....•....•••. 140
33: Habitat X-section 27 (spring fork) ••••••••••••.••.••... 141
34: Habitat X-sectiori 1 (rearing habitat -main channel)... 143
35: Habitat X-section 2 (rearing habitat-main channel) ••• 144
36: Habitat X-section 3 &4 (rearing habitat-main channel.).. 145
37: Habitat X-section 5 (rearing habitat-main channel) ••• 149
38: Habitat X-section 6 (rearing habitat-main channel) •.. 150
39: Habitat X-section 7 (rearing habitat-main channel) •.. 151
40: Habitat X-section 8 &9 (rearing habitat-main channel). . 152
41: Habitat X-section 10 (rearing habitat-main channel) •• 153
42: Habitat X-section 11 (rearing habitat-main channel) •• 154
43: Synthesized levels of Black Lake under regulated and
unregulated conditions. . • . • • • • • • • • • • . • . • • . • • . • . . . • • • • • • 15 7
1: Fyke net, upper Black Lake •..••••.....•.......•••••••.. 47
2: Weighing & measuring outmigrants.. • • . . . • • • • . . . . . . . • • • • . 49
3 -: 6: Section A through D •..••.••.•••.•••••.....•.••• 94 & 95
7: Overhanging riparian vegetation........................ 96
8: Upwelling area, spring fork .••••.•...•.••••.••••.....•• 104
9: Spawning gravels, spring fork.......................... 105
10: Dry streambed, upper lake fork......................... 107
11: Beaver pond near'inlet to Black Lake 107
MAP Fish use and habitat of Black Bear Creek above Black Lake~. rear pocket
vi
1
•
PROJECT INVESTIGATORS
This study has been completed through the joint efforts of Dan
Bishop, project leader, Alexander Milner, aquatic biologist, and Leigh
Smith, wildlife biologist and camp manager.
Leigh Smith has operated backcountry camps in Connecticut, Washington,
Alaska, and Yukon Territory, Canada. He worked five seasons in Glacier Bay
National Park as a field biologist recording observations for a large
mammal survey, and studying the flora and fauna of Southeast Alaska. He
has canoed thousands of miles in the north and, as an active outdoorsman,
has hunted and tracked for twenty years. He is currently nearing
completion of a B.A. in American History.
Alexander Milner, M.Sc. University of London, conducted dissertational
studies of streams in Glacier Bay National Monument to determine patterns
of colonization and succession in streams following glacial recession. He
instructed courses at the University of Alaska, Juneau, in Limnology and
Aquatic Entomology. He anticipates receiving his doctorate in hydro-
biology in 1982 from the University of London.
Daniel Bishop has extensive experience with the bio-hydrology of
coastal Alaskan streams. He worked eleven years as a research scientist
and as hydrologist for the U.S. Forest Service in Southeast Alaska before
beginning land-water resource consultant work in 1973. He has extensive
experience with salmon habitat, salmon hatchery siting, water quality
control and land planning efforts. His most recent work has involved
environmental hydroelectric investigations on Black Bear Creek and West
Creek, near Skagway.
vii
-Acknowledgements -
In particular, we t~nk Steve Hansen, Steve Bates, and the crew
t
at the Alaska Department of Fish and Game Klawock Hatchery, who have
helped us generously over the last two years.
Our thanks also to Bob Wood, Alaska Department of Fish and Game,
for his counsel, to Jeff Koenings, Alaska Department of Fish and Game,
for analyzing water and plankton samples and for valuable advice,
to the National Marine Fisheries Service in Juneau and Auke Bay for
loan of equipment as well as valuable discussions of findings, to
Southern Southeast Regional Aquaculture Association for loan of equipment,
and to Sealaska Timber Corporation for frequent use of aerial photos.
viii
1
INTRODUCTION
This work was completed under a series of contracts with HARZA
Engineering Company of Chicago, Illinois. We have worked with
Mr. Jack Robinson, of HARZA, and Mr. Brent Petrie, of Alaska Power
Authority, to develop a base of hydro-biologic and wildlife information
·----
that can contribute to feasibility, planning and design of the proposed
Black Bear Lake Hydroelectric Project. The first contract work began in
late summer, 1980, and was reported to HARZA December 15, 1980, as
Black Bear Lake Aquatic Study: Phase I. The second contract, in the
spring of 1981, was begun in mid-March, 1981, and reported May 15, 1981, as a
Preliminary Study of Outmigrant Fry from Black Bear Creek, Prince of Wales
Island, Alaska. These efforts led to the present contractual work, which
began in early August, 1981, resulting in an interim report November 2,
1981, for the summer-fall work: An Interim Report on Biological-
Ecological Work on the Black Bear Creek System. In this report, we have
drawn upon all of the previous pieces, focusing the work to date to reach
the objectives of this study.
2
SCOPE AND OBJECTIVES OF WORK
The principal scope of this work concerned fish/fish habitats and
wildlife/wildlife habitats above Black Lake and including Black Bear
Lake. Work extending below Black Lake included fyke net outmigrant
trapping and thermograph operation near the mouth of Black Bear Creek.
as well as at the outlet of Black Lake. Hydrologic and lake observations
and measurements were made as part of this effort.
Due to heavy snow and ice conditions remaining in Black Bear Lake
through June, 1982, no significant work was accomplished to determine
rainbow numbers or spawning area in this lake.
Additional work on stream cross sections was completed in response to
agency concerns expressed regarding effects of variable regulated flow
conditions on spawning and rearing habitats.
The specific objectives established in the program of work (proposal,
June 24, 1981) were as follows:
1. Biological work on Black Bear Lake: to estimate the size of
the stocked rainbow trout population and to identify spawning
areas.
2. Biological work on Black Lake: to estimate the rearing
population of juvenile salmonids in Black Lake and to ascertain
lake productivity with an appraisal of its potential as rearing
habitat.
3. Biological and related physical work on the stream above Black
Lake: to quantify the extent of suitable spawning and rearing
habitat above Black Lake; to determine the number and species
3
of adult and juvenile fish using this section of .the system
where the largest impact of alteration in flow regime is
likely to occur; to evaluate the respective stream flow
contributions of subdrainages above Black Lake; and to
approximate the number of beaver and black bear using this
part of the drainage, identifying key habitats.
I
4
CHARACTERISTICS OF UPPER BLACK BEAR CREEK DRAINAGE
Physical
Climate, weather
The climatic characteristics of Black Bear Creek drainage are probably
most nearly represented by the Craig station record between 1938 and 1952,
shown in Table 1.
Our experience in the drainage, however, has identified some specific
characteristics of Black Bear Creek climate and weather. Winter visits,
particularly in January, 1982, indicate that this drainage is significantly
colder during cold periods. Overnight minimums of O-l0°F in Craig-Klawock
were matched with temperatures about l0°F colder in the vicinity of Black
Bear Creek and even upper Big Salt Lake. Periods when southeasterly
storms were moving through the general area, often produced fierce williwaw
(vertical) blasts of wind coming down (to the north) from the vicinity of
Black Bear Lake. Passage of local fronts produced rapid wind reversals.
TABLE 1: Craig Climatic Information
MONTHLY VALUES
Average Average Average
Month Tem_Q_. Max. Temp. Min. Temp. Precip.
J 34.5°F 39.5°F 29.5°F 12.16"
F 35.6 40.9 30.2 7.69
M 37.6 44.0 31.2 :\8.58
A 42.1 49.0 35.2 8.80
M 48.1 55.9 40.2 5.22
J 52.6 59.7 45.4 3.73
J 56.6 62.7 50.4 4.48
A 56.7 63.4 50.0 5.75
s 53.3 59.5 47.0 9.47
0 46.3 51.5 41.1 14.62
N 39.6 44.4 38.8 13.49
D 36.0 40.5 31.4 11.98
Annual 44.9°F 50.9°F 38.9°F 105.97"
5
Observations were made of rainfall during periods of significant
residence at Black Lake. These are shown in Figure 3, along with
fluctuating levels of Black Lake. No station --at Craig or Klawock
was available for comparison of observed rainfall levels.
Configuration of area
This study focuses principally on Black Bear Creek above the outlet
of Black Lake. Earlier work by CH 2MHill and by Environaid showed that
stream flow and temperature conditions in the creek below Black Lake are
increasingly buffered from impact by the headwater hydroelectric project.
The Black Bear Lake drainage area proposed for regulation, 1.82 square
miles, is simply too small a fraction (about 10.4%) of the total watershed
to impact the lower stream. Yet, this regulated area is sufficient to
impact the stream above Black Lake. Black Bear Lake basin represents
28.9% of the watershed above the Black Lake inlet stream, 34.5% of the
upper watershed which includes the south tributary and 58.7% of the Black
Bear watershed immediately upstream of the south tributary. The area of
principal study for this project is shown in Figure 1. Black Lake, which
acts as major buffer zone for flow and temperature variability in the
upper basin is approximately 60 acres in area with a maximum depth of
35-40 feet (see Appendix Figure 1). The south tributary, above Black Lake,
drains a basin of about 2.2 square miles, much of it in a subalpine basin.
The spring fork is fed entirely by ground water, whil~ the northerly fork,
which leads to the waterfall below Black Bear Lake, is an intermittent
stream, with 400-500 yards of steep, coarse streambed below the large
slide area being dry at intermediate to low flows. The Black Bear Lake
system above the south tributary drains about 3.34 square miles, while
Black Bear Lake, at its mouth, has a watershed of 1.82 square miles.
Streamflow characteristics
Streamflow characteristics of Black Bear Creek, with primary emphasis
on the Black Bear Lake basin, were developed by CH 2MHill for the feasibility
report of 1981. The additional hydrologic work completed for this
environmental investigatio~ has been directed primarily toward the Black
Bear Creek drainage above the mouth of Black Lake. Flow and lake level
lake profile & . sample po1nt
out-migration traps
base camp
FIGURE 1: Black Bear Lake Project Area.
~
lake point
BLACK BEAR
PROJECT
0,
LAKE
AREA 0\
o-11 2 1mi.
I I I
approx. scale
~)
""' <:)
~
;1:
0 ....
lioc
G)
t:.l
"" ol .c
<:)
to
'Pi
~
I
7
data has been collected, and is examined here as a basis for evaluating
possible effects of flow alteration on habitats of fish and beaver below
Black Bear Lake and above the mouth of Black Lake.
Black Lake, estimated at 62 acres from aerial photos (Appendix Figure
lA) is a relatively shallow lake (average depth estimated at 25 feet).
Its outlet is controlled in level by a natural log jam about 1,000 feet
below the mouth. There is no bedrock showing at the mouth and the gravel
stream bottom appears to come from the nearby easterly valley wall. A
series of flow measurements have begun to develop a relation between lake
level and outlet discharge. This relation is shown in Figure 2 and is
used later to estimate change in lake regime and to evaluate inlet
stream cross sections.
300
2.50
200
150
100
50
0
1.5
,·
/ ~·
/,t-"
//'
,/,/
/~··
/:·'
/,···
/ .·
/ .. ··'
//
/ /
1981 rating~ /
/ ,•' .
/ .· .J .....
/ ,/
/ /'fl-re-drawn, 1982
/ ... ··
/ .·
/ ...
/
/ /
/ .
/ .· " /
// .··
.,/ .... ;
/ .·•·
/ / ·-· lt / .....
/ .. ·· .--: ....... ··
2.5 3.0 3.5
Lake ~eight (F~et)
~
/'
FIGURE 2: Black Lake Height-Outlet.discharge relation
s'
,.
3'
2'
,.
8
The observed fluctuations in Black Lake level during our work periods
in the area are shown in Figure 3. In the summer-fall, 1981, Black Lake
fluctuated through a range of about 3~ feet. The spring, 1982, range was
about 3 feet. The lowest lake levels we observed were in early April,
1982, though we did not read the staff until a few days later, when ice
was chopped from the lake staff.
.
\
\
\
\,
'· .......... _ .---___ __, ' ........ .....__
5 10 15 •s
()c-rof3El?. 198! _, SEPT; N8EI{, 198 I
5
FIGURE 3:
to
Chronological records of Black Lake levels and of rainfalls
Summer-Fall 1981 and Spring 1982.
·~. 1\ I ..... J \ J-"' // _ _, '--' \.../. -... _
31 5 10
APRIL, I:JBz MAY, 1~82 J VAll?, I'JSZ
Black Lake controls the water level in the inlet stream extending
upstream nearly to the first stream forks. In the first 2,400 feet of
channel above Black Lake, the stream level at low flows increases only
about 0.3 foot.
2."
1"'
,.
I
9
The stream forks above the low gradient region and separates into
channels of the south tributary and Black Bear Lake-derived waters. (See
large map in pocket.)
The south tributary, which drains approximately 2.2 square miles,
rapidly increases in gradient as its channel swings toward the steep
valley wall. The ~hannel· carries a bedload of gravel and reddish iron-
stained rocks in the tributary's lower reaches, indicating it receives
springflow into the surface channel. The south tributary was periodically
measured just upstream of its first partial confluence with the Black
Bear Lake fork.
Two primary channels derive from Black Bear Lake. The spring fork
is entirely spring fed, with very stable volumes of flow measured at
between 17 and 25 c.f.s. Lowest flow in this channel was not measured,
though observation suggests natural minimum flows which seldom fall
below 10 c.f.s. The gradients found in spring fork vary from a minimum
of around 0.3% up to greater than 2% near the spring flow source of the
flow.
The channel which leads from below the waterfall terminates in an
area extensively dammed, ponded and flooded by beaver activity. Below
the beaver ponds, this branch shortly joins with the spring fork, and
then with the south fork. Above the beaver pond area, the channel
rapidly increases in grade, running with water slopes of 1 to 3% in a
coarse, dominantly cobble-sized streambed, until the perennial bed
terminates about 500 feet upstream of the beaver ponds.
Up channel from the perennial bed, the channel rapidly steepens, with
grades estimated at 5-10%, and many boulders in the streambed. Numerous
logs and windfalls cross the channel up to the vicinity of the power
house site. This location is roughly 1,000 feet beyond the point of
perennial flows and a similar distance below the base of the falls. The
vicinity of the power house is where the moderate to low streamflows
disappear into the boulder bed materials.
I,
!
!
10
More than fifty flow measurements have been taken at various locations
in the Black Bear Creek drainage. Most of these measurements were between
Black Lake outlet and the waterfall below Black Bear Lake. They are
shown in Appendix Table 1. This data has been used in conjunction with
U.S.G.S. flow values for Black Bear Lake outlet, and flow estimates for
Black Lake outlet (derived from lake level observations and Figure 2
rating curve) to compare flow contributions of respective upper drainage
areas. These comparisons are shown as Figure 4, and as Appendix Figures
A-2 and A-3.
Several noteworthy relationships appear on Figure 4, comparing U.S.G.S.
measured flows from outlet Black Bear Lake with estimated flows on the
same days at outlet Black Lake.
August 5-20, 1981, recession flows: This dry-period recession
followed for 15 days after a rainy period which ended in about an inch of
rain on August 5. For the first two days after the heavy rain, Black Bear
Lake discharged at a much higher rate than Black Lake, in terms of their
respective drainage areas. By the third day, the relation of respective
lake discharges had approached more closely to the relation of yield in
accordance with proportioned drainage area. As flows diminished, however,
the contribution of Black Bear Lake became increasingly vital in sustaining
Black Lake outflows. At the lowest point on this recession (August 18,
1981), a discharge measurement at outlet Black Lake showed 7.2 c.f.s.,
while the U.S.G.S. flow value for Black Bear Lake on that date is 4.1 c.f.s.
This illustrates that a 15-day summer recession results in a large part
of Black Lake's outflow deriving from Black Bear Lake. It also suggests
that the groundwater system supplying the spring fork does not contain
much storage capacity, and probably is as much a pipe as it is a
reservoir.
The plot (Figure 4) of daily values in September, 1981, also suggests
high initial yields from Black Bear Lake, and again shows lower flow
values approaching, but not reaching, the relation of proportioned area
yield.
.
00 .
""' .
C,.)
QJ
~ ctt
...:I
~
()
ctt ,...;
lXI ..
-1-J
QJ
IDO ,...;
-1-J
::l
0
.
11
I
I
I I ·s /
s; '-·-. .: . ~ ~Line indicates flow relation when
G) 1 · respective drainages are yielding
a <=>. .: in proportion to watershed area •
I .' (Black Lake drains 3. 82 x' s area
• drained by Black Bear Lake).
G) ;a ~l
<:><e .. ·· l!l
~ ~ .··· ,-<\: .. : .. ····~
G 1!1 .• / 1• )C!J · Pattern of recession relation follow-G)~ 1 / ing summer storm, 5 August, 1981.
C9 :
e I l!S.
·~J : e:·)~·:
<::'a
0/ I /·~
/4
FIGURE 4:
. --
G-
from instantaneous flows, same day •
from USGS provisional values, B.B. Lk.,
lake levels Black Lake, May 1982.
and
EI-from USGS daily flows B.B. Lk. and lake levels
Black Lk., storm period, Sept. 1981.
from USGS daily flows, B.B. Lk~, flow
August 198_1
so
Outlet, Black Bear Lake
100
C.F.S.
Relation of daily flow from Black Bear Lake
(USGS records) to observed level -flow from
Black Lake.
/5"0
·; -
12
.
The relation of comparative flow values in May, 1982, is considerably
different from the previous two periods· examined. DUring this month,
when snow melt water was a major source of flow along with much rain, the
flow relation described in Figure 4 follows closely the line defining
flows in proportion to area.
Similar graphical relationships were developed between estimated
Black Lake discharge values and (a) stream discharge values taken at the
lowest point on the Black Bear Lake outlet fork (Figure A-2, Appendix),
and (b) stream discharge values taken near the mouth of the south fork
(Figure A-3, Appendix). Both of these plots suggest relationships in
which the respective headward fork is producing flows at a lower yield
per square mile than the Black Creek basin as a whole. The number of
points available and, in the case of the south fork, the scatter of points
limits the conclusions which can safely be drawn.
Groundwater emergence
Groundwater emergence plays a vital role in the hydrology and
fisheries habitats of Black Bear Creek above Black Lake. Its characteristics,
however, have been observed wherever possible, but few quantitative
measurements have been taken. Groundwater features are identified and
located in Figure 5.
Much of the spawning gravel area in upper Black Bear Creek probably
receives emerging groundwater. This is evident from temperature
measurements taken with hand thermometer, as well as from the record of
the recording thermograph. It is also indicated by iron deposition on
surface gravel where iron in groundwater solution oxidizes as it reaches
the surface.
Springflows remained over 2°C in the coldest period of winter,
1981-82. Temperatures measured in August, 1981, showed streamflows
enteting groundwater routes below the falls at around l2°C and emerging
at temperatures varying fr~m 9.5 to l2°C according to specific location of
emergence. This information indicates a rapid transit through at least
some groundwater flow routes.
13
streambed
gravels, indicating
upwelling conditions
springfed headwaters
~~-------------1~,/-2------------~t mi.
approx. scale
FiGURE 5: General location and features of groundwater
system of Black·Bear Creek above Black Lake.
during
to low flows
Dissolved oxygen levels of emerging groundwater have not been measured.
Fingerling salmon utilize springfed pools, however.
Flow measurements taken during spring, 1982, in spring fork indicate
the capacity of spring flow is in the range of 17-25 c.f.s. Observation
of the spring fork in January, 1982, suggested a winter minimum of around
10 c.f.s., but this flow was not measured. The summer minimum flow in
spring fork was not measured either, but the flow values cited earlier
for August 18 indicate that the summer minimum was about 5 c.f.s.
14
Stream sediment characteristics
Although it is evident that stream sediments from boulder size to
silts are in downstream migration below the falls, no dramatic streambed
movements or channel shifts have been seen in the perennial flow streambed
above Black Lake. The most important change in channel conditions has
been made by beaver. A new dam on the south tributary has backwatered
a significant area and undoubtedly is trapping sediment of gravel size
and smaller. The beaver dam located on the lake-fed tributary is also an
effective sediment trap.
Boulders can occasionally be seen in pools at several locations along
the sand-silt bedded stream channel for the first 2,000 feet above Black
Lake. An old torrent-flow jam is located not far up the south tributary.
Both the recent and the distant past suggest a more active sediment
movement than we have seen. Years of mild sediment movement and channel
stability below the falls, such as we have seen, may well be punctuated
by major sediment pulses coming from the large slide immediately below
the falls or from torrents in the south tributary.
Stream temperatures
Stream temperatures have been measured in the Black Bear Creek
drainage with both recording thermographs and hand thermometers. Four
thermographs (ENDECO Model 109) were installed in August, 1980, at lower
Black Bear Creek, near tidewater; at the outlet of Black Lake; at the
inlet of Black Lake; and at the outlet of Black Bear Lake. A fifth
thermograph was added in August, 1981, in Black Bear Creek above Black
Lake, installed in gravels of the principal spawning habitat of concern.
The only difficulties encountered in obtaining good records occurred in
lower Black Bear Creek near tidewater, where a log settled on the
thermograph unit, and where the unit was also tampered with. These units
record to the nearest O.l°C and have excellent timers.
Results of thermograph measurements are summarized in Figures 6 and 7.
Temperature data for 1981-~2 is also provided in Appendix Table A-2.
,.
11
,.
IS
,
/:I
12
~II
• '-'
ID
U"l ~
.-1 ~ ' ~ ~ I
~
~
~ •
s
y
z
FIGURE 6·:
BBL:
UBL:
LBL:
MBC:
Mean Daily Water Temperature
for Four Stations on Black
Bear Creek, August 1980
through July 1981
Black Bear Lake Station
Upper Black Lake Station
Lower Black Lake Station
Mouth, Black Bear Creek, near
tidewateT
, LBI-
l l
Llll-/\
f
i
r ~ 88\...
/~,{!'», J .''r-. \
cl'')' \ \ ,'~'{\
Floe \~~ ( \\
Wi •
\\ ;. ~·
\'\/ /
\ t' . ..... ,
;/ '\ l ;~ / \t .. ~:· I .. {·~ f~ /:' =··\r· :' . ri .J~ ·.:: : .... ~,.
~,r.:··~·· .. l ' / .
•\ ,~ :_:'
La~....,f"':t' J: • ,... ,;.. J '\ .,1 MIIC. j" '-..h
• t'l' ~ A ;~/ ~'\ [: ,/""' I I"\ .Jj
, : ,.v-n:;··~ ,J:: 1 -·
··-t':' '. \ ' • I .~;, 1 • .:v \i\1 \:: ),.: /"'
'•>r . • ,:j.N., :'' f'-\ i : • ! ;uaL
\\ 1:\\ ·'{ to..V' ,,, ,... : ,~
1\•/)-. ,. v'' 1 \ , ~.· :t : : :\: ,-
.\I: :•'''' , • • "'J . \ ~ i: ~~~ \! .:.
·. i ! ; ~ :, \ .-:! \,
:!'{\I' \, 1!
ll ~ -Oi i 1: Oj i ~ ..
~
..," ,---.. v-'1 ~ "" '>./'
~
I
I
I
I
I
I
1usL
I
~
~
~ a ~ i = , ~ ,.
~--------------------1980 ------------------+~-----------------------------198/ ----~-----------------------1
I
il!WjrWj;t'i'~' '•'''' ,(,,'IPl;;,.-•;;,;•·J,I~•t"X"?"'"·W;,'ifi;"C?'",>'<·' "2'• ;'·"'" >-,'O.o~.::;:::!;~.:~,l:,;;;.ll;~.:.:i.' ""< '""''*}ir./!fu1'H;":'ii'fli'WP-'11"'Ni'"''t'1i"''-••.•c·,,~c-·l,~~t.=~;:;:;).?.:-~;;._i.~:'.i.<·~~·-;.::.,~;;:,~~: . .,.~:::.;c~';:,.,:''2:;::·.:::.. ,,,,,.:_.:.._..:__:_.~::!;,:..:_;.:;,:;_.:_.:2.;,::.!;:!.1:.;:,.,:,..:~,G~;,.··:.;.;_-_:_ : " "''" -' ·'"'"-'"' '"''·'"'"'""""""'""
_...=::..:.__.=--=----=-==--=-=----===-==-
18
17
16
15
1A
1)
12
11
u
:.... 10
w
0:
:::>
1-
"' 0: w
Q.
"' w ,_
0: w
1-..
""
-
/~~rL ~~.~if\ f ·-·. \ ~Mce \'\ "l .. ---L~ ~B~ VI\ ·~'"<\ ~
I~~ I '>v'l. "'-') ~: 1'1 ~ 1\_;\•":\
.,_ v~\\ ''l VBL ·
v,A( , 11ft. ·. 'J I \ ,...._,.. .. ,.. (' ~ '
\ .. ~ li ~ 1f \ .v. \, \ . ;;; .s\ ...... vv 'il·v \,; -.. , ·-~
:::
" 0 ..
i.
FIGURE 7:
BBL:
UBL:
LBL:
MBC:
" ....
M M .. !l "' .,
"' 1981--·-
· Mean Daily Water Temperature
for Five Stations on Black Bear Creek,
August, 1981, through May, 1982
Black Bear Lake Station
Upper Black Lake Station
Lower Black Lake Station
Mouth, Black Bear Creek, near
tidewater
" .... ....
M . .., ~
> u ~ 0 I!! z .,
..
N .,
1:!
tqaz.
.... " M M
i .. .. ..
fft
·f i
J' :,~ LBL
r4: 'MBC f-!r''·"
BBL
....
M
~
I-'
0\
>.<.
~~~·· .
17
Some features shown on these figures require further comment. In
winter 1980-81, Black Bear Lake outlet temperature reached lower levels
than in winter 1981-82. This may be due to the minimal ice cover in
1980-81, allowing for periods of greater chill and heat loss.
In August, 1981, during a period of warm weather, lower Black Lake
exceeded l7°C, when lake inlet temperature was about 12~°C. Black Lake
surface waters received much heat. During this same period, note that
the outlet of Black Bear Lake reached 15°C, while upper Black Lake had a
maximum of 12.6°C. This drop suggests a temperature decrease in
groundwater routes of 2-3°C, and was also verified by field measurement
with hand thermometer on August 13 and 16. Water temperature of Black
Bear Creek below the falls was measured at l2°C, with upwelling temperatures
at the head of perennial stream flow showing predominantly 9.5°C.
The marked drop of temperature at the mouth of Black Lake (L.B.L.)
following 17 May, 1982, provides an example of the effect on water
temperature of heavy rain falling upon ripe snow.
An interesting set of measurements was made on the sunny days of
June 18 and 20, 1982. On June 18, Black Bear Lake at the outlet was
measured at l°C with hand thermometer. Black Bear Lake outlet on that
date was open only about 100 feet to the edge of the ice. On June 20,
1982, water temperature at the base of the falls was 5.5°C. Air
temperature was 9.2°C. It is unlikely that water temperature at outlet
Black Bear Lake changed much from June 18 to 20. Hence, a warming due
to the waterfall of about 4.5°C is suggested for this condition.
In an effort to examine the temperature range found within specific
days at key times of the years, hourly temperature plots were made for
sunny days in August, 1980 and 1981, and for winter days in December,
1981, and February, 1982. These plots are shown in Figures Sa, b and c.
The two August plots (yigures 8a and b) indicate markedly different
heating characteristics. Days which produce high water temperatures, as
A
~ • ""' Ill ~
~
" ~ :
~ ~
18
..
shown on Figure 8b, also show much greater temperature range. It is also
evident from these plots that sunny weather produces temperature peaks in
the two lakes (B.B.L., L.B.L.) at essentially the same time. Peak
temperatures at the inlet to Black Lake (U.B.L.) appear to lag 3 to 4
hours behind peaks at Black Bear Lake (B.B.L.).
The streambed thermograph (S.G.S.) record was interpreted to show a
lag behind Black Bear Lake (B.B.L.) of about 3 hours.· This time value,
which may bear upon groundwater flow rates, could probably be strengthened
by additional study of the records.
/.S:O
II/.~
/~-"
/3..~
{3./J
/Z.S'
/Z..~
II.~
lt.o
/t7.S
/(7.()
9,.5' lZ z
\ ,;·
"'· I ""-· .,-,_,
_I
/
'I ' 8 '" 1£ J¥ '" " ~ .C.Z. .%/( z.
Ruau.sr :n,. l'f8o
'I I. g I~ IZ II/ II. II Z4 Z.Z. .Zi'
AU(; 11tS1" .28, ,.,So
FIGURE Sa: Hourly fluctuations in stream temperature, Black Bear
Creek, August 27-28, 1980.
/'1.5 .
/f.()
II.S
II.D
/1.~
/7.0
''·>
1(,.0
1$'.~
............
~ /5.0
.z,
IU /'I. -5 ~ ~
~ ~ '"·"
t ~ 13.'5
~ /3.0 It
~
t:J.>
/:J.()
ti.S'
i18C
.
\
' \
\
,, : ' ........... /,,--
' ' I
I .,
\
I
,.-
I I
I I
I I
\ .. .,.. _.,,
19
.1' .. ,
1 ' I I
I I
I I
~
\
r . . / . I
! \ I
I \ ,
! \ ! I . I i \ .
i ·\ I . .
1 UfJL ! ..... -~-....... _... \ 1 ...... .
\ . ..J... • J
~~~·'--· ........... ·· ·-; ..•.. · .... · ... ·~ .....
·"· .. h./ · .... "\• .... /
_quGusT 11 1 t'lf!l
' \ ',
FIGURE 8b: Hourly fluctuat:1.ons in stream temperature, Black Bear
Creek, August 11-12, 1981.
\
\ .....
" '
.....
' ' \
' ~
13BL
" ~
\..,
lb
~ ...
~
l4 A.
~ ~
20
The winter .. plots shown in Figure 8C serve primarily to show contrasting
temperatures between an "open" winter (1980 -81) and a cold winter with
strong ice cover over the lakes Q981-82).Given the fact that February 25,
1982, was a bitterly cold day with air temperature at -l8°C or less, the
record indicates that ice cover favors warmer temperatures than may be
found during winter in open condition in Black Bear Lake (BBL). In contrast,
the outlet of Black Lake (L.B.L., elevation 80 feet) indicates just the
2..5
:Z-"
l..SL-
1.5 ·-. .-./· --. u QL..
I '·-/
I.P
. /-
·~·----· ·-·-. .......-. ..... . , /' /·-.--·, ·-·-·-·" \ ,.__/ ·-· '· ·" ·~
o.S BSL
0.0 lZ 2.. ¥ 8 It> IZ. I~ /Is Ill ~ 2-2. Z'f :Z. ~ /P .g IC IZ. I~ /" IS Zc ZZ. :Z'f
~-5
z..o
1.5
1.0
0.5
o.o I
.. ··· ... ·. . ............ :·-··· ... ·. .. ... ··· ....................... ,............ ..~ .... · ··. ·.· ·•· · .· ·. ·· ........ ·· ...• SGS . ··-.. . ... ·· ··-.... ·
I I I I I I I I I I I I I ' I I ' • I • t .., (o r /0 'I-Iff '" II 2D D. l'l z , " t Ill ,,z, ,, /~ ,,
FE.BRVIIRY 2.5. J9S2.. FEBRIJRRY ~) /982.
FIGURE 8c: Hourly fluctuations in stream temperature,
Black Bear Creek, December 1980, and
February, 1981.
I I
~ zz.
BBL
I
29
LBL
UBL
21
reverse, where ice cover in 1981-82depressed L.B.L. in comparison to the
"open" conditions (1980 -81).
An analysis of water temperature units for 1980-81 and 1981-82 was
made for the time-period 1 September to 30 April. Results are shown in
Figure 9a and b, and demonstrate differences between "open" and "heavy"
winters.
It is unfortunate that the stream gravel thermograph (S.G.S.) was not
installed until August, 1981, since this thermograph probably is nearest
to representing temperature conditions in the spawning gravels above
Black Lake. If an S.G.S. curve were available for 1980, it would
probably be considerably closer to the 1981 S.G.S. curve than other
station comparisons. This temperature unit analysis is an important tool
in examining possible hydroelectric project effects, and is discussed
further in that context.
Lake profile information
These profiles of upper and lower Black Bear Lake and Black Lake
include measures of conductivity, dissolved oxygen, and temperatures for
the 1980 to spring, 1982, period. The spring, 1982, profile for Black
Bear Lake was not taken because of ice cover and access problems. All
measurements were taken with YSI Model 33 (SCT) and Model 57 (D.O.)
meters.
Lower Black Bear Lake profile data is shown graphically in Figures
lOa, b and c. Upper Black Bear Lake data, which is very similar to lower
Black Bear Lake profiles, is found in Appendix Figures A-4 and A-5.
Black Lake profiles are shown as Figures lla, b and c.
Black Bear Lake conductivity is seen to range generally around 10 to
20 mmhos, frequently showing an increase with depth.
Dissolved oxygen in B~ack Bear Lake profiles shows the lowest value
(on 1-21-82) at just under 9 ppm (depth 60 feet), and the highest on the
t I
J
......
~ OCT3l
~
/'IDV SO
-])EC 31
JA/'1 3/
--1/fPR
22 Cu,.,uLArtvE Te,.,,£AA-rv~E UN,r..s (·c)
' \ .
\
\
' \ .
\ .
\
\
\
\
\
\
\.
\
& r
,.........
\.)
~
~
::S
~ ~ ~ ~ ("") ~ N ~
~
\::
11::
-..1
~
t
~
\,)
11>00
1'100
IJOO
/2.00
/100
1000
'100
roo
700
(,00
soo
!'DO
30()
.zoo
/Db
~
1;:
UJ
lfl
~--
FIGURE 9b: Temperature Unit (°C) Accumulation Curve
iii
l:i
0
for the Five Black Bear Creek Stations, 1981-82.
~
> ~
;; ;;:, ~
M ~ Ill ~ , ~
... -.. •'
Oi ~
i ~
1"181 r----------/982 ----------------1
l wmwwr ~ ·w ~~~~~~mme=Mb.-~~~-.-a-.-.MaMB--.-.-~.-~----~~~~-..-.--.-.--.-MM-.a-.--..-.-~--------------~--.-~~---*_..__._.._._._~mw~~~DM-.-. .... ~.
I I!
CCJNDVCT:
12. P.P.M. Oz
DISSOU/Et>
24/:z-; ·-· I •
__...-./ ... _,e-......... ,.®-.-G-----_ .. :.~
~ ....... <!)----e--~ • _ ......... _
~ ' m--!. .. CQ•• ••• w• t!J"······ •r.:t ••• ,.~ .:-.··· I -
1 •• -·a-·· .. ..(!).. ' I
1 .. ca ....... m··· '€1
.... J.-s·····
I
I
_,-.-·:r· --<D-_t., --~
-· ....... _ I!)-··-m-z -··::: :;..[_ ·----<»-···...,..::"~~:...:
-~-<!>---<iJ:-... -e-·--G _,_ -·--/ ~.~· ~------------------~
·-• = B-2o-So
e--c:> = '-Z3-8o
CD-m : Jo---zfl-So
• lOWER BLACK BEAR LAkE
_..,_ a:J---e--a. (£)---~ ...
-S~--li.JD -44:,
FIGURE lOa: Profiles of Conductivity, Dissolved Oxygen, and
Temperature in Lower Black Bear Lake. 1980
~
' :II.
......
I..
~
~
~ ,;t) ,., /tf 0 h $
~
{,.)
~ !dl 11 ~ Oz.. ~
~ II j7pm/;5"C.
..l
()
~ /O f~rl'1 I /40C
A
25
Low=-~ B<ACI< Bt:A/2. LA~:€
.... e--0
.....
G) ....
/
/
/
/ c:::.>--0
/
9-/3-8/ C:t>Nf)VC{7Ut7
......... , .EJ•• • •fil •• • tJ:l, •• ••I:!] 10-2.0-Sol CoAJi)u~TIU1""1 .. ·G· .. ·£::1· •• ·t::l· •• -~· •
-G---G'
\
\
\ .\ \
~ Q
• •.. !!1•. • •t::l• • • •til• •• •GI ••• •Gl""-. G).. • ·C4. • ,....
8 ·II-S I D. 0.
9-t3-81 D.O.
. """ \ .• 'GJ• •• •1-u. ••
. . • \ • • Q7 10-"2.0 -I$ I TcM.?. ~G,
·~0 ...
-~-~0-=0 CJ-13-81 TE:M?.
L_ S-11-8 I reMP.
FIGURE lOb: Profiles of Conductivity, Dissolved Oxygen, and
Temperature in Lower Black Bear Lake. 1981
I,
'I
li:
~
4J
·.-I
::>
i ·.-I
i; ~ 4J
0
[ .. 1 ::s
i'l "0 a
Ill 0 'f.i t)
''I
,!
a
Q)
tTl :>t >:
0
'0
Q)
::>
.-1
0 rn rn
i ·.-I
i!',:: I,
Q
I,
I
40 mmhos
20 mmhos
12 ppm
11 ppm
10 ppm
26
LOWER BLACK BEAR LAKE
~::;.:;. ___ ~::;. January
-20 ft -40 ft
A
-60 ft
A
-80 ft
A
Conductivity
1-31-82
Dissolved
Oxygen
1-21-82
Temperature
1-21-82
-100 ft
FIGURE lOc: Profiles of Conductivity, Dissolved Oxygen, and
Temperature in Lower Black Bear Lake. 1982
12 P.P.J-t. 0
OXYGEN
IO P.P.I\f. ~
wA~-
3~J+ t
,$ceo~
0'.,.. I
__ ,., :
-~ l
•
I
I
I
•••••••• GJ---·-,....-__ ..... _. -.. ..... ···zu
27
(!)---(i) = ~-23 .. 2"1-8,
e:a ···-te =-10 -51-'B'"a
8LACl< LAKE
-Zb-1-1:. -40 -k:: · -~O_;i: . -}O-ff-.
DePTH
FIGURE lla: Profiles of Conductivity, Dissolved Oxygen, and
Temperature in Black Lake. 1980
.I
,II
28
•.•. •'1:1. to-z:r.-8/ WAJDu~Ttutl'1
.. e· ... ··S'·
... f I •
J:&J.• ••• s o cro sea.
-20..(:+ -&of+ -IOO++
FIGUREl~b: Profiles of Conductivity, Dissolved Oxygen and Temperature
in Black Lake 1981
~ .+J
·.-i
:>
·.-i
.+J
0
::l
'tj
~
0
CJ
30 .mmhos
20 mmhos
10 mmhos
29
Conductivity
1-20-8 2 (.t.J
Conductivity 5-4-82(.x)
Conductivity 4-24-82(+)
12 ppm -
11 ppm
10 ppm
~
Q.l 9 ppm C'l
~
~
0
'tj 8 ppm
Q.l
:>
,...j
0 7 ppm en en
•.-i
0
6 ppm
4°C
Q.l ,...
::l
+J
lU ,...
Q.l 2°C c.
E!
Q.l
E-t
,...
Q.l
.+J
lU s: 0°C
-
1-
-20 ft
Dissolved Oxygen 5-4-82(x)
Temperature 5-4-82(x)
Temperature 4-24-82(+)
-Dissolved Oxygen
1-20-82 (A")
A~--Temperature
+Dissolved Oxygen 4-24-82(+)
-40 ft -60 ft -80 ft -100 ft
FIGURE llc: Profiles of Conductivity, Dissolved Oxygen, and
Temperatures in Black Lake, 1982.
I
'
! i
I
I
I
1:
I',
[I
I
I
30
same date at 13.5.ppm (surface). The lake was ice covered on that date.
Other dissolved oxygen values range between 10 and 12 ppm with increases
in values showing as the sample point reaches 30 to 50 feet depth.
The critical feature in temperature profiles for this project is the
rate of change of temperature in the first thirty feet below the suface.
This condition is summarized in Table 2.
Change with reference to surface
Date -10 ft -20 ft -30 ft
8-20-80 -O.l°C -0.2°C -0.4°C
9-23-80 0.0 o.o -0.1
10-29-80 -0.1 -0.1 o.o
8-11-81 -1.5 -2.3 -3.0
9-13-81 0.0 o.o o.o
10-20-81 +0.1 +0.1 +0.1
1-21-82 +0.6 +1.0 +1.2
TABLE 2: Change in profile temperatures,
Lower Black Bear Lake, between
surface and 10, 20, 30 foot depths.
It will be seen that a spring sampling date is lacking.in Table 2.
Based upon examination of other thermal profiles, it is unlikely that
the spring profile after a "heavy" winter will exceed the winter profile
(January 21, 1982) in temperature gradient. In the case of an "open"
winter or early spring, greater lake surface disturbance will reduce the
thermal gradient. Accordingly, the winter gradient is also suggested as
a "worst case" assumption.
Profiles of Black Lake, Figures lla, b and c show·;conductivity values
are consistently low, but increase with depth. Dissolved oxygen levels
drop quite markedly with depth during summer, and when ice covers the
lake or is newly gone (as 4-24-82). In fall-winter months, when ice does
not cover the lake, dissolved oxygen remains high through the water
depth. The lake is isothermal in the fall and spring, but makes pronounced
reversals from increasing ~emperatures with depth (winter) to the reverse
in summer.
31
Water chemistry data
Water chemistry information was collected during Phase I of Black
Bear Creek environmental work. In addition, samples were taken as part
of Phase II work to estimate lake productivity. The Phase I data is
presented here, while the other results have been incorporated into the
biological discussion on productivity.
The results of Phase I water chemistry are summarized in Table 3
and shown graphically in Figures 12a, b and c.
These data show very dilute and unbuffered bicarbonate waters of
acid pH with low hardness. Calcium and magnesium are in the low range
compared with other Southeast Alaskan waters; Ca/Mg ratio is similar to
other southeastern waters. Heavy metal anomalies were not found in sample
results. Phosporus and total nitrogen values are low, as is common for
the region. Total nitrogen may increase at the stream mouth. Stream
color is consistently lacking above Black Lake and increases markedly at
the stream mouth during the September visit. This color increase resulted
from flushing of the lower watershed as a result of .47 inches of rain
24-25 September. Total dissolved solids show a small increase from
surface, Black Bear Lake, to -50 ft. depth and a more graphic increase
from headwater to stream mouth. Small conductivity increases with lake
depths may result from water density differences between deeper lake
waters and surface waters more subject to rainfall dilution. The increase
in conductivity moving downstream may be at least partly due to
dissolution of marine sediments found along the stream channel (particularly
seen about~ mile above the highway bridge). Conductivity measurements
(shown in Figures a, b and c, and in the miscellaneous data of Table 3)
also show small increases with lake depth, particularly near lake bottoms,
and show increases in a downstream direction, as well.
r--32
Table 3: Water Chemistry Data.
Parameter Con~·entrations in P.P.M.
Bl.Bear Lk. Mouth,Black Upper Black Lower Black Mouth Black
-50 Feet Bear Lake Lake Lake Bear Creek
Aug. Oct·. Aug. Oct. Aug. Oct. Aug. Oct. Aug. Oct.
so 4 2.0 < 0.5 2.0 < 0.5 3.0 1.0 2.0 4.0 4.0 3.0
Cl <2.0 < 1.0 <2.0 < 1.0 f<2. 0 <1. 0 <2.0 <1.0 < 2. 0 <.1. 0
K 0.1 0.2 0.1 0.2 0.2 0.3 0.2 0.4 0.2 0.4
Na 0.8 0.8 0.7 0.8 0.9 1.1 0.9 1.0 1.0 1.1
Ca 2.3 1.2 1.9 1.3 1.4 1.3 1.8 1.4 2.4 2.0
~g 0.2 0.2 0.2 0.2 0.3 0.2 0.3 0.4 0.4 0.3
Fe 0.02 .02 0.08 0.01 0.09 0.12 0.19 1.5 0.19 0.19
~0 ~0.02 <0.02 <0. 02 <..O. 02 (0. 02 ~0.02 ~0.02 <.0. 02 <0.02 ~0.02
Cu .013 < .002 <....002 <...002 I<· 007 (. 002 .007 .006 .010 .006
Zn . 018 <. 002 .045 :( . 002 .005 <. 002 .029 (. 002 .018 ~.002
Pb <.. 05 <. .02 <. . 05 <. . 02 <..05 <.. 02 <.05 <. .02 <. • 05 < .02
Ag ~.002 .015 <..002 <.002 ~-002 '. 002 , . 002 <... 002 <.002 <.002
Au <.. 01 <. • 01 <. .01 < .01 <..01 <. 01 <...01 <.. 01 <. • 01 <...01
T diss Sol 12.0 7.0 .7.0 4.0 20.0 20.0 20.0 22.0 23.0 20.0
Alk(CaC0 3 ) 0.0 0.0 0.0 0. 0· 0.0 0.0 0.0 0.0 0.0 0.0
Alk(HC0 3 ) 14.0 4.0 15.0 4.0 10.0 3.0 14.0 < 1.0 13.0 3.0
H'dness 3.0 3.0 2.0 4.0 5.0 3.0 4.0 4.0 7.0 5.0
T.Phos. < .05 <. . 05 <.. 05 <. . 05 <-.05 0.2 ~.05 <. 05 <.. 05 <..05
T. (Kjel)N .01 .04 0.1 <. .1 0.2 0.1 0.1 <. .1 0.3 0.4
Sept. Sept. Sept. Sept. Sept.
Color 5 5 5 5 5 5 5 5 30 5
i' Sept. Sept. Sept. Sept. Sept.
' !: Turbidity 0.7 . 3 0.6 .2 0.6 . 3 1.0 .. 9 1.0 .6 IJ
i!l Sept. Sept. Sept. Sept. Sept.
Bl.Bear Lk. Mouth,Black Upper Black Lower Black Mouth Black
-··· -50 ft. Bear Lake Lake Lake Bear Creek
Aug. Sept Oct. Aug. Sept Oct. Aug. Sept Oct. Aug. Sept Oct. Aug Sept Oct
pH -6.6 6.7 7.0 6.5 6.7 6.3 6.3 6.4 6.2 6.3 6.4 6.5 6.4 6.7
K
P.'P. M.!
s~o . .'
4 .6-
.3 ./)-
2·0-
1.()_
7.tJ-
/.O-
.i-
.3 ..
• "2 -·' -
I. (-
1. o_
D. 9 _
o.tL
D.?.
~-i-
z.a_
~.o .'
1.8'
I.'
1.1/ -
/.2_
/.tJ-
0 .... -
o,3-
o.1 _
o.t _
c.~-
33
Movn-t
GV.C\c..
c.R...
G·~-·-·.· .... / ····· __.-. ----:-Z -···e ·-----. __.,.-----. . . --. < ~ -~--e --< .6 .. ·······-· . .J -------
<Z.o ~o <z.~ <z.,.. ..
<t.o ·----··--<l.o ·---· --<I·• ····-·----E> ··············-<!)
----0---------~ --
• ... -··········_,-CJJ·-· ® ·---------G:>-~ , _____ • -----·
• •
~----_.tD ~~-/------~~-
~~_;/·
FIGURE 12a: Graphical Presentation of Water Chemistry at
Five Stations in Black Bear Watershed
eecoeoeoeooooeoee
Late August sampling, except as shown.
Late October sampling.
I I ,
TOTAL
0\ SSOL.Ve=P
SOLlP.S
AL~Uf\JIT'(.
:J
(CfiC~)
TOTAl..
PHD..SfHOU.V.S
'TOTAL
K.}et"DAHL
N rra.o&elll
As N.
COLOR
TURBIDITY
:P.¥. M.
~.0-
20.0_ ,,,0-
14o_.
s.o -
4.0 -o.o_
/6-D-
J~.O-
12.0-
/0.o _
B.o_
6.0-
~ .o-
2.0-
o.o-
B.o_ -,.o-
4.0-
z..o-
o.o-
.2-
.1 -
.4 -
.-:; -
.'2 -
• J -
4.() -
30.
20.
zo.
o ..
l.o
-~
34
Mo\J'TH_, UPPER
BI.AC.~ Sl.AC.\C:...
Ssztlll U::.. L tc:...
LOWeR
BLA<:.l<:.
U<.
/---------~···---· -----.. ~~~-~,;;::;;.
,
;~ --~-. --f.a}
o. o ···· -----o. o······ --o.o·····-···o. o ··------e>.o
---~~--.
•
~ __ ....... -(9~---• --Q~; ····-·---<:>·.-···· ...... -~ -·
$... ..($) ··..... _o;;::/· . ··...... .. -------;..-:------_ /
_, I ~-·•··· ·~·------<•I .·· ,. ·--"'-o.
·----~.t!J....... • SePT. • ----·---::-=:: ·· · ···· ·· -eoc..-r . . ·
@-•••• -------0-----.. ---.. ,.e··.
FIGURE 12b: Continued.
PAU.A~...-\t::"~C..
Fe. -
Mo -
hiA-·
~21'\----
P.L. -
~
-
&!.,
pH.
SCAlE
'P. P.M.
1,4 -
1;2.
t.() -
. 8 -
.4 -
• e. --
<.oz
~B ..
• 061-
• /)b-
.g-,-
,.01--
.0.3 -
.oz-
.Ol -
,oS" ..
.ol-
.03 -
.tJ2. -
.()1 -
.ol~-
··~ --• oo" --.0112.-
<,OJ
7.0
ro.e
-
~.c. -'-'Y ~ .. 2.
~e:AU.,.
35
MOUTH
GLAC\c:.
J LOWEU...
QLAC'Ir::. taLAC.'c. SlAC:.k:.
L~ -so .ft:;. ~~~-LK. Ll'-. c:R..
0 " ·. , . , ~ . , . , . . . . . , . , . . . , . . . . ' . . . . 0 •· .
(j):-----···-=e-···· --... ··---~--------
<..oz G)·······---.-. -~--······------Q-···· ..... ···::Q -----• -----®
.o,~ ... 7 .o•z. .ot c.
'(bcz. ·-····-<PtlZ~·-····-·-·-~z. e·-···--· .co ···-···-· .• oo c. ..
• ./~~-----
G4t>Z. ·-···~~%. ---·-·-·<·ooez.. --··· -<-~Z. --····-··<·CD~
<.Ds-(.D, (.D5"= (,DS'"= {• b":J
< .a'2.-----·······e-----·· _ ~o2.--•••••• <·" z.. ----.-~.6-z..
e . . . . . . . . . . . .
~o., z ~do,_ ·--••• .<.oo2.. .. -... <.ob2 ------------=------..,. <_.60 z.
< .0 { ··-·-····<.Dt---· ·-<b•t ·---• • --<."o I------<.tJ I
.. • -·: Aoc=.. Me"A..S.
' (!) --.....(!) =-SePT: ,, •
61 .••. -• -·.-··-m. ·"' El ...•... t::7 = C)c.."'T. .. : _lil 0---.. --. .------G ..... .. .... -.... ·· ... m·-··--------. ... ~ -----...
FIGURE 12c: Continued.
Biological -Fisheries
Black Bear Lake
36
A resident self sustaining population of rainbow trout exists in
Black Bear Lake stocked by A.D.F.G. for sport fishing recreational use
to visitors to Black Bear Lake.
Previous statements concerning the levels of this population have
been drawn from the log kept in the U.S.F.S. cabin at Black Bear Lake
by visitors and by verbal communication with persons who have fished the
lake. Reports vary from 'good' to 'poor' or 'slow'. A survey by
A.D.F.G. on August 30, 1973, produced three rainbow trout on rod and
line.
24 em 3+
32 em 4+
39.5 em 5+
It was proposed to undertake a multiple mark and recapture
investigation over a ten-day period in August, 1981, with rod and line.
However, with only one fish being caught on the first day, it was decided
that this approach was not feasible.
Consequently, the proposal was to undertake a survey toward the end
of May, 1982, to observe spawners and areas of spawning and to trap
fish using baited hoop traps at a time when they were more densely
distributed. Unfortunately, ice remained on the lake until the end of
the field season in mid-June and, thus, access with equipment was
impossible.
It is planned to make a further attempt at a multiple mark and
recapture experiment this August with hoop traps and large wire traps.
37
ADULT SALMONID ESCAPEMENT
Introduction
Previous studies of ·adult escapement are limited to 22 years of
aerial surveys, a 1976 A.D.F.G. stream survey, and earlier visual
observations. Pink salmon peak escapement surveys are given in Table 4 •
The average escapement count for pink salmon into the whole system over
a 22-year period is 14,218. In the mid-forties, there were two very
large runs of 350,000 and 110,000. Apart from these peak runs, counts
have ranged from 30 fish in 1978 to 62,000 fish in 1963. Since 1975,
the stream has shown a definite odd/even trend with the heavy runs
occurring in the odd years. In 1981, excellent returns of pinks were
observed in most southern southeastern Alaska, with escapement above
expected numbers (Jones, et al., 1982).
Year(Date) Escapement Year(Date) Escapement
1960 (9/27) 7,000 1971 (8/26) 14,000
1961 (8/15) 11,600 1972 (9/5) 6,100
1962 (9/3) 23,300 1973 (9/7) 7,000
1963 (8/12) 62,000 1974 (9/3) 5,000
1964 (9/10) 23,000 1975 (8/27) 42,300
1965 (9/11) 3,400 1976 (8/23) 510
1966 (9/1) 5,500 1977 (8/16) 8,400
1967 None Seen 1978 (8/2) 30
1968 (8/27) 3,700 1979 (8/13) 22,000
1969 (9/11) 2,630 1980 (8/22) 4,503
1970 (8/27) 20,000 1981 (8/16) 26,600
TABLE 4: Pink Salmon Peak Escapement Surveys'of Black
Bear Creek 1960-1981 (A.D.F.& G., Division
of Commercial Fisheries).
Where the timing of other runs of s~lmon have coincided with those of
pinks, estimates of other species have been made. It is known that chum
runs have previously been recorded up to 10,000, coho up to 6,500, and
sockeye up to 700. It would appear that chum runs are presently on the
38
decline in Southea~t Alaska (Ward, A.D.F.G., pers. comm.).
As the principal effects of the proposed project are likely to concern
the stream section above Black Lake, extensive surveys of adult salmonids
were conducted in this area from the end of July until October 24, 1981.
Surveys were also conducted in the spring of 1982. The method employed
followed the two-man team strategy of Straty (1980). Both members of
the team covered a given length of the stream either on foot or by canoe,
making separate counts of the adults observed. The counts were totalled
and the average recorded. Counts were recorded for respective different
sections of the stream so as to identify the principal spawning areas.
Results
Results are summarized with respect to each species in Tables 5a,b,
c, and d. A diagrametric summary of the distribution of adult salmonids
is given on the map found in the rear pocket of the report.
[No spawning was observed in the section of stream from 160 feet
below the junction of the main stream channel with the west branch of the
south fork to the entrance to the lake.due to the absence·of suitable
spawning gravels.]
Sockeye (Onchorhynchus nerka)
Early counts in August, 1981, showed the majority of the sockeye to
be in the lower section of the stream below any suitable spawning areas.
Although pairing was observed in those fish that were on spawning gravels
at this time, no actual redd digging was observed until August 18 when
1,022 sockeye were recorded above Black Lake. 657 were still in schools
in the lower sections, 283 were in the south fork, and 82 in the spring
fork of the Black Bear Lake system. The peak of sockeye spawning was in
the last week of August when a larger percentage of fish moved into the
Black Bear system with 500 being counted in comparison to 380 in the
south fork. By the middle of September, only 23 live fish were recorded.
Extrapolating for mortality between counts, it is estimated that 700
sockeye spawned in the Black Bear system and 575 fish in the south fork.
39
No sockeyes were observed to spawn in the lake fork of the Black Bear
system above the beaver dam as they were unable to run above it with the
low August flows. A few isolated efforts by sockeye to beach spawn in the
lake were observed. Approximately 10-15% of spawning sockeyes were
identified as 'jacks' or precocious males.
Pink salmon (Oncorhynchus gorbuscha)
An aerial estimate by A.D.F.G. on August 16, 1981, gave 26,600 pinks
in the Black Bear system. At the beginning of August, schools of pink
salmon were observed to be in Black Lake and began congregating around
the mouth of Black Bear Creek where it enters Black Lake. These appeared
to be fish that had moved through the entire section of the lower stream
due to the large numbers of fish competing for spawning habitat. Sixteen
pinks had entered the lower section of the creek by August 18. Three
inches of rain in seven days from the 21st of August caused the stream
to markedly rise, whereupon large schools of pinks entered the creek and
on August 28, 1,168 pinks were counted in the system. By September 5,
1,671 fish were found on spawning grounds in the south fork and 1,487 in
the Black Bear Lake arm. Further rain and rising of the creek permitted
pink salmon to pass over the beaver dams on the lake fork and to utilize
this section of the stream for spawning. The peak of pink salmon
spawning was in the middle of September when 1,900 fish were observed in
the south tributary and 1,730 in the Black Bear system. The total number
of pink salmon that spawned in the Black Bear system above Black Lake was
estimated to be in the region of 2,000 and, in the south fork, 2,400.
In the spring fork a number of pinks were observed spawning right up
to where the upwellings arose from the ground among the moss-covered
stones. Pinks were undoubtedly superimposing on redds previously occupied
by sockeye salmon.
In the lake fork, pinks were observed in all branches up to where
the stream gradient starts to markedly rise in the lake outlet channel.
They were recorded spawning in channels that had previously been dry during
the low August flows. Heavy continual storms in late August and early
September created high flows and allowed pinks to migrate over the beaver
TABLE Sa: Numbers of Spawning Sockeye (Oncorhynchus rterka) in the Stream System Above Black Lake. 1981
Date August August August August August September September
Location 5 10 13 18 28 5 16
Mouth of creek to West Fork of South
tributary 420 345 309 546 165 42 0 '
Main creek from West Fork of South
tributary to junction with the South
tributary NC 60 92 111 145 71 0
West Fork of the South tributary NC 10 34 59 43 36 6
South tributary NC 133 205 224 337 292 10
~
Lake Fork to Beaver Pond NC 0 0 0 0 19 0 0
BLACK
BEAR Beaver Pond on Lake Fork NC 0 0 0 0 0 0
LAKE Lake Fork above Beaver Pond NC 0 0 0 0 0 0
SYSTEM Spring Fork NC 50 90 82 500 396 7
TOTAL 598 730 1,022 1, '190 856 23
--~--~~~=~~--~~ ... > ·-··~···~~~~-~--~-~---~~-~--~.~ •• -.-
TABLE !).b: Numbers of Spawning Pink Salmon (Oncorhynchus gorbuscha) in the Stream System Above
Black Lake, 1981
Date August August August August August September September
Location 5 10 13 18 28 5 16
Mouth of creek to West Fork of South
tributary 0 0 0 16 629 830 121
Main creek from West Fork of South
tributary to junction with the South
tributary 0 0 0 0 51 280 156
West Fork of the South tributary 0 0 0 0 14 270 148
South tributary 0 0 0 0 250 1,401 1, 752
.p-
Lake Fork to Beaver Pond 0 0 0 0 18 22 127 1-'
BLACK
BEAR Beaver Pond on Lake Fork 0 0 0 0 0 0 24
LAKE Lake Fork above Beaver Pond 0 0 0 0 0 0 468
SYSTEM Spring Fork 0 0 0 0 206 1,265 1,111
TOTAL 16 1,168 4,068 3,907
TABLE 5c: Numbers of Spawning Chum Salmon (Ortcorhynchus keta) in the Stream System Above Black Lake, 1981
Date August August August August August September September
Location 5 10 13 18 28 5 16
Mouth of creek to West Fork of so·uth 0 0 3 4 0 0 0
tributary
Main creek from West Fork of South.
tributary to junction with the South
tributary 0 0 0 0 0 0 0
West Fork of the South tributary 0 0 0 0 0 0 0
South tributary 0 0 0 0 0 0 0
Lake Fork to Beaver Pond 0 0 0 0 0 0 0 -ll-
N
BLACK Beaver Pond on Lake Fork 0 0 0 0 0 0 0
BEAR
LAKE Lake Fork above Beaver Pond 0 0 0 0 0 0 o.
SYSTEM Spring Fork 4 4 2 0 0 1 1
TOTAL 4 4 5 4 0 1 1
-· SdU\ii$J::&JII!XI%SWiii·iC'filillti,lf!l.M&rffi•k!i£1mli!Mi\L!!.lAA0illZ~.ffi,_j.ii'JtUV!.:;~s::.UWDiii4Si.. ,, ... ,(.... C;;: I .n. '·"-' 8 ••·-""'--·-· "-"'~·""''' • ·'""'h;···c:.;·,,
TABLE 5d: Observations of Spawning Coho Salmon (Ortco:thyrtchus kiS·utch) in the Stream System Above Black Lake 1981
Date September September October October October
Location 5 16 21 22 24
· Mouth of creek to West Fork of South
tributary 0 3 1 5 16
Main creek from West Fork of South
tributary to junction with the South
_tributary 0 0 0 0 0
West Fork of the South tributary 0 0 1 1 2
South tributary 0 0 7 6 20
.p..
w
Lake Fork to Beaver Pond 0 1 0 0 0
BLACK Beaver Pond on Lake Fork 0 6 1 2 2
BEAR
LAKE Lake Fork above Beaver Pond 0 0 0 0 0
SYSTEM Spring Fork 0 1 4 6 2
TOTAL 0 11 14 20 42
I
I
I
II,
I :
i
!
I.
! :
I
44
dams. 1981 may have been an atypical year in terms of the pink run, for
it is unusual for pink salmon to run through a lake and spawn. Neverthe-
less, other incidents of this occurring have been reported on Prince of
Wales Island, notably Klawock Lake. Here, in the last two years, large
runs have entered the stream from saltwater and have moved through the
lake in search of suitable spawning habitat and spawned in feeder streams
(Steve Hansen, A.D.F.& G., pers. connn.). Below Black Lake pinks were
also observed spawning in shallow, intermittent run-off streams which only
flowed after high levels of rainfall. Three or four pinks were observed
attempting to spawn in an inlet stream in the western part of the lake.
Chum salmon (Oncorhynchus keta)
Only nine chum salmon were observed above the lake. Five spawned at
the upwellings in the spring fork. Four of these fish spawned early in
August. The association of chum salmon spawning with upwellings has been
documented previously.
Coho salmon (Oncorhynchus kisutch)
Eleven coho were observed in the system above Black Lake, six of
these being in the beaver pond on the lake fork. Two counts of coho in
the third week of October located 42 fish above Black Lake, a high
percentage of these fish being in the south tributary. Coho were seen
jumping in Black Lake dur~ng the last week of observations and, thus,
fish probably continued entering and spawning in the creek well into the
winter. Coho have been recorded spawning in the Klawock system as late
as March 1 (Steve Hansen, A.D.F.G., pers. connn.). An estimate, therefore,
of coho spawners was made in conjunction with an evaluation of the fry
migration and rearing populations. Analyzing fry estimates for 1981 above
and in Black Lake and with a rough extrapolation using estimated fecundity_
and mortality, a figure of 85 to 100 coho spawned in 1980. It is likely that
a similar nmnber spawned in 1981 above Black Lake.
45
Steelhead (Salmo gairdneri)
Steelhead trout were observed to enter the creek this spring, 1982.
Twelve fish were estimated to have moved through a pool below a large
log-jam just above the location of the L.B.L. fyke net between May 1 and
May 17. Two steelhead were also observed in the creek near the outlet
of the lake during this time. Rod and line captured three of the fish
in the pool by the log-jam. A fourth fish was hooked near the site of the
M.B.C. fyke net but was not landed, and 3-4 fish were observed visually
in this region of the stream. A survey of suitable spawning areas above
Black Lake showed that no steelhead passed through alack Lake and, thus,
all spawning occurred in the stream section below it. An estimate of 20
to 25 steelhead were in the upper creek below Black Lake this spring.
Catch Statistics
690 mm
406 mm
385 mm
2,350 gms
568 gms
606 gms
6+ 4 fresh, 2 saltwater
no scales taken
s:cales all regenerated
Dolly Varden (Salvelinus malma)
Schools of Dolly Varden were observed in the stream system above
Black Lake in August and September, 1981. The number did not exceed 200
and they were principally located in the south tributary. None were
observed in spawning coloration.
However, Dolly Varden do spawn in the system as shown by the
occurrence of juveniles, which are discussed later. It is possible that
these fish were in the system to feed on salmon eggs.
·~.---· ·:.-:··-· ,._.., --:""" ......
46
OUTMIGRATION STUDIES
Introduction
A preliminary study was undertaken in the spring of 1981 at the
mouth of Black Bear Creek to estimate the timing and relative size of
the outmigration of pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus
keta) salmon fry from Black Bear Creek. The peak of the outmigration
occurred between March 21 and March 24 and this correlated with increases
in water temperature and stream discharge at that time. A smaller peak
occurred between April 4 -6. Two size classes of chum were identified,
one group falling predominantly within 29 and 32 mm, while the other
group was between 38 and 41 mm.
An extensive fyke net program was operated this spring, 1982. Nets
were installed at three sites in an effort to ascertain the timing, and
enumerate outmigrating fry from the Black Bear system, particularly from
the most sensitive area with respect to the project, the section of
stream above Black Lake.
Methods
The three sites selected were as follows. A description of the
operation of the fyke net is also given.
Upper Black Lake (U.B.L.)
To estimate the total number of fry migrating from the spawning
habitat above Black Lake, a net was installed at the entrance of the
stream to the lake. The installation made use of a beaver dam across
part of the creek with the net being placed adjacent to it. The fyke
net, with a 6 foot by 4 foot internal opening and 1/8 inch mesh, was
attached to a steel cable fixed across the stream between two trees by
means of cable clamps and trolling wire. A 5 foot by 3 foot by 2 foot
live box was attached to the cod end of the net and held in position by
two ropes staked out to the bank. This box facilitated holding of the
47
fry live after capture (Plate 1).
Stakes were pounded into the creek at 2 foot intervals just upstream
of the beaver dam and Visqueen plastic sheeting was attached to them so as
to provide a more effective barrier across the stream and direct fish
through the net. The net frame had two 1/8 inch mesh wings, one of 20
feet which was attached to the bank and the other of 6 feet which was
attached to the dam so that fish migrating upstream from the lake could
pass through it.
Plat~ _ _l. ___ _
Although the creek eventually undercut the dam, it basically held
throughout the period of operation, except for a few minor repairs. The
dam functioned to increase the velocity through the net, for the stream
in this area is typically slow flowing.
The net installation was delayed initially due to the presence of
ice on Black Lake, but when it was evident that the situation was not
going to change for a considerable period of time, operations were
carried out by hiking up and down the edge of the lake ice each day.
The net was fished continuously from April 10 until June 8, apart
from a period of 3 days between April 20 and April 22 when it was pulled
48
due to extremely high flows. Fish were evaluated for counts on species
each morning.
Lower Black Lake (L.B.L.)
A fyke net with a 3 foot by 3 foot opening and 1/8 inch mesh net was
placed in the stream 1/3 mile below the outlet of Black Lake. This site
was selected as the natural configuration of the stream increased the
flow and provided sufficient velocity to operate the net for outmigrating
sockeye and coho smolt. An initial attempt was made to fish the entire
width of the stream using wings with 1/8 inch mesh metting but fry
mortality occurred so it was discontinued.
As with the U.B.L. trap, the net was attached to a cable between two
trees with trolling wire and cable clamps. A live box 3 feet, 6 inches
by 2 feet, 6 inches, by 2 feet was connected to the cod end of ·the net.
When the sockeye smolt were near their peak, this box was switched with the
larger one from U.R.L.
The net was fished every two days from April 9 and then on a daily
basis from April 25 until June 9, being set toward sunset and then
emptied the next morning. The net was fished in the same position across
the stream throughout the phase of the operation.
-'•
Mouth of Black Bear Creek (M.B.C ~)
A third fyke net was operated 1/3 mile from the mouth of Black Bear
Creek at saltwater, at the same site as the 1981 outmigrant trapping
program and with a similar installation as at L.B.L.
The net was operated approximately every 3 days or when flow conditions
permitted. On ocaasions of high flow, it was moved from its original
position so that it could be operated. The installation was washed out
in flood conditions on April 20 but was fortunately retrieved downstream
and was repaired and reinstalled.
Each net had a 12 inch long zipper on the top section to facilitate
cleaning of debris trapped in the net.
49
Mode of Operation
At each site total counts of fry and smolt were· made for each
operation of the net. Where numbers of fry exceeded 1,000, an estimate
was made by weighing the total number of fish and then weighing a
representative subsample. The subsample was then evaluated for numbers
of each species. Fork lengths to the nearest millimeter and weights to
1/100 of a gram were made on approximately 25 anaesthetized fish of
each species for each operation of the net. All smolt captured were
measured and a large percentage
Water temperatures were taken at each site when sampling occurred
and discharge levels were related to the height of Black Lake which was
recorded on a daily basis.
In order to estimate the total number of fish outmigrating from Black
Lake, an attempt was made to determine the efficiency of the net.
Captured sockeye smolt were anaesthetized, marked with a tail punch, held
for 12 hours and then released 300 yards upstream of the net. Recaptured
marked fish were then recorded.
Of 243 fish marked, only 21 were recaptured, giving an efficiency of
approximately 9%. This was considered to ,be low, as flow measurements
:l,i'.'
ltil'. li:
50
showed that 15% of the discharge went through the net. Handling and marking
of sockeye smelt produced mortality at Hugh S~ith Lake, sometimes reaching
50% (Haddix, 1981). It is possible that a similar mortality occurred
in this instance·and, thus, an efficiency rate of 15% was used for
computation of total numbers and was considered to be closer to the
actual value.
Results
Each species will be considered separately with regard to outmigration
patterns this spring. (1982)
Sockeye (OncorhyUchus nerka) fry (Figures 13a,b)
Sockeye frywere evident in the first operationof the U.B.L. net
on April 10 and appeared to have two main peaks on April 12 with 2, 365
fish and on April 19 when an estimated 2,445 fish were collected. Numbers
began to fall after April 24, although some catches of 500 were made.
From May 12, numbers averaged less than 100, although fry were taken up
until May 30. The total number of sockeye fry collected ~ntering the
lake was 16,258. Average length was 29.4 mm. and weight 0.190 gms. Only
small variations in fork lengths occurred over the period of the run as
evidenced by the histogram of the mean lengths (Figurel3b).with the
slightly larger fish occurring at.the peak of the run. Heavier fry also
came at the peak of the run and::·the lightest at the beginning and the
~ ' .
end (Figure lJW. However, the regression plot of weight against length
gives a very low r 2 value (correlation coefficient squared) of 0.36,
illustrating the large variability of the length to weight ratio in the
case of these small fry.
It is possible that a large number of sockeye fry entered the lake
before April 10 and that these total numbers are inaccurately low.
Haddix, A.D.F.& G~ (pers. comm.) has observed sockeye fry in Hugh Smith
Lake~s early as late March. However, the peak of the run there is
typically in May. This outmigration will be discussed later in the
summary in conjunction wit~ the sockeye escapement figures.
ll Located 40 miles southeast of Ketchikan on the mainland.
:1JSOO
.2,2.5"0
2,ooo
,,..,~o
"' ~
r,Soo
1 1,2.5o
' r,ooo z
7SO
Soo
25"0
0 c. 4
3
La.uc..
\..\e.~h\
tl .. )
0
I
I
I
I
51
~ 10 (4. rS Z2. 2'-?oo 4 8 12 IC;. 20 2'\-7.8
Mt.l·t
ID · If. 1& :J2. :J" 30 . 4 9 ,,., ac. zo 2'1 :z.a
~fc-\\
10 14 · IS 2Z. 2." 3o 4-a 1::1. IC. :t.o ::t.-4 28 S'
FIGURE 13a: Numbers of outmigrating sockeye fry entering Black Lake
.with associated temperature and di·scharge information.
Spring, 1982.
13
'I'': ,,
1
,,
:1'
jl
; i
,I!;:
i!
II!
:I' '' I·' :'
iii:
t'
30·00
~ ! :S·,S
iv~~so s
-29·2.6
~ ..!l.-~-ao
! :29·,5
t 28·50
0·210
0· 2.1
0·\5
-0·400
-
-
-
-
.
-
.
30
~
26
r--. 54
IQ.l ~
r--
4-ao ll-n aa-~ :z.s-1
Arr·,\
30
~
101 54 ,....._. r--
2£,
r--
4-10 u-q \9-z4 lS-l
or"'''
52
.
~ '~ ~
\E,3
.....-.
lEitO
r---
2.-8 9-1.5
t-\~:\
loj w = 2· " \ \~ \ -3. 81Et
N -= · ,5~
..-:z. • o.ge,
"'3-'-. ()C. ~Q.. C'~ .
sy .. U\~ '~~2 •
·.He.~. ~-135
4m..n.
r--
E,3 \0 ..--...--
\--\e.o..C\ a
·~ ,..--
65 ,.......
10
.....-
1·200 ;-~--------,--------------.------------..------------~------------~.-----------~r------__,
1•30() 1·350 \·400 1·450 l·SOO I•SSO
FIGURE 13b: Weekly mean lengths and weights for sockeye fry migrating into
Black Lake, April 4 to June 5 and a regression plot of length to weight. ·
Spring, 1982
53
Pink (Oncorhynchus gorbuscha) fry (Figures 14a-e)
Large numbers of pink fry were captured from the initial installation
of the U.B.L. net on April 10 until May 12. Smaller numbers were taken
right up until June 1. An average of 11,700 each day were taken during
the major part of the run, with peaks of 29,800 on April 16 and
29,300 on May 5 (Figure 14a) A number of fry were missed when the net
was pulled between April .20 to April 22 and on Hay 6, 7 and 8, when
flood water came over the top of the dam. This accounts for the drop
in the graph on these days. The total number of fry captured was
380,052. Considering that fry must have migrated into the lake before
net installation and the losses aforementioned, it is estimated that
440,000 to 460,000 pink fry migrated from spawning habitat above Black
Lake into the lake. The two peaks would appear to correspond to
increases in discharge at that time (Figure 14a).
The fyke net at lower Black Lake did not capture all the outmigrating
fish. The efficiency factor, using recaptured, marked smolt, may be
inaccurate in its application to fry but it is felt that it gives an
adequate approximation of total numbers.
27,564 pink fry were taken in the net between April 9 and June 1.
The numbers in Figure i4barecalculated to incorporate the 15% efficiency
factor of the net, giving a total of 183,760 pink fry outmigrating from
Black Lake during net operation. Some fry undoubtedly migrated before
net installation and during the first 14 days when the net was only
fished every two days. Consequently, a total estimate is in the region
of 215,000 to 225,000 pink fry.
The peak of the outmigration was on April 27 when an estimated
44,000 left the lake. A smaller peak occurred on the 8th of May. These
two peaks mirror high discharges from the lake on these dates.
Figures 14a & b provide an interesting comparison. The large number
of pink fry that entered the lake from April 10 are not reflected in the
outmigration from the lake until the peak on April 28. Some fry may have
been holding in the lake for a short period while others moved virtually
tO 14 t8 22. Z.'-30 4-
"'r"il·
a e:a tC. ::r.o .a4 28
&3
FIGURE 14a: Numbers of outmigrating pink fry entering Black~~ke with
associated temperature and discharge information., Spring, 1982.
55
44,ooo
401ooo
?,n'R \r~-\..~. L ·
Sfr'n\ \~S2.
3'1oo0
'321000
z&,ooo
"' ~ '-4,000
1 zo,ooo ~ z '"·000
1"1.,000
9,000
4,000 ~~
" 10 14 18 :l2. zc. !lo 4 9 IZ.
,._pril M.a'{
8
7
fp 1o 14 •& 22. 2C. so 4 El 12. '" ao 2.+ z&
~~ .. ·,\. Mo.,
5·0
Figure 14b: Numbers of outmigrating pin~ fry leaving Black Lake with
associated temperature and discharge information, Spring, 1982.
-· 34·25 ~ . _, 34 ·CIO -
--
~·'16
,.-:. 54· 50 -
I 34~25 ..J -
io 34•00 -
·§ -~
. 3~·'15
~ 3S•SQ -
c::
l 33·25 ..
35·0
:52·15
-
-
~ 55·,S
0 ......
33·50 -
t: ~ 3:!1·2:6 ! -
-
FIGURE 14c:
-
-4-10
.--
.
.
r----..
'
o .. ,, . IQ-'Jc\ -lS-\
P.\'C"i\
-
. r--
r--
56
\ . r--o:s.L. -.--
M~C\ ll 35·b -·-
'· r--
. r--
2-6 ~-·~ :16-2.1 .. 23-~ 3Q-5
Mo.~ :) ...A~
-
L3.t..
,__
Hea.n. • 34. \ ft\ft'\ •
r--
4-tO u-l'l IS-24 .25-1 2..-9 9-15 lEt-2Z
A~C"i\ Ha.~-tv\.~.c.
t'\ 33, eQ.n • . "'"' -
r---r-
t--r--
----
~
.--
4•10 n-n IQ-~ 25-1 2.-.6 9-IS lt.-22. 23-~ 30-.S
Weekly mean fork lengths (nnn) for pink fry entering Black Lake"
leaving BJ.ack Lake and mouth of Black Bear Creek (April 4 -June 25, 1982)
0·210
r-"\ ~0·2.~0
~
0·250 ~ ?'Oo-2.40 •01
3
~ 0·2.30
r. 0·22.0
0·2.10
0·290
,-,. O· 2.10
~ 0·2.~
-.._/
~ ..
~ 0·250
i 0;.240
J
0·210
,J. -io 0·2.50
~
3 0·2.40 1 0·8tl
0·2.'2.0
0· 2.10
FIGURE 14d:
-
.
-
.
-
-
-
-
-
...
...
'.
57 •
,, 14~
r---r-n4
145 r--
,...---
46 -
'
4-10 u-,, u~-.l4 . .25-l
. Af'"a .
t4S· 135
~ r-
so ......-~ 2S
,...---
34 r--
so r--
,6 ,...----
23
r-
\5(0
r---
'" r---
~· E,Q ----
91 n 49
r
Y,n\?. \~-~f<"'~~ ,qe,2
"J2 _,.....
~
~ -
\.l. "tl .. \...
t--\ ~C\ =·
2.S2 ~nu .0·
L.'B-\...
t--\Eo.t\ : 0· l,(;,E, ~«\S.
~
..
M .:B.C.
HG!.o..(\ =
0·2598'1 •
4· 10 U-11 16.-24 2S-I 2.-9 '-IS 1&-22. 23-~ 30-5
A "' \ t---\.o."\ :runct. Weekly meanfweights (gms) for pink ~entering Black Lake, leaving Black
Lake and mouth of Black Bear Creek during the piriod April 5 to May 22,1982.
58
straight through. This is possibly reflected by the large variation in
size for that time period, from 28 to 37 mm fork length and 0.210 to
0.410 gms. This peak also closely relates to when the ice went out of
the lake on April 26. It is possible that movement through the lake
was restricted by the presence of ice. The May 8 peak at lower Black
Lake would appear to concur with the May 5 peak of 29,311 for upper Black
Lake. Pink fry numbers become negligible at lower Black Lake on May 19
which is approximately the same time as upper Black Lake. Indeed, a
comparison of estimated total numbers at the two sites is striking
215,000 to 225,000 pink fry leaving Black Lake in contrast to 440,000
to 460,000 calculated to have entered it. This gives a mortality rate
of 49% of fry moving through the lake. The movement of pink fry through
a lake has not been extensively documented and whether they follow lake
currents or migrate around the litoral zone until locating the outflow is
undetermined. Whatever the case, they are subject to heavy predation,
presumably'from resident fish, notably cutthroat, Dolly Varden and coho.
Overwintering Dolly Varden may also play a role. Although some 20-30
Dolly Varden were observed moving out of the system in May no larger
numbers were· found. Predation from this source would also vary from
year to year according to the number of overwintering Dolly Varden, which
may fluctuate widely. For example, in Hugh Smith Lake, 6,000 Dolly Varden
were recorded overwintering whereas in the previous year there were only
200 (Mike Haddix, A.D.F.& G., pers. comm.).
The average length of pink fry migrating from Black Lake is 34.1 mm,
compared to 33.6 mm entering the lake. The weights are higher with 0.266
gms compared to 0.252 gms leaving the lake (Figures 14c & d). These
differences prove.highly significant at the p=.OOl level with the
application of a simple t-test. By examining the weekly mean weights,
it can be seen that the average for April 25 to May 1 is 0.275 gms for
those fry leaving the lake, which is notably higher than the three
previous weeks, again reflecting that fry had possibly remained in the
lake before migrating with the high discharge and the ice going out.
Number of pink fry collected at the mouth (M.B.C.) were extremely
variable. Two main peaks occurred during the first part of May on the
40,ooo
a~:.,ooo
az,ooo
1.&,000
24-,ollO
It
'" 2o1ooo " ,.s.
E IG.,ooo ' z
12.,000
&,ooo
4,1100
0
8
7
oc.
"
.s
4
3
2
c.
La.~ c.. 5·0
\-\q_~n" .4·0
<t) 3·0
.J·O
FIGURE 14e:
10 14 •& 22-Zb 3o 4
10 K 18 ~z ~" so 4
~\'f''t\
10 .... 18 zz. 2.'-30 4-
59
I
.I
0
I ~~
8 IZ 1& zo Z'/ z& s
"'1~j ~nq_
8 12 I C. zo z4 .28 s
,
,..., .. ; 1 ~'I Jun!l.
Numbers of outmigrat1ng pink fry at the mouth of Black Bear Creek
with associated temperature :and discharge information~ Spring, 1982.
60
9th and on the 14th.l/These peaks were later than those recorded for the .
upper Black Lake net, and appreciable numbers of fry were collected
right through until the end of May. This later outmigration reflects the
large number of pinks (approximately 26,000) that spawned below the
lake and it appears from the cumulative temperature unit data (Figure 9b)
that accumulation of temperature units is slower in the lower section
of the stream during winter than above the lake where the spring flows
create higher temperature regimes and, thus, earlier emergence occurs.
Mean fork length of 33.7 mm (Figure 14c)and weight of 0.258 gms, are
similar to the upper Black Lake net. Two large pinks were taken at the
mouth of the creek with a length of 45 mm.
Chum (Oncorhynchus keta) fry (Figures 15a~e)
It is apparent that the migration of chum fry into the lake may have
been partially missed as the largest numbers were on the first day of
operation of the net. In total 538 chum were collected entering the lake
and, using the 15% efficiency factor of L.B.L., 3,753 leaving it. (Fig.15a&b)
C~nsidering that the L.B.L. net was not fished every day until April 25,
it is evident that some chum fry emerged from gravel habitat between the
lake mouth and the location of the net. 3,410 chum were collected at
the mouth of the creek with a peak on April 13 and a smaller one on Apr.26th
Fig.15"e.). The outmigration was virtually completed by the 12th of May.
Mean length and weights for the three sites (Figs. 15d & e)show a negligible
amount of variation. No smaller size class was evident in this year's
outmigration compared to 1981 and it is possible that the smaller group
in that year were sockeye fry which were leaving the system.
Coho (Oncorhynchus kisutch) fry(Figures 16a,b)
Coho fry began to move down into the lake from the stream above
Black Lake on April 11 and fluctuated in number throughout the fyke net
operation at U.B.L. A peak occurred on April 27 when 725 fish were
captured. The total number of coho fry collected entering Black Lake
was 3,029. A larger percentage of the coho fry migrated into the lake
during the middle of May.~/Although it was attempted to screen the entire
ll Fig.14e
~/ Fig.l.oa
61
2~5 c_ h\k<n \.-~ u:S.L
S~t"''C\d \~ .
~00
176
1SO
,.., I:Z.S ~
.P 100 E :s z 75
5o
0 ~ I \ ,'
:15 ~0 ?J::J,' 0
" 10
'""' I 'a Z2. 2'-30 4 6 J2. '" '2.0 Z4 z.s :> ,
April Jl\ay ~\Jne,
5
;Jvrv oc.. 4
5·0
ld~ .4•0
\..\~~\\\-'
3,0
(~)
2•0
10 14 18 22. u 30 4-8 fZ IC. ao .a4 28 S
Af>'i I Mny Jun11.
FIGURE 15a: Numbers of outmigrating chum fry entering Black Lake with
associated temperature and di'Scharge information. Spring, 1982.
. .
-·------. ------------· ---
1,ooo
0oo
7DO
(.oo
!Soo
4oo
!oo
100
0
8
7
62
\
\ o·
10 1-1-19 11. 2'-30 4
~r--''
(II 10 .... 18 2Z. 2" 30 ....
A~r·, \
C.,'n~""' \<'"~ -L:-B-\....
\~@2.
6 1.1 '" :z.o ::Z.-4 2.8
• s '
-:)W\q_
13
10 14 18 2Z. 2.t. 30 4-a 12. a& zo z4 :ze S
Junfl.
FIGURE 15b: Numbers of outmigrating chum fry leaving Black Lake with
associated temperature and aischarge information. Spring, 1982.
6
7
4
2
10 3D 4 8 IZ %0
,·~~
10 14 18 2.2. 2.'-30 4 8 12. II. %0 .1.4 28 5"
Jun!l,
FIGURE 15c: Numbers of outmigrating chum fry at the mouth of Black Bear
Creek with associated temperature and discharge information.
Spring, 1982.
: i
4E"•O
~
f
J.-4\~0
~
f> 40rO z·· -~ -~ ~
J aea
. T
~ 41·0-
-£ --~
-400
~
-:.fL
J 3So0
I
; . ~--:
-·-·------... --"';"-------~-:
. -------------!. •.• --.
---··-...
------.----t---.--··
-
..
-
-
-
·:
... -
-
urn. s
r-·· .
.. ,
I~
r--
4 2
•.. ;---r--
' . . .. --~ .
· . .4-ao u-n· ·as-24 25-l
}4pc•,\
-· ..'. ,.
4\
2.0
4-\0 ·"=-~, . 18-24 25-l
C\{>r·,\
•· ---•. ·--'-·------1 ..•. -.. ---··· •.. ·'· . l
~ --... -:-· --~--.
--··--·····--·---... ---~ ~ --.•..... _:. ...... -.... .:,_ __ ." I -
-l~ \J."B.L.
~~= 3'3·<;,M~· ' r--
-
..
8
r---·-
4
;-2..
r--
3
[~; .
~-9 9-IS IE,-U 23-29 30-S .. !
M~ -:Jun.~.
·L.'B.l.. ..
MB~c.·.
K~. "3~ -o~.
··---~-·---
lb
-~-------. <t· - ------------f --
2.6·--
--. -----.. -~ ---
-i -... -----:_. ---·-~-----·----:--~-~-}-.:. ......... ...
-----.. ! . ----------..!-.. ..:.. .. __:. __________ .__~--·
. ... -. ------~--~:··:·.~-t----~---~--~~=-_:~--=~t--~--
-..
<::;'_
--~ ·S>J
~ sv
o)
-3
' ·a
-1:
6-'\1
o-t.z.
0"4\
()OJCG
o-ee-
c-38
o:~1 -
4
5
2
4·10 \a~n •8-2.4 25-l
.. --~~~·\-..
41
20
~
4-tO 11-11 . 19-24 .25•\
~~,,
.... ; ~ .. &4l. ..
_ _ _. : -~ o4•_ . _ zt
. , .. ---' . . -~-
40.
• ·-:·-------'------------·· __ .....!,
-: ·.c;;·~
8
-_ ehU:rn · ~~ -Sfc-~~ t9S2
K~:: o-.t3 U."B.L.
~...u-.
4
3
15.
i.
!
I
I
I
I
I
I
3
L."'B~L.
0. 4\ ~--.,--. -------------
.tv\.'B.C .. _·
i .. -
t ·------·---··· -----··------------------------.--7··-··
J • L.--
~ . . . -. . . -; ----
r-
____ L_ __________ ! --
! ...
--· ·· · · : · -· · · · o·38 -.-~--....-~..-w.___,._~.....;...J~--L...;.......;;L.,-L~..__.:~..-_ _.;__...;._...;.;.....;.._....;.._
· : , . : .. · · .. ; :. 4..:,o . _ .. _,,-:_ :as-JA. ~ 2!;-1 -2.--~-· 9-~ .. . -. -.. ~ .. ~-~ : -• ..
. ~. -. ~ . .
_ .. ::.· ;;Gtn\~ ~~e; _}JeeKf~~:~~t ~/oi hiJID Tn ~~n~ ii:ck Laie:;:Ili.nn~ : L~~ : ;_ ~ _
· · ---· -: · · L · ·· · Biacl(i.ake-and ·at/ tln:-muutlr-u\E ·Blcn::lc-Bearr Creek· (Apri l-4---, .June-5J ~ ~ --------' ~ ; --; • ~: . H~~:~ Spqyt=7~¥H=·--;-v ~;~-~ • _ -•· --~-.. _ ~)~~~-~w+~;;·;:~r-~}
66
(oha ~~~-\1:B. L.
800-synaJ \9~2.
700 0
600 ~
S'oo -s qoo
1 ~ 300 -z
2.00
100
D
~ 10 1"/ 1.6 zz. Z.C. 30 .... a IZ. I C.. 20 2.</ z.s I s
Arril M.ay J\Jne..
4
1~~---~---~----r---~---,---------r------~-----...--------~-------?---r-~-------.. 10 If 1& :1'-2'-30 4 9 •~ oC.. :Zo 2<1 2.& S CJ 13
-:luC\~
s.o
A-0
.:2 .o -·1------.--.--....---,.----T--:"Y--r--..----..----..----.--.---
JO 14 18 z:z. 2." :Jo 4-9 ra ac. z.o a4 :za S
AJ"'"il Mny JiLJnfl.
FIGURE 16a: Numbers of outmigrating coho fiy entering Black Lake with
associated temperature and discharge information.
Spring, 1982.
--·----··· --···---·-:-:-----.-."":':"------
?
f
.....J
~ c:
Ql -
~
~
c .g
1.
67
3,·0 C.a'no \~ -\J."B. \.. ·
2..
-
60 Sfc-'~ \~S
3Et·S ·r--
~-o Hean = 34·
35·5
35•.0
4 23 ·~ ,.....:... r--r--S4 . 125 --
34·5
34·0 ,,
3'6·6 n (,0 .
r-1
'2.-8 g-IS I~· 22 2!.-29 ~-S n-n \6-14 2.5-1
~pc-i\ ~~~ ~~~~
-
4 .........
2.4
r--
61
rt
II-l1 18-24 2S-\
Afr"a\
so ,....--
1'2.,
~
1'2.S .54 ......... -
59 -
FIGURE 16b: Weekly mean fork lengths for coho fry entering
Black Lake during the period April 11 to June 5.
Spring, 1982.
l--\.C2.0A:O
68
sample of fish in.the live box for coho fry, numbers were principally
estimated from the subsample taken. With the large number of pink fry
being present, it was evident that the presence or absence of a few coho
fry in the subsample would significantly influence the final coho fry
estimation.
Mean length and weight were typically larger in May and at the
beginning of June (Figure 16a. It is probable that these fry had emerged
from the gravel earlier and had spent time in the stream. In the
territorial competition for niches, these fish had become displaced and,
thus, were moving down into the lake to seek out suitable habitat. A
small number of fry probably continued to move down after removal of the
net.
Coho fry were taken in the net at lower Black Lake, principally from
the middle of May onwards. A total of 849 fry were collected. Although
some of these fry may have come through the lake, it is considered that
this movement reflects emergence of fry from below the lake. Their later
movement than the upper Black Lake again indicates possible later
emergence below the lake as a result of lower temperature regimes during
winter.
693 coho fry were captured at the mouth of the creek in the M.B.C. ,
net in five settings between May 23 and June 8. Only 12 fry were
trapped before this date. These nomadic fish are probably being
displaced from the system due to competition for rearing habitat and
the aggressive behavior of dominant individuals (Chapman, 1962).
Sockeye (Oncorhynchus nerka) smolt (Figures 17a -gl
The first smolt commenced to emigrate from Black Lake on April 18
and continued until June 10. The main peak of the run was May 27 and
May 28 (Figure 17~ with numbers showing a marked increase from May 17.
This corresponds to when the temperature of the lake outflow attained
7.0°C. The temperature th~n began to fall, reaching 4.5°C on May 22,
corresponding to fluctuations in number of outmigrants during this time,
·. ·. !l,ooo
~'!OO •
I, Boo
/,700
l,t.oo
(500
1,4oo
/,300
1.100.
•.roo
~ l,ooo
,P '}oo
E :; Boo
z :uo
hoo
S"oo
J/00
3oo
2.00
. 100
0
18 2.1
8
7
0 c.
69
I~
0
vV
24 27 30 3 c. ? IZ. IS 18
~f"' \ Ho.J
'0
:ll .:Z4 27 30
0
~oc..k~e. Srn.o\ \-
-L.~.l.
Sf«''~ l~S2.
~
2. s 8
-:fun~
fp 10 14 t8 22. %~ .10 ""
FIGURE 17a:
Afc-\\
10 14 18 :ZZ. '1.'-:JO 4-8 fZ. llo Z.O .Z4 28 5'
Ap .. il Mny
Numbers of outmigrating sockeye smolt leaving Black Lake with
asso.ciated .temperature and discharge information. Spring, 1982.
r:-
E e
-/
~ ~ ,...
~
0 _.....
~
~
~.
FIGURE 17c:
70
,"3·0
. ,,_.o --
694 ,,.o -H~ 1\·0 mm. ,,0 •
"\0•0
E.C!)·O -\63
66·0 ·-
1&:,
6,·0 ~
E.&·O \4~
~
65-0
I
EA·O
8
63·0 -
ft2.·0
2. -6 9 -IS 16 -22. 23-8 30 -S 6 -\2.
~~ :ru.~e..
-
22.6
-
He.oA • 2· 92 ~~s
-2.0.3
.40 -
-
\3S
-106
-8
2.·'ZO -lOS n
l'a -2.4 2.5 -I 2..-9 ~-IS l~-22.23-2.~ 3o-5
:::f'un4Z.. Ap("i \ tv\ a.~
Weekly mean fork lengths and weights for sockeye
(April 18 to June 12 , 1982.
smolt leaving Black Lake.
71 s~~~ .$~0\'" L.~ .L .
-syc-u\~ \~Q2.
-r--
-"'l= 2,5\&
t-\C2.o.A ~ ,,.o ft\Cl\. -
c 500 j
. -
£ .z 400 -'
-
-
100 -
0 I I l I
51. -ss_ 56-EoO 61-faS EN-10 ,, -15 16-~o Sl -8~ eco-90 c;u -~
FIGURE 17b: Length frequencies of sockeye smolt leaving Black Lake. April 18 -June 12.
'·100
\·000
0·~
0·800
'""' 3 __, 0·,00
~ -iJ 0·600
~
(J
3 0·5()0
tS1 0·400 _j
0·300
0·2.()0
()-100
0·000
(·10
FIGURE 17d:
\.~ U3 : 3. \Ea{) \~ \ -S· 58~
N 1: e2.~
r2 • o-szo
1·1S
Spring, 1982.
Regression of
1·80 1·8~ l·'!O 1·~5 2·00 2·05
log weigh~0~ ;o~~~th ~l sockeye smolt leaving Black Lake.
'r :r
72
before rising bac~to 7.0°C on May 27, when the principal peak occurred.
Temperature appears to have been a more important factor than lake
discharge, although the two are correlated. The fall in temperature from
May 19 corresponds to increased lake levels at that time due to heavy
snowmelt as a result of high levels of rain.
A total of 2,488 sockeye smolt were captured in the L.B.L. fyke net.
Applying the 15% efficiency factor, which was calculated by marking
sockeye smolt and releasing at three different stages of flow, the total
sockeye smolt emigration was estimated to be in the region of 16,500.
Length and weight measurements were undertaken on 827 fish and fork
lengths on a total of 2,306. Length frequencies of sockeye smolt are
presented in Figure 17b & weekly mean lengths and weights are given in
Figure 17c.
Mean length of smolt was 71.0 mm and mean weight was 2.82 gms. The
range was 49 mm to 103 mm and 1.10 gms to 10.95 gms, respectively.
The mean length of the fish increased as the outmigration progressed
with the larger fish occurring at the peak of the run. In the last week
of the outmigration, the fish were considerably smaller than the average.
This pattern contrasts with 1980 Hugh Smith Lake smolt studies (Haddix,
1981) where in the first stages of the outmigration from May 5 to May 16,
larger fish emigrated, 63% being age II smolt. Later in the emigration,
from May 17 to June 22, the fish were typically smaller, 93% being age I
smolt.
Scales were taken from a sample of smolt. At the time of writing,
it has not been possible to age the entire sample, but from a subsample
of 35 fish, all were aged as I. All fish measured less than 78 mm, thus
it is estimated that 85% or greater of the outmigrating smolt were aged I.
The length weight regression plot for the sockeye smolt is given in
Fig·. 17d and a correlation .coefficent (r2) of 0.827 was computed.
73
Fulton's (1911) condition factor (K) was calculated for the sockeye
smolt emigrating from the lake where
w 5 K =-x 10
13
weight in grams
length in millimeters
factor to bring the value of K near unity
(Carlander, 1969)
The value of K = 0.82. This compares with a value of 0.93 for Hugh
Smith Lake.
Sockeye smolt from Klawock Lake display a greater rate of growth and
most age I smolt fall between the 80 to 90 mm range (Ward, pers. comm.).
Coho (Oncorhynchus kisutch) smolt (Fifure 18a-e)
1,141 coho smolt were taken in the L.B.L. net between April 18 to June 8.
Applying the 15% efficiency factor which may be an over-estimate as coho are
more likely to avoid the net than sockeye, 7,606 coho smolt emigrated from
Black Lake and the stream section above it. Mean length was 9L6mm and weight
was 8.75gms. Fulton's condition factor was 1.04. The peak of the run May 13
to May 24 (Figure 18a). The larger fish came out at this time (figure 18b).
The main size range was 85 mm to 100 mm (Figure 18c) being predominantly
2+ fish.
Coho smolt were also trapped at the mouth of the creek (M.B.C.). The
peak of the rUn was over a similar time period as L~B.L. (Figure 18d), with the
largerrfish coming oi.tt at that time, particularly May 16 -22 (Figure 18e) •
Mean length was 92.4 and weight 8.64 gms. Fulton's condition factor was 1.02.
I'
!
11
I
\
74
9oO
C.o\\o srno\\--L3. L
eoo
Sfr'~ \~t?,2.
100
~00
soo
~
...A 400 E ~ 0 z 300 AJ
~00
IDO
-a--_ b
19 2.1 2.4 2.7 30 3 ~ 9 12. IS 18 :Z.I 24-2.7 llo z. s 8
P..pn' Ma'/ .Jv.,e.
8
0 c. 7
5·0
lo..'a~ 4·0
\-\Q.\~h\-
<.~) 3·o· ~.
l·O
10 14-18 zz. ~c. 30 4 8 1 a u, z.o z4 28 S'
FIGURE 18a:
J'p.-il tJ\n'f Jun!l.
Numbers of outmigrating coho smolt leaving Black Lake with
associated temperature and discharge information. Spring, 1982.
r"-'M·O
t e C34·0 ....._;
~ 90·0 ~ oJ ~-o ..,;
~. 82·0
0 ~
18·0 g
14·0 ~
,0·0
E»EJ·o
10·0
':;' '3·0
~ 8·0 ....._.;
~ 1·0 ~ J
oJ 6-0 3
a 5·0
-1 4·0
3·0
2·0
..
-
.
..
-
-
-
.
25
9
'~
8
r---
75 Ca'no sma\\-l.'B· L · ·
S~""'n~ ~81.. \
H4 404 2e~· t-{Q.Q.(\ :
128
105
I
'
2.-s ~-as a(:. -22 a-29 ao-s 6-l2.
~ ~~ :lu.n.Q..
~
'~ \92 H.eo.t\ = S·lS~s.
92. 29
l8 -24 2.5 -\ 2. -8 ~ -IS t(:.-22 .23-2'3 30 -S
. P.\'r.,\ ~0.."\
FIGURE 18b: Weekly mean fork lengths and weighfJ for coho smolt leaving Black Lake.
~C\ca..
-spring 1902.
180
\60 .
140
120
! \00 1
j eo z
~ .
.40 .
2.0
0
1·150
\•SOO
O·SCIO
0250
FIGURE 18c:
76 C.o'no s~o\\-L3'.l.
r--Sf<''~ \~82 . ..
. .--Ht20A= ~\., M«ft • ....-
r--
r--r--:
,
r--
.--
.--r--
r1n nnn.--
\·~\ -4· 550
N = ses
= 0· 9\0
1·950 2·050 2·150
Length frequencies\_~coh:e~~ le~~ng Black Lake during the period
April 18 to June 12 and length -weight regression plot. Spring, 1982.
8
0
.,
c. "
.5
""
3
2
"
5.-E)
La..~q_ 4·0
\-\~h\-
3·'-' ( .ft")
l··'-'
FIGURE 18d:
77
ID 14. 18 21 2" 3D 4 ,
. O..fc-i\
10 14 18 2Z. 2.~ 30 4-8 1:1. 11. :r.o ~4 .Z8 S
,..~;I f'o'IA"f J\ln!l.
Numbers of.outmigrating coho smolt at the mouth of Black Bear
Creek with associated temp~rature and discharge information.
Spring, 1982.
·~2·0
/'"" 98-o
e
E ~.
~
~ 9,0:0
~ 86·0· --... :.::--
14·0
13·0
~ U·O ..,
~ lO·O
~
J. CJ·O
...s;
f1a-o
3
1·0
5·0
4·0
3·0
'
.
.
.
-
G
.
.
.
.
.
78
Hec..n • ~2.·411'-n \4~ syc-'n
.
'
10(0 -lO~
53 \4
:n
8
2
" -,, \6 -14 2£)-' 2. - 8 ~ -15 lEI -22 2'3 -29 30 -S
~v--·,\ . t---\~ . -:ru.C\Q..
2.9
He.o.A\~ <a-~ d~
50
4\
53
.3
2
I I
I\ -,, \S -.2.4 2 -a ~ -, s a(,-22 2.!»-2.g
Ape-·,\ Ha..q
FIGURE 18 e: Weekly mean fork 'lengths and weights fo~oho smolt at the mouth of
B lack Bear Creek for a period April 11 to June 5. Spring, 1982.
79
BLACK LAKE
An evaluation of the role of Black Lake in the Black Bear Creek system
as a supporter of fish production in terms of resident trout and rearing
juvenile salmonids was undertaken.
The lake is populated by cutthroat trout (Salmo clarki), Dolly Varden
(Salvelinus malma) and by rearing coho (Oncorhynchus kisutch) and sockeye
(Oncorhynchus nerka) salmon. Threespine sticklebacks (Gasterosteus
aculeatus) are abundant.
Cutthroat trout
Large wire minnow traps baited with salmon eggs were fished throughout
the lake. for an eight-day period from September 7 to September 14. In
32.settings, one cutthroat (125 mm) was trapped. Rod and line fishing in
August and September yielded only two fish.
Three cutthroat trout were captured in the U.B.L. fyke net migrating
downstream into the lake in spring, 1982.
342 mm
340 mm
201 mm
365 gms
452 gms
76.26 gms
5+
scales mounted-all regenerated
3+
Fishermen report having taken cutthroat from the lake but the fishing
was termed as 'slow'.
These observations indicate that the cutthroat population of Black
Lake is low.
Dolly Varden
In the extensive mark'and recapture experiment described later for
coho juveniles, only two Dolly Varden were captured in eight days.
80
Resident rearing population of Dolly Varaen appears to be extremely
low.
20 to 30 Dolly Varden were known to overwinter in Black Lake this
year and left the lake at the beginning of May.
Coho juveniles
A multiple mark and recapture over an eight-day period from September
7 to September 15, 1981, was undertaken using minnow traps of 1/8" and
1/4" mesh. 45 traps were placed at suitable intervals in the literal
margins of the lake each day. Fish captured were marked with a caudal
fin punch and numbers of recaptured fish with marks each day were recorded.
Fish <65 mm were considered young of the year (O+) and >65 mm
fingerlings (1+).
A population estimate for 0+ and 1+ coho juveniles was then made
using Schumacher and Eschmeyer's (1943) estimate.
Coho 1+ = 2,628
95% confidence limits = 2,196 to 3,271
Coho 0+ = 2,394
95% confidence limits = 1,930 to 3,154
see Table 11.
These figures represent a ratio of 1+ to 0+ coho in Black Lake of 1.09.
A regression plot of length to weight is given in Figure 19a for 1+
coho. Mean length was 72.7 mm and weight 4.23 gms. The regression
coefficient squared (r2) was high= 0.97, indicating a strong correlation.
Fulton's condition factor (p ), K, was calculated for the 1+ coho
collected.
K = 1.115.
81
From minnow trap returns, young of the year were typically found in
similar areas to the 1+ fish. The most productive areas of the lake were
1/
the extensive shallow litoral zones near the northeasterly end of the lake end :in
the s .w. corner on the southern shore near the mouth of the lake. Many
of the banks on the northern shore are steep-sided with restricted
litoral areas and here minnow trap returns of coho were small.
It is thought that Black Lake provides important over-wintering
habitat for coho juveniles as visual observations indicated that very few
fish were present in the stream system during February.
Carrying capacity of Black Lake
The potential yield of Black Lake for fish production was investigated.
Ryder (1965) considers fish production in lakes to be affected by
morphometric, edaphic and climatic factors and developed a morphoedaphic
index (MEI) for estimating potential productivity in north temperate lakes.
MEI _ Total Dissolved Solids (mg/1)
-Mean Depth (feet)
21 For Black Lake the MEI = 25 = 0.84.
Values of the MEI for 22 other lakes in Southeast Alaska are given in
Table 6 • Black Lake has a higher MEI than 14 of these lakes.
However, the predictive power of the MEI depends upon constraints
imposed by the range of mean depths, lake surface area, and total
dissolved solids over which the indices apply. Hanson and Leggett (1982)
consider the MEI performs poorly when compared with other available
indices using unconstrained data. They favor an indice based on total
phosphorus concentration.
Consequently, water samples were taken after the spring overturn in
1982 at 1/3 and 2/3 rds of ·the water column at the sampling station
established in the deepest point of the lake (approximately 12 meters).
!/ See Appendix Figure A-1.
TABLE 6: Morphoedaphic index of 22 lakes in southeast Alaska. l/
Residue Dissolved
Specific Conductance Calculated Sum Surface Area i Depth Potential Yield**
Lake (pmhos) (mg/1) (ha) (m) MEl* (kg/ha)
Red 93 65*** 166 10.4 6.25 2.41
Finger 28 20*** 347 10.7 1.87 1.32
Tammy 25 18*** 134 10.0 1.80 1.30
Green 39 22 70 12.3 1.79 1.29
Klawak 39 24 1,177 17.7 1.36 1.13
Auke 28 20 46 19.0 1.05 0.99
Virginia 18 13*** 258 13.0 1.00 0.97
Manzanita 60 42*** 625 49.0 0.86 0.89
Salmon Bay 30 21*** 388 26.7 0.79 0.86
Heckman 17 14 163 19.7 0.71 0.81
Spurt 16 14 107 22.2 0.63 0.77
Karta 26 16 508 27.6 0.58 0.74
DeBoer 13 13 51 23.0 0.58 0.72
Wilson 51 36*** 468 54.0 0.67 0.69
Ella 47 33*** 710 70.0 0.47 0.66
Patching 17 14 207 30.2 0.46 0.66
Blue 33 22 538 52.0 0.42 0.63
Turner 15 10*** 1,270 30.0 0.33 0.55
Osprey 20 14 109 60.0 0.23 0.46
Swan 20 16 208 91.4 0.18 0.41
Lonieof 5 4*** 179 55.1 0.07 0.25.
Rezanof 3 2*** 354 71.2 '0.03 0.17
·MEl= Morphoedaphic Ind.:~<= fatal Dissolved Solids (Ryder 1965).
Mean Depth
**Ryder (1965) described the equation y"' 2 VX where y =yield in pounds per acre and mean depth was in feet. The metric expression (Ryder et al. 1974) is ther.,tore yv-o 0.966 vx
where yield is fish yield as kg/ha and x =MEl.
•••calculated as 0.70 x specific conductance inmicromhos.
Source: Schmidt, 1979,
Jj This table was taken from: An Assessment of Environmen~al Effects of Construction and Operation
of the Proposed Tyee Lake Hydroelectric Project Petersburg and
Wrangell,~·Alaska, AEIDC October, 1980
00
N
83
The samples were analyzed for phosphorus and other nutrients that influence
lake productivity (Table 7 ).
Conductivity was low and the lake is poorly buffered. Silica levels
were above limiting values. The nitrogen to phosphorus ratio·-(N:P) was
85:1, which is well in excess of the 15:1 ratio considered to indicate a
nitrogen limitation. Values of phosphorus are very low and is the limiting
nutrient for primary and, consequently, secondary production in Black
Lake. Comparative values of total phosphorus for other lakes in the region
are given in Table 8 and it can be seen that Black Lake is fairly
similar.
To supplement this chemical nutrient information and to obtain a
further indication of lake productivity, zooplankton samples were collected
in August, 1981, and in May, 1982. Vertical hauls were made from the
bottom to the surface at the sampling station on Black Lake using a 153
micron mesh net with a 0.5 meter circular mouth. Two samples were taken
for each collection date and preserved in 4% formaldehyde. The samples
were enumerated and types identified (Table 9 ).
Black Lake zooplankton in August, 1981, was dominated by low numbers
of die,cladoceran Bosmina longirostris. No other cladocerans were evident.
The copepod Cyclops ~· was found in smaller numbers with chydorids and
rotifers also present. In the sample this May, rotifers were more
abundant, they being frequently the first plankton to develop after the
spring turnover. Numbers of Bosmina longirostris were extremely low.
The mean length of Bosmin~ was 0.29 mm to 0.3 mm and these were some of
the lowest values recorded in other Alaskan lakes (Koenings, A.D.F. & G.,
pers. comm.) •
This information indicates heavy predation pressure by the sockeye on
the zooplankton. Their preferred prey, the cladoceran Daphnia~· may
have been entirely grazed to negligible ntimbers. Thus, the sockeye were
having to utilize the less preferential Bosmina resulting in low density
and small size.
84
Chemical parameter 3.5 m 7 m
Conductivity (mmhos -1 em
at 25°C) 19 15
pH -1 6.05 5.80
Alkalinity (mg L as
Caco 3) 3 2
-1 2.3 1.6 Calcium (mg L 21 Magnesium (mg L ) <o.5 <o.s -Total Phosphorus (~g L
as P) 4.0 to 5.0 3.5
Total filtered phosphorus
(~qL-1 as P) 4.85 3.9
Filtrate reactive
phosphorus (~qL-1 as P) 2.3 2.6
Nitrate & nitrite (~qL-1 as N) 91.5 85.8
Ammonia N (~gL-l as N) 11.36 1.8
Reactivr Silica
149.8 144.1 (~qL-as Si)
Iron Fe (~qL-1 as Fe) 120.3 80.85
TABLE 7: Chemical data for Black Lake at spring
turnover (sampled May 15, 1982).
Lake Eplimnion HypolimnioiJ
Bakewell 3.8 .2.6
Haida 3.8 5.3
Heckman 3.6 3.2
Hugh Smith 5.2 5.5
Keegan 4.6 3.9
Klawock 4.4 4.6
McDonald 2.9 4.2
Salmon 3.6 6.1
TABLE 8: Total Phosphorus (~gL-1 ) in May for
other lakes in vicinity of Black Lake
(courtesy of Jeff Koenings, A.D.F. & G.,
Soldotna).
':':
Date of Sample August 5, 1981 August.l5, 1981. May 4, 1982
2 nos/m3 2 3 2 3 nos/m average nos/m nos/m average nos/m nos/m
Zooplankton 12 meter size 11 meter size 11 meter
water water water
column column column
Chydoridae . 255 21 153 13 257 23
Cladocera Bosmina longirostris 39,083 3,258 0.25 mm 35,205 2,951 0.3 mm 41 4
Copepoda Cx:cloEs ~· 433 36 0.49 mm 1,079 90 8 1
Rot if era Kellicottia longi·s_l)_ina .. 1,546 .141 492 45
AsElanchna ~. 331 28 357 30 1,595 145
--
TABLE 9: Zooplankton abundance and average size in Black Lake, summer, 1981, and spring, 1982. Counts from the
average of two hauls.
average
size
- -
86
In contrast, the.mean length of plankton from Black Bear Lake
(Table 10 ) which was sampled in August, 1981, were Bosmina 0.44 mm and
Cyclops 0.76 mm. Predation pressure was not so extensive. The zooplankton
community was characteriz-ed by copepods with Diaptomus ~· being dominant.
Rainbow trout will select for cladocerans and avoid the copepods.
An examination of the outmigrating sockeye, smolt data gave 16,500
fish leaving Black Lake this spring. Approximately 85% of these fish were
age I.
Mean length was 71.0 mm and the condition factor (K) equal to 0.8~.
Average length for the age I smolt was approximately 69.0 to 70.0 mm,
being just above the 60-65 mm at which smoltification occurs.
The small size and low condition factor of the sockeye smolt, coupled
with the zooplankton and total phosphorris data, indicate that Black Lake
is at full carrying capacity with respect to sockeye fish production and
possibly exceeding the maximum level it can optimally support.
This data is still in the process of being evaluated, in particular,
the contribution that the spawned out carcasses of pinks, soc~eye and
coho make to the phosphorus levels of the lake.
Date of Sample AU!mst 1
:
nos/m2 "-
3 Zooplankton 30 m water nos/m average size
column
Cladocera Bosmina longirostris 2,694 88 0.44
HoloEedium ~· 10,112 337 0.98
Copepoda CycloES ~· 13,347 445 0.76
DiaEtomus ~· 24,785 827 1.85
IR.otifera Kellicottia longisEina 943 31
TABLE 10: Zooplankton abundance and average size in Black Bear Lake,
summer, 1981. Counts from the average of two hauls.
mm
mm
mm
mm
87
REARING JUVENILE SALMONID POPULATIONS IN THE
STREAM SYSTEM ABOVE BLACK LAKE
Estimates were made of the rearing populations in four sections of
the stream above Black Lake and in associated beaver ponds. Sections A,
B, C, and D were approximately 300 to 350 feet long and are described
under the habitat section (p.-92) and their location given on the foldout
map.
Minnow traps (1/8 and 1/4" mesh) baited with boraxed salmon eggs were
used to trap fish. Other possible methods of capture, for example, seine
nets and electro-shocking, were thought to be unsuitable due to the large
amount of fallen logs and log debris in the stream and the presence of
large numbers of adult spawning salmonids.
In the stream, 40 traps were placed in each section, principally
along the margins. Fish captured were marked with a hole in the caudal
fin. Traps were set in the same location the following day and the ratio
of marked fish to unmarked fish recorded. Population estimates were then
made using Chapman's (1951) modification of the Petersen formula.
A multiple mark and recapture technique as employed in the lake (p. 79)
was used in the two major sets of beaver ponds and estimates made from
the method of Schumacher and Eschmeyer.
Table 11 summarizes the estimates obtained. Coho were divided into
young of the year (0+) and fingerlings (1+) according to fork length. This
varied with relation to the date of sampling. In the middle of August,
the dividing length used was 55 mm and this was increased to 65 mm by the
middle of September.
Length weight regressions were plotted for 1+ coho
for these two locations (Figures 19b&c ) and Fulton~ s condition factor K
calculated (Table 11 ) •
This data will be evaluated in conjunction with the habitat survey
(p. 92).
COHO (0+) COHO (1+) Coho 1+ Dolly Varden
95% 95% Condition to 95%
Date of Method of Fork Popn Confidence Fork Popn Confidence Factor Coho 0+ Popn Confidence
Location Sample Estimate Length Estimate Intervals Len_gth Estimate Intervals (K) Ratio Estimate Intervals
Black Lake 9/7 to Schumacher <65mm 2,394 1,930 to )65mm 2,628 2,196 to 1.12 1.09 low
9/15 & Eschmeyer 3,154 3,271
Section A 9/3 to Petersen <60mm 1,962 1,780 to >60mm 372 240 to 1.13 0.18
(approx, 350 ft) 9/4 2,16.5 341
Section B 8/8 to Petersen Percentage of marked fish recaptured too low to give an accurate estimate.
(approx, 350 ft) 8/9
Section C 8/29 to Petersen >60mm 213 119 to
(approx. 325 ft) 8/30 434
Section D 9/1 Petersen Juvenile fish of very low density -insufficient to complete mark and recapture experiment.
(approx. 250 ft)
Beaver Ponds 8/15 to Schumacher <55mm 588 471 to >55mm 504 440 to 1.15 0,86 50 46 to.
south side near 8/19 & Eschmeyer 787 593 55
mouth of creek
Beaver Ponds 8/30 to Schumacher <60mm 777 541 to >60mm 442 344 to 0.57 82 74 to
on lake fork 9/1 & Eschmeyer 1,319 615 92
------
TABLE 11: Population estimates of resident rearing juvenile salmonids in Black Lake and stream system above the lake.
00
00
I· 2.00
•· 1()0
\·000
-"" ~ 0·800
~ ol
3
gJ 0·100
_.J
0·500
.. ,so
·\..o~ w
N •
r2. c
K --
.. ,go
• 3-\S~
99
0· q,
, .. \2
1·930
89
\~ \ -5·2~<l
H!to
Coho .\\-+)
3 \o..~'R \_a.\2~
'·
··~0
FIGURE 19a: Length and weight regression plot for 1+ coho in Black Lake,
Spetember 1981. K = Fulton's condition factor.
2.·02.0
1·250
. . .
~1 .. oao
..,..........
3 (>8-"J£. -
~-
~ O·"tt=;o
3
g"J
--' 0·62f
o-500.,.
\
0~315·.
[
~
90
lo~ ~:: 2-S~~ t~ \ -4 · ,o\S
__ N ~ 99
('1.:: 6-<?,,
K = ~~ \3
+ --------;---· -----------------~ ' .
i . --. --i -. --f. .
f.
!
t
--~
-~-
·---~---··· ·--·····-
. ;
-·· i . . I -----·----· t .
: .. -. i
' ------ . -t
.--L--._._
. -l ..
. l --~
·-· ·----------~ ---. ·t··· . -..------r--. -------~ -
· · ~ -~-:--:·:~t~· :-~.:--~-~--:---:·;\)~~--: ~·. ~,~~~ ·: ·.--~•·a~-~ ~~: ~,:g9a------· :_ ~-z.-o1o--.-: :__~2~.,b0----~-·
l . • I · · r --.: . -·_ ~ . ------.. . i . · ~..:. _ + ~---
·· :. ~-~-:.~~ ~-~-: ~ ;_ · :=: -· : ::-; ~ ~~-~-~-__ rl. ~-~.---~---~--~~:~.: · r·_Loo<\ \ __ en~~-:._·.-.. · .. _·{ t_ ) , . , ·· ··-. ... t:=-~
.···--------t--.. ·--·----· · C) cJ .. --.---. · -·-·:-:.T=~-:
. ~:::~~r~;i~iEl~e~~~~D&<~~:;I:ei&ht~ • .g~;,;iD_n pili~ £1r l~ =oho frnni s~~tl§;[=~-. ~~: r:~
-.----··.: ;.-----· . . . ~ .ln. zone~~I1of ttie _llla_l.n~t..r.eam C!:D.9VE! LBp:rck L-ake, :sey~~~~-~~-~98_1_. _ ·--=+-_
.. 1-~;~~·~".~ -+/::~=~~~?~+ ·-~~j~~~~t):: i • ~!~i:4~ =~}~~E;
_:~·-:=~-~-~:· .. ~ l ·· ~ ==--=~--=-=1: ~ = = _: __ -_~_:_-_--~-------~---· ~---~-~r_: __ ,· __ :· :··=-~=~-~=~_,_ ~i : : -=-=---=-~_-_=_-----.=--~;=··. --~_:.~~-----~_=_:-__ --. -~----=~_-_=--__ :-~-i·::=-~--==-=-~ : ·· +.:..:=.:.:~=-==-~-~-.--· --~_:::--=~:: ::-:: ~--·.:·~:=-·:-:::':.::T--. . .. ----------. -[ 9i :· . -.; -·~--------· .
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--· - ---------------· r----~ ---~--~ _ - -i . -----~----------_ ~-~-.:..:=~:-----~l .. ---·----r -----~1 ... .....:.....:.=~:..:.:i -· · · · · ---· ~ · --·-----"-----
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.\• 115 \•82.0 \·S~ 1·8~
. lo~ \e(\~~ ~ t)
FIGURE 19c: Length -weight regression plot for 1+ coho from beaver pond
near stream entrance to lake. August 1981.
\·911
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92
HABITAT STUDIES ABOVE BLACK LAKE
To evaluate and characterize the use of the Black Bear system above
Black Lake by rearing and spawning ·salmonids and to examine the effects
of regulated flow regimes, an extensive survey of stream habitats was
undertaken.
A scale map (1 inch to 50 feet) was made of the stream channel,
displaying gradient, side channels, beaver dams and associated beaver
ponds. This map was then used to identify principal spawning areas from
escapement observations, major rearin~ areas for resident juvenile fish,
undercut banks, streambank vegetation, streambed substrate characteristics,
fallen logs and log debris and streamflow regime types. The map produced
is in the back of the report.
From this initial survey, we considered that the Black Bear System
could be divided on a habitat basis into four distinct zones, I to IV.
ZONE I
ZONE II
From the entrance of Black Bear Creek into Black Lake to
the junction of the west branch of the south tributary
with the main channel.
From the west branch of the south tributary to where the
gradient of the main stream channel from Black Lake
starts to markedly increase.
ZONE III From the above point to the base of the falls from Black Bear Lk.
ZONE IV The beaver ponds.
To further characteri~e zones I and II, two representative sections
of approximately 300 to 350 feet were mapped in detail in each zone --
93
sections A and B in zone I and C and D in zone IL (Figures 20a to d ) • A
scale of 1 inch to 50 feet was used and the characteristics recorded are
given in the key (Figure20~· The location of these sections are given
on the foldout map. Plates 3 to 6 are taken from the bottom of each
section looking upstream.
To examine the effects of regulated streamflow on the habitat, 27
cross sections were surveyed. In each of the four sections, A to D, five
cross sectional transects were made together with a further seven at
locations where habitat effects may occur. Depths were recorded at one-
foot intervals across the. channel. The left bank was viewed in an upstream
direction. Average substrate size was measured every foot and the
compactness and shape of spawning gravel was estimated. The cross sections
are shown later in the report in relation to the discussion of pre and
post-project flows and their location on the map.
Zone I
Immediately above Black Lake begins about 3,000 feet of streambed
with sustained, slow-moving water in a channel that is principally between
50 to 75 feet wide. This zone of the stream encompasses sections A and
B. The gradient is negligibl~ approximately .04%. A series of beaver
dams along this area of stream enhance the slow-flowing, ponded condition
of the stream. The streambed i:$,, predominantly made up of sands and silts,
..-?...L
occasionally over~lai~ by fine organic matter. Log debris and numerous
logs are present on the streambed (see Figures 20a & b ) which occasionally
have some sparse filamentous algae attached. Some cobbles are present as
exemplified in the upper part of section B but this is rare.
The flow regime can be termed as a "flat", being typically slow-
flowing, estimated at 0.2 to 0.3 feet/sec. Pools range from 6-8. feet deep
even at low water. Numerous indentations occur in the banks and there
are a number of side channels which are principally attributable to beaver
runs. These are frequently overhung by riparian vegetation.
94
Plate 3: Section A
'" "'
Plate 4: Section B
95
Plate 5: Section C
Plate 6: Section D
,,
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96
As illustrated by cross sections in Figures 34 to 41, the banks on
both sides are typically vertical, reaching 4 to 8 feet above the
streambed. The banks are usually stable, although some erosion and
collapse was noted on the south side. Banks are frequently undercut,
typically 1 to 1~ feet, this being more characteristic of the south
bank.
The riparian vegetation is extensive on both banks. Sedges, ferns
and grasses frequently overhang the water's edge and Hellebore (Veratrum
viride) and skunk cabbage (Lysichitum americanum) are prevalent. Taller
vegetation is principally made up of Devil's club (Oplopanax horridus),
salmonberry (Rubus spectablis), high bushcranberry (Viburnum edule), deer-
berry (Maiantheum dilatatum) •. Other plants on the banks in less abundance
are twistedstalk (Streptopus roseus), red elder (Sambucus callicarpa) and
Sanguisorba stipulata. The vegetation is in many stretches overhanging
the stream bank, sometimes to 6 feet or more and this is mapped in
Figures 20a and b and illustrated in Plate 7. More overhanging vegenat.ion
occurs on the south bank.
Plate 7
97
Old growth Sitka spruce (Picea sichensis) and western hemlock (Tsuga
heteropylla) dominate the nearby terrain with some alder (Alnus rubra).
These stands are fairly open and provide a negligible amount of canopy
cover to the stream. Blow down trees are common and their branches
provide further areas of instream cover.
No spawning by salmo~ids was observed in this area due to the unsuitable
substrate and flow conditions. Mark and recapture experiments described
earlier indicate the importance of this area for rearing coho. 372 (240
to 431 95% confidence intervals) was the population estimate of l+coho
for section A in early September, 1981, giving an estimated value of
3,100 (1,978 to 3,552 95% confidence intervals) for the length of zone I.
Coho in their second year provide perhaps the most useful index of the
state of the juvenile population since mortalities among fry can be as
high as 90%.
Results from the minnow trapping and visual observations indicate
that juvenile coho are predominantly distributed along the margins of
the streams, selecting the cover of the overhanging vegetation, the
undercut banks and logs and branches of fallen trees. Minnow traps
placed in central areas of the stream typically had poor returns. The
indentations and beaver runs were also favored by immature coho,
particularly fry. These areas are probably of importance at higher
stages of the main channel as the current velocity in them is negligible.
At lower stages, these retreats are not so critical due to the slow
flowing nature of the main channel. However, at low August flows , it was
observed that the height of the main channel did not maintain water in
a large number of these side channels and their role as habitat was lost .
Additionally, low summer flows resulted in some loss of cover in terms
of overhanging vegetation and the undercut banks.
Only a very few Dolly Varden were recorded in this section of the
stream but the threespined stickleback was abundant. No other species
were trapped.
98 1 ,1 j, i I
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2)~ .. ~~ yoa\s.
103
Zone II
From the junction of the west branch of the south tributary up to
where the gradient starts to markedly rise constitutes zone II. This
includes the two major forks of the Black Bear system --the lake fork
and the spring fork.
Two sections, C and D, were extensively mapped in this
zone (Figures 20cand d )~ Section C is in the lower part and section D
in the upper part of the spring fork. The total length of zone II is some
1,000 feet and channel width is variable.
For the first 300 feet to the primary forks and the separation of
the south tributary from the Black Bear Lake system, the substrate is a
mixture of fine sand and silt together with coarse gravel and small cobble
averaging 3 to 8 em, which is uniformly iron-stained. Numerous fallen
logs are present on the streambed and overhanging the stream. Banks are
stable, vertical and with little undercutting. Width is typically
between 35 to 50 feet. Gradient is nearly 1%.
Above the junction with the south tributary extends some 700 feet of
streambed in two forks, the lake fork and the spring fork. Channel width
is between 25 and 30 feet in each fork, except where the channel divides
and it may be considerably narrower. Logs and fallen trees provide
significant hydraulic controls. The gradient is higher toward the upper
end of the zone, reaching 2% in section D.
The substrate is predominantly coarse gravel and small cobble from
3 to 12 em. The streambed material tends to be larger toward the upper
sections of this zone, with less fine sand and silt. The gravels and
cobble are typically angular, compact and embedded at a maximum of 25% in
finer material. No iron staining is present in the lake fork but was
observed in the spring fork.
"Riffles" and "glides" dominate this zone, which at times is subject
to large fluctuation in flow, particularly in the lake fork. The spring
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104
fork tends to be more uniform. Numerous plunge pools exist created by
logs on the streambed and a number of dammed pools are present behind
logs. These are most evident in the lake fork below the beaver dam, where
the stream flow is moderated. Backwater pools are present behind root
wads and in larger indentations in the main channel. Two examples can
be seen in the lower and upper parts of section C, but these areas of
slow-moving water are restricted. Pools within secondary channels are
found in the upper sections of the lake fork at low summer flows.
Banks are typically stable, rising vertically 2 to 3 feet above the
stream bottom, although some gradual bars of gravel and shallow sloping
grass banks are present.
The riparian vegetation is less dense than in zone I but the species
are similar. It is frequently overhanging. A few stands of alder are
present in close proximity to the stream, providing some canopy cover as
do closely b~rdering old growth hemlock and Sitka spruce. Undercut banks
are present but not to the same extent as in zone I and are principally
located in the spring fork.
A negligible amount of filamentous algal growth occurs in this zone.
Near the upwellings that feed the spring fork and part of the lake fork,
moss covered cobble was present,. indicating the stability and uniformity
of these flows.
105
This zone is the principal area of salmonid spawning, together with
some 700 feet of channel in the south tributary which was not surveyed.
The distribution of species has been previously discussed in the
escapement survey.
The spawning gravels immediately above the fork were first selected
by the early spawners possibly because of their smaller more uniform
nature and potentially higher 9 ) •
Later in the run the spawners became widely distributed throughout
the zone• The beaver dam on the lake fork provided an impassable barrier
for sockeye, but at higher flows in September, pinks were able to migrate
over it and spawn in this section of stream. Spawning gravels in this
area are of lower quality in that the substrate is larger than in the
spring fork, being made up principally of small cobble (6.5 to 13 em) with
some materia~ up to 25 em. Flows are more variable and certain areas are
liable to drying up at low flows.
Spawnings density were high in 1981 and it was observed that super-
imposition of redds occurred, notably in the case of pinks overdepositing
on sockeye. This was particularly true in the lower areas of the spring
fork.
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106
Rearing populations of juvenile salmonids in this zone are low.
Results from extens ive minnow trapping in sections C and D and in other
areas support the mapping survey that suitable habitat for rearing is
limited. The most productive areas were the backwater pools,
particularly below the beaver dam in the lake fork .and in certain areas
of section C. The flow through the dammed pools was in many instances
too swift for rearing fish, as was the case with the main channel even
where undercut banks and overhanging vegetation provided cover. Small
numbers of coho fry were visually observed in the pools liable to
dessication in the main channel ·of the lake fork at the low August flows.
Zone III
Beyond the channel on the lake fork that is il·lustrated on the map
is an intermittently flowing channel originating below the falls from
Black Bear Lake. The gradient is steep (approximately 5-10%) and the
substrate is typically large, composed of large cobble (13 .0 to 25 em) and
boulder (greater than 25 em). Many fallen logs and trees cross the
streambed. The flow regime is variable, and when it is continuous cascade
type riffles dominate. Here the water flows in a series of steps with
many small pools behind rocks and below small waterfalls. During periods
of receding flow the stream loses its flow into the bed and will become
intermittent and then dry if lower flow conditions persist. (Plate 10)
The banks are variable . due to the extreme fluctuation in flow and
frequently difficult to define. Bordering vegetation is similar to zone II.
No spawning and very little rearing occur in this zone.
107
-·P-late 10
Zone IV
Beaver pond habitat makes up zone IV. Two principal areas occur.
The first is near the mouth of the creek on the south shore where the
beaver have ponded run-off water that enters the main channel by a series
of small dams (Plate 11) . ~,
-~-===-----.-~
Plate 11
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108
The area is made up of a series of pondse connected by narrow channels
• (Figure 21).
Figure 21
Mid-August temperatures were l0°C and pH between 6.15 to 6.3. Depth
which is fairly constant varies between 2 feet to 5 feet. The area is
dominated by sedges and some grasses which frequently overhang the channels.
Skunk cabbage is also abundant.
The second set of major ponds is on the lake fork created by two
principal dams. A number of fallen logs are present and grasses, sedges
and alder are the bordering vegetation. In the long backwater to the
side of these ponds the alder provides significant canopy cover.
Significant populations of rearing juvenile salmonids were found in
these ponds (Tablell). An estimate of 504 (95% confidence intervals 440
to 593) for 1+ coho juveniles was obtained for the beaver ponds near the
mouth of the creek. A condition factor of 1.15 was slightly higher than
section A in zone I of the main channel (1.13) and Black Lake (1.12).
There was a high ratio of 1+ coho to fry (0+) in these ponds --0.86
compared with the stream (zone I), which recorded a ratio of 0.18. This
is presumably a function of access to these ponds only being at extremely
high flows and thus many fish may move into these ponds only with the
109
fall storms. These ponds may provide important overwintering habitat.
The beaver ponds on the lake fork had a ratio of 1+ coho to 0+ of 0.57,
probably as a result of the easier access for young of the year. 442
1+ coho (95% confidence intervals 344 to 615) were estimated. Hence, a
total estimate of 946 for 1+ coho (95% confidence intervals 784 to 1,265)
for the major areas of beaver ponds was obtained. This contrasts wi~h
an estimate of 3,100 (95%. confidence intervals 1,978 to 3,552) for zone I,
the principal rearing area of the stream, indicating the significant
percentage that the beaver ponds contribute to coho rearing habitat --
above Black Lake --an estimated 15-20% taking into account the limited
amount that occurs in zone II.
The beaver ponds also support the principal Dolly Varden (Salvelinus
malma) rearing populations, although numbers are low. Dolly Varden were
not found in significant numbers in any other zones of. the stream or in
Black Lake. The threespined stickleback (Gasterosteus aculeatus) was
present in large number in the beaver ponds.
Extensive minnow trapping throughout the system did not produce any
cutthroat (Salmo clarki)or steelhead(Salmo gairdneri).
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110
SUMMARY
The Black Bear Creek system is used by chum, coho, pink and sockeye
salmon and cutthroat, Dolly Varden and steelhead trout.
All four species of salmon spawn in the stream above Black Lake. The
principal spawning areas are the south fork &infueBlack Bear Creek system
from the junction of the west branch of the south fork to where the
gradient starts to markedly rise in the main channel (Zone II).
In 1981, the peak of the sockeye run was late August. 700 sockeye
were estimated to have spawned in the Black Bear Creek system, 575 in the
south fork. No sockeye spawned above the beaver dam on the lake fork of
the Black Bear system.
With a fairly large run of pink salmon in 1981 estimated at 26,600
into the system, some 4,400 fish moved through Black Lake and spat•:ned
above it. An estimated 2,400 spawned in the south fork and 2,000 in the
Black Bear system of which all channels were used, including the lake
fork above the beaver dams. In this fork, fish spawned in channels that
are dry at low flows. Pink salmon superimposed on.redds previously used
by sockeye, with their peak of spawning being in the middle of September.
A small number of chum spawned near the upwelling in the spring fork.
From outmigration studies of fry, it is evident that some chum also spawn
below Black Lake.
Coho counts in October, 1981, located 42 fish above Black Lake.
Analyzing fry estimates for 1981 above and in Black Lake and with a rough
extrapolation using estimated fecundity and mortality, a figure of 85 to
100 coho spawned in 1980. It is likely that a similar number spawned in
1981 above Black Lake.
111
Dolly Varden trout are known to spawn in this section of stream,
although numbers of rearing fish are small. Steelhead trout did not spawn
above Black Lake in 1982.
From outmigration studies in the spring of 1982, the emigration of
pink and chum fry were later than in 1981 due to the colder winter.
Pink fry migration through Black Lake resulted in large mortalities
which were estimated to be in the region of 50%. Some fry remained in
the lakefor a short period, possibly due to the presence of lake ice.
The peak of the outmigration through the lake was related to a high
lake discharge and the ice leaving the lake.
Assuming a 50:50 ratio of females to males and a 1,800 to 2,000 egg
fecundity rate, it is calculated from the estimated 440,000 tq 460,000
pink fry that entered Black Lake and the 4,400 adults that spawned above
Black Lake in 1981 that the egg to fry survival rate was 10.8%.
Similarly for sockeye, assuming a 4,000 to 5,000 fecundity rate and
a 50:50 ratio of females to males, the egg to fry survival rate was 0.7%.
This is extremely low and is possibly attributable to large number of fry
moving into the lake before the net was set on April 10. However, the
heavy mortality could have been a result of the superimposition of
sockeye redds by the high density of overspawning pink salmon.
Rounsefell (1958) reported a similar situation in the Karluk River system,
Alaska.
The sockeye smolt emigration from Black Lake in spring, 1982, was
estimated at 16,587. Approximately 85% were age I. Assuming a typical 1%
survival rate from egg to smolt, if no large mortality of eggs occurred
would give an escapement figure in 1980, using a 4,000 to 5,000 fecundity
rate, of 313 females or 626 total. Although this figure is below the
number of adults observed in 1981, it indicates that there was no abnormal
mortality at the egg to fry stage as may have occurred this year. In 1980,
the pink escapement was only 4,503 and thus it is probably that all the
I !I
112
fish spawned below•the lake due to low spawning density. Thus overspawning
upon the sockeye redds is unlikely to have occurred. ·
If the egg to fry survival rate was as low as 0.7%, then the
anticipated sockeye smolt outmigration in 1983 will be considerably lower
than this year. The peak of the outmigration in 1982 was when the
temperature reached 7.0°C.
Figure 9b gives information on the number of temperature units for
egg to fry emergence for pink and sockeye from spawning gravels above Black
Lake using peak of spawning and peak of fry outmigration dates. The
result for sockeye was calculated assuming that no substantial number of
fry entered the lake before April and, thus, this figure should be
considered possibly inaccurate.
Temperature Units
egg to fry emergence
Sockeye -1,240
Pink -1,048
Outmigration studies showed that pink fry emerged earlier from spawning
gravels above Black Lake than below it. A comparison of the thermograph
records (Figure 9b) show a greater accumulation of temperature units
during the winter at S.G.S. (spawning gravels, spring fork) than at
L.B.L. and U.B.L. This is a result of the higher temperature regime of
the spring flows.
The major areas of coho rearing above Black Lake are the slow-flowing
stream section below the forks (Zone I) and the beaver ponds. The
beaver ponds make up a significant percentage of the rearing habitat and
had a higher ratio of 1+ coho to fry (0+) than the ~tream. The beaver
ponds are ,important for Dolly Varden juveniles and also as overwintering
habitat for coho. The lake, from population estimates, had a high number
of 1+ c.oho in relation to fry and is also significant in providing
0verwintering habitat for coho. Densities of Dolly Varden and cutthroat
in the lake were low.
113
Total spring phosphorus levels, zooplankton number and speciation
and the size and condition factor of the outmigrating sockeye smolt
indicate that Black Lake is at its full carrying capacity for sockeye.
I
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114
Biological -Wildlife
Methods of observarion
On all access hikes to gather daily salmonid fry measurement data,
weekly stream flow measurements, and frequent juvenile salmonid rearing-
habitat mapping excursions, stream banks were closely examined for mammal
sign. This sign included tracks, den and bedding sites, feeding areas,
scats, remnant hair from animal passage, bones, and actual sightings.
This sign was recorded as observed.
In addition to mammal data collected during routine fisheries biology
and hydrology work which was stream-and lake-intensive, five traverses
of upper Black Bear Creek valley were made in late summer of 1981, three
in the spring of 1982 with the sole objective of observing mammal sign.
Two hikes from Black Lake to Black Bear Lake were made as well, in August,
1981, and June, 1982, in order to service the Black Bear Lake thermograph
and to observe mammal use of the valley headwall area.
Numerous hikes inland from upper Black Bear Creek on both sides were
undertaken, crisscrossing the muskegs and blowdowns and following the
forest fringe with the sole purpose of seeking mammal sign. By means of
the above itineraries, two complete circumambulations of Black Bear Creek
valley above Black Lake were achieved, with more intensive, frequent
thrusts into areas found on these hikes to be heavily used by mammals.
Black bear tracks were measured to identify individual animals. Three
to five front tracks were measured across the widest point of the pad and
then averaged (after Streveler and Smith, 1978), thus distinguishing one
bear's tracks from another. By actual sightings and frequency and location
of tracks, bear territories were approximated and mapped. Wolf tracks
were catalogued in the same manner.
Deer, beaver, and mustelid tracks were observed primarily for frequency
and location, with no attempt at identifying individual territories.
115
Specific Observations
Black Bear (Ursus americanus) (Figure 22)
1981-From 7/31 to 8/17, the tracks of one small individual prevailed
throughout the study area; this was the only animal present until 8/18
when the tracks of a larger black bear were first observed in the muskeg
fringe back of the lower beaver ponds southeast of Black Bear Creek above
Black Lake, and on the southeast shore of Black Lake. The tracks of this
bear correspond in size to those of a large black bear seen swimming across
upper Black Lake in March, 1981. These two animals staked out their
territories, with the smal'ler bear ranging widely throughout the Forks
area of Black Bear Creek and using bedding sites along spring fork and south
fork, and the larger bear using the area from upper Black Lake to just
below the Forks. Both bears fed heavily on sockeye and pink salmon during
August and early September.
On 9/3, the tracks of a third bear were first observed on the north
bank of Black Bear Creek just above the lake. This bear was accompanied
by two cubs with identical-sized tracks.
These five bears, as of 9/16, all fed heavily on the pink salmon in
the three upper branches of Black Bear Creek, with many feeding access
trails appearing through the brush. On 9/16, while walking the system for
an escapement count, over 200 fresh, partially-eaten pink salmon
carcasses were seen hauled out on the stream banks, with heavy bear sign
abundantly dispersed throughout the upper Forks area.
During the late-October coho salmon escapement counts, the tracks of
the smaller bear were still abundant and fresh throughout the Forks area.
By this time, these were the only bear tracks occurring in the study area,
with the exception of one set of tracks belonging to the larger bear
(noted above) heading down the lake from behind the lower beaver ponds.
On 10/22, a bear scat was found on lower west branch shoreline
containing de~r hair; the only known deer carcass in the area was found on
10/21 near the M.B.C. thermograph station by the mouth of Black Bear Creek
just above the bridge by Big Salt Lake.
----
·.,,
if,fj
. ,t,/fl.Y.t _;!).JY.'(~· 'J,f';t!i<.f/J i· (jpl!f
~
1 scale -approx. 3"= 1 mile 1
BLACK BEAR
• bedding site
~ key habitat
.... -----bear trai Is ·
;$ windth.row * I:">'· slide · c .
FIGURE 22
..
t-'
t-'
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117
1982 -During the course of a week in late January, while walking
and skiing through the study area, no black bear sigrt was observed.
Several possible den sites were examined for evidence of recent bear use
with negative results.
From 4/8 to 5/29 the tracks of one small bear were found in the study
area above Black Lake. These tracks correspond in size to those of the
bear resident in the summer and fall of 1981. Sign was restricted to the
sedge tussock areas fringing the upper end of Black Lake, the skunk
cabbage-dominant marshes surrounding the muskegs --in particular, around
the lower beaver ponds --and casual browsing around the shores of Black
Lake. Toward the end of May, tracks and scats were observed in the Forks
area.
On 5/29, a large black bear was seen on the southeast shore of Black
Lake, grazing extensively on sedges. This bear was seen again in the
same area on 6/8. Sign of this animal occurred regularly from 5/29
onward on the south side of Black Bear Creek up as far as the lower south
fork and inland to the base of the ridge above the valley floor.
As of 5/29, there were two black bears using the valley. The
larger bear (13.5 em. track) ranged from Black Lake to the lower south
fork and inland; the smaller bear (12.0 em. track) used the opposite side
of Black Bear Creek, ranging from lower Black Lake up to the vicinity of
the proposed power house.
On 6/18, during a climb of the valley headwall north of Black Bear
Lake falls, sign of a third, smaller bear (11.3 em. track) was observed.
This animal appeared to be resident on this steep slope. Several heavily
used bedding sites were examined, with 11.3 em. bear tracks profusely
distributed from the area of the power house upstream on the north side of
Black Bear Creek and up the slide area which joins Black Bear Creek
approximately 75 meters below the falls. The headwall above and northeast
of the falls all the way to the top of the ridge above Black Bear Lake
was found to be crisscrossed with this bear's tracks and scats and sign
of feeding, particularly on Fauria. Tracks of this bear were also seen on
the ice near the mouth of Black Bear Lake on 6/18.
1il
[I
I ,,
i
118
Beaver (Castor.c~nadensis) (Figure 23)
1981 -Beaver sign was found_throughout the study area from the upper
Black Bear Creek valley down to Black Lake and all the way down Black
Bear Creek to Big Salt Lake. This sign consisted of shrub and sapling
cuttings, tracks, gnawed stumps, peeled sticks, dams, scent mounds, scats,
riverbank slides, and actual sightings. There is abundant old beaver
sign along Black Bear Creek, lake fork, spring fork, and west branch of •
south fork. Several old dams occur in the main flow of Black Bear Creek
between the Forks and Black Lake, as well as on lake fork above the
existing pond, and on the west branch of south fork fifteen meters above
its confluence with Black Bear Creek. These dams appear to be many years
old, with the logs and saplings of the structures well-rotted; the dam
above the present pond on lake fork as 3-4" diameter alders growing on
top of it. There are many old, beaver-chewed stumps in close proximity
to these dams.
Heavy, fresh beaver sign was consistently found on lake fork from its
confluence with spring fork to approximately 100 meters upstream. This
pond on lake fork had between 8 and 12 regularly visited scent mounds on
its perimeter, with well-maintained dams. Fresh cuttings were observed
nearby on thirty occasions.
Beaver use of the lower ponds adjacent to Black Bear Creek appeared
to be regular, although light in the presence of people. Eight days of
intensive minnow trapping in this area drove the beaver upstream; they
returned ·to the ponds two days after the minnow trapping was concluded.
An adult beaver was seen swimming in Black Bear Creek just opposite
the lower pond on the morning of 8/13 --the only beaver seen all summer.
No small tracks ascribable to juvenile beaver were seen, but frequent
adult tracks were observed along Black Bear Creek streambanks during times
of low water in Black Lake (8/9-8/20; 8/28-9/5) and in the mud along the
shores of west branch and lake fork.
\
~
...-! ~
co
.....
I . scale -approx. 3" = 1 mile I
BEAVER
in winter 0 den site
@key habitat
FIGURE 23
II
120
Beaver were aoeive throughout the Black Bear Creek system between
Black Lake and the Forks, with most of the approximately 40 riverbank
slides used frequently enough to inhibit revegetation.
1982 -On January 21, fresh beaver tracks were observed in the snow
around the pond on lake fork. Many recently cut alder saplings were seen
under the ice on the pond, as well as several piles of these cuttings in
a food cache on shore within 6 feet of the water's edge, underneath large
fallen logs and well-protected from snowfall. Fresh tracks were also
seen on the shores of spring fork just south of the lake fork pond. No
fresh beaver sign was observed anywhere else in the Black Bear Creek
system above Black Lake.
In early April, beaver sign was found to be heavy in the vicinity of
the Forks and along the banks of Black Bear Creek down to the lake. The
lower stream section had numerous well-used riverbank slides or runs on
both sides and the lower pond edges were beaver-trampled, with fresh-cut
shoots on the dam and the pond runways cleared of aquatic vegetation.
The lake fork pond showed heavy, current use, with eight fresh scent
mounds on its perimeter, 300-500 peeled sticks washed up against the dam
from winter feeding, and many tracks around the shores. At this time of
the year, beaver were feeding on a variety of plants, most notably skunk
cabbage (Lysichiton americanum) which is abundant throughout the study
area and provides an important early season food resource for bear and
deer as well.
A dam was discovered at this time on the south fork approximately 50
meters upstream from the confluence with spring fork. This dam was not
present in October of 1981 and had been built during the late fall~ winter
and early spring of 1982. A pond of approximately five thousand square
feet was impounded by this new structure, and the perimeter was marked
with occasional scent-mounds, fresh cuttings, tracks, and access slides.
Adult beaver were seen several times in the early evening along the
shores of lower Black Bear Creek above the lake, as these crepuscular and
121
nocturnal animals took to the streambanks to feed. On all occasions they
tailslapped in alarm and dove when they sighted the observer; throughout
the study period the beaver in this drainage have been chary of humans.
Deer (Odocoileus hemionus sitkensis) (Figure 24)
1981 -Deer sign in the study area was sparse throughout the study
period. In light of this·, all observations are listed below as summarized
from .notes:
8/7 -tracks of one animal seen in upper Black Lake bottom silt; no
good estimate of age.
8/8 -recent tracks of one deer were seen along lower Black Bear
Creek shore, disappearing into the marsh on the south side of the creek.
8/13 -tracks several days old of one deer on the north shore of
lower Black Bear Creek; these tracks were exposed by falling water level
in the creek.
8/24 -evidence of at least one deer's passage toward the high
country, in the form of a scat pile and old tracks ~mile northwest of
Black Bear Creek falls.
10/21 -deer skeleton, 2-3 weeks dead, found in Black Bear Creek
below Black Lake by M.B.C. thermograph station. Skull missing, with the
remainder of the frame intact. Unable to determine the nature of death.
This was the only deer seen in the drainage over the course of fourteen
months.
Pilots who regularly fly over the area stated that they have in the
past seen deer on the slopes above both lakes during the summer months
but had seen none this year. All of the sign seen in August could be
attributed to one deer's passage.
1982
1/20 -one set of tracks seen on logging road one mile downstream
from Black Lake.
4/7 -one set of fresh tracks crossing the logging road in the same
area as above, headed toward the dense old growth forest on opposite side
of lower Black Bear Creek.
~ .E ,.... II -('t) LJ.. (/) (/) __,. ..J ~~ N X 0 (.) (.)
r:q co co § .e s: '-'---H .........
-(1) r:r.. co a: '-
<D-'"C w (1) 0 ·-w '"C ~ (/)'
(1) 0
co " I. " /A (.)
" /!_A (/)
tv *
123
4/10 -clumps of deer hair trapped in detritus in fyke net at head of
Black Lake.
5/10-winter kill discovered 200 meters downstream of fyke net
station at mouth of Black Lake. Heavy sign of wolf traffic around this
skeleton, dating to winter.
5/26 -two does seen on logging road in same spot as mentioned above.
6/8 -one spike buck seen in same area on logging road.
No deer sign was observed in the drainage above Black Lake during the
spring fyke-netting period from 4/5 to 6/22.
Wolf (Canis lupus) (Figure 24)
1981 Tracks of two individuals were seen on two occasions, indicating
the passage of a large adult downstream near the head of Black Lake on
8/13; a smaller adult's tracks were seen in the same area on 8/10. There
was no other wolf sign encountered in the study area, although intermittent
game trails of .the sort wolves frequent were discovered on the south side
of Black Lake and on the north side of lake fork above the beaver pond and
heading up toward the general area of the falls.
-1982 -On 1/21, fresh tracks of two adults were encountered on the
snow on Black Lake, headed up-valley. These two animals ranged widely
throughout the valley, along both banks and back on the muskeg fringe of
the lower beaver pond, thence upstream to the Forks area. Wolves were
heard howling in the early morning of 1/21 in the vicinity of Big Salt Lake.
In early April, fresh tracks of two adults were seen on the snow on
Black Lake heading· down toward the clearcut. Two wolves were seen on the
logging road one mile downstream from Black Lake, heading toward the
creek. On 4/26, tracks of three adults were seen on the edge of Black Bear
Creek in the mud, just above the U.B.L. thermograph site, heading downstream.
Two adults were seen again on the logging road in early May, different
wolves than those observed earlier.
Mustelids (Figure 25)
Mink (Mustela vison)
124
Mink tracks were commonly seen along the creek banks on virtually
every trip upstream, in the summer of 1981, in January of 1982, and
throughout the spring fyke-netting session, April through June.
Otter (Lutra canadensis)
Otter sign was first observed in the study area in October, 1981.
From this time onward, otter sign was noted regularly from just below
Black Lake all the way up to the Forks area, dispersed thinly throughout
the area, with several preferred haulout sites along the banks of Black
Bear Creek between the lower beaver pond and upper spring fork and lake
fork.
Otter tracks were seen on the snow on Black Lake during a January
visit, and along upper Black Bear Creek beyond the Forks. Scats were
found containing small fish bones, and fresh sign was common in the Forks
area.
In April through June, widely dispersed otter sign was found in the
area above Black Lake, particularly heavy by the lower beaver pond, at
the Forks, and along lake and spring forks.
Marten (Martes americana)
Marten sign was seen to be less abundant than mink, but occurred more
diffusely throughout the upper valley, extending up south fork to at least
the lower falls; up spring fork and lake fork, sign was less abundant.
Marten tracks were seen in snow along the shores of Black Bear Creek above
Black Lake in January, 1982, several sets. Two marten were seen in the
old growth forest near Black Lake camp in May, 1982, as was one marten
apparently resident in a slash pile along the lower side of Black Lake.
ll'l
N
. .-I
......
~
· scale -approx .. 3" = 1 mile I . I
.•SMALL MAMMALS
MARTEN e sightings
MINK @ use area
OTTER o haulout site
'*slide -r;-..
FIGURE 25
General Observationa
Black Bear
126
In 1981, one small black bear resided in the drainage above Black
Lake in mid-summer; this bear was joined in mid-August by another adult,
and in early September by a sow with two cubs.
These arrivals of the latter four bears coincided with the return of
large numbers of spawning sockeye and pink salmon to the drainage, and
all five animals fed heavily on salmon during September. As the supply of
fish in Black Bear Creek expanded, the territories of the bears diminished
and overlapped, until in mid-September, all five animals were working
the Forks area in close proximity to each other.
The marshy areas back of lower Black Bear Creek appeared to be
important feeding areas in the spring, when sedges and skunk cabbage
were heavily grazed~ In mid-summer, these areas were used for access
to the upper valley and to the extensive blueberry (Vaccinium ~.) and
salmonberry (Rubus spectabilis) patches along Black Bear Creek, its
tributaries, and amongst the windthrows and old growth forest.
Bears use the headwall of the valley for transit to the high country
for spring and summer feeding.
In 1982, one small bear was found in the drainage above Black Lake
in the early spring. This bear's tracks correspond in size to those of
the small bear resident in the area in summer of 1981. It is probable
that this bear overwintered in the valley. In January, 1982, some effort
was given to finding bear den sites, with negative results. It is likely
that an overwintering bear would use the heavy, extremely brushy and
jumbled windthrow areas at the base of the valley walls.
The second bear in the area in 1982 left tracks similar to the large
bear which arrived in late summer 1981. It is possible that this is the
same bear.
Bears use the logging road for access to the Black Lake area and have
been seen on the road by loggers in the past years.
127
As the salmon spawning in upper Black Bear Creek tapered off, all
but one bear left the area, until by late October, the small bear
mentioned above was the only resident animal, and was ranging widely
throughout the Forks area.
Black bears are commonly seen on the slopes above Black Bear Lake in
the summer and fall, as attested to in the visitor log in the Forest
Service cabin on the lake. One was seen by the observer in September,
1980, 300 feet above the lake on a south-facing slope in the afternoon.
The bear population in the area between Black Lake and Black Bear
Lake is estimated to be no more than two full-time resident adults, with
a transient number of animals coming into the area to feed on salmon in
September, of which there were three in 1981. Presently, in June, 1982,
there are three adults in the study area.
Beaver
Beaver sign is heavy throughout the system, with the hub of year-
round activity occurring in the pond on lake fork.
Beaver maintain the dams on the two lower ponds on the south side of
Black Bear Creek, showing consistent heavy presence from early spring to
late fall, but appear to depart this area in winter, visiting only
occasionally for casual feeding, on salmonberry and high-bush cranberry
stalks and alder saplings.
Beaver in the study area are extremely wary of humans.
The beaver population in the study area appears to be expanding, as
shown by the new dam on south fork and much increased activity in this
immediate vicinity.
The ponded areas created by beaver dams contain many young coho
salmon.
128
It is likely tbat the beaver population in the study area consists of
one extended family group. During cold and snowy winters it is known
that beaver sometimes utilize a communal lodge, abandoning summer
dwellings (Hay, 1958). In this instance, it is likely that dwellings in
undercut banks are abandoned in favor of communal life in the lake fork
pond, where the only large stored food supply was found, and where the
added thermal value inherent in the close proximity of kin would reduce
one element of climatic stress. The lake fork area abounds with small
alders, which are a mainstay food item in this biome; extensive groves of
small alders do not occur in immediate proximity to the lower ponds.
The presence of much old beaver sign, estimated at ten to twenty
years old and older, in conjunction with recent sign, of perhaps five years
past, intimates that this is a recently reestablished beaver population.
An old tent platform on the southeast shore of Black Lake and several old
marten sets suggests the presence some years past of a trapper. It is
speculated that this population was trapped out about ten years ago and
has returned to the study area in recent years. No trapping records for
this area can be found.
It is estimated that the beaver population in the area above Black
Lake is 7-12 animals.
Deer
The study area is not currently heavily used by deer. Deer sign is
much more abundant in the area between Black Lake and Big Salt Lake along
the creek and in the adjacent old growth forest~
There are no indications that deer use the upper Black Bear Creek
drainage for winter habitat.
Deer populations are lower this year than in recent years and may
account in part for the scarcity of sign.
129
Wolf
Wolves are infrequent visit6rs to the study area, and appear to use
the logging road for acces to Black Lake.
It is probable that wolves hunt more regularly in the drainage below
Black Lake due to the larger presence of deer. Wolf visitation to upper
Black Bear valley would increase proportionate to increased deer use
(Wood, pers. comm.). The tracks observed in January,.l982, indicated a
day trip to the upper valley from below Black Lake; there were no resting
sites identified, and although the tracks indicated a fairly extensive
search of the area, no signs of predation were seen and the tracks headed
back down the lake.
It is not known if wolves use the upper valley as an access route to
the high country, although there is a fairly well-used, intermittent
game trail parallelling the upper creek in the direction of the falls and
a steep, passable slide area.
130
EFFECTS OF PROPOSED HYDROELECTRIC
PROJECT ON FISHES AND THEIR HABITAT
Black Bear Lake habitat
Effects on rainbow trout and habitats of Black Bear Lake cannot be
evaluated at this time. The late snow-ice melt season on Black Bear Lake
in spring, 1982, prevented the accomplishment of necessary field work.
Principal questions requiring examination include magnitude of rainbow
population, preferred residence habitats, and usable spawning areas.
Spawning habitats above Black Lake
Spawning habitats above Black Lake which may be affected by the
hydroelectric project are found in zone II (seep. 92), principally in
spring and lake forks of the Black Bear Lake outflow. While the south
tributary contains roughly half the spawning habitat above Black Lake, its
flows or water quality are not likely to be affected by the project. It
was not studied in detail in the course of our investigations.
The principal physical features which may influence fish and fish
habitats in the course of a hydroelectric project include stream discharge,
water temperature, springflow characteristics, streambed dynamics and
streambed quality, and water quality features including dissolved oxygen
or water chemistry. The first three of these elements are closely
interrelated and form the core of this analysis of effects on spawning
habitat. The other elements --streambed and water quality features --
are handled more briefly.
In general terms, the flow regime proposed for this project (summarized
in Figures W-5 through W-17 of Exhibit W of the FERC License Application)
compares with natural conditions as follows:
January
February
March
April
May
June
July
August
September
October
November
December
131
Average project flow releases exceed mean monthly
natural flows, as synthesized. Neither peak nor
low regulated flows reach the extremes expected
under natural conditions.
Average project flows coincide with mean monthly
natural flows. Range of regulated flows less than
natural.
Average project flows less than natural; but range
of project flows less than natural.
Average project flows less; range of low flows the
same,~C!$ natural; peak flow range less than natural.
Average project flow greater than natural range of
low flows reduced from natural but high flows
increased above,natural.
Average project flow greater and ranges less than
natural flows •
Average project flow same as natural.: ranges reduced.
Average project flow less than natural: range of low
flows same; high flows reduced compared to natural.
Average project flow coincides with natural: ranges
reduced.
Average project flow less than natural; range of low
flow similar to natural; high flows less than
natural.
This overview suggests that during the spawning-incubation period
(August through April) projected flows, as a singular feature, could be a
problem primarily in October and December.
The effects of altered flow conditions in October and December were
examined by use of stream cross sections which were surveyed throughout
the fisheries habitats above Black Lake. The principal objective of this
work was to provide a tool to evaluate present, as well as regulated,
conditions of channel flow, identifying loss or gain of spawning or rearing
habitats.
132
Cross sections•l2 through 27, as identified on the map in the rear
pocket, are located on spawning habitats of varied quality. The results
of this survey work are discussed here in convenient groupings. Wherever
possible or useful, individual cross sections were rated showing
projected stream levels for normal (N) and regulated (R) flows in October
and December, the two most critical flow months in the regulated regime.
Cross sections 12 and 13 are located in the first spawning habitat
area in zone II, immediately below the confluence of the south fork with
the lake-fed stream. These cross sections, while descriptive of the
channel characteristics, could not be fitted with projected flow levels
because of the confounding pattern of partial south fork confluence with
the lake-fed system immediately upstream (see map). The sections serve,
however, to indicate that this spawning habitat area is not particularly
susceptible to exposure as the water level drops. That is, the banks are
sufficiently steep so that spawning gravels are not readily exposed until
quite low flow conditions.
About 300 feet upstream of sections 12 and 13 is the confluence of
the south fork with the lake-fed system. Cross section 14 lies at the
mouth of the south fork and is not essential to this work, while cross
section 15 is also the stream discharge station used for the lake-fed
system. The flow rating lines shown on cross section 15 (Figure 27)
represent the Harza Feasibility Report's October and December synthesized
flows under unregulated (Natural) and projected (Regulated) regimes for -1/
the point on the drainage immediately upstream of the south fork.-This
section indicates that October and December project flows (R) are at levels
which are not likely to limit spawning success in the vicinity of cross
section 15.
Cross sections 16, 17, 18, and 19 were not evaluated with regard to
levels of regulated flows. In this section of the stream, the major flow
source is the spring fork, but an important second source comes from
overflows from the lower lake fork near and above the beaver pond area
(see map). This made meaningful approximations of projected flow levels
difficult.
~/ See figures W-5 and W-13 of FERC License Application -Exhibit W.
(V")
(V")
M
0
2
3
4
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6
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X -Se.c \-tot\ l 2.
FIGURE 26
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u•re~v.l~r u•e~n. s~n.li!~ c.a~b\cz. t,C\~ ac:..n.d. .. \C)'
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10 20 250 40
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FIGURE 27
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3 3
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137
The cross sections 16 through 19 show channels with generally vertical
banks and form capable of dropping at least ~ foot below the early June,
1982, level before significant dewatering of the bed occurs.
The upper spring fork is represented by cross sections 20, 21, 22,
and 23. These sections are shown only with the flow level, 17-25 c.f.s.,
which, from limited observation and measurement, seems to be the upper
limit of spring-fed waters into this fork. As noted elsewhere, flows in
spring fork are believed to drop to around 5 c.f.s., but the shape of the
cross sections, with characteristically vertical banks, and quite flat
streambeds, limits the dewatering of the bed. The flow levels for October
and December are not shown because this channel area receives only ground-
water regulated flows from upper lake fork. A flow criteria recommended
for use in groundwater related designs for this project is to maintain at
least 10 c.f .. s. in this channel area during spawning period --August
through September--and a winter minimum of 5 c.f.s.
Above the beaver ponds found on the lake fork is the remaining channel
of zone II. This spawning area is represented by cross sections 24, 25, 26,
and 27. These sections (Figs. 31-33) illustrate the rougher, more troughed
character of this channel. Banks often show more sloped, as opposed to
vertical, sides. These channel characteristics are responses to the large
streambed materials, the variable flow conditions, and the more active
bed load present.
In order to evaluate the October and December flow levels with
synthesized (_!atural) and projected (Regulated) conditions, an allocation
of respective flows below the power house was made. (See also Figures W-5
and W-12 of FERC License Application, Exhibit W). The assumptions are:
unregulated regulated allocation allocation
flow at flow below to to
vicinity of tailrace sprin fork lower lake fork
powerhouse using N i.ising R. using_ N using R
(N) (R)
October 48 cfs 38 cfs 18 17 cfs 30 21 (est)
December 25 17 13 10 12 7 (est)
0
2.
3
4·
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142
These assumptions are conservative values for lower lake fork, because
neither N nor ~ va!ues include additional flows generated by the watershed
below Black Bear Lake. The assumed December level for a regulated flow of
7 a.f.s. above the lake,fork beaver ponds is significantly lower than the
assumed mean monthly (~atural) flow for December, suggesting that spawning
habitat is lost, as interpreted in Figures 31,32 & 33. However, a realistic
comparison should also recognize that the unregulated December flows drop
this fork below the 12 c.f.s. means, as our observatiohs have also found.
The predicted December average minimum flow over the synthesized record
(30 years) is about 7 c.f.s. at the outlet of Black Bear Lake, which _would
yield very little flow in the lake fork spawning section. Thus the spawning
habitat in the lake fork may fare better under the regulated regime, if the
anticipated 7 c.f.s. minimum flow in the channel is delivered.
In order to similarly evaluate stream temperature difference during the
spawning-incubation period, a table showing spring fork stream temperatures
under Natural and Regulated conditions was developed. It will be seen that
construction of Table 12 involves speculative assumptions which have been
discussed earlier.
1/ :!:_/ Intake '}_/ 2/
Temperature Temperature Temperature, Temperature in stream
mouth of at base of Bl. Bear Lk. at groundwater emergence
Month B.B.L. falls (at -17 ft depth) Natural Regulated
Aug 11.0°G 11.5°C (-1.8°C) = 9.2°C 9.5 8.5
Sept 10.5 10.5 ( o.o ) =10.5 9.0 9.0
Oct 7.5 7.5 (+0.1 ) = 7.6 7.5 7.5
Nov 6.5 5.5 (+0.3 ) = 6.8 7.0 7.0
Dec 2.0 1.0 -(+0.5 ) = 2.5 2.5 3.0
Jan 1.5 0.5 (+0.8 ) = 2.3 2.5 3.0
Feb 1.5 0.5 (+0.8 ) = 2.3 2.0 2.5
Mar 2.0 1.5 (+0.5 ) = 2.5 2.5 3.0
Apr 2.o· 2.0 (+0.2 ) = 2.2 3.0 2.5
May 4.0 4.5 (+0.0 ) ' = 4.0 5.0 4.5
June 8.0 9.0 (-0.2 ) = 7.8 8.0 7.0
July 10.5 11.0 ( -1.0 ) = 9.5 9.0 8.5
TABLE 12: Speculative derivation of ~atural and !egulated water temperature
in stream at groundwater emergence into spring fork.
~/ Interpreted from two seasons of record.
2/ From interpretation of miscellaneous measurements. See text. lf Mid-operating range for each of the three intake ports would occur at
17 ft. below lake surface. Thus, ;assuming use of one intake port at a
time, temperatures of intake waters were taken at -17 ft. depth from
lake profiles (Figures lOa, b, c,) for respective seasons of the year.
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146
Table 12 sexyes particularly to illustrate the interactions which
produce stream temperature conditions under natural or regulated conditions,
-respectively. It also suggests that differences in stream temperature
conditions under regulated conditions during the spawning and incubation
period are more likely in December through April, with December through
March being warmer under regulated conditions by a half degree and April
regulated stream temperatures being a half degree cooler. Not shown is
the likelihood that temperatures under regulated conditions are apt to
be more consistent from day to day.
The effect of these changes in temperature regime upon salmonids
could be somewhat earlier emergence of fry from the streambed in the
spring. One-half degree increase in intragravel water over December
through March (120 days) suggest 60 more temperature units as· of 1 April,
and perhaps several weeks earlier fry emergence. Sockeye and coho fry
would migrate earlier into Black Lake, or into downstream rearing habitats.
Pink and chum fry would reach the estuary earlier.
A major key to interpreting project impacts upon spawning above
Black Lake will be the degree of success obtained in reintroducing tailrace
water in the groundwater·route of.flow, whether through the existing
natural channel or by engineered design. The groundwater aquifer regime
produced several beneficial conditions-. First, it stabi~izes spring fork's
flow regime within an observed range of about 4 to 25 c.f.s •
. Secondly_, it acts to dampen the extremes of water temperature --this is
probably most useful in winter when freezing conditions are prevented.
Thirdly, the position of the spring fork, being somewhat removed and
isolated from the natural channel, makes the bed of the spring fork more
stable with reduced mortality. In this evaluation, it has been assumed
that the groundwater system will remain under regulated conditions, though
possibly altered in temperature conditions, as suggested in the preceeding
section.
The effects of hydroelectric regulation on streambed dynamics and
bedload movement have only been observed casually in this investigation.
147
It is evident that the lake fork carries a sizable volume of coarse
bedload which produces frequent channel changes. Equally evident is the
conclusion that this activity will be reduced when the outflow from Black
Bear Lake becomes regulated. This change could prove beneficial to the·
spawning habitat of the lake fork if the new flow regime re-forms the bed
and its materials toward a new dynamic balance with lowered peak flow conditions.
No adverse effects are expected of this project with regard to
dissolved oxygen or water chemistry. The primary way in which super
saturation of gases could occur in this hydroelectric project would be
through allowing a vortex to develop above the lake intake, thus entraining
air into the penstock and through the turbines. This condition is as
important to avoid from an engineering standpoint as it is from the view
of water quality.
In summary, if the groundwater system is maintained, the principal
effect on spawning habitat may be alteration of temperature regime. This
change is difficult to evaluate because of the_important; but poorly
understood, role of groundwater flow in moderating water temperatures.
The temperature changes expected are small--l°C or less--but a
cumulative temperature unit effect on fry emergence may occur. Earlier
emergence by sev~ral weeks is possible. For rearing spe~ies, sockeye and
coho, this alteration might have little significance, since the fry would
move earlier into Black Lake or into stream habitats. For the few chum
salmon, or the pink run. (suspected to occur erratically or on alternate
years above Black Lake), earlier emergence and migration into the estuary
may induce greater mortality.
The flow and streambed characteristics of spawning habitat in the
lake fork could be improved. This would principally benefit the pink run,
which seems to utilize this area.
Rearing habitats above Black Lake
Rearing habitats above Black Lake, identified as zone I in this report,
include the mainstream channel and the beaver ponds located on the westerly
II
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148
side of the lower creek and in the lake fork. Coho fry and fingerling are . .
the principal users, along with a few Dolly Varden. About 80-85% of
coho fingerling use was in the main stream, with the remainder being
nearly evenly divided between the lower beaver ponds and the upper ponds
on the lake fork.
Principal hydroelectric effects which may influence rearing habitat
and production are water level/water velocity and water temperature. In
addition, the indirect effect of improved access to trap and remove the
beaver population may impact pond rearing areas.
The first 2,500-3,000 feet of stream channel above Black Lake is in
zone I, and channel cross sections 1 through 11 (Figures 34 -42 ) are
provided to evaluate effects on channel water levels from hydroelectric
regulation. These cross sections have been fitted with average monthly
flow levels for June and August, which are derived from the evaluation of
Black Lake levels under regulation shown in Figure43 o June and August
were selected because they show the largest regulated change from natural
conditions of months during the active rearing season. Also used are
elevation adjustments according to small, surveyed increases in stream water
level upstream from Black Lake. This amounted to 0.3 feet between the lake
mouth and cross section 11.
Cross sections 1-11 show that the regulated reductions of averaged
June water levels will have little effect on stream habitat, nor do the
regulated increases in August show much change compared to the monthly
mean of natural levels. The stream level difference produced under
regulated versus natural flow regimes are more likely to be a function of
the extremes than the means, as suggested in the figures by the level of
the observed low, August, 1981, which clearly shows in a number of sections
the loss of streamside habitat valuable to rearing coho. A display of
levels of extreme lows under natural and regulated regimes was not attempted,
but the earlier work by Harza with synthesized flows (Feasibility Report and
FERC license application ) clearly shows that sizable reductions in the
range of low flows and consequently beneficially reducedrange of lake and
atream levels compared to natural conditions. are anticipated in all summer
months.
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155
This will reduce lows such as in August, 1981. In that month, for example,
the measured low flow at Black Bear Lake (U.S.G.S.) for August was 4.1 c.f.s.
This compares with a projected tailrace discharge for August ranging
between 23 and 39 c.f.s. Rearing fish will benefit from the more constant
stream levels with regulated flows.
The changes in water temperatures suggested in the Effects on spawning
habitat section are generally valid here, although the differences between
natural and regulated temperatures will be less in this downstream location.
These temperature differences will have little direct effect on rearing
habitat. A temperature factor of greater importance is the more sustained
volume of flow during summer months, which prevents or reduces the
occurrence of local high temperature along shoreline pool areas. The sum
of project effects on coho habitat in the mainstream is likely to be
favorable.
Beaver pond areas above Black Lake are not likely to fare as well
with regard to rearing habitat. Two factors may combine to reduce the
effectiveness of beaver pond habitat: loss of access into the ponds by
salmon adults and young during high water periods; and reduced beaver pop-
ulation froin possibly trapping with resulting deterioration in beaver dams
and swim routes.
In time, the lack of beaver maintenance of ponds may result in
elimination of the pond area in the lake fork, and in gradual reduction
in ponded area in the lower part of the system.
Reduction in number of beaver in the upper drainage will depend upon
trapping pressure and also immigration of new beaver populations. The
more conservative assumption, however, is that beaver will be eliminated
and their ponds after them. Accordingly, possible losses in productive
coho rearing area may result from increased human access.
In summary, the most important mainstream rearing habitat will not be
harmed by hydroelectric project regulation, and may well be benefitted. No
quantitive fix was attempted on the magnitude of this benefit.
156
On the other ~and, much of the beaver pond habitat could be damaged
from ill).proved access. The portion of the rearing fish in the beaver pondr;
in zone I is about 15 -20% of the total.
Black Lake as a rearing habitat and migrating route for salmonids
An evaluation was made of Black Lake levels during averaged flow
conditions with and without regulation. The discharge/lake level relation
shown in Figure 2 was used to convert flow assumptions provided in the FERC
License Applicationinto average monthly lake levels (Figure 43). The
flows assumed for this synthesis (see Table 13) are derived from the FERC
License Application, Figure W-16 of Exhibit W.
UNREGULATED CONDITIONS REGULATED CONDITIONS
Outlet; Black Lake Black Lake Outlet, Black Lake Black Lake
Month Unregulated Flow Level Regulated Flow Level
Jan 53 cfs 2.88 ft 63 cfs 2.98 ft
Feb 48 2.82 61 2.96
Mar 36 2.68 49 2.83
Apr 65 3.00 65 3.00
May 108 3.42 97 3.32
June 109 3.42 93 3.30
July 60 2.95 76 3.10
Aug 55 2.90 76 3.10
Sept 88 3.25 88 3.25
Oct 150 3.80 140 3.70
Nov 116 3.50 114 3.48
Dec 104 3.40 96 3.32
TABLE 13: Assumed Black Lake outflows under regulated and unregulated
conditions, used to derive corresponding Black Lake levels.
Assumed outflows are from the License Application·. Unregulated
flows are synthesized monthly means. Regulated flows are taken
as mid-point of environmentally modified regulated flow regime,
with no spill.
Levels of Black Lake in January, February, March, July, and August
are projected to rise about 0.1 foot with regulation. Levels during May,
June, and October would lower by a similar amount.
feet
above
assumed
datum
157
~ ~ Average monthly lake level, unregulated
............... , ..-' • = Average monthly lake level, regulated,
and without spill
FIGURE 43: Synthesized levels of Black Lake under regulated and unr-egulated
conditions.
These projected levels do not, of course, reflect the natural
variability in level which will result from rain or drought periods. The
small differences in average level shown in Figure 43 also indicates those
periods when normal peak or low extremes of lake levels will be moderated,
probably much more-than the mean levels shown. This larger moderation of
extremes will reflect the fact that about 25% of the Black Lake watershed
will be under total regulation.
A related flow effect on Black Lake may concern ice forming and
melting conditions. December flows, as projected with no spill(Fig. W-15,
License App. Exhibit W) will be reduced about 9% under the normal mean:
January flows increase 22%; February flows increase 30%; and March flows
increase 40%. This change in flow regime will markedly influence the
I!
158
heat balance in B~ack Lake. The likely effect may include earlier ice
formation if cold weather comes in December, but most importantly, Black
Lake ice, when formed, is not as likely to stay or to form thickly, due
to a much increased supply of heat laden water. Lake breakup will come
earlier.
Change in heat flow into and out of Black Lake does not, however,
suggest sizable change in lake water temperatures. We do not have
sufficient lake and weather information to calculate lake surface heat
losses or gains --and then to evaluate changes in lake temperatures --
but it is likely that lake surface temperatures in winter will show little
increase, with the small increases anticipated upstream, and surface
temperatures could actually decrease because the water surface is not
protected by ice cover, and is exposed to wind chill •.
Summer surface water at the inlet to Black Lake may experience small
reductions in temperature as a result of regulations, but this effect is
likely to be masked in the lake itself by much larger heating or cooling
effects observed to occur in Black Lake. Little change in surface
temperature regime is anticipated in Black Lake.
Winter-spring dissolved oxygen levels in Black Lake may increase as
a result of reduced ice cover but there has been no evidence of significant
oxygen depression in most of the water column of this lake.
No evidence has been found indicating that Black Lake's naturally-low
productivity will be significantly altered by upstream regulation.
It is possible that as a result of altered ice conditions in Black
Lake, fry and smelt migration out or through the lake will be changed.
Below Black Lake
Effects of flow regulation of the hydroelectric project upon Black
Bear Creek fishery habitats below Black Lake will result primarily from
alteration in stream temperature or streamflow regimes. Both of these
features were examined by Environaid in our Phase I study (12-15-80).
159
Subsequent to that report, it was decided to limit further work to effects
above the mouth of Black Lake. Accordingly, no comprehensive attempt
will be made to further review possible impacts below Black Lake.
Briefly, those physical effects were determined then, and are still
believed, to be:
Temperature
Flow
Very small effect at the lower river for most flow
conditions. During winter low flow periods: small
temp. increases downriver. Summer low flow
periods: small temp. decreases downstream.
The magnitude of winter temp. projected changes
established in the December, 1980, study was
based upon 2°C difference between unregulated and
regulated water temperatures, since the role of the
groundwater system was not recognized at that time.
Consequently, the predicted differences at the
mouth of Black Bear Creek between unregulated and
regulated temperatures in earlier.work were higher
than are now expected.
Low flows in both winter and summer would be
significantly augmented. A reduction of about
15% in twenty-year peak flow at the stream mouth
is projected. Intermediate flows would feel
little effect.
We have not studied the fisheries of the stream below Black Lake, and
have attempted no review of project impacts upon this resource.
160
•
EFFECTS OF PROPOSED HYDROELECTRIC PROJECT ON WILDLIFE AND THEIR HABITATS
Bear
The major effect on large mammals in the upper valley will be the
increased access to the area by humans via the road to the power house.
Bear hunting is very popular on Prince of Wales Island, and in a small,
confined area such as this valley, it will be easy to eliminate the one
or two resident bears by hunting. With the bear hunting season running
from September to June, the transient bears that come into the area to
feed upon salmon will also become targets.
If care is not taken with the disposal of garbage during the
construction phase and thereafter~ bears may well become camp nuisances,
foraging in the waste and abandoning some of their wilrl ways in favor
of an easy handout.
If the salmon runs are adversely affected by the project, bear use
of the upper valley may decrease.
Vegetative destruction necessary for the access road is not likely
to be of major significance to the bears, nor is the construction of the
power house and road. Bears will probably use the road to some extent for
transit.
Beaver
Increased access is likely to increase trapping pressure on furbearers,
particularly when fur prices are high. One good trapper would have little
difficulty in trapping out the beaver population in the valley above
Black Lake. As these animals are marvelously efficient in maintaining
ponded areas for their own use, simultaneously creating extensive coho
rearing areas, efforts should be made to protect them.
161
If the access road to the power house site skirts the valley wall and
does not come close to the creek, and the animals are not trapped, it is
possible they may continue to reside in the valley. In the event that
the beaver are trapped out, the substantial population of beaver below
Black Lake may serve as a reservoir --these beaver will probably
repopulate upper Black Bear Creek in time, provided the area remains in a
natural state.
Fluctuating water levels may adversely affect beaver habitat,
particularly in winter when a stable water level in a resident bond is
desirable.
Deer
Deer use of the study area is presently very low. Increased hunting
pressure may occur as a result of increased access, although it is possible
that the confined nature of the valley does not lend itself to increased
deer use. The major effect on deer is the loss of important old growth
habitat in the lower valley below Black Lake; with this habitat
diminished, deer are less likely to occur in the drainage.
Wolf, Mink, Marten, Otter, Weasel
These animals are likely to face increased trapping pressure due to
greater access by humans. All of these species feed upon salmon as well,
and would be directly affected by reductions in anadramous fish
populations.
Much of the human pressure upon these resident mammals could be
relieved by closing the road from Black Lake to the power house. In the
two years of the study, only seven people have walked or paddled to the
upper reaches of Black Lake during the time the study team was in the area.
The dense brush and generally poor walking conditions preclude all but
the highly motivated from venturing up Black Bear Creek above the lake.
However, the logging road access to Black Lake has greatly increased
sportfishing pressure on the lower lake, and it is likely that when word
gets out about the furbearer population in the upper valley, it_ is merely
a matter of time and price before these animals are subjected to trapping
pressure pressure which the beaver population cannot bear.
I I!
I
162
APPENDIX
Date
8-13-81
8-18
8-28
9-5
9-7
9-16
10-22
10-24
4-16-82
4-25
5-5
5-17
5-18
5-20
5-26
5-28
5-31
6-18
6-20
6-21
163
APPENDIX TABLE 1: Streamflow Measurements in Upper-Black Bear Creek.
1/ 2/ . 3/ 4/
mouth, Bl. 1000' Lk. fk. in below Bl.
Bear Lk. below near spring-Bear Lk. south fk. at mouth
(daily mean) falls springE fed system tributary Bl. Lk.
fork
-cfs--cfs--cfs--cfs--cfs--cfs--cfs-
0800= 2.50 "':" --0900= 7.79 1000= 3.25 1500=12.38
1200= 2.83
1200= 1.41 ---1300= 4.29 1400= 1.72 1600= 7.20
1800= 2.13
0800= 9.7 ---0900=18.38 1000= 9.89 1500=39.51
0800=15.1 -·--0900=24.2 1000=32.07 1500=34.64
1200=17.1
0700=110 ---0800=112.53 0900=54.64 1300=291.26
1200= 92
0800=50.8 ---0900=65.96 1000=37.16 1500=143.75
1200=46.5
0800=12.4 ---1000=19.52 1100=13.28 1400=47.54
1200 .. 12.0
0800= 9.96 ---0900=19.29 1000=29.36 1400=70.54
1200= 9.96
6.5 ---1700=27.05 1800= 7.42 (70)
9.0 ---22.21 7.72 32.41(30)
11.0 -- -
1530=28.39 1630=24.46 50.13(55)
30 -----1100=114.18(105)
39 ---48.27 88.24 (135)
53 -----223.64
228.88(210)
46 ---1000=56.42 1100-34.79 158.30(164)
36 --17.30 42.49 1330=37.06 (135)
55. --24.58 --(185)
53 -----(135)
(staff rdg) -59.18 28.53 ---(145)
--21.07 16.24 --(115)
21.90 16.90
ll Provisional U.S.G.S. data, except where indicated. Drainage area= 1.92 mi2 •
ll Drainage area= 3.34 mi2 • Measurements 3/4 mile below Black Bear Lake.
1{ Drainage area= 2.20 mi2 • Measured near (l/), where tributaries meet.
~I Drainage area= 7.34 mi2 • Values in () are from rating curve.
Others are-measurements.
164
TABI.E A2: Daily Mean Water Temperatures ( °C)
BBL SGS UBL LBL MBC
Date Mean Mean Mean Mean Mean
8-7-81 15.8
8 12.4 15.3 14.9
9 12.3 16.0 15.8
10 12.0 12.5 16.0 16.6
11 14.5 11.8 12.6 17.1 16.3
12 14.6 11.7 12.6 16.8 16.5
13 14.4 11.5 12.0 16.7 15.9
14 14.4 11.4 11.9 16.8 15.9
15 15.0 11.3 12.3 17.2 16.1
16 14.6 11.1 11.5 16.4 15.6
17 14.5 11.1 12.1 16.0 15.2
18 14.7 11.0 12.2 16.3 15.3
19 13.9 11.0 11.8 16.2 15.1
20 13.3 10.8 11.5 15.6 14.8
21 13.3 11.4 10.9 ·15.2 13.4
22 13.1 11.9 11.1 14.4 13.8
23 13.4 11.8 11.2 14.1 13.8
I
24 13.5 11.8 11.3 14.6 13.9
25 13.2 11.7 11.2 14.3 13.9
26 13.1 11.8 11.0 14.3 13.1
27 13.2 11.8 11.1 14.0 13.5
28 12.9 11.8 11.2 13.5 13.4
29 13.1 11.7 11.5 13.7 13.3
30 12.9 11.4 11.2 13.5 13.3
31 12.5 11.4 11.3 13.9 13.3
9-1-81 12.8 11.3 11.4 14.4 13.6
2 12.9 11.0 10.9 13.9 13.3
3 12.6 11.0 11.1 13.8 13.5
4 12.6 11.0 11.3 13.8 13.5
5 12.2 10.9 10.8 13.8 12.7
6 12.4 11.2 11.3 13.2 12.3
7 12.3 11.7 11.7 12.6 12.4
8 12.1 11.9 11.6 12.2 12.2
9 11.9 11.9 11.4 12.1 12.0
10 11.7 11.7 11.1 11.8 11.6
11 11.4 11.4 10.7 11.5 11.2
12 11.1 11.1 10.5 11.2 11.0
13 11.1 11.0 10.5 11.5 11.3
14 10.7 11.0 10.6 11.4 11.3
15 10.7 11.1 10.8 11.0 11.1
16 10.9 10.9 10.5 11.5 11.1
17 11.0 10.8 10.9 11.5 11.7
18 10.6 10.8 10.9 11.5 11.7
19 10.4 10.8 10.5 11.5 11.2
20 10.4 10.8 10.4 11.6 11.0
21 10.5 10.5 10.2 11.9 10.9
22 10.4 10.4 10.0 11.8 11.0
23 10.0 10.3 9.7 11.6 10.7
165
BBL SGS UBL LBL MBC
Date Mean Mean Mean Mean Mean
9-24-81 10.2 10.2 9.9 11.6 10.7
25 10.0 10.0 9.5 11.1 10.1
26 9.8 9.8 9.1 11.2 9.5
27 9.8 9.8 9.3 11.1 9.9
28 9.4 9.6 9.1 10.7 9.7
29 9.1 9.6 9.0 10.4 9.5
30 9.2 9.6 9.1 10.1 9.1
10-1-81 9.0 9.3 8.5 9.6 8.9
2 8.9 9.1 :;8.4 9.3 8.7
3 8.7 9.0 8.3 9.1 8.3
4 8.6 8.7 7.9 8.7 7.6
5 8.1 8.6 8.1 8.6 7.9
6 8.1 8.6 8.2 8.8 7.9
7 8.1 8.4 7.9 8.8 8.2
8 7.7 8.3 7.8 8.5 8.0
9 7.9 8.1 7.2 8.3 7.2
10 7-.:8 8.0 7.0 8.1 7.1
11 7.8 8.0 7.1 8.0 7.0
12 7.8 8.0 7.4 8.2 7.3
13 8.2 8.0 8.0 8.7 8.4+
14 8.2 8.1 8.4 9.5 9.3
15 8.0 8.2 8.4 8.8 8.6
16 8.0 8.3 8.4 8.6 8.4
17 7.9 8.4 8.7 8.6 8.4
18 7.8 8.3 8.0 8.2 7.9
19 7.6 8.0 7.7 8.0 7.7
20 7.9 7.9 7.2 7.7 7.4
21 8.3 7.8 7.8 8.4 8.1
22 8~0 ··:7,. 7 8.2 8.7 8.4
23 8.4 8.1 8.6 8.8 8.6
24 8.5 8.4 9.0 8.9 8.7
25 8.3 8.4 8.6 8.8 8.6~
26 7.9 8.1 8.2 8.7 ::s 8.4 1'"1'
27 7.8 8.0 8.2 8.5 ::r' 8.2 (1)
28 7.5 7.9 7.9 8.3 8.0 f!
29 7.4 7.6 7.7 8.1 7.8 ~
30 6.8 7.4 7.4 7.8 7 50.. • <:
31 6.7 7.1 7.2 7.4 7 .11»
11-1-81 6.6 7.3 7.3 7.2 6. 9 c:
2 6.5 7.0 7.0 6.9 6.6 ~
3 6.4 6.8 7.0 6.8 6.4
4 6.6 7.3 7.7 6.9 6.6
5 6.7 7.6 8.0 7.7 7.4
6 6.6 7.3 6.9 7.5 7.2
7 6.1 7.1 6.5 6.8 6.4
8 6.1 7.2 7.2 6.7 6.3
9 6.4 7.2 7.9 6.9 6.6
10 6.4 7.5 8.1 7.3 7.0
11 6.4 7.6 7.9 7.6 7.3
12 6.1 7.4 7.3 7.5 7.2
13 5.9 7.2 7.3 7.3 7.0
166
BBL . SGS UBL LBL MBC
Date Mean Mean Mean Mean ·Mean
11-14-..,81 5.9 7.1 6.9 6.9 6.6
15 5.7 6.9 6.9 6.8 6.4
16 5.5 6.9 6.6 6.5 6.1
17 5.1 6.8 6.2 6.1 5.7
18 4.7 6.7 6.0 5.9 5.5
19 5.2 6.7 6.7 6.2 5.8
20 5.3 • 6.1 6.6 6.7 5.7
21 5.2 6.7 6.7 6.1 5.7
22 5.2 6.7 6.9 6.1· 5.7
23 5.2 6.7 6.8 6.1 5.7
24 4.9 6.5 6.5 5.9 5.5
25 5.0 6.4 6.2 5.9 5.5
26 4.9 6.4 5.6 5.5 5.1
27 4.9 6.3 5.8 5.6 5.2
28 5.2 6.2 6.4 5.7 5.3
29 5.0 6.2 6.0 5.7 5.3
30 . 4.5 6.0 5.8 5.6 5.2
12-1-81 4.3 6.1 5.8 5.4 5.0
2 4.2 6.0 5.5 5.0 4.6
3 3.9 5.9 5.5 4.9 4.4~
4· 3.4 5.9 5.5 4.7 4.2;
5 3.4 6.0 5.5 4.8 4.4;"
6 2.8 5.9 5.0 4.7 4.2 ~
7 2.5 5.5 4.6 4.4 3.9 ~
8 2.3 5.5 4.3 4.3 3.8P..
9 2.0 5.2 3.8 4.0 3.5 ~
10 1.9 5.2 3.3 3.7 3.2:;'
11 1.7 5.2 3.4 3.7 3.2 m
12 1.7 5.1 3.6 3.5 3.0
13 L1 5.0 3.1 3.2 2.7
14 1.0 5.0 3.3 3.2 2.7
15 1.8 5.1 3.9 3.3 2.8
16 1.7 5.1 4.2 3.3 2.8
17 1.8 5.2 4.6 2.7 2.1
18 2.4 5.1 5.3 3.5 3.0
19 2.7 5.0 5.0 4.1 3.6
20 2.6 5.1 4.6 4.1 3.6
21 2.2 4.9 4.5 3.7 3.2
22 2.1 4.8 4.5 3.9 3.4
23 1.8 4.8 4.5 3.8 3.3
24 1.8 4.5 4.5 3.8 3.3
25 1.9 4.6 4.5 3.7 3.2
26 1.8 4.6 4.2 3.6 3.1
27 1.8 4.5 3.9 3.4 2.9
28 1.7 4.4 3.0 3.4 2.9
29 1.7 4.2 2.3 3.3 2.8
30 1.6 4.1 1.8 3.1 2.6
31 1.6 4.0 2.0 2.8 2.2
1-1-82 1.6 3.9 1.9 2.5 1.9
2 1.6 3.8 1.7 2.3 1.7
3 1.6 3.6 1.7 2.0 1.4
167
BBL SGS UBL LBL MBC
Date Mean Mean ·Mean· · Mean· Mean
!.1-4-82 1.7 3.5 1.6 1.3 0.7
5 1.6 3.5 1.6 0.8 0.2
6 1.4 3.6 1.6 1.2 0.6
7 1.4 3.9 1.8 1.2 o. 6·
8 1.6 3.7 1.5 1.5 o. 9·
9 1.6 3.6 1.7 1.9 1.3:
10 1.8 3.8 3.0 1.7 1.1
11 1.8 3.9 3.2 2.1 1.5
12 1.8 3.7 3.2 2.3 1.7
13 1.8 3.7 2.6 2.1 1.5
14 1.8 3.7 3.3 2.5 11.9
15 1.8 3.4 2.5 2.5 1.9
16 1.7 3.3 2.9 2.3 1.7
17 1.8 3.3 2.9 2.1 1.5
18 1.7 3.1 2.0 2.2 1.6
19 1.6 3.2 1.6 2.1 1.5
20 :1.6 3.0 1.5 1.6 1.0
21 1.5 2.7 1.4 1.0 0.4
22 1.4 2.2 0.8 1.0 0.4
23 1.5 2.4 0.8 0.9 0.3~
24 1.4 2.6 0.8 1.0 0.4"'
25 1.3 2.8 0.9 1.1 0.5 g
26 1.5 2.6 0.8 1.0 0.4 ~
27 l.6 2.6 0.8 1.0 0.4 ~
28 1.7 2.7 1.2 1.1 0. 5 ii
29 1.5 2.7 1.3 1.1 0.5 ~
30 1.6 2.7 1.6 1.1 0.5 ~
31 1.6 2.7 1.5 1.1 0.5 ~
2-1-82 1.6 2.8 1.6 1.4 0.8
2 1.9 2.8 1.5 1.4 0.8
3 1.8 2.8 1.7 1.4 o.s
4 1.6 2.7 1.9 1.5 0.9
5 1.6 2.7 2.1 1.5 0.9
6 1.7 2.6 1.9 1.7 1.1
7 1.7 2.6 1.6 1.7 l.l
8 1.7 2.7 1.5 1.7 l.l
9 1.8 2.7 1.7 1.8 1.2
10 1.7 2.7 1.9 1.8 1.2
11 1.5 2.6 1.5 1.7 1.1
12 1.4 2.6 1.5 1.8 1.2
13 1.6 2.7 0.9 1.6 1.0
14 1.7 2.6 0.7 1.4 0.8
15 1.8 2.5 0.8 1.3 0.7
16 1.6 2.7 0.7 1.2 0.6
17 1.4 2.7 0.8 1.2 0.6
18 1.4 2.7 0.9 1.1 0.5
19 1.6 2.7 1.0 1.3 0.7
20 1.5 2.7 0.7 1.2 0.6
21 1.5 2.7 0.8 1.1 0.5
22 1.5 2.6 0.9 1.1 0.5
23 1.4 2.5 0.7 1.1 0.5
168
• BBL SGS UBL LBL MBC
Date ·Mean Mean Mean Mean Mean
2-24-82 1.4 2.4 0.6 0.8 0.2
25 1.4 2.3 0.6 0.8 0.2
26 1.4 2.4 0.6 0.8 0.2
27 1.4 2.4 0.6 0.8 o.i
28 1.3 2.4 0.6 0.7 o.i
3-1-82 1.3 2.5 0.6 0.9 0.3
2 1.4 2.5 0.7 0.8 0.2
3 1.5 2.6 0.7 0.9 0.3
4 1.4 2.5 0.7 1.0" 0.4
5 1.5 2.6 0.7 0.9 0.3
6 1.4 2.7 0.9 1.0 0.4
7 1.5 2.7 1.4 1.1 o.s
8 1.4 2.8 1.3 1.3 0.1
9 1.4 2.7 1.6 1.4 0.8
10 1.3 2.6 1.4 1.4 0.8
11 1.4 2.5 1.6 1.6 1.0
12 1.4 2.6 1.5 1.4 0.8
13 1.5 2.5 1.7 1.6 1.0
14 1.5 2.6 1.8 1.6 1.0
15 1.5 2.5 1.9 1.7 1.1~
16 1.6 2.5 1.8 1.8 1.2~
17 1.8 2.5 2.0 1.8 1.2;"
18 2.1 2.5 1.8 1.9 1.3 i!
19 2.0 2.6 2.4 1.9 1.3~
20 1.9 2.6 2.4 2.0 1.40.
21 1.8 2.7 2.2 1.9 1.3~
22 1.9 2.8 2.7 2.2 1.61:'
23 2.2 2.8 2.7 2.6 2.om
24 1.4 2.9 2.0 2.3 1.7
25 1.4 2.8 2.0 2.6 2.0
26 1.4 2.8 2.0 2.4 1.8
27 1.5 2.8 1.9 2.4 1.8
28 1.5 2.8 2.6 2.7 2.1
29 1.6 2.8 2.3 2.5 1.9
30 1.7 2.9 2.6 2.5 1.9
31 1.7 2.9 2.7 2.7 2.i
4-1-82 1.7 2.8 2.3 2.6 2.0
2 1.6 2.9 2.9 2.8 2.2
3 2.1 3.0 2.6 3.0 2.5
4 2.4 2.9 3.1 3.2 2.7
5 2.7 2.9 2~9 3.3 2.8
6 3.1 3.0 3.0 3.8 3.3
7 3.4 3.0 3.4 4.0 3.5
8 3.5 3.1 3.5 4.2 3.7
9 2.5 3.1 2.9 3.9 3.4
10 2.0 3.1 2.7 4.0 3.5
11 1.4 3.1 2.4 3.7 3.2
12 1.4 3.0 1.7 3.3 2.8
13 1.5 3.0 2.3 3.5 3.0
14 1.5 2.9 2.5 3.5 3.6
15 1.4 2.9 2.2 3.3 2.8
169
BBL SGS UBL LBL MBC
Date Mean Mean Mean Mean Mean
4-16-82 1.3 2.9 1.9 3.0 2.5
17 1.3 2.9 2.1 3.3 2.8
18 1.3 2.9 2.3 3.5 3.0
19 1.2 2.9 2.2 2.7 2.1
20 1.4 2.7 1.7 2.8 2.2
21 1.7 2.6 2.1 2.7 2.1
22 1..7 2.6 2.6 3.1 2.6
23 1.7 2.6 2.8 3.5 3.0
24 1.7 2.7 2.9 4.0 3.5
25 1.8 2.7 3.2 4.4 3.9
26 1.7 2.8 3 .• 0 4.2 3.1
27 1.6 2.9 2.6 4.2 3.1
28 1.7 2.9 2.7 4.5 4.0
29 1.7 2.8 2.8 4.4 3.9~
30 1.7 2.9 2.5 4.3 3. 8;;
5-1-82 1.7 2.9 2.8 4.5 4.0;
2 1.8 3.0 3.0 4.8 4.4 ~
3 1.8 2.9 3.5 5.4 5.0 ~
4 1.8 3.0 3.4 5.5 5.1 0.
5 1.8 3.1 3.3 5.5 5.1 ~
6 1.8 3.2 2.9 5.3 4.9 ~
7 1.8 3.2 3.2 5.6 5. 2IX
8 1.8 3.1 3.4 5.7 5.3
9 1.8 3.1 3.7 5.7 5.3
10 1.8 3.2 3.4 5.7 5.3
11 1.7 3.3 3.3 6.1 5.1
12 1.8 3.3 3.4 5.7 5.3
13 1.7 3.3 3.4 5.6 5.2
14 1.8 3.4 3.8 6.3 5.9
15 1.9 3.4 4.2 7.5 7.2
16 1.8 3.4 3.9 8.4 8.1
17 1.8 3.5 3.9 7.9 7.6
18 1.8 3.6 3.8 7.1 6.8
19 1.8 3.6 3.7 6.1 5.7
20 1.8
21 1.8
22 1.8
23 1.8
170
TABLE A3: Cumulative Temperature Data (1981-82) • .
Date BBL SGS UBL LBL MBC
9-1-81 12.8 11.3 11.4 14.4 13.6
5 63.1 55.2 55.5 69.7 66.6
10 123.5 113.6 112.6 131.6 127.1
15 178.5 169.2 165.7 188.2 183.0
20 231.8 223.3 218.9 245.8 239.7
25 282.9 274.7 268.2 303.8 293.1
30 330.2 323.1 313.8 357.3 340.8
~0-1-81 339.2 332.4 322.3 366.9 349.7
5 373.5 367.8 355.0 402.6 382.2
10 413.1 409.2 393.1 445.1 420.6
15 453.1 449.5 432.4 488.3 461.2
20 492.3 490.4 472.4 529.4 501.0
25 533.8 530.8 514.6 573.0 543.4
30 571.2 569.8 554.0 614.4 583.3
U-4-81 604.0 605.3 590.2 649.6 616.9
9 635.9 641.7 626.7 685.2 650.8
14 666.4 678.5 664.2 721.8 685.9
19 692.6 712.5 696.6 753.3 715.4
24 718.4 745.8 730.1 783.6 743.7
29 743.4 777.3 760.1 812.0 770.1
12-4-81 763.7 807.2 788.2 837.6 793.5
9 776.7 835.3 811.4 859.8 813.5
14 784.1 860.8 828.1 877.1 828.3
19 794.5 886.3 851.1 894.0 842.6
24 805.0 910.4 873.7 913.3 859.4
29 813.9 932.7 891.6 930.7 874.3
1-3-82 821.9 952.1 900.7 943.4 884.1
8 829.6 970.3 908.8 949.4 887.1
13 838.4 989.0 922.5 959.5 894.2
18 847.2 1,005.8 936.1 971.1 902.8
23 854.8 1,019.3 942.2 977.7 906.4
28 862.3 1,032.6 946.7 982.1 908.6
2-2-82 870.5 1,046.3 954.2 988.2 911.7
7 878.9 1,059.7 964.4 997.0 916.5
12 887.0 1,073.1 972.5 1,005.8 922.3
17 895.1 1,086.3 976.4 1,012.5 926.0
22 902.6 1,099.7 980.7 1,018.3 928.8
27 909.6 1.111. 7 983.8 1.022.6 930.1
3-4-82 916.5 1,124.2 987.3 1,026.9 931.4
9 923.8 1,137.7 993.2 1,032.6
14 930.9 1,150.5 1,002.2 1,040.2 938.7
19 939.9 1,163.1 1,012.1 1,049.3
24 949.1 1,176.9 1,024.1 1,060.3
29 956.5 1.190.0 1.034.9 1.072.9 962.4
171
Date BBL SGS UBL LBL MBC
4-4-82 967.7 1,208.3 1,051.1 1,,089. 7
9 982.9 1,223.4 1,066.8 1,108.9 992.5
14 990.7 1,238.5 1,078.4 1,126.9
19 997.2 1,253.0 1,089.1 1,142.7
24 1,005.4 1,266.2 1,101.2 1,158.8 1,034.6
30 1.015.6 1.283.2 1.118.0 1.884.8 1.057.6
1 mile at 1:12,000 photo
(2788 squares/mi2)
Scale: 1" = 1000 ft
Deepest point in Black Lake is
approximately -40 ft from
soundings. Shoal areas are
shaded in drawing. Average
depth is estimated at 25 ft.
FIGURE A -1: Black Lake surface area, and general depth conditions.
1-'
"'-1
N
300
200
100
173
50 100
This line indicates the flow
relation if respective
drainages were yielding in
proportion to watershed area,
i.e., Black Lake drains
2.20 x's area drained by
Black Bear Creek below
Black Bear Lake.
150
cfs -Black Bear Creek below Black Bear Lake
FIGURE A2: A General Comparison of Streamflow in Black Bear Creek below
Black Bear Lake and Outflow from Black Lake. This relation
is based upon limited information.
l
I
I I Q) I. ..l<:
Cl!
...:I
..l<:
C)
Cl!
.--!
f'Q
.j.J
Q)
.--!
.j.J
;::l
0
Cll
4-l
C)
i I
300
200
100
174
G
50
This line indicates the flow relation
·if respective drainages were yielding
in proportion to watershed area, i.e.,
Black Lake drains 3.34 x's area drained
by fiouth Fork.
100 150
cfs -South Fork, above Black Lake
FIGURE A3: A General Comparison of Streamflow from South Fork and Outflow
from Black Lake. This relation is based upon limited information.
CONOUCT'.
12 f!I?M. Oz..
OlSSOLV
OXYGEN
WATER
1':\::--0---<!>--
;-· ,'~ ·-· 1:!>--~
....... --G····· .. -· a:r •• ··-a ···~·-·----Gt '/ '-· C!t ··--· az ·····-GJ··-·-· til-···-·~JJ
. /
--0---G---G>----~.,. .. Gl
----·----·----·"tt:==================~
f
• '• :::: 8·2c -fo
0---Q = '-23-Bo
El-.... ·-GJ -:. 1o -2!' -go
UPPER BLACK BEAR LAKE
----~ ~---~ ... --0----. .......
4o.--.6 '"t:)
. ·--. :J-~-~ \
·-----.-!"~ \ -. . -----~ ....... ·~ \
•., \ ' \ \ \ . '· ~ ··-..,. ...... 61-·--G--&J-... ~~ ,... ____ .. ___ __,
·-~~
FIG~E A -4:
•z.c-Pl:.
DEPTH
... ~---~~ ...:,., ....... ~--~ -~-=-----· -·· ""' ---<:::>
-8o.f.i:.
Profiles of Conductivity, Dissolved 02, and
Temperature in Upper Black Bear Lake
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FIGURE A -5: Profiles of Conductivity, Dissolved Oxygen and Tempera~ure
in Upper Black Bear Lake
177
FIGURE A -6a
CALCULATIONS OF CHANNEL ROUGHNESS (MANNINGS "n") FOR TWO MEASURED REACHES
Method
See U.S.G.S. WSP 1849, Roughness Characteristics of Natural Channels.
As applied to two-section, confining reaches:
n 1.486
Q
(h + hv)l -(h + hv)2
Ll"2
zlz2
where, h = elevation of water surface at respective sections above a
h = v
L1.2 =
zlz2 =
connnon datum;
2 velocity head at the respective sections = a V /29
channel length between the two sections
AR 2 /3 for sections 1, 2 respectively.
---------·-------------·-
SPRING FORK
0 1 2 4 9 1 5 ft
average velocity = .632 fps
1
(1) at "sec. 8"
2 ft-~-1,8 1? )0 2} 2,2 2,3 ~ 2,7 ~ 3~ ft
ft -Area= 411 sq's = 25.69
Perimeter = 30.0 ft
Hydraulic radius = .8563 ft
25 24 23 22 21
(2) 75 ft below
"section 8"
2 Area = 150 sq's = 9.375 ft
Perimeter = 15.3 ft
Hydraulic radius = .6127 ft
Calculation of Manning's roughness "n"
n = 1. ~86 v_c.h-hv) 1 -(h-hv) 2
1 1'2
zl z2
__ 1.486, I 1.2447
n -16.57 \1 75
156.""665
= 0.1446
l I
~ '------,-
Distance between sections = 75 ft.
Averaged elevation, water surface section (1)
is 1.289 ft higher than averaged elevations
for water surface, section (2).
(h + hv)l = 1.289 + (.632)2/(8.02)2 = 1.2952 ft
(h + hv)2
11.2 =75ft
FIGURE A -6b
0 + (1.802)2 /(8.02)2 = .0505
difference = 1.2447 ft
z1 = (25.69)(.8563)2 /3 = 23.1657
z2 = (9.375)(.6127)2 /3 = 6.7628
z1 z2 = 156.665
..... .......
00
w;;:;a;~;:J!Mllii-··L·MR!.th~"}.;!%?-t,;;,1!•,""·J~:'!:. -.: .• :, .. ,_· •. ,.iP·ti'Bf'b .. ~wm !111144i--"'tct·.;:,rl'.~;:~;r~m:..~,, .... _________________________ ..,. .. ..,.....,..,...,_..,..,....., _____ ...,,.. ______ ..,. ____ ..
1
' ·'
LAKE FORK
3 ft 4
(1) at "x-sec A"
-1ft
- 2 ft
(2) 68 ft downstream
from section (1)
5 6 7 8
average velocity = 1.297 fps
2 Area= 260 sq's = 16.25 ft
Perimeter = 20.25 ft
Hydraulic radius = .80 ft
14
-2ft 2 Area= 164 sq's = 10.25 ft
Perimeter = 15.5 ft
Hydraulic radius = .67 ft
4
NOTE: Checked elimination
of indicated section.
Result showed only
small change in "n".
ft
Distance between sections = 68 ft
Averaged elevations, water surface, section (1)
is 1.00 ft. higher than averaged elevations of
water surface, section (2).
1-' .......
1.0
Calculation of Manning's ~roughness,_ "n"
n = 1. ~86 { (h + h) 1 -(h + hv) 2
L1•2
(h + hv)l = 1 + (1.297)2 /(8.02)2 = 1.0262
(h + hv)2 = 0 + (2.136)2/(8.02)2 = 0.0709
difference= .9553
L1 •2 = 68 ft
z 1 =(16~25)(~8)2 /3=i4.00~
Z2= (10. 25) (. 67) Z/3=7. 8482
z1 z2=109.9038
zlz2
n =2i::~~5v=·~f53-
10g:-9038
= 0.0859
I I
L ,---
FIGURE A-6c
180
CITATIONS
Carlander, K.D., 1969, Handbook of Freshwater Fishery Biology. Vol. 1,
Iowa State University.
Chapman, D.G., 1951. Some properties of the hyperzeometric distribution with
applications to zoological sample censuses. Univ. Calif. Publ. Stat.l, 131-160.
Chapman, D.W., 1962. Agressive behaviour in juvenile coho salmon as a cause
of emigration. J.Fish. Res. Bd. Can. 19 (6) 1047 -1080.
Haddix, M., 1981. 1980 Hugh Smith Lake sockeye salmon smelt and fry studies.
Southern Southeast Lake fertilization project progress report. FRED Division,
A.D.F.G.
Hansen, J.M. W.C. Leggett, 1982.
uield. Can. J. Fish Aquat. Sci. 39
Empirical prediction of fish biomass and
257 -263.
Hansen, Steven, 1982. A.D.F.G. Klawock Fish Hatchery. Personal communication.
Hay, K.G., 1958. Beaver census methods in the Rocky Mountain Region. J. Wildl.
Manage. 22 395 -402.
Rounsefell, G.A., 1958.
River, Alaska.Ibid. 58
Factors causing decline in sockeye salmon of Karluk
83-169 (Fish BulL no. 130.
Ryder, R.A., 1965. A method for estimating the potential fish production
of north-temperate lakes. Trans. Am. Fish. Soc. 94 214 & 218.
Schumacher, F.X. & R.W. Eschmeyer, 1943.
lake or ponds. J. Tenn. Acad. Sci. 18
The estimate of fish population in
228 -249.
~traty, R.R., 1960. Methods of enumerating salmon in Alaska. Trans 25" North.
Am. Wildl. Conf. 286 -297.
Streveler, G.P. and L.A. Smith, 1980. In Lituya Bay Environmental Survey.
National Park Service, Juneau. 350 p.p.
Ward, Mike, 1982. A.D.F.&G. Ketchikan. Personal communication.
Wood, R. 1982. A.D.F.&G. Ketchikan.;' Retsonal communication.
BLACK
LAKE
)
J
~ ;.·/ / .. ...
d. . .
OUT MIGRANT FRY TRAPPING ,
STATIO N , SPRING' 198«2 'L I ..
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I. I •
MA'ISH
I-
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, 'UPPER BLACK lAKE THERMOGRAPH
i
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-
MUSKEG
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f ' . • •
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0
l
SC ALE: I" = 50'
ELEVATIO N DATUM: 0.0' ON BLACK LAKE
GAUGE EQUALS AN ASSU MED ELEV. OF 100.0 '.
'
TERMINATION OF OBSERVED SALMON SPAWNING
MAIN CHANNEL FRC».i BLACK BEAR
LAKE. GRADENT BEGINS TO
MARKEDLY NCREASE. SUBSTRATE
R
~ BECOMES LARGE COBBLES·
-12.7 to 25.4 em .
s-~~.c.;;\ MODERATE WATER TEMPERATURES
~ ), J UPWELLINGS AT LOW FLOWS,
J :k\ THIS AREA FO RMS POOLS AT LOW
FLOWS WHICH ARE SUBJECT TO
/ ~ DRYI NG U:_. :"' i\! ,.. ·r-j·
/ ... !~.) ; ... ~ r.:. . .,; . ,J _ .... . . . . . . . . . . . . . . .. . ... . . . .....
-·· ....... -l : 1 :, .
I \ • • •
I • .J : "( l,
··---' I : !. .. :._.: ...
LEGEND :
SHORELINE
BEAVER DA M
ELEVATION
CROSS SECTION
f
MOSS COVERED STONES
UPWELLINGS
UNDERCUT BANKS
LOG IN STREAM
AERIAL LOG
OLD GROWTH
HE MLOCK a SPRUCE
ALDER
~ -
FORK SOUFRCE
.... .J:9. .. f.~.I, . .L$ .BEI,.Q.W ... :·:.
BLACK BEAR L AKE · · .
RIPARIAN VEGATATION MAOC
UP PRNCFAUY Of DEVILS
CLUB, SALMON3ERRY,
OEERBERRY, REO ELDER a
HIGH BUSH CR AN BERRY
SEDGES, HELLEBORE a
GRASSES
SPAWNNG GRAVEL a
COBa.E WITH
PREDOMNATE SIZE
SUBSTRATE OF SAND &
SILT WITI1 SO ME
DETR ITUS
. ...__,.
~
3-8 em
li
•
MUSKEG
RIFFLES-SHALLOW WATER
WITH TURBULENCE AND
BROKEN SURFACE
GLIDES-NORMALLY
MODERATELY SHALLOW
WITH EVEN FLOW
POOLS
FLATS-DEEPER, SlOW
FLOWING WATER,
NORMALLY OVER A SAND
AND SILT Sl.BSTRATE
PRINCIPAL LPCATIONS Of
SPAWNING PINK SALMON
SPAWNING SOCKEYE SALMON
SPAWNING CHU M SALMON
SPAWNtlG COHO SALMON
RESIDENT REARING
SALMONIDS, PRINCIPALLY
COHO
PRINCIPAL HABITAT ZONES
R
G
p
F
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VICINITY
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T 72 :.
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MA P
F IS H USE AND HAB I TAT OF BL ACK BEAR
CREEK AB OVE BLACK LAKE
FOR: ENVIR ONAID
CONSTRUCTION ENG INEE RING SERVICES
DATE:
Tv ly /feZ SHEET I of I
3~70 "1 £..1 0