HomeMy WebLinkAboutG8_Elfin Cove Hydro-Fisheries Survey Report FINAL 7-30-13
Technical Report No. 13-08
_________________________________________________________________________________________
A Fisheries Survey of Crooked and Jim’s Creeks and Jim’s Lake on Chichagof Island
near Elfin Cove, Alaska
by
Bruce M Barrett
July 2013
______________________________________________________________________
Alaska Biological Consulting
PO Box 322
Lakeside, MT 59922-0322
Tel: 406-844-3453
E-mail: alaskabiol@yahoo.com
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INTRODUCTION
In June 2009, Polarconsult Alaska, Inc. was authorized by the Non-Profit Community of Elfin Cove to
complete a reconnaissance and feasibility analysis of potential hydropower resources for Elfin Cove. The
study, completed in 2011, identified Crooked Creek and Jim’s Lake and Roy’s Creek as potentially suitable
project sites (Polarconsult 2011). The community has since chosen Crooked and Jim’s creeks and in
accordance has employed Polarconsult to conduct further analyses and design work in addition to permitting
the project which necessitates cataloging the environmental resources that may be impacted.
The hydropower development being considered would entail diverting up to 5 cfs of flow from Crooked
Creek at approximately mile 0.55 (Figure 1) into Jim's Lake, and developing a hydropower project between
Jim's Lake and Little Sandy Beach, utilizing Jim's Lake as a storage reservoir and an access and power line
corridor to Elfin Cove.
The purpose of this report is to define the fisheries resources that occur within the project area which
includes Jim’s Lake and Jim’s and Crooked creeks located on the west side of Chichagof Island about two
miles south of Elfin Cove (Figure 1). Also addressed is the fisheries impact that can be expected with stream
flow and diversion and lake level and volume changes from the proposed hydroelectric project.
OBJECTIVES
1. Determine fish distribution and relative abundance by species in Jim’s Lake and Crooked and Jim’s
creeks by species.
2. Determine average fish size by species in the study area.
3. Describe the general habitat characteristics of Jim’s Lake, and Crooked and Jim’s creeks.
4. Define the expected impact to area fisheries resources should the proposed hydro project be built ,
and recommend mitigation options to the extent necessary to ensure no net loss of area fisheries
production/resources.
METHODS
The study area was Jim’s Lake and Jim’s and Crooked creeks (Figure 1). Jim’s Creek in its entirety was
sampled along with Jim’s Lake, while Crooked Creek was sampled from intertidal to a gauging station located
0.55 miles upstream.
Four standard minnow traps were fished in Jim’s Lake, five in Jim’s Creek, and seven in Crooked Creek (Figure
2). Soak time ranged from 15 to 25 hrs. For Jim’s Lake, the average was 19 hrs., Jim’s Creek 21 hrs., and
Crooked Creek 20 hrs. The traps were baited with disinfected sockeye salmon (Oncorhynchus nerka) roe
treated by a 10-m soak time in 1/100 Betadyne. One cut section of roe (20-25 g) wrapped in cheesecloth
was used in each trap. In streams the traps were fished in pools with the axis parallel to the current, and
each trap was anchored by one or two cobbles placed inside the trap. At Jim’s Lake each minnow trap was
weighted by a single cobble and fished off shore at an average 5 ft. depth. All traps were securely tied to
substrate by line and the line marked with survey tape to prevent loss.
Additionally at Jim’s Lake, two seine hauls were made using a hand seine measuring 20 ft. x 4 ft. with ¼ mesh
web. The sets were made off the western end of the lake with each haul covering about 800 square feet of
surface area. At Jim’s Lake a gill net was also deployed and fished for 5 ¼ hrs. nearly midway off the lake’s
west side. The net was set perpendicular from the shore to beyond the lake’s midpoint and anchored in 20+
ft. of water (Figure 3). The gill net measured 100 ft. by 8 ft., and mesh size was 1 inch.
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Originally, hand seining was also intended for Jim’s and Crooked creeks, however the relatively narrow width
and shallowness of the streams coupled with small pool sizes and in-stream materials (logs) precluded
effective seining.
All fish sampling efforts in the two streams and the lake using minnow traps, seine gear, and a gill net were
authorized by Fish Resource Permit # SF 2013-231 as issued by the Alaska Department of Fish and Game
(ADFG).
Hook and line sampling was also conducted at Jim’s Lake. Slightly more than one hour was fished using
spinning gear and small lures (Mepps # 1’s and 2’s) and effected under ADF&G SF license 3770183 2013
AAO1.
All stream and lake minnow trap sites and the lake gillnetting location were identified by GPS, and
photographs were taken of representative fishing gear locations and catch.
Pursuant to the terms of the ADFG fish sampling permit, 8 hrs. of minnow trapping coupled with one hour of
hook and line sampling were required prior to the use of the gill net in Jim’s Lake. Further encumbering was
the provision that the gill net could not be used if the other gear produced any game fish other than Dolly
Varden (Salvelinus malma) or cutthroat trout (Salmo clarki clarki). These terms were met along with the
restriction that the net be constantly monitored to minimize incidental fish, bird, and mammal mortalities
and not soaked for more than 12 hrs.
All fish captured were identified by species in accordance with Pacific Fishes of Canada (1973), measured (tip-
of-snout to fork-of-tail, mm), and released alive. The exception was that the largest fish captured was
necropsied for sexual maturity.
Opportunistically throughout the course of the field work, visual inspections were conducted in the study
waters for fish presence with special attention given to stream slack water areas and pools and to lake
shallow areas.
RESULTS
The fish sampling findings are presented in Tables 1-4. Photographs not referenced in text of Jim’s Lake and
several of the minnow trapping locations in Crooked and Jim’s creeks and of the fish migration barrier 50 yds.
above MHHW on Jim’s Creek are provided in Appendices A-1 through A-7.
At Jim’s Lake, gillnetting, hook and line, seining, and minnow trapping efforts produced no fish (Table 1,
Figure 2). The same was the finding in visual monitoring of the lake’s shallows and of fish potentially rising
and/or jumping at the lake’s surface.
In Jim’s Creek which was minnow trapped from the intertidal to within about 100 yd. of the lake outlet with
five traps, no fish were caught nor were any visually observed during the four days of study (Table 2, Figure
2). In the lower stream reach immediately above the intertidal, there were but two pools both relatively
small averaging each about 8 inches deep. The first pool was about 30 yds. above the intertidal zone, while
the second was another 20 yds. upstream. At the head of the second pool which was about 50 yds.
upstream of MHHW a series of 3-4 ft. high waterfalls and a stream slope of about 30-35% began posing a
formable barrier to upstream fish passage.
At Crooked Creek, Dolly Varden (DV) were caught at two locations in the stream’s lower reach within 150
yds. of the intertidal zone. In the lower reach three relatively small pools were considered suitable for
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minnow trap deployment. The first and the third were fished, and a total of 8 DV were captured, three in the
pool closest to tidewater and five upstream in a pool at the base of an 8 ft. high waterfall and the beginning
of a fish impassible gorge with about a 40% slope and a series of nearly continuous waterfalls. The DV
caught in the upper trap averaged significantly larger than those taken in the lower trap. (t stat. 4.54, P
0.0019, df=6). In the former DV averaged 12.9 cm FL and in the latter 11.0 cm (Table 4). The largest DV
(13.7cm FL) in the second trap catch was a sexually mature male (Figure 6).
In the upper reach of Crooked Creek, above the gorge which started about 150 yds. above the intertidal
zone, five minnow traps were set (Figure 2). The first was deployed in the first fishable pool above the gorge
and the last at the gauging station approximately 0.3 miles upstream (Figure 2). None of the five traps
produced any catch (Table 3). Above the gorge no fish were seen in the pools and relatively slack water
areas examined.
From the gorge in Crooked Creek to about 60 yds. upstream of trap site C-6, the streambed gradient ranges
from 0.5 to 1% and the streambed is mostly cobble followed by gravel. In this reach the stream channel is
well shaded by canopy cover and blow down, and relatively heavily seeded with large woody in-stream
material (logs) (Table 3). Between trap sites C-6 and C-7, encompassing about a 500 ft. stream reach,
average gradient is approximately 30%. From below trap site C-6 to above C-7 Crooked Creek flows through
a rubble field formed from past mass-wasting events spawned from the cliffs to the immediate east, and the
stream bed varies from sands and gravels to house-sized boulders.
In the intertidal for both Jim’s Creek and Crooked Creek there were no areas found suitable for hand seining
or minnow trapping (Figures 7-8). In the intertidal areas of both, the beach had about 15 degree slope, and
the dominant substrates at Jim’s were cobble at 75% and boulders 25%, while at Crooked Creek boulders
were about 80% and cobble 20%. Gravel represented less than 1% at both. Average water depth was about
one inch on Jim’s Creek and 3-4 inches for Crooked Creek in the intertidal. Neither stream had a defined
channel as their flows tended to spread laterally across the intertidal through relatively loose materials
(cobbles and boulders). Both streams were moderately exposed to open ocean sea/weather conditions.
Although some locals from Elfin Cove refer to the area as “Little Sandy Beach,” no sand was visible during the
survey period (7/15-18/2013). There was no recognizable fin fish habitat found within the intertidal of Jim’s
Creek or Crooked Creek.
DISCUSSION
Jim’s Lake and Jim’s Creek were found to be void of all fish life based on the assessment methods employed
from July 15-18, 2013. Likewise Crooked Creek was determined to support no fish with exception of the
stream’s lower reach immediately above MHHW, in the first 150 yds.
The relatively small number of DV found to occupy lower Crooked Creek were likely non-anadromous,
resident fish based on the lengths of the eight caught and the finding that one was sexually mature at 13.7
cm (5.4 inches). This aligns with the finding of Hart (1973) that anadromous DV maturation occurs in the
ocean and return migrations take place in the fall after spending 2 or more years at sea.
Given the limited habitat in the lower reach of Crooked Creek and general trap effectiveness, it is probable
that not many more DV occupied the 150 yd. reach from intertidal to the gorge than the eight taken in the
combined 38.2 trap hrs. fished. Further, given the fish length differences measured between the two trap
catches, it would appear that segregation may be occurring with the smallest DV occupying the lower pool
and the largest the upper pool at the start of a fish-impassable gorge (Figure 9). This could be indicative of
poor recruitment success and limited rearing and/or spawning habitat.
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While not occupied by fish, Jim’s Creek would likely support small resident DV if access were not limited just
above intertidal by a 100 ft. steep reach of stream channel containing a series of waterfalls and about a 40%
grade. In Jim’s Creek’s upper reach, the several minnow trap sites fished had relatively low gradient (<1%),
good cover, stability, and insect life for feed. Jim’s Lake which has 20+ ft. depths, macro aquatic vegetation
(lily pads), and supports terrestrial and aquatic insect life offers fisheries habitat, but it too is not colonized by
fish as determined from the July 15-16, 2013 sampling efforts there. Although also found not to be occupied
by any fish life, the upper reach of Crooked Creek above the gorge which begins just above intertidal appears
to be better fisheries habitat than upper Jim’s Creek due to lower gradient and greater stream length and
width as well as ample cover, spawning gravel, and macro invertebrate production.
From the observation of the intertidal areas of Crooked and Jim’s creeks coupled with their lower reaches it
is apparent that neither offer habitat for salmon or other anadromous fish. This aligns with ADFG’s omission
of both streams from their Catalog of Waters important for Spawning, Rearing, and Migration of
Anadromous Fishes (2012).
Relative to the proposed hydro project, calling for diversion of Crooked Creek through a pipeline into Jim’s
Lake and a penstock from Jim’s Lake to a powerhouse sited within a 100 yds. of Little Sandy Beach, little to no
adverse impact to area fisheries can be expected. The few DV that occupy Crooked Creek just above the
intertidal zone should not be displaced. This is because stream flow, albeit reduced, will be maintained by a
lateral right-side tributary entering Crooked Creek approximately ¼ mile below the proposed diversion
structure to Jim’s Lake and by main stem watershed contribution below the proposed hydro diversion site
(Figure 10). The tributary should maintain about 11% of the current main stem flow in Crooked Creek (Joel
Groves P.E., pers.com., 7/7/13). This coupled with flow off the 65 acres of watershed downstream of the
diversion point, adding an estimated 13%, should ensure that about 24% of the current flow regime is
maintained. Some benefit may be derived from reduced flows if it lessens flood damages to fish spawning
habitat and permits more accumulation of stream bed gravels for spawning area where currently bedrock,
boulders, and large cobble only show. Expectedly, the power house discharge will offer some fisheries
habitat at least sufficient to compensate for any losses that may occur in lower Crooked Creek due to flow
reduction.
LITERATURE CITED
Alaska Department of Fish and Game. 2008, updated 2012. Catalog of waters important for spawning,
rearing, and migration of anadromous fishes, ADF&G, Sport Fish Div., Juneau, AK.
Hart, J.L. 1973. Pacific Fishes of Canada. Bull. 180; Fish. Res. Bd. Canada.
Polarconsult Alaska, Inc. 2011. Crooked Creek and Jim’s Lake Hydroelectric Feasibility Study Final Report.
Polarconsult Alaska, Inc. Anchorage, AK.
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Table 1. Fish catch by gear type and location at Jim's Lake near Elfin Cove, AK, July 15-16, 2013.
Method LOCATION DATE TIME CATCH (fish #'s)MISC. NOTES
Dolly Varden other
Minnow N 58° 10.585 7/15/2013 1604 hrs.Trap set 20 ft. offshore at 3 ft. depth.
Trap W 136° 19.561 Air: 68 F; water 62 F; lilly pads in western end of lake.
L-1 7/16/2013 1124 hrs.0 0 1- one inch water beetle in trap
Minnow N 58° 10.582 7/15/2013 1635 hrs.Trap set 15 yds. offshore at 6 ft. depth.
Trap W 136° 19.522 West wind: <5mph; light overcast
L-2 7/16/2013 1158 hrs.0 0 South shore set; I dragon fly larvae in trap
Minnow N 58° 10.558 7/15/2013 1725 hrs.Trap set 3yds. offshore at 8 ft. depth.
Trap W 136° 19.517 Air 64 F, water 62 F; steep drop-off from shore.
L-3 7/16/2013 1235 hrs.0 0 Southside shore set; insect hatch moderate
Minnow N 58° 10.499 7/15/2013 1747 hrs.Trap set 3yds. offshore at 3 ft. depth.
Trap W 136° 19.486 Site approx. 150yds from east end of lake off south shore.
L-4 7/16/2013 1310 hrs.0 0 Dense shoreline growth: alder, cedar & spruce trees, and blue berry bushes
Hook & Line L-1 thru L-3 7/15/2013 1615 hrs.South shore spin casting using #1 and #2 Mepps spinners, silver & gold
Trap sites 1720 hrs.Casts were 45+ yds.; 2/3 south shoreline fished.
Hand Seine Trap L-2 to 7/16/2013 1130 hrs.-Seine 25 ft. X 4 ft., 1/4" mesh
lake's west end 1147hrs.0 0 2 hauls made; no catch other than 1 water beetle
beyond L-1
Gill Net N 58° 10.558 7/16/2013 1235 hrs.-Net set off minnow trap site L-3; extending perpendicular to shoreline
W 136° 19.517 1750 hrs.0 0 Net extended beyond 1/2 lake width; offshore end at 20+ ft. lake depth
No waterfowl or water-use mammals observed
Gill net: 100ft X 8 ft. 1 inch mesh; total time fished: 5 h 10 min.
Lakeshore veg.: cedar, alder, willow, blue berry & spruce
Table 2. Fish catch by species with a standard minnow trap by location in Jim's Creek near Elfin Cove, AK, July 16-18, 2013.
TRAP LOCATION DATE TIME CATCH ( fish #'s)NOTES
#Dolly Varden OTHER
J-1 N 58° 10.637 7/17/2013 1540 hrs.Air: 61F; water 55F; elev. 20 ft. above MHHW;1st fishable pool above MHHW;
W 136° 20.025 35-40% gravel; fractured bed rock & boulders (60%); 3-4 ft. high series of
7/18/2013 0950 hrs.0 0 waterfalls; pool 30 yds. above MHHW.
J-2 N 58° 10.577 7/17/2013 1505 hrs.Avg. pool depth 16"; stream width 4.5 ft.; stream under cut bank; pool
W 136 19.880 7/18/2013 0955 hrs.0 0 immediately below 5 ft. waterfall; pool 3.5 x 5 ft.
J-3 N 58 10.586 7/17/2013 1445 hrs.1/2% grade; gravel bed.
W 136° 19.771 7/18/2013 1005 hrs.0 0
J-4 N 58° 10.574 7/16/2013 1435 hrs.Stream width 4 ft. avg.; slope approx. 15%; macro-invertebrates <1/2
W 135° 19.685 7/17/2013 1415 hrs.0 0 per cobble(n=10); 60% angular gravel (1") & 40% cobble (angular)
J-5 N 58° 10.562 7/16/2013 1308 hrs.Stream width 4 ft. avg.; pool depth max. 16"; 10% grade downstream
W 136° 19.610 Bed sharp angular cobble and gravel at approx. 50% each;
7/17/2013 1402 hrs.0 0 20% grade above trap site& 10% below trap; air 58 F & water 61F.
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Table 3. Fish catch by species with a standard minnow trap by location in Crooked Creek near Elfin Cove, AK, July 15-18, 2013.
TRAP LOCATION DATE TIME CATCH ( fish #'s)MISC. NOTES
#Dolly Varden OTHER
C-1 N 58° 10.719 7/15/2013 1906 hrs.1st pool immediately above intertidal; at base of several waterfalls
W 136° 20.143 approx. 8ft. above MHHW; trap depth 18"; 20% slope upstream;
7/16/2013 0955 hrs.3 0 air 62F & water 44.5F (7/16/2013).
C-2 N 58° 10.733 7/16/2013 1024 hrs.Approx. 2.25 macro. Invertebrates on 5-6" cobbles (n=20); boulders
W 136° 19.989 and bed rock dominate bed composition; no gravel; 20% slope
downstream; approx. 150 yds. above MHHW; 3ft avg. pool depth; pool
at base of 8ft. high waterfall w/ waterfalls continuing upstream thru gorge;
7/17/2013 0950 hrs.5 0 slope upstream approx. 40%; largest DV (5.4" FL) sexually mature male.
C-3 N 58° 10.780 7/17/2013 1040 hrs.2nd pool immediately above gorge; approx. 25yds from top of gorge;
W 136° 19.820 slight 2-3% slope; stream width avg. 6ft. ; 85% cobble, 10% boulder, 5%
7/18/2013 1110 hrs.0 0 gravel; air 52F & water 44.5F (7/17/2013)
C-4 N 58° 10.784 7/17/2013 1111 hrs.bed: 35% cobble, 65% gravel; 16" avg. pool depth; pool 20 ft. X 12 ft. Stream
W 136° 19.788 7/18/2013 1104 hrs.0 0 slope 1/2%; pool shaded by fallen timber; approx. 50 yds. above site C-3.
C-5 N 58° 10.792 7/16/2013 1711 hrs.1% stream grade; riffle below pool 85% cobble & 15% gravel; pool 18'x 5'.
W 136° 19.652 7/17/2013 1135 hrs.0 0 80% canopy cover; pool depth avg. 18"; under-cut stream bank
C-6 N 58° 10.759 7/16/2013 1647 hrs.1% stream grade; pool 6 x4 ft.;13" avg. pool depth; 85% cobble & 15% gravel.
W 136° 19.519 7/17/2013 1252 hrs.0 0 stream width 5 ft.
C-7 N 58° 10.741 7/16/2013 1602 hrs.Trap at gauging station; streambed: 50% cobble, 50% gravel; 1/2% slope.
W 136° 19.323 7/17/2013 1235 hrs. 0 0 Air: 58 F, water 47 F (7/16/13).
Table 4. Fork lenghts (mm) of Dolly Varden sampled
by minnow trap # and catch date in Crooked
Creek near Elfin Cove.
Trap # C-1 Trap # C-2
Specimen 7/16/2013 7/17/2013
#
1 109 122
2 107 130
3 114 119
4 135
5 137
Mean 110 124
Median 109 130
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Figure 1. Aerial map showing the location of Jim’s Lake, and Crooked and Jim’s creeks, and other features
relative to the community of Elfin Cove, Alaska. (Map courtesy of Polarconsult Alaska, Inc.)
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Figure 2. Aerial map identifying the approximate minnow trapping locations at Jim’s Lake, Jim’s Creek, and
Crooked Creek. (Map courtesy of Polarconsult Alaska, Inc.)
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Figure 3. Gill net deployed in Jim’s Lake on the west side at the trap site L-3, July 16, 2013.
Figure 4. One of three Dolly Varden caught by minnow trap at Crooked Creek site C-1 just above MHHW.
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Figure 5. Dolly Varden catch at Crooked Creek trap site # C-2 showing the five fish captured. The white
material in the minnow trap is the salmon roe wrapped in cheese cloth.
Figure 6. Sexually mature male Dolly Varden (13.7 cm FL) from Crooked Creek trap site # C-2
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Figure 7. Jim’s Creek in the upper and mid intertidal area with the stream shallowness, and the
preponderance of cobble and boulders, July 15, 2013.
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Figure 8. Crooked Creek from mid to lower intertidal showing the preponderance of boulders and
cobble in the streambed, July 15, 2013.
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Figure 9. The falls in the background is the beginning of a fish-impassable gorge on Crooked Creek
which starts about 150 yards above MHHW. The pool in the foreground is trap site C-2
that produced a five Dolly Varden catch, July 16-17, 2013.
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.
Figure 10. Tributary of Crooked Creek located between trap sites C-4 and C-5 on the north side, July 18,
2013.
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APPENDIX A
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Appendix A-1. Northern end of Jim’s Lake from the lake’s west side where two seine hauls were conducted
on July 16, and minnow trapping occurred at site L-1, July 15-16, 2013.
Appendix A-2. Jim’s Lake looking southeast toward trap site L-2, July 15, 2013.
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Appendix A-3. Jim’s Creek looking dowstream from trap site J-5, 7/16/2013.
Appendix A-4. Jim’s Creek looking down stream at trap site J-4, July 16, 2013.
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Appendix A-5. Crooked Creek at gauging station and trap site site C-5. Trap is dark cylinder object mid-
frame, July 16, 2013.
Appendix A-6. Jim’s Creek at trap site J-2 looking downstream, July 17, 2013.
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Appendix A-7. Jim’s Creek in lower reach about 50 yds. above MHHW; showing start of a series of 3-4 ft.
waterfalls, stream slope of 30-35% grade, and fish impasse.