cutthroat trout as successful urbanites · 2005. 10. 21. · bingham creek smolt production coho,...
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Cutthroat TroutAs Successful Urbanites
Dave Seiler, Laurie Peterson & John SerlWashington Department of Fish & Wildlife
Roger TaborUS Fish & Wildlife Service
Location of Trap Sites: Cedar River & Bear Creek
Coho adult
Coho fry
Big Beef Creek upstream/downstream migrant trap
Bingham Creek downstream migrant trap
Skagit River screw & scoop traps, near Mt Vernon
Cedar River Screw Trap
Big Bear Creek Screw Trap
Thornton Creek fence trap
Big Beef Creek Smolt ProductionCoho, Cutthroat & Steelhead 1978-2004
0
10,000
20,000
30,000
40,000
50,000
1978 1981 1984 1987 1990 1993 1996 1999 2002
Smolt Year (i+1)
Smol
t Pro
duct
ion
CohoCutthroatSteelhead
Bingham Creek Smolt ProductionCoho, Cutthroat & Steelhead 1982-2004
0
20,000
40,000
60,000
80,000
1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
Smolt Year (i+1)
Smol
t Pro
duct
ion
CohoCutthroatSteelhead
Flow Comparison of Two Lake Washington Tributaries
Mercer Creek & Rock Creek, 2005
0
20
40
60
80
100
120
140
160
180
Feb Mar Apr May Jun
Date
Flow
(cfs
)
Mercer Cr (46% TIA)Rock Cr (9% TIA)
Outmigrant Population Ratios forWestern Washington Streams & %TIA
1385Average
CutthroatSteelheadCohoNumberSpan
60132000-200251%Thornton Creek
10112000>15%Issaquah Creek
10761999-200415%Big Bear Creek
111561999-2004~5%Cedar River
Now
138131976-1978LowNorth Creek
128831976-1978LowLittle Bear Creek
Then
Lake Washington Tributaries
18833552000-2004~5%Green River
1327151990-2004<5%Skagit River
17265231982-2004<5%Bingham Creek
1236271978-20045%Big Beef Creek
RatiosTrapping Years%TIAStream
Average Density of Juvenile Cutthroat & Cohoin Six Lake Washington Streams
Summer 1993 & 2003
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
1993 2003
Sampling Year
Den
sity
(fis
h/m
2)
CutthroatCoho
Purse-Seining in Ballard Locks
In-River Survival of Hatchery Sockeye FryReleased at Landsburg Hatchery, Cedar River 1995
0%
25%
50%
75%
100%
0 500 1000 1500 2000 2500 3000 3500
Flow (cfs)
Surv
ival
Rat
e
Bear Creek Egg-to-Fry Survival & Migration Flow (Feb1 thru Mar31)
2000
1997
19992003
2002
1998
2001
1996Ice Storm
R2 = 63%
0%
5%
10%
15%
20%
25%
50 100 150 200
Average Flow (cfs)
Surv
ival
Gut Content Analysis of PredatorsBear Creek: March 14, 2001
17847Torrent Sculpin
2817910>150711211< 150
Cutthroat
49916Coho 1+
#Fresh fry/ Gut
Average Size (mm)
Number SampledSpecies
Cutthroat Trout
Rainbow trout
Cutthroat photo
Cutthroat Trout Captured in Lake Washington Coho Gillnet Fishery, October 2004
Cutthroat Trout Captured in Lake Washington Coho Gillnet Fishery, October 2004
Size range of fish above – 55-59cm FKL; two 4 yr. olds, one 3 yr. old
Size at Age of Cutthroat CapturedLake Washington Gillnet Fishery 2004
0
10
20
30
40
50
60
70
1+ 2+ 3+ 4+ 5+
Age
Len
gth
(mm
)
Average
Lake Washington Cutthroat SamplingGut-Content Analysis
Gut Contents of Large Cutthroat
Sok Keo with 14.9 lb cutthroat he caught in Lake Washington, August 2002