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