Movement of Movement of AdfluvialAdfluvial Bull Trout Bull Trout in Chester Morse Lakein Chester Morse Lake

Heidy Barnett and Dwayne Paige, Seattle Public Utilities

and

Eric Jeanes and Catherine Morello, R2 Resource Consultants

• Natural falls barrier downstream Chester Morse Lake blocks anadromous/migratory species

• CRMW managed under 50-year HCP (signed 2000)

•No commercial harvest, active restoration (forest, aquatic, roaddecommissioning)

Chester Morse Lake Fish CommunityChester Morse Lake Fish CommunityBull Trout Bull Trout –– located in deep parts of lake but located in deep parts of lake but also along shoreline also along shoreline

Rainbow Trout Rainbow Trout –– primarily located in littoral primarily located in littoral zone of lake and deltaszone of lake and deltas

Pygmy Whitefish Pygmy Whitefish –– food source for food source for adfluvialadfluvial bull bull trout, reside in deepest part of lake (bottom 2.5 trout, reside in deepest part of lake (bottom 2.5 meters)meters)

ShortheadShorthead SculpinSculpin –– food source for bull trout, food source for bull trout, distributed around shorelinedistributed around shoreline

Project ObjectivesProject Objectives

Determine year round horizontal and vertical Determine year round horizontal and vertical distribution of distribution of adfluvialadfluvial bull troutbull trout

Determine timing and other characteristics of individualDetermine timing and other characteristics of individualAge of fishAge of fishTiming of spawning Timing of spawning –– difference between males/femalesdifference between males/femalesGrowthGrowth

Investigate differences between horizontal and vertical Investigate differences between horizontal and vertical distribution of distribution of adfluvialadfluvial bull trout and rainbow troutbull trout and rainbow trout

Chester Morse Lake Chester Morse Lake -- Reservoir Reservoir Operational EffectsOperational Effects

Water levels vary 14Water levels vary 14--20 feet annually 20 feet annually Temperature profile changes Temperature profile changes Fish species behavior and ecologyFish species behavior and ecologyForage types Forage types –– productivity and availability of food productivity and availability of food resourcesresources

Acoustic Telemetry Acoustic Telemetry

}Pygmy Whitefish

VR2 Hydrophone – collects data in internal memory, runs constantly, low maintenance

Range of tags used in study

Bull trout and rainbow trout

Fish Capture and TaggingFish Capture and Tagging

PIT tagged at time of acoustic tag implant

Floy Tag

Scale samples taken to age fish

133 individual fish with acoustic tags!!38 BLT (17 depth, 6 temp), 61 RBT, 34 PWF

0

2

4

6

8

1 0

1 22 7

53 0

03 2

53 5

03 7

54 0

04 2

54 5

04 7

55 0

05 2

55 5

05 7

56 0

06 2

5

F o r k l e n g t h ( m m )

Num

ber

of b

ull t

rout

Chester Morse Lake - Water Elevation

1 5 4 0

1 5 4 5

1 5 5 0

1 5 5 5

1 5 6 0

1 5 6 5

1 1 /1 9 1 /8 2 /2 7 4 /1 8 6 /7 7 /2 7 9 /1 5 1 1 /4

Res

ervo

ir el

evat

ion

(feet

)

20062007

W in te r S p ring S um m er F a ll

1.0%0.8%

2.6%

7.7%

20.6%

21.3%11.4%

21.6%

12.9%

Horizontal Distribution of Bull Trout in 2007Horizontal Distribution of Bull Trout in 2007

Low use in west end of reservoir

High use in deep part of reservoir and deltas

0.5%0.1%

3.0%

6.3%

13.1%

22.3%2.0%

17.4%

35.3%

Summer Horizontal Distribution of Bull TroutSummer Horizontal Distribution of Bull Trout

1. Lowered use in west end

2. Similar proportional use of deltas.

3. Increased use of river habitat (by >20%)

Rainbow Trout

Bull TroutPygmy Whitefish

High Use AreasHigh Use Areas

Note that blues indicate greatest depth in CML and orange/red color represents shallower habitat.

2004 Chester Morse Reservoir Temp Profiles

0

5

10

15

20

25

30

35

400.0 5.0 10.0 15.0 20.0 25.0

Temperature (oC)

Dep

th (M

)

January-04February-04March-04April-04May-04June-04July-04August-04September-04October-04November-04December-04

Lost Buoy

Graph from Moya Joubert, SPU

Chester Morse Lake Temperature Profile

Vertical Distribution of Bull Trout in Main Lake Basin

Mean Depth

Fall = 16.3 m

Spring = 16.7 m

Summer = 18.5 m

Winter = 15.1 m fallspring

summerwinter

0

8

16

24

32

40

Dep

th ( m

)

Mean Depth

Fall = 2.0m

Spring = 4.3m

Summer = 4.7m

Winter = 3.0mfall

spring

summerwinter

0

2

4

6

8

10

Dep

th ( m

)

Vertical Distribution of Bull Trout in River Deltas

Temperature at Bull Trout LocationsTemperature at Bull Trout Locations

fallspring

summerwinter

0

5

10

15

20

Tem

pera

tur e

(C)

Main lake basin Deltas

Mean = 9.9 C Mean = 10.6 C

fallspring

summerwinter

0

5

10

15

20

Tem

pera

tur e

(C)

Fish #6 Movement of November 20, 2006Male Bull trout

-5

0

5

10

15

20

25

30

35

0:00 2:24 4:48 7:12 9:36 12:00 14:24 16:48 19:12 21:36 0:00

Dep

th (m

)

Cedar delta lip

Off McClellan and Greenpoint Creeks

Cedar delta lip

Lake level held “higher”- typically winter and spring (very little thermal stratification)

Fish have more room to spread out, use shoreline habitat and river deltas

Lake level held “lower”- typically summer and fall (thermal stratification)

Fish are more concentrated, limited access to shoreline habitat and river deltas, and are observed moving into river habitat for temperature refuge

Acknowledgements- Ed Connor, Seattle City Light- Kyle Meier, Forest and Channel Metrics- Moya Joubert, SPU- Jon Workman, SPU- Churchill Aho, SPU- Dave Beauchamp, UW- Jamie Thompson- Nathan Zorich