Courtney pegus sctc

Climate-driven changes in rearing habitats of juvenile Chinook salmon in the Kenai watershed

Courtney Pegus, Mark Wipfli, and Daniel Rinella

The Big Picture Climatic changes and consequences Climate change

Landscape changes

Hydrological changes

Changes in food resources

Salmon habitat/abundance

Climatic changes and shifts in weather patterns might be transforming several ecological features within Alaska.

Broad research question How do climate-driven changes in landscape/fluvial dynamics affect rearing habitats of juvenile Chinook salmon in the Kenai River watershed?

Kenai’s projected temperature changes (SNAP 2008)

Haufler et al., 2010

Variability of temperatures among streams observed in a similar study

Lisi et al., 2013

The Kenai watershed has a diverse array of sub-drainage basin types including: glacial, groundwater-fed, and runoff each having unique properties (water temperature, dissolved oxygen, flow etc.)

Groundwater dominated streams

Precipitation dominated streams

Glacial dominated streams

Juvenile Chinook rear in different habitat types in the Kenai watershed and are therefore exposed to a range of different environmental conditions

Temperature

Food

Flow

Salmon require relatively cold water habitats throughout the life cycle

Warm water temperatures can: (1) Impede growth (2) Lead to mortality

(Objective for summer 2013): Determine if certain rearing habitat types were more vulnerable to experiencing unfavorable conditions (e.g., unsuitable temperatures and low D.O.) as the summer progressed Surface runoff fed streams

Groundwater fed streams

Glacial fed streams

Conceptual model depicting how salmon rearing habitats might change during the summer months Key Optimal Temperature and D.O. Optimal growth

Surface runoff fed streams

Glacial fed streams

Unsuitable Temperature and/or D.O. too hot Little growth Unsuitable Temperature and/or D.O. too cold Little growth

Early Summer Mid Summer Late Summer

Groundwater fed streams

Summer Research 2013- Temperature loggers were deployed in various streams in the Kenai watershed

Hobo temperature loggers

Hydrolab sensor deployed in Beaver Creek

Summer Research 2013- Temperature loggers were deployed in various streams in the Kenai watershed

Hobo temperature loggers

Hydrolab sensor deployed in Beaver Creek

Deployment sites for temperature loggers (21 Total)

18 13 8 6/15

23

7/5

7/25 8/14 Time (D)

9/3

13 7/5

7/25 8/14 Time (D)

23

Beaver Creek

18 13 8 6/15

7/5 7/25 8/14 Time (D)

9/3

Bishop Creek

Funny River

18

8 6/15

Temerature (°C)

Moose River

9/3

Temperature (°C)

Implications: Stream temperatures approached upper tolerance limits of juvenile Chinook in some habitats, suggesting that some rearing habitats may become unsuitable during warm summers.

23

Temperature (°C)

Finding: Stream temperatures peaked in late July (15-22°C).

Temperature (°C)

Stream temperature data from 2013 field season

23 18 13 8 6/15

7/5 7/25 8/14 Time (D)

9/3

18 13 8 6/15

23

7/5

7/25 8/14 Time (D)

9/3

13 7/5

7/25 8/14 Time (D)

23

Beaver Creek

18 13 8 6/15

7/5 7/25 8/14 Time (D)

9/3

Bishop Creek

Funny River

18

8 6/15

Temerature (°C)

Moose River

9/3

Temperature (°C)

Implications: Stream temperatures approached upper tolerance limits of juvenile Chinook in some habitats, suggesting that some rearing habitats may become unsuitable during warm summers.

23

Temperature (°C)

Finding: Stream temperatures peaked in late July (15-22°C).

Temperature (°C)

Stream temperature data from 2013 field season

23 18 13 8 6/15

7/5 7/25 8/14 Time (D)

9/3

18 13 8 6/15

23

7/5

7/25 8/14 Time (D)

9/3

13 7/5

7/25 8/14 Time (D)

23

Beaver Creek

18 13 8 6/15

7/5 7/25 8/14 Time (D)

9/3

Bishop Creek

Funny River

18

8 6/15

Temerature (°C)

Moose River

9/3

Temperature (°C)

Implications: Stream temperatures approached upper tolerance limits of juvenile Chinook in some habitats, suggesting that some rearing habitats may become unsuitable during warm summers.

23

Temperature (°C)

Finding: Stream temperatures peaked in late July (15-22°C).

Temperature (°C)

Stream temperature data from 2013 field season

23 18 13 8 6/15

7/5 7/25 8/14 Time (D)

9/3

Stream and air temperatures recorded at Beaver Creek 25

Finding: Stream temperatures appeared to be strongly influenced by air temperatures.

30

25

20

15

15

10 10

5

0 5

Water Temperature -5

Air Temperature 0 6/15

7/5

7/25

8/14

9/3 Time (D)

9/23

10/13

-10 11/2

Air Temperature (째C)

Water Temperature (째C)

20

Stream and air temperatures recorded at Beaver Creek 25

30

Water Temperature 25

Air Temperature 20

15

15

10 10

5

0 5 -5

0 6/15

7/5

7/25

8/14

9/3

Time (D)

9/23

10/13

-10 11/2

Air Temperature (째C)

Water Temperature (째C)

20

Temperature and Dissolved Oxygen data from 2013 field season

Temperature (째C)

18

Dissolved Oxygen

10.5

17

10

16

9.5

15

9

14

8.5

13

8

12

7.5

11 7/25

7/30

8/4

8/9

Time (D)

8/14

8/19

7 8/24

Dissolved Oxygen (mg/l)

Finding: Stream temperatures and dissolved oxygen levels in late summer were within optimal parameters for juvenile Chinook.

Temperature

Next steps

Track temperature and food resources in streams to understand if certain habitats and stream types become unsuitable for rearing Chinook salmon.

Through bioenergetic modeling, determine how food abundance and temperature interact to affect juvenile Chinook growth/condition in key rearing habitats.

Acknowledgements

Robert Ruffner Rebecca Zulueta Erik Schoen Sue Mauger

References

Haufler, J.B., C.A. Mehl, and S. Yeats. 2010. Climate change: anticipated effects on ecosystem services and potential actions by the Alaska Region, U.S. Forest Service. Ecosystem Management Research Institute, Seeley Lake, Montana, USA.

Lisi P.J., D.E. Schindler, K.T. Bentley, and G. R. Pess.

2013 Association between geomorphic attributes of watersheds, water temperature, and salmon spawn timing in Alaskan streams Geomorphology. 185, 78-86