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