Welcome to the Alaska Climate Webinar: Climate Change and Potential Impacts on Bristol Bay Sockeye Salmon Populations

Transcription

1 Photo courtesy of Matt Druckenmiller Welcome to the Alaska Climate Webinar: Climate Change and Potential Impacts on Bristol Bay Sockeye Salmon Populations With: Rebecca Aicher, Science and Technology Policy Fellow for the American Association for the Advancement of Science hosted by the U.S. EPA; and Jason Todd & Joe Ebersole, Office of Research and Development, U.S. EPA

2 Climate change and potential impacts on Bristol Bay sockeye salmon populations

3 Arctic warming D R AF T D AT A Twice the global rate over the last few decades Experiencing greatest regional warming on the planet Projected changes show continued warming with the largest changes during winter months

4 Arctic warming Arctic Biodiversity Trends 2010-Selected indicators of change. CAFF International Secretariat, Akureyri, Iceland. May 2010.

5 Alaska warming: Observations AT A Detectable changes have already occurred D R AF T D Warmer temperatures, melting glaciers, declining sea ice and permafrost Productivity in terrestrial and aquatic systems are changing due to changes in nutrient cycling and hydrology Some changes are occurring faster than predicted in the 2004 ACIA (e.g. loss of summer sea ice)

6 Climate change in Bristol Bay watersheds Arctic Biodiversity Trends 2010-Selected indicators of change. CAFF International Secretariat, Akureyri, Iceland. May 2010.

7 30-year Mean annual air temperature difference

8 30-year Mean watershed air temperature difference Temerature Diff. ( C) Egegik Kvichak Naknek Nushagak Togiak Ugashik Bristol Bay Watershed

9 30-year Mean seasonal air temperature difference Temperature Diff. ( C) Winter Spring Summer Fall Annual Season

10 30-year Mean precipitation changes

11 30-year Mean precipitation changes

12 Bristol Bay and sockeye salmon D R AF T D AT A Sockeye salmon are the most abundant salmon species Supports ~46% of average global abundance of wild sockeye salmon Average annual inshore run ~37.5 million fish ( ) Average annual harvest ~27.5 million fish ( )

13 Alaska warming: Predictions Changes in Bristol Bay watersheds Shifts in species ranges across ecosystems Species tolerances to abiotic changes will differ Species inhabiting areas previously unsuitable Altered interspecific and intraspecific competition for resources

14 Environmental impacts of climate change on Pacific salmon populations in Bristol Bay, Alaska (Present ) DRAFT DO NOT CITE atmospheric CO 2 levels anthropogenic emissions of greenhouse gases anthropogenic climate change air temperature LEGEND human activity source proximate stressor additional step in causal pathway modifying factor mode of action biotic response ocean acidification ( ph) marine community composition food quantity and quality Δ marine nutrient cycling and availability sea surface temperature Δ ocean currents Δ species interactions Δ salmon migration evapotranspiration Δ hydrology Δ marine-derived nutrients Δ ecosystem productivity community composition Δ aquatic habitat Δ migration patterns Δ precipitation amount/timing/type Δ metabolism and development freshwater temperature disease/ infection community composition Δ ecosystem productivity Δ food resources Δ species ranges competition Δ aquatic habitat Δ food resources Δ salmon quality, quantity, or genetic diversity

15 Environmental impacts of climate change on sockeye salmon populations in Bristol Bay, Alaska (Present ) Complex Model DRAFT DO NOT CITE Burning of fossil fuels greenhouse gas emissions atmospheric C0 2 levels air temperature ocean acidification ( ph) availability of calcium carbonate calcium dependent organisms (shell-forming organisms) plankton community composition El Niño Southern Oscillation Δ coastal stability Δ marine nutrient cycling and availability Δ marine ecosystem productivity Pacific Decadal Oscillation Δ ocean currents hatchery salmon populations sea surface temperature Δ salmon migration evapotranspiration Δ flow intermittency Δ aquatic habitat fragmentation Δ smolt emigration Earlier spring ice break up Δ timing of match/mismatch with plankton blooms Δ aquatic habitat availability, quality & complexity Δ adult spawning immigration glacial retreat Geomorphology & geology Δ magnitude and timing of water flow Spawning habitat classification Δ base flow volume Δ timing and magnitude of peak flow Δ marine-derived nutrients Δ ecosystem productivity Lake ice extent migration patterns Δ amount of precipitation Δ timing of precipitation metabolism and development summer freshwater temperature disease/ parasites Δ type of precipitation (snow to rain) dissolved oxygen (water column) freshwater temperature (streams and lakes) intensity and duration of stratification winter freshwater temperature Δ species ranges abundance of non-native species Δ freshwater geochemistry Δ ecosystem productivity community composition Δ food resources food quantity and quality Δ competition and predation thermal habitat area stream community composition riparian community composition Δ competition and predation Δ food resources in-stream habitat Δ mortality Δ growth Δ condition behavior development Δ reproductive success LEGEND human activity source modifying factor additional step in causal pathway biotic response additional step in causal pathway (freshwater) proximate stressor (freshwater) mode of action (freshwater) biotic response (freshwater) Δ salmon quality or quantity Δ salmon genetic diversity additional step in causal pathway (marine) proximate stressor (marine) mode of action (marine) biotic response (marine)

16 Environmental impacts of climate change on sockeye salmon populations in Bristol Bay, Alaska (Present ) Marine Pathways DRAFT DO NOT CITE atmospheric C0 2 levels Burning of fossil fuels greenhouse gas emissions air temperature LEGEND human activity proximate stressor source modifying factor additional step in causal pathway biotic response mode of action ocean acidification ( ph) availability of calcium carbonate calcium dependent organisms (shell-forming organisms) plankton community composition food quantity and quality El Niño Southern Oscillation Δ coastal stability Δ marine nutrient cycling and availability Pacific Decadal Oscillation Δ marine ecosystem productivity Δ competition and predation hatchery salmon populations sea surface temperature Δ ocean currents Δ salmon migration thermal habitat area Δ magnitude and timing of water flow Δ mortality Δ growth Δ condition behavior development Δ reproductive success Δ salmon quality or quantity Δ salmon genetic diversity

17 Sea surface temperature and oscillations Climate regime shifts track salmon abundance PDO and ENSO Relationship with prey availability Thermal habitat in North Pacific predicted to shrink

18 Coastal stability Freshwater-marine interaction Hydrologic changes Migration

19 Ocean acidification Preliminary literature review indicates potential problem Few studies have measured the effect of acidification on salmon populations Potential link between impact on prey and salmon

20 Summary of marine effects Regional climate patterns have impact on sockeye in marine environment Prey availability (timing and abundance) are likely to be key in understanding response of sockeye in future Interaction with freshwater environment Timing of migration Coastal stability

21 Environmental impacts of climate change on sockeye salmon populations in Bristol Bay, Alaska (Present ) Freshwater Pathways DRAFT DO NOT CITE atmospheric C0 2 levels Burning of fossil fuels greenhouse gas emissions air temperature evapotranspiration Δ timing of match/mismatch with plankton blooms Earlier spring ice break up Δ food resources Lake ice extent glacial retreat Geomorphology & geology Δ magnitude and timing of water flow migration patterns riparian community composition Δ amount of precipitation in-stream habitat Δ timing of precipitation metabolism and development summer freshwater temperature disease/ parasites Δ type of precipitation dissolved oxygen intensity and duration of stratification abundance of nonnative species winter freshwater temperature Δ species ranges freshwater temperature Δ freshwater geochemistry Δ competition and predation Δ ecosystem productivity community composition Δ food resources LEGEND human activity modifying factor source proximate stressor additional step in causal pathway mode of action biotic response Δ mortality Δ growth Δ salmon quality or quantity Δ condition behavior Δ salmon genetic diversity development Δ reproductive success

22 Freshwater temperature Summer vs winter temperature changes Similarities: Metabolism and development Timing of life history transitions, movements Differences: Winter: precip form, and effects on winter streamflow, snow/ice cover, thermal stability Summer: metabolism and foraging, biotic interactions

23 Metabolism and development Increase scope for growth Forage availability/temperature trade-offs Increased energy demand during migration Interaction with streamflow Growth and timing of life-history transitions, movements

24 Diseases and parasites Fraser River, Columbia Basin studies Mortality often associated with multiple stressors Increased incidence in warmer years No compelling signal (yet) for SW AK

25 Ecosystem productivity Specific effects can be difficult to disentangle Climate, catchment geology and organic inputs, marine derived nutrients all contribute Lake zooplankton responses Abundance Species composition Vertical distribution

26 Lake stratification Intensity and duration Implications for plankton bloom, sockeye fry mismatch Summer thermal habitat Sockeye beach-spawning habitats influenced by upwelling and wave action Climate and geomorphology can interact

27 Community composition, species ranges, and non-natives Altered species pools Shifts in competition/predation with temperature change

28 Food Resources Marine derived nutrient inputs provide feedback mechanism Timing of daphnia production timing and timing of sockeye fry lake entry has become less optimal in Lake Washington complex phenological responses may be common as the climate continues to change (Hampton et al. 2006)

29 Freshwater Temperature Effects Life history-specific effects Lake vs stream spawners affected differently Timing and synchrony effects Photo courtesy of Thomas Quinn, University of Washington

30 Summary of freshwater temperature effects Many effects are broadly applicable: Physiology thermal limits Photo courtesy of Thomas Quinn, University of Washington

31 Summary of freshwater temperature effects But almost all effects have some regional or population specificity

32 Regional and population-specific factors Climate, geology Photo courtesy of Thomas Quinn, University of Washington

33 Regional and population-specific factors Biocomplexity System resilience

34 Interaction of temperature and streamflow hydrology temperature

35 Environmental impacts of climate change on sockeye salmon populations in Bristol Bay, Alaska (Present ) Freshwater Pathways DRAFT DO NOT CITE atmospheric C0 2 levels Burning of fossil fuels greenhouse gas emissions air temperature Δ flow intermittency Δ aquatic habitat fragmentation Δ smolt emigration evapotranspiration Δ base flow volume Δ timing of match/mismatch with plankton blooms Earlier spring ice break up Spawning habitat classification Lake ice extent glacial retreat Geomorphology & geology Δ magnitude and timing of water flow Δ timing and magnitude of peak flow Δ adult spawning immigration Δ marinederived nutrients Δ ecosystem productivity Δ amount of precipitation Δ aquatic habitat availability, quality & complexity migration patterns Δ food resources riparian community composition in-stream habitat Δ timing of precipitation summer freshwater temperature Δ type of precipitation winter freshwater temperature freshwater temperature Δ freshwater geochemistry Δ competition and predation LEGEND human activity source modifying factor additional step in causal pathway biotic response Δ mortality Δ growth Δ condition behavior development Δ reproductive success additional step in causal pathway (freshwater) proximate stressor (freshwater) mode of action (freshwater) biotic response (freshwater) Δ salmon quality or quantity Δ salmon genetic diversity

36 Freshwater hydrology Flow magnitude and timing cms /1 11/1 USGS NUYAKUK R 12/1 1/1 2/1 3/1 4/1 5/1 6/1 7/1 8/1 9/1 USGS NUYAKUK R

37 Flow magnitude Peak flows shape channel morphology Can influence migration costs Low flows can limit habitat volume/availability, increase fragmentation

38 Flow Timing Salmon life histories aligned to flow regime Juvenile migration Adult migration

39 Hydrology summary Magnitude and time of flow impacts salmon at different life stages including migration Changes in hydrology are likely to affect freshwater habitats (availability, temperature, fragmentation)

40 Temperature Hydrology Biology Habitat

41 Complexity and change Complex correlated factors impacting species at multiple spatial scales (local, regional, global) Shifts in productivity of fisheries-regional climatic and environmental factors Interactions between marine and freshwater systems needs more attention Feedbacks within system (dampening and amplifying) Fisheries will face challenges in predicting how the interacting factors will affect species

42 Will climate change impact sockeye salmon populations? Population level responses to changes in climatic factors Alaska salmon populations appear to be resilient, but southern populations may be at limit Habitat protection crucial to maintaining biocomplexity

43 Research needs Adequate sampling designs and monitoring programs Experimental studies to evaluate effects of environmental changes in freshwater and marine environments Attributes providing resilience to sockeye salmon in the face of climate change

44 Acknowledgements Carol Ann Woody, Fisheries Research and Consulting Glenn Suter, US EPA Greg Blair, ICF International Jason Leppi, The Wilderness Society Jeff Frithsen, US EPA Jim Wigington, US EPA Joel Reynolds, Western Alaska Landscape Conservation Cooperative Kate Schofield, US EPA Phil Brna, US Fish and Wildlife Phil Loring, UAF Phil North, US EPA Rick Parkin, US EPA Steve Gray, USGS Alaska Climate Science Center

45 Discussion Questions 1. What important pathways are missing from our diagram? 2. What are the most important set of contextual constraints for identifying Bristol Bay-specific responses to climate change? 3. We identified the primary sources of complexity as: synchrony (e.g., fw-marine timing; hydrology-life history timing) synergies (e.g., fw-marine linkages) feedbacks What other sources of complexity need to be incorporated?

46 Contact Information Rebecca Aicher Science and Technology Policy Fellow, AAAS Hosted by the U.S. EPA