Project title: Climate, embryonic development, and potential for adaptation to warming water temperatures by Bristol Bay sockeye salmon.
Personnel Morgan Sparks (MS 2016) Funding source(s): Western Alaska Landscape Conservation Cooperative Project description: Rapidly warming water temperatures associated with climate change represent a substantial disturbance to the habitat of aquatic ectothermic organisms. For salmonid fishes (family Salmonidae), early life history survival and timing of reproduction and development are closely tied to temperature, such that altered thermal regimes could alter patterns of survival or shift phenology into a mismatch with the environment. Because temperature is the dominant driver of developmental rates, empirical statistical models have been developed to predict the timing of hatching and fry emergence based on incubation temperature. In this thesis I explored how the timing of hatching and emergence may shift in response to warming temperatures and how spawning timing across an Alaskan landscape is shaped by incubation temperatures experienced by sockeye salmon (Oncorhynchus nerka) embryos and alevin. Additionally, I quantified the relative roles of genetics and environmentally induced plasticity on the timing of hatching in two populations of sockeye salmon from the Iliamna Lake system, Alaska by rearing them in common garden conditions in the laboratory. To meet these goals I reformulated a widely cited developmental model to incorporate variability in natural regimes and use it to predict hatching timing over the course of the spawning duration for 25 populations of Bristol Bay sockeye salmon. Additionally, I hind- and forecasted lake temperature based off historical and predicted air temperatures to estimate and predict hatching for a single population. I found that predicted hatching timing for wild populations varied between 58 and 260 days, and was largely variable as a result of habitat thermal heterogeneity and parental spawn time. I also predicted a three-week decrease in hatching timing over the course of the next century for a single beach spawning population, which was just beyond historic variability. Counter to expectations, for a subset of populations hatching and emergence timing variability exceeded that of spawning timing, indicating the relationship between spawning timing and incubation temperature may be weaker than expected. The results of the common garden experiment revealed indistinguishable differences between populations in hatching timing across five temperature scenarios, but strong plasticity as timing differed between 74 and 189 days in the warmest to coolest treatment. Furthermore, I detected family-specific differences in hatching timing both within and among treatments, consistent with heritable developmental rates and gene by environment interactions in days to hatch, where the interaction between treatment and family was as high as 10 days difference in hatching. Population or family-specific survival in this experiment did not differ in response to temperature suggesting a lack of thermal adaptation during this life stage in these populations. Alevin mass and length upon hatching varied little among treatments (<10%), but did significantly decrease with cooling temperatures. Taken as a whole this study indicates that the effects of climate change during the early life history stages may be buffered by phenotypic plasticity and variability in populations and habitats will be important for maintaining diversity in the face of climate change. Co-Investigators: Peter Westley - UAF Tom Quinn - UW Milo Adkison - UAF Daniel Schindler - UW Krista Bartz - NPS Dan Young - NPS |
Outreach:
Products: Peer-reviewed publications: Sparks, M.M., Falke, J.A., Westley, P.A.H., Adkison, M.D., Bartz, K., Quinn, T.P., Schindler, D.E., and D. Young. 2019. Influences of spawning timing, water temperature, and climatic warming on early life history phenology in western Alaska sockeye salmon. Canadian Journal of Fisheries and Aquatic Sciences 76:123-135. https://doi.org/10.1139/cjfas-2017-0468 Sparks, M.M., Westley, P.A.H., Falke, J.A., and T.P. Quinn. 2017. Thermal adaptation and phenotypic plasticity in a warming world: insights from common garden experiments on Alaskan sockeye salmon. Global Change Biology 23:5203-5227. https://doi.org/10.1111/gcb.13782 Thesis: Sparks, M. S. 2016. Climate, embryonic development, and potential for adaptation to warming water temperatures by Bristol Bay sockeye salmon. Unpublished Master's thesis. School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska. 100 pp. Oral and poster presentations: Falke, J., Sparks, M., Torvinen, E., and P. Westley. 2017. Climate vulnerability and salmonids in Alaska: hind- and forecasting freshwater growth and phenology across species and habitats. Western Division American Fisheries Society Annual Meeting, Missoula, Montana, 23-25 May, 2017. Sparks, M., Westley, P., Falke, J., and T. Quinn. 2016. Experimental tests for thermal local adaptation and heritable phenotypic plasticity in hatching timing by sockeye salmon using a common garden approach. Evolution 2016. June 17, 2016. Austin, TX. Sparks, M., Westley, P., Falke, J., and M. Adkison. 2015. Predicting Sockeye Salmon (Oncorhynchus nerka) hatch timing by incorporating natural variability into an existing model. Alaska Chapter American Fisheries Society Annual Meeting, Homer, Alaska, 4-6 November, 2015. (POSTER) Falke, J., Ching, J., Sparks, M., Cunningham, C., and P. Westley. 2015. Fine-scale resource selection by Sockeye Salmon (Oncorynchus nerka) in groundwater-fed ponds, Bristol Bay, Alaska. Alaska Chapter American Fisheries Society Annual Meeting, Homer, Alaska, 4-6 November, 2015. (POSTER) |