You are here:
Tough places and safe spaces: can refuges save salmon from a warming climate? (2020)
Citation:
Snyder, M., N. Schumaker, Joe Ebersole, M. Keefer, J. Dunham, R. Comeleo, J. Halama, P. Leinenbach, D. Keenan, AND J. Palmer. Tough places and safe spaces: can refuges save salmon from a warming climate? (2020). To be Presented at North American Chapter of Conservation Biology, Virtual, Virtual, July 27 - 31, 2020.
Impact/Purpose:
Climate refugia are places where the effects of climate change are much less severe or will be experienced more slowly, due to buffering by groundwater, complex terrain, microclimate, or other moderating factors. Refugia thinking is increasingly incorporating complexity of spatial and temporal scales via incorporating of new technologies and modeling advances. Here we use an individual based model to explore the advantages and disadvantages of cold water refuge use along upstream migration for anadromous salmonids in the Columbia River migration corridor. The model integrates key life history parameters, behavioral plasticity, and the composition of the landscape to understand the influence of cold water refuge use on fish fitness outcomes.
Description:
In freshwater systems in the western US, there is evidence that warmer water temperatures along migration corridors have increased energetic costs of migration, decreased reproductive fitness, and increased premature mortality in anadromous salmonids. Behavioral thermoregulation has been observed across all life stages of anadromous salmonids and thought to be a beneficial strategy that can help mitigate costs to fish fitness of water temperature increases. In spite of the potential importance of cold water refuge use to mitigate increasing water temperatures, directly linking thermal exposure of adult salmonids during upstream migration to survival and fitness outcomes has been challenging. We use a hybrid probabilistic-mechanistic simulation model to evaluate the buffering potential of cold water refuge use for anadromous salmon and trout migrating upstream in the Columbia River from Bonneville dam to the Snake River confluence. The simulation model, developed within HexSim, is built around a mechanistic behavioral decision tree that drives individual interactions with their spatially explicit simulated environment. To evaluate the advantages and disadvantages of behavioral thermoregulation on fitness at individual and population scales, we use emergent model properties, including observed passage times, energy use, cumulative exposure, and survival rates.