Year Established: 2019 Start Date: 2019-06-18 End Date: 2020-06-17
Total Federal Funds: $41,737 Total Non-Federal Funds: $83,579
Principal Investigators: Taylor Stewart
Abstract: Lake water temperatures are increasing and winter ice cover frequency and duration are decreasing in Lake Champlain, and both trends are expected to continue not just locally but also globally. Such changes in lake conditions make it necessary to understand how managed resources will adapt (or not) to such changes. Freshwater whitefishes, Salmonidae Coregoninae, are of great socio-economic value but critically sensitive to the effects of increased water temperatures because they are cold, stenothermic fishes. The evolutionary responses of many species are predicted to be inadequate to counter the speed and magnitude of climate change leaving species vulnerable to decline and extinction. Shifts in physiology or reproductive phenology of populations living close to their physiological limits (e.g., coregonines in Lake Champlain) will be required if species are to persist as water temperatures continue to increase across the globe. We propose to use a cross-lake, cross-continent, cross-species approach to evaluate the response of coregonine eggs, larvae, and adults to changing thermal regimes. We will use modeling and experiments to identify environmental mechanisms driving latitudinal variation in reproductive phenology and egg and larval development, growth, and survival across a suite of congeners with similar and contrasting life history traits to provide insight to future climate-driven shifts in population dynamics. Phenological shifts and higher annual variability in reproduction could lead to mismatches between larval fish and their zooplankton prey and negatively influence metabolic demands, which could be related to the worldwide declines in coregonine recruitment. Determining the differences and mechanisms driving thermal resilience across populations, at critical early-life stages, will be important for sustainable management practices for coregonines in Lake Champlain and beyond.