Climate change poses a great threat to cold-water fish species. This is particularly true for lake dwelling cold-water fish as they are often limited in their capacity to disperse to avoid stressful conditions. Our ability to predict and plan for the effects of climate change is constrained by our understanding of the capacity of populations to adapt to changing conditions. This understanding requires knowledge of the genetic diversity and molecular mechanisms that underpin species’ ability to adapt. We are studying the effects differing climates have in shaping molecular responses to thermal stress in several distinct, but geographically close, populations of brook trout (Salvelinus fontinalis). Brook trout of eastern North America is a sentinel cold-water species, with decreasing suitable thermal habitat. We are using a system of stratified and unstratified lakes as a natural climate change experiment, where the unstratified lake populations persist in thermally stressful conditions, while populations in stratified lakes have access to thermal refuge habitat at the bottom of the lakes.
We are taking a genomic approach to address two questions: 1) Are there differences in gene expression among fish from different lakes and lake types (stratified vs. unstratified) in response to thermal stress, demonstrating local adaptation? and 2) Are there regions of the genome associated with differences in susceptibility and phenotypic response to thermal stress? We will be using this information to develop an approach for assessing the genetic diversity associated with thermal adaptation in other brook trout populations. The information gained from this study will be invaluable for understanding the molecular basis for local adaptation and its relation to climate change resiliency planning, and in designing management actions that sustain brook trout and their habitats into the future.
Huffington Post: “Can Trout Evolve to Survive Climate Change? 5 Questions for Dr. Mariah Meek” http://www.huffingtonpost.com/tim-ward/can-trout-evolve-to-survi_b_9406796.html