OCE-PRF Comparing the genomic bases of adaptation to seasonal and spatial temperature gradients in a widespread marine copepod

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

Copepods are some of the most abundant animals on the planet and play important roles in marine food webs and biogeochemical cycles. Ocean warming may negatively impact copepod populations, with cascading disruptions throughout marine ecosystems. However, in many regions, this warming occurs against a background of large seasonal shifts in temperature. Adaptation to the different conditions experienced over this annual temperature cycle may increase genetic diversity in copepod populations, better enabling them to cope with long-term warming. Understanding the effects of seasonal temperature fluctuations on copepod populations will enhance our ability to predict, plan for, and mitigate the effects of climate change on coastal fisheries and the communities that rely on them. Based at the University of Vermont, this project will provide opportunities to work with marine animals in a landlocked state, engaging students who may not otherwise have the chance to participate in the marine sciences. This project will combine field work, laboratory common garden experiments, and population genomics to investigate the prevalence and adaptive significance of seasonal thermal adaptation in a dominant coastal copepod (Acartia tonsa) across a large latitudinal thermal gradient. This integrative approach will provide important insights into the genomic bases of thermal adaptation, how concordant these patterns are over spatial and temporal scales, and the potential for seasonally fluctuating selection to enable marine copepods to respond to long-term warming. This project has three specific objectives: 1) Examine seasonal variation in thermal limits in populations of Acartia tonsa from sites across a large latitudinal thermal gradient; 2) Quantify and compare seasonal and spatial variation in allele frequency; and 3) Determine if seasonally adapted genotypes differ in key fitness-related traits (thermal limits, body size, and the temperature sensitivity of egg production and hatching success). Because of their important roles in marine ecosystems, this mechanistic understanding of how copepod populations respond to spatial and temporal temperature gradients will help us better predict their responses to climate change, and provide key insights into the future of marine ecosystems This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.