Cooperative Fish and Wildlife Research Units Program: Maine
Education, Research and Technical Assistance for Managing Our Natural Resources

Many glacial relic populations of fishes and other taxa inhabitat small refuge habitats that are often isolated and thus presumed vulnerable to interacting abiotic and biotic factors that could compress their niche to the point of collapse. However, this outcome, and many future species range models, assume a relatively fixed species niche and do not factor in that glacial relics exhibit intraspecific trophic diversity, representing the capacity to exploit multiple alternative niches. We propose an organismal-eco-evolutionary framework for assessing the role of trophic trait diversity and change (via evolution or plasticity) in resilience to climate change, that links the genetic and plastic components of trophic trait variation, to population demography, and environmental context effects on eco-evolutionary potential. Landlocked Arctic charr in Maine, USA, are the most southern populations of this species in North America and present a powerful system to address these linkages by means of an exceptional long-term dataset of Arctic charr trait and mark-recapture data, combined with genomic analyses, movement behavior, diet and bioenergetics, food web structure analysis, limnology, and climate projection models.