What mechanisms allow populations and species to persist in a changing climate?
In order for populations and species to persist in a changing climate (as opposed to go extinct, either locally or globally), they need to have adequate coping mechanisms. These can include mechanisms of tolerance, acclimation, adaptation, and re-distribution. We have used physiological experiments to assess spatial variation in climatic tolerances of marine invertebrates. This space-for-time approach gives us an idea of whether acclimation and adaptation could allow population persistence as the climate changes.
When physiological mechanisms aren’t enough to allow population persistence, then populations must move to track encroaching temperature isoclines. We have been focusing on whether sessile invertebrates with dispersive larvae can shift their ranges poleward where dominant currents flow equatorward, including the Labrador Current in the Gulf of Maine and California Current in the northeast Pacific. Work funded by MIT Massachusetts Sea Grant (to Sorte, Robyn Hannigan, and Ron Etter of UMass-Boston) has been using historical, survey, and geochemistry approaches to determine whether blue mussels are declining in the Gulf of Maine and patterns of population connectivity that could be important in persistence of this important foundation species. In addition, we are collaborating with the Davis Lab at UCI to integrate modeling and field observations to examine the potential for California mussels to disperse northward along the US west coast.