1. Collaborative Research: Copepods in a Warming Climate: A Pan-Regional Model of Arctic and Northwest Atlantic Systems coPIs: Davis, Ji, Beardsley, Chen Objectives 1) merge our NWA and AO physical models via a new global model grid, extending our lower food web model (NPZD) across the pan- regional domain, to generate present and future (2050) environmental conditions. 2) use these modeled environmental conditions together with life histories of key species to determine their population growth potential within and across regions, 3) use an individual based model (IBM) parameterized for key species to examine effects of transport and behavior on population growth and resulting pan-regional distribution patterns, 4) develop a new evolutionary IBM for a generic copepod to determine selection of optimal life history traits under existing and future (warm) conditions across the pan-regional domain.

3. Hypotheses General hypothesis: Global warming will cause a retraction of endemic Arctic copepod species range and will extend the range northward of species from lower latitudes. Despite SW transport of low salinity water, the optimal population growth conditions will shift northward for both Arctic and NWA populations resulting in a concomitant northward increase in NWA species and shrinkage of Arctic species range. H10: Boreal species in the NWA, Calanus finmarchicus and Pseudocalanus newmani and P. moultoni will expand into Arctic Ocean despite limitations due to the mean southwest advective flow. H20: Arctic species, Calanus glacialis and C. hyperboreus, abundance will decrease in the NWA and their ranges will be contracted within the Arctic Ocean itself. Alternatively, (H2a) abundance of these species will increase in the NWA due to increased Arctic outflow. H30: Calanus marshallae will expand into the Arctic and be carried through the Canadian archipelago into the NWA H40: The warm water NWA species, Centropages typicus and Centropages hamatus will expand northward increasing abundance the Labrador Sea and Canadian archipelago. The rate of expansion will be slower for Centropages hamatus which lays bottom resting eggs. H50: The mechanisms controlling biogeographic patterns in copepod species can be understood by modeling the evolution of optimal life history traits for given environmental conditions and climate scenarios.