Range shifts in marine species: Testing ecological hypotheses against four decades of observations

Background/Question/Methods

Some commonly predicted impacts of climate change are poleward shifts in species ranges as they track preferred environmental conditions. Key questions remain, however, about the processes affecting these shifts, the factors driving differences among species, and the predictability through time. Tests of these questions are often limited by the narrow spatial scale of sampling or the infrequency of surveys. Using four decades of annual or triennial research surveys in two oceans on the continental shelves of North America, we tested how the direction and magnitude of range shifts among eighty demersal fish and invertebrates relates to climate trajectories, life history, and history of fishing.

Results/Conclusions

We find that range shifts vary substantially among species, but that local differences in climate velocity can explain otherwise surprising differences in direction and magnitude of shift. Life history traits explain additional variation among species, suggesting that future range shifts may be more predictable than previously thought. More broadly, the results provide guidance for mechanistic modeling of species responses to climate change and the community consequences of these changes over large spatial scales.