An ensemble high-resolution projection of changes in the future habitat of American lobster and sea scallop in the Northeast US continental shelf

Aim To address the uncertainty associated with climate-driven biogeographical changes in commercial fisheries species through an ensemble species distribution modelling (SDM) approach. Location Northeast US Continental Shelf Large Marine Ecosystem (NEUS-LME). Methods We combined an ensemble SDM platform (BIOMOD 2) and a high-resolution global climate model (NOAA GFDL CM2.6) to quantify spatiotemporal changes in habitat of two commercially important species in the Northeast US Continental Shelf Large Marine Ecosystem (NEUS-LME); American lobster (Homarus americanus); and sea scallop (Placopecten magellanicus). An ensemble SDM was calibrated using multi-decadal fisheries-independent surveys (1984-2016). Statistically weighted species-specific ensemble SDM outputs were combined with 80 years of projected bottom temperature and salinity changes in response to a high greenhouse gas emissions scenario (an annual 1% increase in atmospheric CO2). Results Statistically significant changes (p < .05) in habitat suitability for both species were found over a large portion of the study area. Sea scallop undergoes a northward shift over the study period, while American lobster moves further offshore. The ensemble projections showed that several management zones were identified with increases and decreases in species-specific habitat. Uncertainty due to variations in ensemble member models was also found in the direction of change within each management zone. Main conclusions This study provides ensemble estimates of climate-driven changes and associated uncertainties in the biogeography of two economically important species in the United States. Projected climate change in the NEUS-LME will pose management challenges, and our ensemble projections provide useful information for climate-ready management of commercial fisheries.