Potential impact of climate change on northern shrimp habitats and connectivity on the Newfoundland and Labrador continental shelves

Abstract

The effect of climate change on ocean circulation and environmental conditions will likely impact important fisheries species which have a limited habitat range and a prolonged larval dispersal phase. Based on projections from a regional scale ice-ocean model (RCP 8.5 scenario), we investigated the spatial distribution variability of the bentho-pelagic northern shrimp (Pandalus borealis) preferred depth and thermal habitat and larval settlement patterns in the Newfoundland and Labrador waters for the next 70 years. Our projections of ocean temperature revealed the persistence of major shelf-scale temperature features, but a gradual increase of bottom water temperatures by more than 4°C by 2090. Such warming led to an expansion of the potentially suitable habitat for northern shrimp from 2010 to 2050 prior to a decline and shift towards more coastal and southern areas from 2060 to 2090. The modification of the northern shrimp suitable habitat distribution, associated with changes in the ocean circulation features, affected the settlement patterns from larval dispersal simulations and the temperatures encountered by larvae. During the projection period, historically important areas were mostly negatively impacted in terms of suitable habitat and settlement potential, whereas areas that had been less important in the past (e.g., the north and the shallow area to the south) were projected to receive more settlers in comparison with the historical period. Our study demonstrated the important role of shelf-scale processes in determining larval connectivity and suggests that regional scale ocean models are needed to assess potential impacts of climate change on fisheries and ecosystems.