Temperature and depth dependence of the spatial distribution of snow crab

Abstract

The cascading effects of rapid climate change is a reality with which all biota are challenged. In this context, we examine the spatiotemporal probability of occurrence of snow crab as a means to express viable habitat. This is attempted for three demographic components, morphometrically mature males and females and immature adolescent crab in the Scotian Shelf region of the northwest Atlantic, Canada. We use a robust approach, known as Conditional AutoRegressive models, to define viable habitat. Further, we focus upon viable habitat, conditioned on the marginal influence of temperature and depth as they are known to be important constraints on snow crab. We observe some niche partitioning in terms of depth and temperature. We also note declines in viable habitat marginal to depth and temperature since 2010 for all demographic groups. This population representing the southern-most distribution of snow crab in the northwest Atlantic are vulnerable to degradation of viable habitat attributable to rapid climate change. One-Sentence SummaryRapid climate change and a decadal scale change in the viable habitat of snow crab of the Scotian Shelf ecosystem.