Effects of temperature and gadid predation on snow crab recruitment: comparisons between the Bering Sea and Atlantic Canada

Snow crabs Chionoecetes opilio are found in many subarctic ecosystems, where they are important components of marine food webs and support large commercial fisheries. Snow crab abundance is highly variable, but the causes of large changes in year-class strength are poorly known. We used a regression approach to examine the effects of snow crab spawning stock biomass, bottom water temperature, cold area or sea ice extent, and predation by Pacific cod Gadus macrocephalus or Atlantic cod G. morhua on snow crab recruitment in each of 3 ecosystems: the eastern Bering Sea, the Newfoundland-Labrador Shelf, and the southern Gulf of St. Lawrence. Comparing results across systems showed that cold ocean conditions during early life history were associated with increased snow crab recruitment or recruitment indices in all 3 ecosystems. However, we found no consistent evidence that spawning stock or gadid biomasses were significantly related to subsequent snow crab recruitment. Our results underscore the value of comparing multiple ecosystems and demonstrate the importance of ocean conditions in driving variability in snow crab populations.