Winter mortality of the blue crab (Callinectes sapidus) in the Chesapeake Bay

Abstract

Over its range, the blue crab (Callinectes sapidus) is exposed to a wide range of environmental conditions. At mid-latitudes, within its range, overwintering mortality may play an important role in regulating local blue crab populations. A 121-day 2x2x2 factorial experiment was used to test for the effects of temperature (3C, 5C), salinity (10, 25) and sediment (sediment, no sediment) on survival. An accelerated failure time model was fit to the survival data. Time to death significantly increased with increasing temperature, salinity, and crab size. I applied a temperature and salinity-dependent survival model to empirical temperature and salinity data to explore spatial and interannual patterns in overwintering mortality in the Chesapeake Bay. Predicted survival was highest in the warmer, saline waters of the lower Bay and decreased with increasing latitude. There was also significant interannual variation in that predicted survival was lowest after the severe winters of 1996 and 2003.