Marine Heat Waves Effects on Stone Crab Physiology 

 Peyton Seidle, Eckerd College, Marine Science Discipline and Stratford Abbott, Eckerd College, Environmental Studies Discipline

Abstract
Marine heat waves (MHW) are defined as periods of abnormally high ocean temperatures lasting at least five consecutive days. These events are becoming increasingly common as climate warming intensifies, particularly within shallow coastal habitats that warm quickly. The stone crab (Menippe mercenaria) supports a valuable fishery in Florida worth $35 million annually, with most fishing activity occurring within these shallow coastal environments. During the winter fishing season, legal-sized claws are removed and the crab is returned to the water, allowing for potential claw regeneration. No research has examined how MHWs influence the post harvest physiology and survival of stone crabs following claw removal. Here we used a 30-year temperature record from Tampa Bay to simulate MHWs during the stone crab fishing season to determine the combined effects of thermal stress from MHWs and physical stress experienced during declawing. Crabs were gradually exposed to elevated temperatures over several weeks (ramp-up period) and then maintained at heat-wave temperatures for the average duration observed for each winter month. Mortality, animal movement (accelerometers), and physiology (respirometry) were measured before and after claw removal. Results showed that crabs with both claws removed experienced mortality within 24-hrs. Crabs with one claw removed also exhibited mortality within 2-3 days during MHW exposure, had higher stress, reduced movement, and elevated oxygen consumption. Crabs with no claws removed survived longer but still experienced mortality after 6-11 days of heat exposure. These findings suggest that stone crabs may struggle to survive declawing when exposed to prolonged stress associated with MHW.

For more information: 

peseidle@eckerd.edu | smabbott@eckerd.edu