Date of Award

5-2017

Document Type

Open Access Thesis

Department

Marine Science

First Advisor

Blaine Griffen

Abstract

The stone crab, Menippe spp., is harvested in a claw only fishery along the Gulf and southeastern Atlantic coasts of the United States. As climate change continues to warm these areas, crabs are forced to cope with higher water temperatures and lower dissolved O2 concentrations. These altered environmental conditions may influence crab energetics by altering both energy intake and expenditure. To inform fishery sustainability as well as prepare for a potential range expansion of the crab, this study investigates the energetic intake and expenditure of individual stone crabs. Crabs were found to respire 80 and 69% more following the loss of major and minor claws, respectively. The Q10, the factor by which the mass-specific respiration rates change as the temperature is increased by 10°C, was found to be 1.536. Mortality as a result of first and second claw loss were 6.25 and 13.3% when using stimulated sequential autotomization. Consumption of oysters in field cages increased by 15.8% of the crabs’ weight for every 10°C increase in water temperature. Ingestion efficiency did not significantly vary with crab size, water temperature, or claw loss. I hypothesize that the ingestion efficiency of soft tissue did not change with the loss of the claws due to the unique feeding behavior of the stone crab. The front four walking legs were used more in food manipulation than both major and minor claws. Although current regulations were designed to promote the reentry of previously harvested crabs to the commercially available stock, the results of this study suggest stone crabs may struggle to cope with fishery-style claw loss in warming conditions expected with continued climate change, especially in areas that are O2 depleted.

Rights

© 2017, Eric R. Hancock

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