Anthropogenic activities are increasing seawater temperatures at an unprecedented rate, with shallow costal environments experiencing these changes more rapidly Some organisms may not be able to acclimatize to the rate of temperature increase in shallow coastal environments. Here we determined the physiological response of female stone crabs (Menippe mercenaria) to elevated temperatures ranging from 24℃–36℃. Metabolic rates (mg O2 hr-1) were measured using closed respirometry. Hemolymph was extracted to measure lactate and protein serum concentrations. The reflex action mortality predictor test (RAMP) was also performed to measure sublethal stress. During exposure to extreme temperatures (36℃) stone crabs had higher lactate (202%), higher protein levels (21%), and RAMP scores on average were 5x higher in comparison to the ambient (24℃). Oxygen consumption also increased as temperatures increased. These results suggest that adult stone crabs may have physiological difficulty compensating for thermal stress resulting in more predation or mortality and potentially contributing to a loss for the commercial fishery in the absence of acclimatization.

For more information:  jmballard@eckerd.edu