Lethal and sub-lethal effects of insecticides on blue crabs (Callinectes sapidus): malathion, resmethrin and carbaryl

Blue crabs (Callinectes sapidus) are ecologically and economically important estuarine species, but, their populations throughout the US are declining. The decline continues to occur despite fishing regulations and stocking programs, suggesting that there may be alternative causes for the dwindling populations. Spending most of their lives in estuarine waters, blue crabs are exposed to non-point sources of pollution such as insecticide run-off that may have significant but unqualified effects on their populations. This study will investigate the lethal (consumption) and sub lethal (behavioral) effects of three common and diverse insecticides (malathion, resmethrin and carbaryl) in order to achieve a better understanding of how realistic concentrations and combinations of insecticides affect blue crabs. Survivorship behaviors (eyestalk reaction speed, consistency of responses, and characterization of responses) and righting time (the time it takes a crab to resume its normal position after placed on its back) of juvenile (8-35mm) and adult (60+ mm)  blue crabs will be affected by different concentrations and combinations of three common insecticides. Currently existing knowledge on anthropogenic pollution and how it affects blue crabs is limited to fresh water systems. By investigating blue crab toxicity it will generate in depth knowledge on three commonly used pesticides and how they affect blue crab populations in local estuarine systems.