Abstract

Stone crab Menippe mercenaria represent an important and growing fishery in Florida and the Caribbean, but one with unique challenges for managers. It is a trap-based, claw-removal fishery wherein legal-sized claws are removed and live crabs returned to the water. Though laboratory and field studies suggest that only 20-40% of harvested animals survive the trauma of two claw harvest, landings suggest that at least a small portion of crabs (it is estimated that 4-13% of claws landed are regenerated) survive to regenerate claws and re-enter the fishery. Released crabs, including sublegal individuals, have been in traps for up to a month, where close contact with conspecifics could lead to rapid disease transmission. Crabs that survive harvest have limited access to prey, which could be detrimental to their nutritional condition, could lead to a trophic shift, and also could affect disease transmission. To examine disease and trophic structure of fished crabs, we collected stone crabs from Florida Wildlife Research Institute’s regularly monitored traps in Cedar Key (n = 155) and Harbor Key (n = 128) in 2019-2020. All crabs were necropsied and screened for disease via histopathology and molecular diagnostics. Trophic status was assessed through carbon and nitrogen stable isotope analysis of the muscle and hepatopancreas to determine longer- and shorter-term diet, respectively. This study is the first to assess stone crab diet changes after harvest in the wild and will help managers better understand the impacts of harvest and whether returning animals to water affects disease ecology.

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