Indirect effects of recreational fishing on behavior of the spiny lobster Panulirus argus

Sublethal disturbance may lead to behavioral modifications that have detrimental consequences for the individual. Sublethal disturbance is an indirect effect of fishing that has seldom been examined. In summer 2003, we conducted surveys on the Caribbean spiny lobster Panulirus argus in the Florida Keys, USA, before and after a 2 d mini-season exclusively for recreational sportdivers to assess the frequency of injured lobsters. We also conducted (1) a tethering experiment to assess the influence of disturbance and injury on predation-induced mortality, and (2) Y-maze laboratory experiments to assess the effect of injury and disturbance on the shelter choice of conspecifics. Injury surveys revealed an immediate increase (to 27.16%) in the percentage of injured lobsters from preto post mini-season within patch reef habitats, but only a small increase in injured lobsters amongst patch head habitats. Tethering trials revealed that injured lobsters were more likely to succumb to predation than uninjured controls, while the shelter choice experiments demonstrated that the usual ability to attract conspecifics was altered by injury. Considering the ability of this fishery to unintentionally injure >25% of the lobster population in patch reef habitats in just 2 d, the potential population consequences to spiny lobsters must be examined.