Actions for restocking of the European lobster (Homarus gammarus): a case study on the relevance of behaviour and welfare assessment of cultured juveniles

Restocking and stock enhancement of marine organisms are increasingly becoming a common practice to replenish populations of fish and invertebrates. As for aquaculture, they raise several conservation and welfare issues. Here, we focus on lobsters (Homarus sp.), crustacean decapods that have been cultivated and released since the end of the nineteenth century. In Europe (H. gammarus), in the last three decades these actions have been prompted by dramatic stock depletion and efficient rearing technology, yet often overlooking ecological and behavioural data. We emphasize the relevance of behaviour and welfare assessment of cultured juveniles during the early benthic phase and report an experimental case study in which rearing conditions of juveniles were varied shaping distinct profiles in sheltering behaviour. Simple rearing procedures of environmental enrichment coupled with behavioural tests may allow improving and assessing the survival skills of individuals that will be released, at the same time ameliorating their welfare conditions and eventually increasing restocking success.