Interactions between finfish aquaculture and American lobster in Atlantic Canada

Globally, lobsters are one of the most economically valuable wild species caught in capture fisheries. Catches are dominated by American lobster (Homarus americanus) landed entirely in Atlantic Canada and northeastern United States. In Atlantic Canada, lobster fishing and marine finfish aquaculture take place in the same coastal waters creating the potential for negative environmental, as well as social, interactions. We review the state of knowledge of environmental interactions between American lobster, their habitat and fishery, and marine finfish aquaculture. We first provide a brief overview of key biological, behavioural, and ecological processes and environmental stressors of American lobster at different life-history stages followed by an overview of the pathways of effects of marine finfish aquaculture on coastal ecosystems in general and on American lobster. Our review found that certain finfish aquaculture-lobster interactions have received considerable study (e.g., chemical use), whereas knowledge of other interactions are either limited (e.g., net pens, waste discharges) or lacking (e.g., disease, noise, lights, and odours). An ecosystem-based approach to aquaculture has been proposed for managing these interactions but implementing this approach has proven to be a challenge in part because of complex multi-sector, multi-stakeholder and multi-agency governance issues. While governance solutions await development, practical measures based on the results of scientific research identified in this review, such as better use of existing oceanographic and bathymetric data, habitat and human impact assessment tools, and toxicity information offer regulators ample information and management tools, at least at the farm- and bay-scale, to avoid negative finfish aquaculture-lobster interactions in Atlantic Canada. Bridging the governance gap will likely require new community-based management models that more effectively identify, generate, and integrate local community and fisher knowledge and concerns.