PREDICTING MARICULTURE'S IMPACTS ON WILD FISHERIES

Jessica Couture, UC Santa Barbara, Bren School of Environmental Science and Management, Santa Barbara, CA, United States, Steven Gaines, University of California Santa Barbara, Santa Barbara, CA, United States and Benjamin Halpern, UC Santa Barbara, Santa Barbara, CA, United States
Abstract:
The ability of wild fisheries to supply society’s demand for healthy marine-based protein has grown insufficient, as global wild fisheries yields have remained stagnant over the past decades. As a result, the world is turning to marine aquaculture as an efficient solution to a growing demand for protein to minimize conflicts with dwindling resources such as land and water resources, but fisheries also still provide a substantial portion of marine derived protein to human diets. Therefore, as we push farming out into the wild ocean, it is important to understand how these farms will impact our wild fish resources. So far we have seen cases of high pollution and eutrophication from mariculture decimate wild fished populations, moderate levels of eutrophication and increased structure aggregate and increase food availability for commercial species, and some farms that seem to have little impact on wild fisheries. Is there a way we could anticipate how wild fisheries will react to a mariculture farm? How can different management and spatial planning strategies be used to mitigate negative impacts on wild stocks? To address these questions, we constructed a framework to predict the responses of wild fisheries to different mariculture farm designs and management strategies. Applying theory about the impacts of marine protected areas and population dynamics, this multi-species bioeconomic model estimates the total benefits from fishing and farming relative to a baseline yields in the absence of a farm and can be used to predict the impacts of different farm designs and types on local fish populations and fisheries.