This article examines the role of risk aversion on the sustainable management of mixed fisheries. We consider a bio-economic model of multiple species harvested by a single fleet with uncertain costs ...of effort. We assume that the regulatory agency aims at reaching MMEY (Multispecies Maximum Economic Yield) by maximizing the expected utility of total profits, where the utility function captures risk aversion. We show analytically that such a risk-averse MMEY mitigates the risk of biological and economic overexploitation of the different species and thus of biodiversity loss. However excessively high risk aversion also may also lessen food production at MMEY. Thus, risk aversion implies a trade-off between different bio-economic goals. These findings are illustrated with the case study of the Australian South East Fishery, where intermediate risk aversion levels allow for balanced bio-economic management objectives, therefore fostering sustainability.
This paper examines the role of risk aversion on the sustainable management of multispecies fisheries with technical interactions. We consider a bio-economic dynamic model of multiple species ...harvested by a single fleet with uncertain costs of effort. We assume that the regulatory agency aims at reaching MMEY (Multispecies Maxi-mum Economic Yield) in an uncertain context by maximizing the expected utility of total profits, where utility is a quadratic function capturing risk aversion. We ana-lyze the impact of risk aversion on optimal fishing effort, profit, production, biodiver-sity and conservation. We show analytically that such a risk-averse MMEY promotes bio-economic sustainability as it mitigates the risk of biological and economic over-exploitation of the different species. Risk aversion also enhances biodiversity in the sense of evenness within the portfolio of the fishery. However, by reducing the effort, risk aversion lessens the expected profit and food production. Thus, a trade-off be-tween different bio-economic goals is exhibited through risk aversion. We illustrate the analytical findings with the case study of the Australian South East Fishery, where small risk aversion levels allow for high global bio-economic performances and balanced management objectives, therefore fostering sustainability.
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