A computational approach to ecological and economic sustainable harvest management strategies in a multi-species context, with implications for cod recovery plans

Multi-species models consider interactions, particularly predation, between and within species. Traditional harvest management strategies, such as maximum sustainable yield do not account for these interactions. The exploitation of a single species can be maximised, but this does not mean that the entire ecosystem is being harvested sustainably or at its economic maximum. I present a computational technique (evolutionary algorithms) that can simultaneously optimise harvest management strategies of many species and can easily be modified to allow for factors such as stock recovery, sustainable yields or maximum levels of economic sustainable exploitation. I demonstrate that in an ecologically sustainably managed system where a stock is recovering, maximum economic yield is identical to the maximisation of yield by mass. These findings may have important implications for long term conservation aims and long term profits by fishers.