Natural ecological communities exhibit complex mixtures of interspecific biological interactions, which makes finding optimal yet sustainable exploitation rates challenging. Most fisheries management advice is at present based on applying the Maximum Sustainable Yield (MSY) target to each species in a community by modelling it as if it was a monoculture. Such application of single-species MSY policies to strongly interacting populations can result in tragic overexploitation. However, the idea of ‘maximising the yield from each species separately’ can be extended to take into account species interactions. This leads to a form of Nash Equilibrium, where the yields of each species are simultaneously maximised. Here we present ‘nash’, an R package that streamlines the computation of Nash equilibrium reference points for fisheries and other systems represented by a user-defined multispecies or ecosystem model. We present two real-world fisheries management applications alongside performance benchmarks. Satisfactory search results are shown across models with an approximate factor 7 increase in performance when compared to the expensive round-robbing sequential optimisation algorithms used by other authors in the literature. We believe that the nash package can play an instrumental role in fully implementing ecosystem-based management policies worldwide.

中文翻译：

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寻找相互作用鱼类种群的多物种 MSY 的有效工具

自然生态群落表现出种间生物相互作用的复杂混合物，这使得寻找最佳且可持续的开发率具有挑战性。目前，大多数渔业管理建议都是基于将最大可持续产量（MSY）目标应用于社区中的每个物种，将其建模为单一养殖。将单一物种 MSY 政策应用于强相互作用的种群可能会导致悲惨的过度开发。然而，“分别最大化每个物种的产量”的想法可以扩展到考虑物种相互作用。这导致了一种纳什均衡，其中每个物种的产量同时最大化。在这里，我们提出了“ nash ”，一个R包，它简化了渔业和由用户定义的多物种或生态系统模型表示的其他系统的纳什平衡参考点的计算。我们展示了两个现实世界的渔业管理应用程序以及性能基准。与文献中其他作者使用的昂贵的轮询顺序优化算法相比，各个模型都显示出令人满意的搜索结果，性能提高了大约 7 倍。我们相信，纳什一揽子计划可以在全球范围内全面实施基于生态系统的管理政策方面发挥重要作用。