Well-established single-species approaches are not adapted to the management of mixed fisheries where multiple species are simultaneously caught in unselective fishing operations. In particular, ignoring joint production when setting total allowable catches (TACs) for individual species is likely to lead to over-quota discards or, when discards are not allowed, to lost fishing opportunities. Furthermore, economic and social objectives have been poorly addressed in the design of fisheries harvest strategies, despite being an explicit objective of ecosystem-based fisheries management in many jurisdictions worldwide. We introduce the notion of operating space as the ensemble of reachable, single-species fishing mortality targets, given joint production in a mixed fishery. We then use the concept of eco-viability to identify TAC combinations which simultaneously account for multiple objectives. The approach is applied to the joint management of hake and sole fishing in the Bay of Biscay, also accounting for catches of Norway lobster, European seabass and anglerfish. Results show that fishing at the upper end of the MSY range for sole and slightly above Fmsy for hake can generate gains in terms of long-term economic viability of the fleets without impeding the biological viability of the stocks, nor the incentives for crews to remain in the fishery. We also identify reachable fishing mortality targets in the MSY ranges for these two species, given existing technical interactions.

完善的单一物种方法不适用于混合渔业的管理，在混合渔业中，多种鱼类在非选择性捕捞作业中同时被捕获。特别是，在为单个物种设定总允许捕捞量时忽略联合生产很可能导致超额抛弃，或在不允许抛弃的情况下失去捕捞机会。此外，尽管在世界范围内许多司法管辖区都明确了基于生态系统的渔业管理目标，但在制定渔业捕捞战略时却没有很好地解决经济和社会目标。考虑到混合渔业中的联合生产，我们将操作空间的概念引入为可达到的单一物种捕捞死亡率目标的集合。然后，我们使用生态可行性的概念来识别同时考虑多个目标的TAC组合。该方法适用于比斯开湾的无须鳕和单一捕鱼的联合管理，也可用于捕捞挪威龙虾，欧洲鲈鱼和and鱼。结果表明，在MSY范围的高端进行唯一捕捞，而在无须鳕上稍高于Fmsy进行捕捞，可以在不损害种群生物生存力的情况下获得船队的长期经济生存力，也不会激励船员留下来在渔业中。考虑到现有技术上的相互作用，我们还确定了这两个物种在MSY范围内可达到的捕捞死亡率目标。还占挪威龙虾，欧洲鲈鱼和and鱼的捕获量。结果表明，在MSY范围的高端进行唯一捕捞，而在无须鳕上稍高于Fmsy进行捕捞，可以在不损害种群生物生存力的情况下获得船队的长期经济生存力，也不会激励船员留下来在渔业中。考虑到现有的技术相互作用，我们还确定了这两个物种在MSY范围内可达到的捕捞死亡率目标。还占挪威龙虾，欧洲鲈鱼和and鱼的捕获量。结果表明，在MSY范围的高端进行唯一捕捞，而在无须鳕上稍高于Fmsy进行捕捞，可以在不损害种群生物生存力的情况下获得船队的长期经济生存力，也不会激励船员留下来在渔业中。考虑到现有技术上的相互作用，我们还确定了这两个物种在MSY范围内可达到的捕捞死亡率目标。也不鼓励船员留在渔业中。考虑到现有技术上的相互作用，我们还确定了这两个物种在MSY范围内可达到的捕捞死亡率目标。也不鼓励船员留在渔业中。考虑到现有技术上的相互作用，我们还确定了这两个物种在MSY范围内可达到的捕捞死亡率目标。