Increasing habitat fragmentation is a major contributing factor to dramatic reductions in populations of migratory species worldwide. Diadromous fish species in particular are affected by this anthropogenic disturbance, resulting in historically low population abundances. Despite a plethora of management measures and considerable investment, desired results are often lacking. Here, we highlight five important considerations – the “Big Five” – for diadromous species management: removal of barriers to migration, installation of fish passages, habitat restoration, restocking, and fisheries management. We review current management measures and their effectiveness, and propose a way forward. Current management of diadromous fish populations largely focuses on mitigation of migration barriers, but management will likely fail if other fundamental aspects of diadromous species’ life cycles are overlooked or disregarded. We therefore propose an integrated management strategy that takes into account the five major factors influencing diadromous fish species, with the ultimate goal of restoring their populations.

中文翻译：

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制定双河鱼类保护路线图：五大考虑因素

越来越多的栖息地破碎化是导致全球迁徙物种数量急剧减少的一个主要因素。这种人为干扰尤其会影响双河鱼类，导致人口丰度处于历史低位。尽管采取了过多的管理措施和可观的投资，但往往达不到预期的效果。在这里，我们强调了对洄游物种管理的五个重要考虑因素——“大五”：消除洄游障碍、安装鱼类通道、栖息地恢复、重新放养和渔业管理。我们审查当前的管理措施及其有效性，并提出前进的方向。目前对逆流鱼类种群的管理主要侧重于减轻迁移障碍，但如果忽视或无视环游物种生命周期的其他基本方面，管理可能会失败。因此，我们提出了一种综合管理策略，该策略考虑了影响洄游鱼类的五个主要因素，最终目标是恢复它们的种群。