Assessing the role of supplementation stocking: A perspective

Although it is widely accepted that stocking hatchery-cultured fish can increase the number of fish, decades of scientific evidence have shown that most often those stocking efforts fail to provide the desired demographic boost to a naturally reproducing, self-sustaining target population. Despite this evidence, fish stocking remains a mainstay of fisheries management programmes, even as the biodiversity of wild fish populations and other aquatic organisms are at serious risk due to habitat loss and/or overexploitation across the globe. In this perspective piece, we summarise the reasons why wild and hatchery-produced fish are not equivalent and describe the genetic and ecological risks associated with stocking programmes. We then present our perspective on the institutional changes that need to occur to assess these risks and offer ways to transition fisheries management strategies to become more effective in conserving levels of aquatic biodiversity from populations to landscapes. We propose that a critical first step to control ill-conceived fish stocking programmes is to have each country develop, implement, and enforce a scientifically sound National Fish Stocking Policy. To achieve the long-term sustainability of native fish populations, it is imperative that ecological and evolutionary principles be better integrated into future conservation strategies and management actions.

Automated summary

While stocking hatchery-cultured fish is known to increase fish populations, evidence suggests that it often fails to boost naturally reproducing populations. Despite this, fish stocking remains a common practice in fisheries management programs, even as wild fish populations and other aquatic organisms are at risk due to habitat loss and overexploitation. This perspective piece highlights the genetic and ecological risks associated with stocking programs and proposes institutional changes to assess and manage these risks for the conservation of aquatic biodiversity.