Something fishy in the effect of fishery management

Today Anthropocene Magazine published “Contrary to popular belief, fish stocks are not declining in all parts of the ocean,” by Emma Bryce. The article describes a new study claiming that ocean overfishing is not as widespread a problem as people might think.

the study showed that wherever fisheries are being scientifically monitored, there has actually been an average increase in abundance over the past few decades. The researchers put this down to improved management in these monitored fisheries – which allows stocks to recover and replenish, thanks to measures including catch limits designed to curtail overfishing.

Regions with intensive fishery management tend to show improving stock abundance. Fishery improvement is welcome news and critically important for biodiversity protection and ocean health. However, the article does not address what could be the underlying reason management is associated with fishery improvement, and that underlying reason should raise alarms rather than congratulations.

Intensive fishery management often occurs in response to fishery collapse. If management is caused by fishery collapse, fishery improvement under intensive management might start from a baseline of extremely low fishery abundance. So, rather than intensive fishery management causing healthy fisheries, it might be the case that extremely unhealthy, dying fisheries cause governments to adopt intensive management in an effort to save the fishery from extinction.

This alternative explanation undermines the author’s interpretation that the study “provided evidence of a concrete link between reduced fishing pressure – driven by better management – and more abundant fisheries.”

Instead, fishing pressure is reduced by overfishing-induced fishery collapse. The collapse also creates political pressure to allocate tax money to intense fishery management to “save the fishery,” though such management is more often motivated by preserving communities and ways of life that were enabled by the overfishing that caused the collapse.

While the article frames the study as reporting good news for fisheries, there is an underlying story of harm to fisheries that is required to motivate intensive management. Though the study suggests “management really does work,” it is not evidence that management prevents fishery collapse and potentially permanent abundance declines from happening in the first place.