The world’s fish stocks are dying. More than 85% of the world’s fisheries have been pushed to or beyond their biological limits from overfishing, and that’s not considering broader ecosystem threats like pollution and climate change.

Scientists, environmentalists, and even economists are increasingly paying attention to an idea to help renew fish stocks that at first seems radical, and then seems completely reasonable the more and more it’s studied: A ban on fishing in international waters, an area that covers 60% of world’s oceans.





“Doing this can serve as a cushion, or a form of resilience, for the global oceans,” says Rashid Sumaila, director of the University of British Columbia’s Fisheries Economics Research Unit and lead author of a recent study in Nature Scientific Reports.

Fishing is divided into two areas today. Nations have “exclusive economic zones” within 200 miles of their coastline where they manage all fishing activities, and 90% of fish are caught in these areas today, according to Sumaila. High seas fishing, therefore, is only a small sliver of total fish caught, but it is a disproportionately destructive sliver. Management of the high seas is a mess of rules today, and the lack of protection for biodiversity in these areas results in unlimited fishing of vulnerable species like tuna and related problems with bycatch and habitat destruction. These are the reasons why the UN recently agreed that a new international treaty is needed to address this ecological crisis.

Winners and losers with a high seas ban, Credit: Rashid Sumaila/Nature Scientific Reports

This is all the background in which Sumaila–an economist, not an ecologist–has done his work. He started looking into the idea that high seas fishing should be banned in 2005 and came to the conclusion that not much money would be lost. When he presented before the Global Ocean Commission, a group of NGOs, world leaders, and business groups, several years ago, he briefed them on the “bold idea” (they were looking for bold ideas). “They jumped on their seats. Half of them like it, and half of them thought it was madness,” he says.

Other scientists are paying more and more attention. A study last year found that a ban would be a triple win: It would increase fishery profits, fishery yields, and improve fish stock conservation dramatically.

Since many fish caught on the high seas also migrate into coastal areas, closing fishing in international waters would both serve as a protected reservoir and cause “spillover,” therefore boosting coastal catches by at least 18%, according to Sumaila’s estimates. If that was achieved, overall catches globally would at least stay the same and probably would increase, he says.