With demand for seafood increasing and numerous fish species declining due to overfishing and other threats, scientists are proposing a seemingly drastic solution: close the high seas to fishing and turn it into “a fish bank for the world.” Don’t worry, they say, doing so won’t affect the fishing industry’s economic returns, and will ensure that profits from fisheries are more equitably distributed.
Marine areas within 200 nautical miles of countries’ coasts are designated the countries’ “Exclusive Economic Zones” (EEZs). Beyond the EEZs are the high seas, international waters that “belong” to the people of the world. After depleting fish stocks close to the coasts, many countries have taken to fishing in the high seas. This contributes to overexploitation of commercial fish species and threatens nontargeted species with habitat destruction, by-catch, and other problems. Currently, high-seas catches are worth about $16 billion annually — roughly 15 percent of the global catch’s annual worth of $109 billion.
Regional Fisheries Management Organizations (RFMOs) — international organizations formed by countries that fish in a particular area — have been trying to protect marine ecosystems in some parts of the high seas by implementing fisheries closures. Otherwise, the only legislation governing fishing in the high seas is the United Nations Convention on the Law of the Sea, an international agreement that recognizes all states’ right to freely fish the high sees, but lays down only general principals for conservation and management.
“The world community has been trying to reduce the common property problem by encouraging the formation of RFMOs,” fisheries researcher Rashid Sumaila of the University of British Columbia told mongabay.com. “However, most analysts have come to the conclusion that many RFMOs have not been successful.” Two-thirds of the stocks with known status being managed by RFMOs were depleted or overfished, studies show.
Another solution was needed. A 2014 study proposed the bold idea of closing the high seas to fishing outright, and found that doing so would actually increase the profits earned by fisheries as well as improve fish stocks.
To investigate the plausibility and likely outcomes of this idea, Sumaila and a team of international fisheries experts examined catch data for 2000 to 2010 from the Sea Around Us global catch database and landings data for 1950 to 2010 from the UN Food and Agriculture Organization. They published their paper in February in the journal Scientific Reports.
Sumaila’s team could see that just 19 out of the 1,406 targeted species were fished exclusively from the high seas. 802 were caught only within EEZs and 585 “straddling species,” as the study calls them, were fished from both the high seas and EEZs. Less than 0.01 percent of the quantity and value of commercial fish come from catch taken exclusively in the high seas, they found.
Crunching the numbers some more, the team showed that closing down fishing in the high seas would not lead to losses in the global catch. That presumes that the catches of straddling taxa would increase by an average of 18 percent in the EEZs, a reasonable expectation if the increased biomass of fish in the high seas spills over into the EEZs, as the study predicts. In fact, the mathematical models used in the study show that the biomass of the straddling species would increase by 10 to 70 percent.
The study found that the world as a whole would actually achieve net economic gains if fishing on the high seas were shut down. Most coastal countries — 120 of them — including developing countries, stand to gain, according to the paper. Sixty-five countries stand to lose, and seven would neither gain nor lose. Moreover, the distribution of fishing profits would become more equitable. Currently, just ten fishing countries capture most of the high seas catch and economic benefits.
Sumaila’s team noted additional benefits, too. “In general, vessels fishing the high seas travel longer distances, spend longer searching for fish, and therefore incur a higher cost per unit weight of fish than vessels fishing solely within EEZs. This means that closing the high seas would, all else being equal, reduce the burning of fossil fuel and the cost of fishing globally,” the authors write.
“This is an interesting idea that a number of scientists and economists are beginning to explore,” said Karen Sack, managing director of Ocean Unite, an advocacy group that is part of the Virgin Group’s corporate foundation. “Given the threats to ocean health from overfishing, climate change and pollution, all of which are putting huge strains on marine life, we need to be open to exploring bold ideas,” she told mongabay.com.
“Any such closures have to matched with sustainable fisheries policies that make sure that where fish can be caught, scientific quotas are set that do not deplete the stock, and that fishing gear that is used does not destroy fish habitat and associated biodiversity,” added Sack.
However, before enacting a ban on fishing in the high seas, further testing of theoretical predictions using actual data is necessary, said Crow White, a fisheries expert with the Sustainable Fisheries Group at the University of California, Santa Barbara, and the lead author of the 2014 paper that proposed closing the high seas.
One nagging question is how such a closure might actually be enforced, given the vastness and remoteness of the high seas, and the lack of jurisdiction of any existing governing authority. Implementing a closure “would require fundamental reform of ocean governance,” the authors acknowledge, but they argue that such reform is possible and may eventually even be inevitable given increasing human activity on the high seas.
“I think this kind of regulation is more enforceable now than ever before in human history, for at least two reasons,” White told mongabay.com via email. “One, satellite technology enables remote monitoring of ships. No longer is it a cat and mouse game of enforcer and poacher, but instead an eye in the sky game. Second, the world spends ~$2b/year subsidizing high seas fisheries. With the closure, some of that money can be spent on enforcement.”
- White, C., & Costello, C. (2014). Close the high seas to fishing?. PLoS Biology 12(3): e1001826.
- Sumaila, U.R., Lam, V.W., Miller, D.D., Teh, L., Watson, R.A., Zeller, D., Cheung, W.W.L., Côté, I.M., Rogers, A.D, Roberts, C., Sala, E. & Pauly, D. (2015). Winners and losers in a world where the high seas is closed to fishing. Scientific Reports 5: 8481.