Global fisheries are declining faster than we thought: What can be done?

In a comprehensive study of all the world’s fisheries, including small-scale or illegal ones, a team of researchers found that catches have been declining three times faster than the United Nations had projected.

Since the peak of marine fishery production in 1996, at 130 million metric tons, catches have declined every year by more than one million metric tons. The study authors suggest that this is because of overexploitation and hope the results will help inform countries' fisheries management practices. 

Between 1950 to the early 1990s, industrial fishing rose as fleets expanded globally, meaning that fisheries from countries like the United States and China began fishing in the seas of developing countries. As fish export became continental rather than local, small-scale fisheries that traditionally supplied seafood to coastal rural regions failed to compete with the industrial fleets.

With more than 400 researchers around the world contributing to the study, published Tuesday in the journal Nature Communications, the results reflect a decade’s worth of work. It entailed looking at a large volume of analysis outside the reportings of the UN’s Food and Agriculture Organization, which the scientists say underestimated the highpoint of catches as well as the extent of decline.

“Our results differ very strongly from those of the FAO,” Daniel Pauly, a professor the University of British Columbia in Canada and lead author of the study, told reporters during a press call. “Our results indicate that the decline is very strong and is not due to countries fishing less. It is due to countries having fished too much and having exhausted one fishery after another.”

The FAO data, which projects that the peak in catches was 86 million metric tons, does not account for small, subsistence, or illegal fisheries and the number of fish released as bycatch. In this trajectory, the annual decline is only 0.4 million metric tons. But by closely examining fishing and fish consumption reports at the local level – including data as specific as hotel invoices for locally bought fish – the researchers were able to greatly supplement the FAO figures.

Understanding the extent of overfishing means it’s now important for rebuild the stock of fish through restrictive measures.

“The fact that we catch far more than we thought is, if you like, a more positive thing,” Dr. Pauly told reporters. “Because if we rebuild stocks, we can rebuild to more than we thought before.”

Some Norwegian herring and cod fisheries, for instance, have been able to successfully revitalize the stock of fish. But it’ll be vital for other countries to realize the problem as well.

“I expect a continued decline because I don’t expect countries to realise the need to rebuild stocks. I don’t see African countries, for example, rebuilding their stocks, or being allowed to by the foreign fleets that are working there, because the pressure to continue to fish is very strong,” Pauly added. “We know how to fix this problem but whether we do it or not depends on conditions that are difficult.”