December 14, 2021 — A scientific paper (Cabral et al. 2020, A global network of marine protected areas for food) that claimed that closing an additional 5% of the ocean to fishing would increase fish catches by 20% has been retracted by Proceedings of the National Academy of Sciences of the United States of America (PNAS), the journal in which it was published.

At the time of publication, the paper’s findings were immediately covered by The Economist (Stopping some fishing would increase overall catches) and Forbes (Protecting 5% More Of The Ocean Can Increase Fisheries Yield By 20% According To New Research) and other mainstream outlets, including the New York Times, Axios, National Geographic, and The Hill.

Representative Deb Haaland, now the Secretary of the Interior, who recently restored Obama-era prohibitions on fishing in the Northeast Canyons and Seamounts Marine National Monument without scientific or economic review — and without meeting with affected fishermen —  submitted the now-retracted paper as supporting evidence for the “30×30” provisions of the Ocean-Based Climate Solutions Act. The provision calls on the federal government to conserve at least 30% of Federal waters by the year 2030. (For a longer critique of the 30×30 initiative see this piece by Dr. Roger Mann of the Virginia Institute of Marine Science at the College of William and Mary).

It has since been determined that the paper had both conflict of interest as well as data and model assumption problems.

PNAS determined that the person responsible for assigning Cabral et al.’s peer reviewers, Dr. Jane Lubchenco, currently White House Deputy Director for Climate and Environment, had a conflict of interest. According to the editor-in-chief of PNAS, the frequent collaboration relationship Lubchenco had with the paper’s authors constituted a conflict of interest, as did her personal relationship with one of the authors, Dr. Steve Gaines—her brother-in-law.

Several close collaborators of the Cabral et al. group wrote scientific critiques that pointed out errors and impossible assumptions that suggested the paper was inadequately peer reviewed.

According to an analysis of the paper from Sustainable Fisheries at the University of Washington:

Cabral et al. 2020 assembled a computer model out of several kinds of fishery data to predict where marine protected areas (MPAs) should be placed to maximize global sustainable seafood production. MPAs meant to increase food production do so by reducing fishing pressure in places where it is too high (overfishing). Asia and Southeast Asia have some of the highest overfishingrates in the world—reducing fishing pressure there is a no-brainer, but the model determined many of those areas to be low priority for protection.  The results should have been red flag for the peer reviewers of Cabral et al. 2020. Why were MPAs prioritized all around the U.S., where overfishing has been practically eliminated, but not prioritized around India, Thailand, Indonesia, Malaysia, Vietnam, and China?

Clearly, something was wrong with the model.

For more about the problems with this paper, as well as a look at concerns with another headline-grabbing study that suggested carbon emissions from bottom trawl fishing are similar to emissions from global aviation, see the Sustainable Fisheries analysis here.