EEZs deter unauthorized fishing – but only in high-value fisheries

Exclusive economic zones (EEZs) deter unauthorized fishing by foreign vessels, but only in a handful of countries where the value of the fishery surpasses steep enforcement costs.

A new study finds that unauthorized fishing is 81 percent lower just inside the 200-mile EEZ boundaries compared to just outside them, an indication that assigning nations fishing property rights could lead to protecting fisheries from unauthorized fishing.

This deterrence effect suggests that some countries make an effort to enforce their EEZs, despite the high costs of doing so. After all, sending patrol boats and aircraft 200 miles from shore to track down interlopers isn't cheap. And the confrontations that ensue can raise diplomatic hackles between countries, as when the Argentine Coast Guard opened fire on a Chinese vessel it claimed was illegally fishing in its waters.

"Exclusive economic zones are one of the toughest enforcement challenges in the ocean," Gabriel Englander, author of the study and a PhD student at the University of California, Berkeley, told SeafoodSource.

Access is not enforced equally everywhere. High value fisheries — which the study categorized as those with the highest net primary productivity —  incentivize countries to spend spend money on enforcement. Just 10 EEZ sea regions accounted for the vast majority of the global deterrence effect, 97 percent of it. The regions were Argentina, Iceland, Norway, Faroe Islands, Falkland Islands, Canada, Marshall Islands and Peru, with the biggest effect in Argentina, Peru, and Chile.

"The large global effect is coming from just a couple places," Englander said. "The costs of enforcement are so high and so it's only worth it for countries to enforce their EEZs if it's very valuable.”

The world’s remaining EEZ-sea regions either had small deterrence effects (56 EEZ-sea regions) or did not deter unauthorized foreign fishing at all (112 EEZ-sea regions). Of those 112 EEZ-sea regions, 27 did not have enough unauthorized foreign fishing near the boundary to estimate an effect. In the remaining 83 EEZ-sea regions did not deter unauthorized foreign fishing, which is actually slightly higher inside the EEZ boundary.

The 200-mile EEZ boundary was first established in the 1970s, extending the previous three-mile boundary and giving nations authority over the fish, oil and mineral resources within 200 miles of their shorelines. Sometimes countries prohibit all fishing by foreign vessels inside their EEZs; other times they allow it in exchange for payment by foreign vessels or governments. Countries can negotiate access agreements, specifying allowable target species, quantities, and fishing methods.

While convenient, EEZ boundary lines are ecologically arbitrary, with no difference in ocean depth, sea surface temperature, or net primary productivity on either side of the boundary. Some fisheries lie entirely within a single country's EEZ, but many others straddle areas managed by two or more countries or the high seas.

“These straddling stocks have to contend with exploitation by all the coastal states plus fishing by distant water nations operating in the high seas,” Scott Barrett, a professor of natural resources economics at Columbia University, who wrote a commentary about the study, told SeafoodSource. 

The arbitrary nature of the EEZ boundary means that differences in unauthorized fishing activity on one side or the other could be attributed to the EEZ itself.

While the study determined that EEZs effectively deter unauthorized fishing, at least in some instances, it's a separate question whether EEZs actually deter overfishing. Just because a country has sole control over a fishery does not mean the country will prioritize conservation.

“Coastal states may not manage fishing inside their EEZs efficiently. For political economy reasons, or a lack of domestic sovereignty, too much fishing may occur within the EEZs,” Barrett said. “This study is able to show that there is more unauthorized fishing outside the EEZ than inside, but it isn’t able to show that there is less fishing effort overall with the EEZ than without one.”

Answering that question will be important for countries currently negotiating a proposed United Nations high seas treaty — put forward by the Intergovernmental Conference on Marine Biodiversity of Areas Beyond National Jurisdiction, or BBNJ — that would allow for the creation of marine protected areas on the high seas.

While policing the boundaries of a high seas marine protected area could be prohibitively expensive, extending national property rights further into the ocean could incentivize policing, Englander said.

"Enforcement costs are even larger than enforcement costs for EEZs because they're even farther from shore," Englander said. "I would worry that it's an even more challenging enforcement problem."

Photo courtesy of Gorodenkoff/Shutterstock