Many existing marine protected areas might be something like screen doors on a submarine, at least as far as their impact on ocean conservation.

A new study finds that only a third of the world’s largest marine protected areas (MPAs) currently implement meaningful conservation measures.

Increasingly, marine conservation is the art of separating humans from parts of the ocean. More often than not, marine protected areas, swaths of the sea that are set aside and managed to preserve sea life and its habitats, are the flagship models for government efforts to accomplish this.

However, a recent analysis published in Conservation Letters revealed alarming inadequacies in the effectiveness of the world’s largest MPAs. The study, conducted by an international group of researchers spearheaded by the Marine Conservation Institute in Seattle, Washington, focused on the largest 100 MPAs in the world, which together encompass over 7 percent of the world’s ocean area.

“There are 18,000 MPAs, but a hundred of them make up 90 percent of the area,” said Beth Pike, director of the Marine Protection Atlas and the study’s lead author. “These are the big needle movers.”

Pike and her colleagues found only a third of these MPAs’ total expanse to be under high or full protection—just 2.6 percent of the global ocean footprint. They found another third of these MPAs’ territories allowed for destructive activities, such as mining and industrial fishing, making them inherently incompatible with conservation. Additionally, another quarter of the protected area they analyzed were deemed “paper parks,” meaning that while these ocean spaces had been officially proposed or designated as MPAs, they had yet to implement any subsequent conservation measures. For example, over 60 percent of the OSPAR MPA network, which jointly covers roughly 7 percent of the Northeast Atlantic Ocean, appears to have benefited from no protection activities aside from its listing as a protected area.

These findings stand in stark contrast with the agreement by 188 governments to protect 30 percent of the world’s lands and waters by 2030—the 30×30 initiative—in the Kunming-Montreal Global Biodiversity Framework adopted during the United Nations Biodiversity Conference (COP15), in December 2022. 

While the 7 percent of the ocean conserved by 2024 already lags the pace required to protect 30 percent by 2030, this new study questions whether governments that joined the COP15 agreement have achieved even that amount of progress.

“We haven’t finished the job on the stuff we’ve done,” Pike said. “There’s a big push to meet these targets, but if you turn around to look at what’s in the bank already … we’re still allowing activities that are incompatible with the goals of MPAs.” 

To collate these results, Pike and her colleagues pooled data from the publicly available World Database on Protected Areas, which tallies MPAs and their coverage as they become designated by governments around the world. The authors then used the The MPA Guide, a scientifically informed set of assessment criteria, to differentiate the areas by their real-world effectiveness. 

“This gives us more nuance to our understanding than just looking at lines on maps,” said Jessica MacCarthy, a conservation analyst at the Marine Conservation Institute and the study’s second author. “We can look for MPAs that are active on the water and adaptively managed.” 

Even effective MPAs are often having less impact than they might, the study also found, because most of these MPAs were nestled in wilderness and far from human settlement, likely for political expediency. The United States, for instance, has 98.6 percent of its well-protected areas entirely in its territories far offshore. If its entire MPA expanse were a basketball court, its well-protected area near shore would amount to the floor space of a walk-in closet. That leaves much of the nation’s most heavily pressured seas unprotected.

“Countries like the United States are going to have to stop working where people aren’t and start working where people are,” Pike said. “We’re going to have to start working in our own backyards.”

Mark Spalding, president of The Ocean Foundation and an expert on ocean law, said the article confirmed what many marine scientists already believe. “The article is good. It confirms everything we all believe about lack of political will, lack of financial resources and lack of effectiveness of MPAs,” he said. “We need to have the government, the will, the strategy and the financial resources put behind marine protected areas to make them actually effective.”

Although the new study focused on just the world’s largest MPAs, many ocean scientists believe smaller MPAs are just as important.

 “Some of our most effective [MPAs] might be the smaller ones,” said Spalding.

Part of the reason for this could be that smaller areas are easier to puzzle together with human demands of the sea, especially in the places with high human traffic and high biodiversity value.

“You’re always having to make tradeoffs between human dependency on resources and maintaining ecosystem services and productivity from nature,” explained Tim McClanahan, a Kenya-based marine scientist and senior conservation zoologist at the Wilderness Conservation Society. “That usually requires working on a smaller scale, where humans and nature are close to each other.”

While most governments are missing the mark on 30×30 goals, the objective itself has not been without controversy. Many conservationists want to ensure that, in addition to the quantity of protection, MPAs do not skimp on the quality of their protection either.

“Some people are very concerned about the area of protected areas,” says McClanahan. “There are other people, I would be more among them, that are more concerned about the state of nature in these MPAs.” 

That might require governments to focus less on meeting goals for the amount of ocean they conserve and to put more effort into bolstering protections in the areas they’ve already set aside. “We can’t lose sight that the real goal is conservation, and to achieve that, we also need to be looking at quality and making sure that the areas we’re designing are going to be effective,” MacCarthy emphasized.

As prospective spaces for protection become increasingly sparse, governments will increasingly need to consider the equity aspect of MPAs—where they are placed, and who might bear the brunt of well-meaning but potentially unjust policies.

But for some ocean advocates, protecting only parts of the marine environment is acquiescing to the human presumption that the rest of the ocean is fair game for exploitation. “I have a real problem with these artificial goals and any kind of percentage goals,” Spalding said. “The burden of proof should be shifted: 100 percent of the ocean should be protected, and then if somebody wants to use part of it, make them prove that they’re not going to do any harm.”

Spalding espouses a public trust doctrine approach in which “the presumption should be protection, and use is balanced with sustainability and regeneration,” he said. “We all need to remind governments that these are common spaces and governments are supposed to collaborate in order to fulfill that trust that the public is putting in them to keep these things healthy.”

The scientific community agrees that the stakes are high. Live coral cover has dwindled to half of what it was in the 1950s. Marine species are facing elevated extinction risks from climate change and a host of other man-made pressures. Part of the success of MPAs will likely depend on getting the public to recognize how the decline of the ocean environment they can see might be slowed or reversed by pushing for the real-world protection of ocean spaces both close to home and far away.

“People are seeing the change right in their backyards now,” Pike said. “The beach I grew up on doesn’t have these cool little cucumbers anymore, these little sponges we used to play with as kids. It has more jellyfish.”