Mutton Snapper are spawning again at Riley's Hump in Tortugas South Ecological Reserve.

The Science (and Art) of Marine Protected Areas

About 70 miles west of Key West, and 100 feet below the surface of the Gulf of Mexico, is an underwater oasis: a seamount called Riley’s Hump that plays host to a dizzying dance of fish. Dive into the water and you might encounter black grouper, snaggle-toothed dog snapper, hogfish, ruddy cubera snapper, yellowfin grouper with their golden mohawks, and the hump’s biggest success story — mutton snapper, an Atlantic loner that clusters there each spring to spawn.

Less than two decades ago, the mutton snapper was in grave peril. Though fishing was officially barred from April through July to protect its spawning cycle, authorities looked the other way as hundreds of thousands of pounds were hauled in every spring. Eventually no more than a couple of dozen fish were left to gather and reproduce. A subsequent conservation program, however, turned 160 square nautical miles into a strictly enforced “no take” ecological reserve within the Florida Keys National Marine Sanctuary, so that today, the fish are back — and spawning like champions.

Before the area was designated a marine protected area, or MPA, Riley’s Hump “was like a ghost town,” says Don DeMaria, a commercial fisherman from Key West who supported the designation. “Now it’s just amazing. If you swim there in May and June on a full moon, you see thousands of them at sunset.”

But the protected zone, called the Tortugas Ecological Reserve, is an exception. Around the world, only about 4 percent of coastal and marine areas have some form of official protection, and the process for assigning and safeguarding them is erratic and often ambiguous. Experts estimate that only 1 percent is truly protected from overfishing, pollution, oil and gas exploration, anchoring and mooring of ships, and snorkeling and diving.

“What we know is that we don’t have enough of these areas around the U.S. and the world,” says Billy Causey, director of the National Oceanic and Atmospheric Administration region that includes Riley’s Hump. “And the more we have them, the more the public and fishermen will see the benefits, and the more this will be recognized as a method for conserving and protecting fish populations.”

The Convention on Biological Diversity, a United Nations treaty, calls for 10 percent of the world’s oceans to be protected by 2020, and many scientists and conservation groups say the goal should be three times that. But even if governments enact such protections, conservationists are skeptical that they will have the necessary teeth.

“All too frequently, the necessary assessment and evaluation end once the MPA is declared,” says Graham Edgar, a professor of marine ecology and conservation science at the University of Tasmania, Hobart, and the lead author of a 2014 paper in Nature that is considered the gospel on effective marine reserves. “And that’s very ineffective and potentially dangerous to assume that it’s achieving the goals.”

In that study, Edgar and colleagues identified five attributes that set effective MPAs apart from nominal ones. They are remembered by the acronym NEOLI: no take, enforced, older than a decade, larger than 39 square miles, and isolated by deep water or sand. Taken together, the authors say, these characteristics deliver a powerful boost to population, size, and biodiversity of fish, including sharks, which help maintain the balance of the entire food web.

Out of the 87 MPAs the authors studied around the world, only nine had as many as four or five of the NEOLI features.

Still, progress is being made. In 2015 alone, approximately 1 million square miles of ocean were set aside for protection, according to the Pew Charitable Trusts. That is more than half the total protected area in the world. Many of the new reserves are massive, including the Pitcairn Island Marine Reserve in the South Pacific (332,000 square miles), Palau’s National Marine Sanctuary (193,000 square miles), New Zealand’s Kermadec Ocean Sanctuary (239,000 square miles), and Chile’s Nazca-Desventuradas Marine Park (115,000 square miles). Chile has also proposed to designate an Easter Island Preserve (243,630 square miles).

“In the last couple of years, I’ve seen the exponential increase in marine reserves and increased attention politically for ocean conservation at a level we’ve never seen before,” says Matt Rand, director of Pew’s global ocean legacy project. “I think we’re headed in the right direction.”

The world’s first large marine park — Hawaii’s 140,155-square-mile Papahānaumokuākea Marine National Monument — was established ten years ago. At the time, it dwarfed other marine parks, which averaged just 2.3 square miles. Now it is in eighth place.

Large MPAs have benefits that go beyond sheer size. They can enfold numerous ecosystems, such as mangroves, sea grasses, coral reefs, sea floor, and deep sea. Fish and marine mammals can travel between habitats freely and safely. And the cost of protecting large areas is far lower, per square mile, than that of smaller ones.

But the location of marine protected areas can depend on factors that have little to do with ecological best practices. Bob Pressey, a marine scientist at James Cook University in Townsville, Australia, who has examined the issue, noted that after studying the placement of marine parks around Australia, he found that many were positioned to avoid conflict — favoring areas that are remote or unappealing to fishing interests and oil and gas exploration.

“We are using up limited options by reserving the bits that don’t need protection while others get trashed,” he says. “That’s not cause for celebration.” He believes the true measure of effective conservation is how much societies are willing to give up for other species.


Most experts suggest that a diverse array of MPAs and MPA networks are needed to truly turn the tide on species and habitat loss. Marine protection, they say, is both a science and an art, and the initial work leading to the creation of a reserve — or “step zero” — is crucial for laying a strong foundation.

The authors of a 2012 paper in the journal Marine Policy identified stakeholder involvement — from local citizens to commercial interests to national governments — as a fundamental component of successful marine conservation. This means understanding why the MPA is necessary, appreciating what it hopes to achieve, and knowing its location and how it will function. After all, any protection effort, no matter how well conceived and executed, will limit the use of the oceans, and that will affect a broad array of human activity, including recreation, fishing, and tourism.

And as the Riley’s Hump experience shows, ongoing vigilance is necessary. “You can devise rules and regulations, can identify species that are doing good or bad, and identify critical habitats,” says Jayson Horadam, president of MPA Enforcement International, a private natural resource management that works to improve MPA oversight in the Caribbean and Central America. “But unless you can safeguard the natural resources through enforcement, people can still do what they want to.”

In Florida, the ecological reserve that includes Riley’s Hump is vigorously policed by the Coast Guard, the Florida Fish and Wildlife Conservation Commission, and NOAA. Without such enforcement, the ocean’s assets disappear. That’s what’s happening in Jamaica, says Horadam. Pollution, overfishing, thoughtless development, and corruption have devastated not just its fisheries but also its coral reefs, only 8 percent of which remain alive, and its tourism, which accounts for 25 percent of the country’s jobs.

But effective marine protection can’t be left entirely to enforcement agencies, advocates suggest. People need to care, and it’s easier to cultivate an ethic of stewardship in those whose well-being cannot be separated from the sea. “For us in the Pacific Region, the connection to the ocean is a reciprocal one — one where you have to care for it to be fed by it,” says Kalani Quiocho, a native Hawaiian who works as a longline fishery observer for NOAA Fisheries’ Pacific Islands regional office and who wants to see the Papahānaumokuākea MPA expanded further.

Still, the task ahead is daunting — and barely begun, despite the recent progress. Only about 10 percent of existing MPAs have achieved a substantial recovery of fish stocks. Even if the global treaty’s target of protecting 10 percent of the world’s oceans by 2020 is achieved, that would mean a total recovery rate of just 1 percent.

“We design reserves to fail when we try to make everyone happy,” says DeMaria, the Florida fisherman. “But when we do it right like at Riley’s Hump, it’s pretty remarkable.”

Robynne Boyd is an Atlanta-based writer covering energy and the environment, and an editor for the International Institute for Sustainable Development Reporting Services.