It took nearly two decades for United Nations member countries to negotiate the so-called “High Seas Treaty,” an internationally binding agreement aimed at conserving marine biodiversity in international waters. But the accord, signed March 4, appears close to becoming a reality—thanks in no small part, experts say, to marine-protection momentum established in recent years by Latin American nations.

“Latin America is a world leader in marine conservation,” says Maximiliano Bello, international ocean policy director at Mission Blue, an international marine-conservation nonprofit. “The region was of key importance in enabling the agreement to be concluded.”

The new agreement, signed by nearly 200 countries, was formally adopted on June 19 but cannot take effect until it is ratified by 60 of the signatory nations. It addresses three principal areas of marine policy. These are the creation of marine protected areas in international waters; the required use of environmental-impact studies for new marine exploitation in those “high seas” waters; and the protection of genetic resources in those areas.

A key aspect of the treaty are its provisions for creating large-scale marine protected areas (MPAs) with the goal of conserving at least 30% of the world’s international waters. The treaty defines these waters as those lying beyond the 200-mile limits of coastal countries’ Exclusive Economic Zones (EEZ).

Under the 1982 UN Law of the Sea Convention, countries have special rights to explore and use marine resources within the 200-nautical-mile Exclusive Economic Zone. But until now, there has been no process for establishing reserves in the outlying international waters. As a result, the high seas are the focus of a free-for-all of unregulated fishing, shipping, and seabed prospecting, threatening biodiversity and adding further pressure to the impact of climate change.

Experts say that giving countries the ability to create high-seas marine reserves makes it more likely they will be able to meet the goals of the “30 by 30” agreement signed in December 2022 at that year’s world climate summit in Montreal, Canada. Under that accord, signatories committed to protect at least 30% of the world’s ocean waters by 2030.

“There was no way we could meet the target of protecting 30% of the world’s oceans if we had to do it within the economic exclusive zones,” says Bello. “By allowing marine protected areas to extend beyond waters under national jurisdiction, the high seas treaty offers the possibility of meeting the 30 x 30 targets.”

Much of the momentum for such efforts comes from Latin America, where some coastal nations have taken significant marine-conservation steps.

The region, to be sure, is not a paragon of ocean protection. Chronic overfishing by national fleets in Ecuadorian, Peruvian, Chilean, and Argentine territorial waters and by enormous Chinese fleets in adjacent areas of the high seas has taken a steep environmental toll. (See "Case builds for bigger Galápagos Reserve" —EcoAméricas, June 2021; and "Chinese vessel’s hold is portal to sharks’ plight" —EcoAméricas, August 2021.)

So has the relentless targeting of particularly lucrative species. Among such examples are the wholesale slaughter in the eastern tropical Pacific of sharks, whose fins fetch high prices in Asian markets, and the illegal fishing of totoaba in Mexico’s Gulf of California. The nets used to catch totoaba, whose swim bladders are highly prized in Asia, also have captured and drowned the upper Gulf’s vaquita porpoises to the point of near extinction. (See related story—this issue.)

But experts point to major strides the region has made in creating and expanding marine reserves in which restrictions on fishing and other potentially damaging activities apply.

A regional leader is Panama, which has pledged the highest share of marine protected areas in Latin America. In March, Panamanian President Laurentino Cortizo announced plans to expand the country’s Banco Volcán Managed Resources Area (Banco Volcán AMR), a protected area of Caribbean waters, from 14,000 square kilometers (5,400 sq. miles) to 93,000 square kilometers (36,000 sq. miles). If the expansion is implemented, Panama’s reserve status will extend to 54% of its territorial waters, which include its exclusive economic zone. In addition, the government aims to establish a portion of the reserve into an adjacent area of the high seas beyond its 200-mile EEZ limit.

The expanded reserve, which would encompass four underwater mountain formations, is home to 120 deep-sea marine animal species. Among these are the hammerhead shark (Sphyrna lewini) and two other shark varieties listed as critically endangered, as well as the whale shark (Rhincodon typus) and four other types of shark that are considered endangered.

The marine-protection strategy envisioned by Cortizo includes high-seas waters that could potentially form transnational marine conservation corridors leading to marine reserves in neighboring Colombia, Nicaragua, Honduras, Jamaica, or Costa Rica. With High Seas Treaty signatories confident the agreement will be ratified, governments elsewhere in the region and world are laying the groundwork for such efforts. Experts say this work could connect Panama’s Banco Volcán AMR with the protected waters of Colombia’s Seaflower Biosphere Reserve, a Caribbean archipelago featuring coral reefs and atolls.

Bello, who advised Panama on its June 2021 expansion of the Coiba marine reserve, a Unesco World Heritage Site on the country’s Pacific coast, says the nation has built solid marine-conservation expertise.

“Panama has a strong environmental ministry that has understood that scientific evidence tells us we need to protect more than 30% of biodiversity if conservation is to be effective,” Bello says. “Panama stands out in applying this information and providing strong measures which all countries should be following in response to the global crisis.”

A study carried out by Panama’s Environment Ministry in collaboration with the Smithsonian Institute of Tropical Research forecasts that successful expansion of the Banco Volcán AMR will bring multiple benefits. Among these are greater connectivity among protected marine migratory routes critical for the survival of deep-sea and coastal species. (See "More protection sought for whale “blue corridors”" —EcoAméricas, April 2022.)

Panama is not the only Latin American country pushing ocean conservation. On March 2, Ecuadorian Cabinet member Julio José Prado announced that waters within eight nautical miles of its shoreline will be declared a marine reserve.

“We aim to be a model to the world in sustainable fishing, demonstrating our commitment to implement responsible practices and advance towards a bioeconomy,” said Prado, the minister of production, foreign trade, investment and fishing, on the day of the announcement.

The previous year, Ecuador had established the Brotherhood Marine Reserve. The new reserve has effectively extended the already sizable marine-protection zone around the country’s iconic Galápagos Islands to cover waters frequented by marine species that migrate to and from the archipelago. (See "New protected area to link Galápagos, Cocos reserves" —EcoAméricas, January 2022.)

Chile has made strides as well. The country has 42 marine reserves, but these are concentrated in its southern regions. In March it announced the creation of its first in northern waters, near the port of Pisagua. The 730-square-kilometer (282-square-mile) reserve encompasses habitat of the Humboldt penguin (Spheniscus humboldti), the South American fur seal (Arctophoca australis), marine otters (ontra felina), macroalgal forests, and marine bird nesting sites.

Experts say use of the High Seas Treaty could bring particular conservation benefits to the Salas y Gómez and Nazca ridges, a pair of connected underwater mountain chains located off Chile and Peru. Bello forecasts that the treaty will enable the two countries to protect the entirety of the two chains, which collectively extend 2,900 kilometers (1,800 miles) and include an estimated 110 seamounts located outside Chilean and Peruvian national waters.

The western end of the Salas y Gómez ridge intersects with the East Pacific Rise inside the Chilean EEZ of the Easter Islands and its eastern end adjoins the western end of the Nazca ridge. The Nazca ridge’s southern end includes part of the Chilean EEZ of San Felix Island, while its northern end goes into the Peruvian EEZ.

“This is one of the most biodiverse regions of the world, with one of the highest numbers off endemic species on Earth,” Bello says. “This region is an example of how marine conservation is going to be able to go far beyond that protection work that we have previously been able to do when limited to national waters.”

Adds Bello: “Protecting individual species is not enough, we need to protect systems. We need to protect the habitats that are the key for life and those processes associated with their features. If we protect complete ecosystems that make life happen in the ocean, we have a much better chance of protecting the ocean and all the services it provides us.”

Though the signing of the High Seas Treaty has drawn applause from scientists and environmentalists, experts caution that the agreement must be accompanied not only by the creation of new reserves, but also by greater marine-policing capacity.

Among those making that point is Ixchel López, a biologist at the National Autonomous University of Mexico (UNAM) and deputy director of Oceans for the Mexican office of the environmental group WWF. Having worked for a period as an official with Mexico’s Environment and Natural Resources Secretariat (Semarnat), López says she is particularly mindful of the difficulty of monitoring ocean waters—and also of the opportunity.

“The ocean is a difficult and complex place to protect,” she says. “For this treaty to be successfully executed, institutional structures that will allow surveillance to be successfully carried out need to be clearly defined.”

Adds López: “It will be extremely complex to implement [the treaty], and specialized training will be essential. If users and technology are integrated into the plan, I think that interesting things can be achieved in this urgent mission to protect the oceans that afford us so many key eco-systemic services.”

Funding such activities is a major question, though Ecuador recently helped provide a partial answer in May by inking a debt-for-nature swap that will generate an estimated US$450 million for Galápagos Islands marine-conservation efforts. (See "Double dose of good news for Galápagos archipelago" —EcoAméricas, May 2023.)

López and other ocean conservationists warn that while the new treaty would protect biodiversity by restricting economic activities such as fishing or seabed mineral exploration inside high-seas marine protected areas, it does not address these activities in adjacent international waters.

Negotiators left that subject to be resolved through changes in agreements that target these and other specific high-seas activities.

“For now, the high seas treaty leaves a missing link between biodiversity and economic activities,” López says. “We need to see an integration between different treaties and the different economic activities that are occurring in the oceans if there is to be a real benefit for biodiversity and economic systems.”

Historically the fishing industry has lobbied hard against marine reserves, and more such opposition can be expected. However, recent research published in the journal Scientific Advances finds that marine reserves actually promote a flourishing of biodiversity without negatively affecting the fishing industry.

The study was conducted in and around Revillagigedo National Park south of Mexico’s Cabo San Lucas. Researchers found that the six-year-old park—at 147,000 square kilometers (57,000 square miles), the largest marine reserve in North America—acts as a nursery for regional fish stocks.

They concluded that by bolstering populations of fish that then move into waters where fishing is allowed, the reserve has not depleted stocks available to the region’s fishermen, caused food insecurity or forced local fleets to exploit distant waters. All of those outcomes were forecast by fishing-industry representatives in arguing against Mexico’s creation of more marine protected areas.