The four newly designated marine protected areas (MPAs) will cover an area of more than 920,000 square kilometers (355,200 square miles) in the Atlantic Ocean.

Two of the MPAs will cover waters around the archipelago of Trindade, Martin Vaz and Mount Columbia, located more than 1,000 kilometers (620 miles) east of the Brazilian mainland.

The remaining two MPAs will be located around the São Pedro and São Paulo archipelagos, some 900 kilometers (560 miles) off the northeast coast.

However, some marine biologists worry that these large, remote MPAs may do little to safeguard biodiversity.

Brazil will soon have four vast marine protected areas (MPAs) in the Atlantic Ocean, covering an area of more than 920,000 square kilometers (355,200 square miles).

The new designation will increase the coverage of Brazilian MPAs from 1.5 percent to about 24.5 percent of the country’s waters, exceeding the international target of protecting at least 10 percent of marine areas by 2020.

“This measure will help safeguard our rich biodiversity, and renew our commitment to a more sustainable world,” President Michel Temer said in a video address to the 2018 World Ocean Summit held in Mexico last week.

All four MPAs, created far away from the Brazilian coast, will protect remote sets of islands.

Two of the MPAs will cover waters around the archipelago of Trindade, Martin Vaz and Mount Columbia, located more than 1,000 kilometers (620 miles) east of the Brazilian mainland. One MPA, encompassing 402,377 square kilometers (155,359 square miles), will allow some sustainable use of fishing resources. The protected area management plan, which will define what activities will be restricted and regulated, is currently being developed by the Ministry of Environment, said Jenny Parker McCloskey, vice president of media at Conservation International (CI). The other MPA, covering 69,155 square kilometers (26,701 square miles) of the sea, will prohibit all human activity.

The remaining two MPAs will be located around the São Pedro and São Paulo archipelagos, some 900 kilometers (560 miles) off the northeast coast. Again, one of the protected areas, stretching across 407,052 square kilometers (157,164 square miles), will allow some human activity. The second protected area, covering 42,498 square kilometers (16,409 square miles), will remain closed off to human use.

These remote archipelagos are home to a vast range of threatened and endemic species, including the critically endangered Atlantic goliath grouper (Epinephelus itajara) and the endangered scalloped hammerhead shark (Sphyrna lewini). The waters off the islands also hold a rich diversity of algae, corals, fish, sharks, rays, octopus, whales, dolphins and turtles.

Protecting the two archipelagos will be key to maintaining and recovering fish stocks, Cláudio C. Maretti, director of the Chico Mendes Institute, the administrative arm of the Brazilian Ministry of the Environment, wrote in a statement. “For the sustainability of food security, the entire world needs to make strong efforts in the recovery of fish stocks,” he said. “Large marine protected areas, including important no-take zones, can be crucial in that.”

McCloskey of CI told Mongabay that “the creation of these areas highlights Brazil’s commitment to meeting global environmental goals such as the Aichi Targets that stipulate member countries must establish at least 10% of marine and coastal areas as protected by 2020.”

“The designation also means that these remote areas will be protected from industrial fishing, mining and other detrimental activities,” McCloskey said, adding that Conservation International worked closely with the government of Brazil in establishing these protected areas.

However, some marine biologists remain skeptical.

“I’m encouraged that countries, including Brazil, are thinking about marine biodiversity conservation,” said Natalie Ban, a marine biologist at the University of Victoria, Canada. However, the Brazilian MPAs may do little to actually protect marine biodiversity, Ban said.

“They are placed in the most remote regions of the Brazilian EEZ [exclusive economic zone],” she said. “They cover the most remote seamounts, yet fishing is still allowed in the most sensitive areas around the islands or rocks.”

The designation is also unlikely to protect against deep-sea mining, Ban said.

“Such mining is unlikely to happen in this area because the average depth is around 5000m [16,400 feet], deeper than the current viable deep sea mining operations,” she said. “Thus, while I think steps to protect marine biodiversity are urgently needed, I fear that these MPAs are simply designed to meet Brazil’s Aichi target commitment without actually protecting threatened areas.”

Whether these remote MPAs succeed will depend largely on enforcement, conservationists say.

“Because several coastal MPAs already struggle to be effectively implemented in developing countries, it is questionable whether governments will endeavour to protect these large MPAs in the open ocean, which are much more costly,” Ban said.

NOTE: In a recent reporting series, “Conservation Effectiveness,” Mongabay evaluated the scientific evidence on marine protected areas to see whether they work. Read the story here. View the infographic here.