The Seychelles, an archipelago in the Indian Ocean, has established 154,000 square miles of marine protected areas, fulfilling a pledge to protect nearly a third of its vast territorial waters. About half of the newly protected areas will be “no-take zones,” where economic activity such as fishing and mining will be prohibited. Limited economic activities will be permitted in the other half of the protected areas.

Seychelles President Danny Faure signed the decree last week, saying the marine reserve would help protect the nation’s fisheries resources and safeguard a host of species, from endangered sea turtles, to sharks, to the Indian Ocean’s last remaining population of dugongs, a marine mammal similar to manatees.

The funds for managing and protecting the new marine reserves will come from a so-called debt-for-nature deal, Mongabay reported. That agreement, worked out with the help of The Nature Conservancy, will allow the country to restructure $21.6 million in foreign debt in exchange for protecting its marine resources and enacting climate adaptation measures.

“Expanding Seychelles’ MPA [marine protected area] network is a major first step in the conservation of Seychelles’ biodiversity, but it is only the first step,” Rabia Somers and Vanessa Didon, from the Marine Conservation Society Seychelles, said in a statement to Mongabay. “The conservation of Seychelles’ biodiversity ultimately depends on multiple factors, such as enforcement, public-private partnerships, and innovative management models.”