It may prove to be one of the biggest deals ever when it comes to protecting the environment: a group of 24 nations and the European Union have reached an agreement to establish the largest marine protected area in the world in Antarctica by making the Ross Sea off limits to commercial fishing and other activities. That’s 600,000 square miles of ocean filled with marine life like whales and penguins and krill that is currently threatened by overfishing.

A total of 28 percent of that square mileage will be set aside for research zones. It’s a major development that scientists are hailing as an important step to protect increasingly threatened marine areas. Overfishing threatens many ecosystems around the world, and is a big concern for conservationists.

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) met in Hobart, Australia to hammer out the agreement recently.

CCAMLR Executive Secretary, Andrew Wright, called the agreement exciting.

“This has been an incredibly complex negotiation which has required a number of Member countries bringing their hopes and concerns to the table at six annual CCAMLR meetings as well as at intersessional workshops. A number of details regarding the MPA are yet to be finalised but the establishment of the protected zone is in no doubt and we are incredibly proud to have reached this point,” said Wright in a statement.