Australia plans to allow fishing across 80 percent of its protected maritime sanctuaries, the government said on Friday in a proposal that would vastly extend commercial activity in the world’s largest marine-reserves network.

If the plan, backed by the government of Prime Minister Malcolm Turnbull, is approved by Parliament, it will be the first time a nation has scaled back its regulations in protected maritime areas. The move could set a precedent for other countries, including the United States, that are considering similar reversals.

More than one-third of Australia’s waters — home to endangered species of sharks, turtles and whales — are protected by law.