Australia has unveiled plans to create one of the biggest marine reserves the world has ever seen.

The proposed marine reserve in the Coral Sea covers a total area of around 990,000 square kilometres off the northeast coast of Australia. The Great Barrier Reef, which also lies off this coast, is already protected by an existing reserve.

Announcing the proposal on Friday, environment minister Tony Burke said his government would be creating the world’s largest marine protected area as the last component of a huge marine-planning exercise.

“In the space of one lifetime, the world’s oceans have gone from being relatively pristine to being under increasing pressure,” said Burke. “The environmental significance of the Coral Sea lies in its diverse array of coral reefs, sandy cays, deep sea plains and canyons. It contains more than 20 outstanding examples of isolated tropical reefs, sandy cays and islands.”

However, only 507,000 square kilometres of the Coral Sea reserve are designated ‘no-take’, areas where all fishing is banned. In other areas, commercial and recreational fishing are permitted. In contrast, the British government’s reserve around the Chagos Islands in the Indian Ocean is 544,000 square kilometres and is entirely no-take, making it the largest no-take marine reserve in the world.

Conservation groups immediately protested that the plans do not go far enough and called for a greater area to be given higher levels of protection.

“The government’s proposed plan is for a multi-use marine reserve, which doesn’t go far enough, and is piecemeal with only 2 reefs out of 25 in the Coral Sea set to receive full protection,” said the Green Party’s Queensland senator, Larissa Waters. “To protect the region as a whole instead of creating a Swiss cheese of different-use zones would make it much easier for the government to manage and monitor the area.”

Imogen Zethoven of the Pew Environment Group agrees. “Protection levels need to be stronger — particularly in vulnerable areas — to ensure the Coral Sea’s long-term protection,” Zethoven said in a statement.

Australia is part-way through moves to create regional plans for all its waters, setting out what activities are permissible in different areas. Proposals from earlier this year related to its southwest region have also been criticized for failing to ensure that examples of all the wide variety of habitats in these regions were adequately protected under the plans.