Update, 16 November: As of today, more than 2.3 million square kilometres of ocean around Australia are now protected by law from over-fishing and oil exploration. Read about this historic move below:

The Australian government has just announced it will create the largest marine reserve in the world, keeping mining, oil exploration and most fishing out of the vital Coral Sea. The measure will help safeguard some of the world's most important tropical waters.

It's a major win for campaigners who lobbied the Australian government for months over the plan. Last month, in just 72 hours, more than 28,000 Avaaz members flooded the public record with comments in favour of the plans. In total, over 601,000 people signed Avaaz's petition calling on Australia's environment minister Tony Burke to act. The Pew Environment Group, which spearheaded the campaign, believes this is the highest level of public support ever received by the Australian government for an environmental issue.

Some experts say the protection measures don't go far enough, with significant areas of ocean still open to exploitation for minerals and fishing. Andrew Macintosh, associate director of the ANU Centre for Climate Law and Policy, warns the Australian government is overstating its impact. Nonetheless, it's a huge step forward. Ocean ecosystems are literally dying under pressure from pollution and uncontrolled industrial fishing: this change offers a real cause for hope.

Learn more: See maps of the areas that will be protected, and watch environment minister Tony Burke explain just how important – and big – this plan is: