The analysis comes months before governments make critical decisions that will direct the fate of the ocean for generations to come.

The analysis shows that every dollar invested to create marine protected areas – commonly known as MPAs – is expected to be at least tripled in benefits returned through factors like employment, coastal protection, and fisheries.

“The ocean is central to all of our lives and we need to be both its stewards and its managers. A healthy ocean safeguards our coasts, stores carbon, creates employment and feeds families,” said Marco Lambertini, Director General of WWF International.

“Marine protected areas can have the double impact of contributing to a healthy ocean and creating important economic opportunities.”

Current international targets for ocean protection range from 10 per cent by 2020 through 30 per cent protection by 2030. At present, less than 4 per cent of the ocean is designated for protection, with many MPAs lacking effective implementation and management.

Among the major threats facing the ocean are overfishing, pollution, sedimentation, and habitat destruction. Warming seas and increased acidification caused by climate change are expected to have devastating impacts on coral reefs and other important ocean systems.

“We cannot continue to overstrain and underinvest in the ocean,” said Mr Lambertini.

“The ocean is collapsing before our eyes, but the good news is that we have the tools to fix it. It is possible for the ocean to make strong contributions to lives and livelihoods while we also secure its habitats and biodiversity for future generations.”

The new analysis is based on a WWF-commissioned study produced by Amsterdam’s VU University, modelling MPA expansion at both the 10 per cent and 30 per cent target levels.

The report found that increased protection of critical habitats could result in net benefits of between $490 billion and $920 billion accruing over the period 2015-2050. WWF recommends 30 per cent global coverage of MPAs by 2030 in order to secure the most complete benefits for people and the ocean.

Existing protected areas in regions like the Mediterranean, the Coral Triangle and coastal Africa, demonstrate how people can benefit from increased ocean protection. Locally managed marine areas in Fiji demonstrate that MPAs can reduce poverty, strengthen governance and benefit human health and gender equality.

This year is particularly important for the ocean. In September, governments will meet to agree on a set of goals as part of the UN post-2015 sustainable development agenda. WWF's analysis recommends that the agreement include strong targets and indicators for the ocean, and commitments to coherent policy, financing, trade and technology frameworks to restore and protect ocean ecosystems.