A new report says the economic value of the world's oceans is eroding fast.
The report assesses the economic output of the seas, excluding offshore oil and gas, at $USS2.5 trillion a year. This would make it equal to the world's seventh largest economy. Its capital value is put at $US25 trillion.
But the report found that this is being put in jeopardy by pollution, ocean acidification, overfishing and other ills, and its value is declining faster than it has done for for tens of millions of years.
This problem would affect New Zealand, which controls a vast swathe of ocean via the fourth largest exclusive economic zone in the world.
The report was done by the World Wildlife Fund (WWF), the Boston Consulting Group and the University of Queensland.
"The ocean rivals the wealth of the world's richest countries, but it is being allowed to sink to the depths of a failed economy," said Marco Lambertini, Director General of WWF International.
"As responsible shareholders, we cannot seriously expect to keep recklessly extracting the ocean's valuable assets without investing in its future."
According to the report, more than two-thirds of the annual value of the ocean relies on healthy conditions to maintain its annual economic output.
Collapsing fisheries, mangrove deforestation, as well as disappearing corals and seagrass, are threatening the marine economic engine that secures lives and livelihoods around the world.
The report stresses the environmental benefit of hard economic reporting.
"Being able to quantify both the annual and asset value of the world's oceans shows us what's at stake in hard numbers; economically and environmentally," said Douglas Beal, a partner and managing director at the Boston Consulting Group.
"We hope this serves as a call for business leaders and policymakers to make wiser, more calculated decisions when it comes to shaping the future of our collective ocean economy."
The report's lead author is Ove Hoegh-Guldberg, the director of the Global Change Institute at Australia's University of Queensland.
"The ocean is at greater risk now than at any other time in recorded history," he said. "We are pulling out too many fish, dumping in too many pollutants, and warming and acidifying the ocean to a point that essential natural systems will simply stop functioning."
The report goes on to stress not just the economic value of the oceans, but their role in absorbing carbon dioxide and emitting oxygen via tiny plant life near the surface of the sea.
To preserve oceans, the report wants at least 10 percent of coastal and marine areas to be conserved by 2020, and 30 percent by 2030.
It also wants sustainable development and reduced carbon emissions.