THE world faces the nightmare possibility of fishless oceans by 2050 unless fishing fleets are slashed and stocks allowed to recover, UN experts warned.
"If the various estimates we have received... come true, then we are in the situation where 40 years down the line we, effectively, are out of fish," Pavan Sukhdev, head of the UN Environment Program's green economy initiative, said.
A Green Economy report due later this year by UNEP and outside experts argues this disaster can be avoided if subsidies to fishing fleets are slashed and fish are given protected zones - ultimately resulting in a thriving industry.
The report, which was opened to preview overnight, also assesses how surging global demand in other key areas including energy and fresh water can be met while preventing ecological destruction around the planet.
UNEP director Achim Steiner said the world was "drawing down to the very capital" on which it relies.
However, "our institutions, our governments are perfectly capable of changing course, as we have seen with the extraordinary uptake of interest. Around, I think it is almost 30 countries now have engaged with us directly, and there are many others revising the policies on the green economy," he said.
Environmental experts are mindful of the failure this March to push through a worldwide ban on trade in bluefin tuna, one of the many species said to be headed for extinction.
Powerful lobbying from Japan and other tuna-consuming countries defeated the proposal at the CITES conference on endangered species in Doha.
But UNEP's warning was that tuna only symbolises a much vaster catastrophe, threatening economic, as well as environmental upheaval.