Non-governmental organizations on Sunday called on RIO+20 summit leaders to back a new treaty to protect the high seas.

"A new Treaty for High Seas protection will be a game changer for the future of our ocean and the millions dependent on it for their survival," said members of the High Seas Alliance and the Deep Sea Conservation Coalition attending the UN conference on sustainable development here.

The High Seas Alliance, launched in 2011 as a united voice for the protection of the high seas, groups 23 NGOs plus the International Union for the Conservation of Nature (IUCN).

It stresses the need for a change in governance on the high seas, to address the impacts of climate change, biodiversity loss as well as increasing interest in fisheries exploitation, marine genetic resources and mineral extraction.

"Rio+20 is the moment to finally create effective protection for the high seas and stop its uncontrolled destruction," said the groups as they hailed Brazil's decision as conference host to include an ocean' section in the new negotiating text to be submitted to the upcoming Rio+20 summit.

"Brazil should be applauded for making ocean conservation one of the four priorities for this meeting and we commend its leadership in steering a challenging process," the groups said.

The issue will be hotly debated when world leaders meet here from Wednesday to Friday to mull prospects for steering the planet toward a greener and more sustainable future.

Many developing nations want sustainable fisheries to ensure food security and livelihoods.

"However the (US) administration is currently blocking this critical measure. We can only hope that Secretary of State (Hillary) Clinton will deliver the change needed to secure a potential win for our ocean here in Rio," the NGOs said.