There were calls for the swift adoption of an international treaty being discussed at the UN to protect international waters.

The EU and US have pledged €816.5 million and €5.65 billion respectively to protect the oceans on the first day of the "Our Ocean" conference, which was opened by the White House's special climate envoy, John Kerry.

The agenda on Friday will focus on the fight against illegal fishing, with several organizations joining forces to call for more transparency from governments on overfishing.

"One-third of commercial (marine) species are overfished," noted Monica Espinoza of Global Fishing Watch, an NGO that monitors boats by satellite.

Governments must "require their fishing fleets to be traceable, all the time, by satellite so we know they are fishing honestly," Andrew Sharpless, executive director of the NGO Oceana, told AFP.