Twenty-six nations agreed Friday to take steps to protect sea mammals that reportedly are threatened with extinction, including dolphins and porpoises in the North Sea and Baltic Sea.

A conference convened by the U.N. Environment Program also agreed to demands by the Greenpeace environmentalist organization for a global study of the danger to dolphins, porpoises and small whales.Greenpeace said the three species of sea mammal face extinction because at least 130,000 and perhaps as many as one million are killed every year by pollution, being caught in nets, or being deliberately hunted for meat.

As many as 100,000 dolphins drown annually in U.S. and Latin American tuna fishing nets in the eastern tropical Pacific, the organization said.

The conference agreed that after the North and Baltic Seas, priority must go to saving dolphins in the eastern tropical Pacific, the Mediterranean and the Black Sea, to narwhals in the Arctic, and the Ganges River dolphin in India.

"This is a small but important step in the battle to save the world's dolphins," Greenpeace representative Lisa Beale said.

"We know of many dolphin kills around the world, including the massive kills by Japan, Korea, Taiwan, Sri Lanka and the Faroe Islands where tens of thousands of dolphins and small whales are being killed without any control whatever," she said.