A Greenpeace report, published to coincide with a U.N. meeting in Brazil on biodiversity, said that 40 percent of the world’s oceans should be placed in nature reserves.
Just 0.6 percent of the oceans are protected reserves at present, compared with 12 percent of the world’s land, according to U.N. data.
While that protection is put in place, trawling along the ocean bottom should be banned, Greenpeace said.
"An immediate U.N. moratorium on high seas bottom ?rawling is essential to stop the destruction of deep-sea life whilst a global network of marine reserves is established," professor Callum Roberts of York University said in a Greenpeace statement.
The U.N. meeting in Curitiba, Brazil, which lasts until the end of March, will discuss ways to expand protection both on land and at sea to slow the accelerating rate of extinction of animals and plants caused by human activities.
The meeting will discuss the principle of extending marine protection, but will not reach a formal agreement.
The United States is not a signatory to the Convention on Biological Diversity, an international conservation agreement signed by the 188 countries which are meeting in Brazil.
Greenpeace also urged better protection of forests, saying its satellite maps showed that intact forests covered less than 10 percent of the world’s land area, threatening thousands of species of animals and plants.