Relentlessly rising human demand for deep-sea resources such as fish, gas and oil, is posing such a risk that international co-operation is needed if aquatic ecosystems are to be saved, US scientists warn.

The doubling of the world’s population over the past five decades is putting great strain on the deep-sea ecosystems, they told an annual science congress in Chicago on Sunday.

The ecosystems are now threatened by the same kind of mass industrialisation common on land during the 20th century, according to researchers gathered at the American Association for the Advancement of Science meeting.

“At the same time, human society has undergone tremendous changes and we rarely, if ever, think about these affecting our ocean, let alone the deep ocean,” said Lisa Levin, who heads the Centre for Marine Biodiversity and Conservation at the Scripps Institution of Oceanography in California.

“As we exhaust many coastal stocks, commercial fishers have turned toward deeper waters,” she said.

The quadrupling of energy demands over the past 50 years have led companies to search for oil and gas in the deep seas, defined as waters more than 1000 metres deep.

Today there are some 2000 platforms drilling on deep sea ocean floors, “bringing with it the potential for environmental disaster of the sort we saw with the Deepwater Horizon,” Levin said, referring to a massive 2010 BP oil spill in the Gulf of Mexico.

At the same time, the demand for hard-to-find rare earth elements needed for portable electronics and batteries for hybrid vehicles is pushing mining companies to scour the ocean floors.

“Vast tracts of deep seabed are now being leased in order to mine nodules, crusts, sulfides, and phosphates rich in elements demanded by our advanced economy,” said Levin.

Human knowledge of the deep sea ecosystem however has not kept pace with the growth of human activities affecting the deep seas, she said.

Levin called for “international cooperation and an entity that can develop and oversee deep-ocean stewardship.”