"Ghost fishing" by lost nets damages seas: U.N.

By Alister Doyle, Environment Correspondent

OSLO (Reuters) - Lost or abandoned nets in the oceans can keep on "ghost fishing" for years in a growing threat to marine stocks, a U.N. report said Wednesday.

About 640,000 tonnes of discarded fishing gear gets added to the oceans yearly, or 10 percent of the world total of marine debris, according to the study by the U.N. Food and Agriculture Organization (FAO) and U.N. Environment Program (UNEP).

Fishing gear "will continue to accumulate and the impacts on marine ecosystems will continue to get worse if the international community doesn't take effective steps to deal with the problem of marine debris as a whole," Ichiro Nomura, an FAO assistant director-general, said in a statement.

The study recommended measures such as cash incentives for fishing fleets to bring broken nets to port, better mapping of subsea hazards to avoid losses or new designs such as nets that dissolve if left in the water too long.

Nets sometimes snap in storms, get snagged on coral reefs or can get entangled in other fishing gear.

They can then start what the report termed "ghost fishing" -- pointlessly ensnaring fish or creatures such as turtles, seabirds or whales for years or even decades.

The report did not estimate overall damage to the oceans or economic losses to fishing fleets from gear littering seabeds from the South China Sea to the Mediterranean.

"It's very difficult to estimate the impact," said David Osborn, coordinator of UNEP's Global Program of Action on land-based sources of marine pollution.