Stop deep-sea trawls to protect coral, scientists urge

1,000 of world's top marine scientists call on UN to stop deep-sea trawls, saying it destroys newly discovered cold water coral species

More than 1,000 of the world's top marine scientists called for a moratorium Monday on deep-sea trawling that destroys coral and sponge ecosystems rich in life.

"Shallow-water coral reefs are sometimes called 'the rain forests of the sea' for their extraordinary biological diversity, perhaps the highest anywhere on Earth," the 1,136 scientists from 69 countries said.

"However, until quite recently, few people – even marine scientists – knew that the majority of coral species live in colder, darker depths."

The statement was released concurrently at the 7th Conference of the Parties of the UN Convention on Biological Diversity in Kuala Lumpur, Malaysia and the American Association for the Advancement of Science annual meeting in Seattle.

Scientists recently discovered coral in the cold and deep ocean habitats of Japan, Tasmania, New Zealand, Alaska, British Columbia, California, Nova Scotia, Maine, North Carolina, Florida, Colombia, Brazil, Norway, Sweden, U.K., Ireland and Mauritania.

Some corals resemble trees, growing up to 10 metres tall. Others form dense thickets supporting thousands of species. 

An immediate UN moratorium is needed to give scientists time to learn more about the diversity, importance and vulnerability of deep-sea coral, said fisheries biology Prof. Daniel Pauly of the University of British Columbia in Vancouver.

Bottom trawling in particular gouges coral and sponges by dragging heavy chains, nets and steel plates across the ocean floor. The trawlers search for valuable, increasingly rare groupers and redfish that live in reefs, as well as shrimp, cod, orange roughy and Chilean sea bass.

"Because deep-sea corals are so slow-growing, they'll take centuries to recover, if ever," said biology Prof. Martin Willison of Dalhousie University in Halifax.

"In Canada's Maritime provinces, hook-and-line fishermen, who use more sustainable fishing methods, have led efforts to protect crucial sea floor habitat. But Canada's government, like the U.S.A.'s, has utterly failed to curb destructive fishing practices such as trawling," he added in a release.

The signers were hopeful, saying it's not too late to save most of the world's deep-sea coral and sponge ecosystems.

Australia, New Zealand, Canada and Norway were commended for taking the first steps towards protecting coral ecosystems under their jurisdiction.

The non-profit Pew Center also released a report at the Seattle annual meeting, calling global warming a triple whammy that harms coral reefs by:

  • Stifling life-giving algae.
  • Preventing tiny sea anemone-like polyps from building their limestone skeletons since spiralling levels of carbon dioxide acidifies sea water.
  • Increasing the vulnerability of reefs to threats such as overfishing, disease and coastal pollutants. 

The report's authors urged governments and conservationists to curb greenhouse gas emissions and manage ecosystems to reduce the harmful effects of fishing and pollution.