Newly discovered European corals need protection
Scientists from the UK, France and Norway are calling for immediate controls to stop destructive fishing practices in the northeast Atlantic, where rare cold-water coral reefs are being reduced to rubble by unregulated, deep-sea trawling.
The scientists’ research, published in latest edition of The Royal Society’s scientific journal, Proceedings B, shows that these large, 4,500 year old reefs are suffering wide-scale fishing damage. Modern trawl nets, which are dragged along the sea bed to catch fish, have been found to have destroyed large sections of the reefs, whose existence has only recently been discovered.
Conservation group WWF has joined the campaign, and is urging the EU to protect all of the deep-water coral reefs around Europe’s coasts under the Habitats Directive. The cold-water coral, Lophelia pertusa, does not contain the symbiotic algae found in tropical reefs, which capture energy from sunlight. Instead, Lophelia relies on catching passing food from the water to survive. Colonies tend to live between 200m and 400m deep, in areas where there are strong currents that remove smothering sediments and waft food to them.
Large-scale fishing did not take place on outer edges of the north eastern Atlantic continental shelf until the 1980s but has become intensive in recent years. The damage was only discovered because commercial interest in offshore oil reserves has prompted extensive surveys of the northeast Atlantic continental shelf break. Deep-sea submersibles have recently revealed spectacular coral communities off Ireland, Scotland and Norway.
Detailed study of the reefs has only just begun, but seabed photographs, acoustic surveys and analyses of commercial trawls show trawl scars up to 4km long, damaged habitats, dragged rocks and turned-over sediment among these ancient habitats. By-catches from commercial trawls included large pieces of coral broken from reefs and an array of coral-associated flora and fauna. Delicate bottom-dwelling species such as sea pens, sponges and giant, single-celled Xenophyophores have also been destroyed.
One of the report’s authors, Dr Jason Hall-Spencer, who works at the University of Glasgow and Millport marine station, says: “Most of us associate coral reefs with warm, well-lit waters off tropical coasts – it surprises many that the grey, northeast Atlantic harbours these amazing reefs. Heavy trawls are bringing up coral that has been in place for thousands of years. We urgently need improved management of offshore areas world-wide both to protect ancient deep-water habitats and the fish that they support.”
WWF is also demanding that the forthcoming review of the Common Fisheries Policy add an environmental protection clause to prevent the destruction of rare habitats by fishing. “These magnificent coral reefs should be off limits for fishing. This year, the list of marine sites to be protected under the Habitats Directive is supposed to be finalised and the Common Fisheries Policy is up for review,” said Stephan Lutter, director of WWF’s North East Atlantic Programme. “Both provide excellent opportunities to safeguard our amazing underwater natural heritage.”
“We know that corals have been damaged accidentally by trawling when reviewing deep water trawl fishery survey by-catch records,” said Dr Anthony J Grehan, Chairman of the Irish Coral Task Force, which was set up last year following unconfirmed allegations of deliberate trawling over corals in Ireland. He added: “We are actively pursuing action in terms of the national application of the Habitats Directive and the inclusion of a suite of coral conservation measures in the next Common Fisheries Policy.”
Last year, WWF published an initial list of all offshore sites known to be eligible for protection under the Habitats Directive. This shows that at least two thirds of the known cold-water reefs are in Irish waters. WWF has urged the Irish government to act quickly to designate offshore coral reefs for protection under the Habitats Directive.