A new report raises concerns about damage caused by French trawlers to the magnificent coral growths off the Irish coast, writes Lorna Siggins, Marine Correspondent.
An Irish deep-water coral reef dating back more than 4,500 years has been "smashed to pieces" by French fishing vessels, according to a paper recently published by the Royal Society. Dr Jason Hall-Spencer of the University of Glasgow, who wrote the paper, says photographs of the seabed and an analysis of commercial trawls show unregulated deep-water fishing is causing extensive damage to the ancient coral habitats.
He says a new EU policy is urgently required to control or restrict harmful fishing. Deep-water areas were thought to be barren until recent research showed otherwise, including last summer's Franco-Irish research expedition to the Porcupine Seabight - or recess - and Rockall Trough. Using a remotely-operated vehicle owned by Ifremer, the French marine-research agency, the team highlighted the richness of the areas.
"Most associate corals with warm, well-lit waters off tropical coasts," notes Dr Spencer-Hall. Yet the cold north Atlantic also has its share of these remarkable organisms, building their huge underwater structures.
Dr Spencer-Hall has analysed commercial fish catches aboard two French trawlers on eight quarterly trips between December 1995 and August 1997. The vessels were typical of the fleet currently fishing off the west of Ireland, around the continental shelf.
Taken every four to five hours over a 24-hour period, the hauls included by-catches of coral, large amounts of sponge and rock. In a total of 229 hauls analysed, five had substantial quantities of coral, which carbon dating found to be almost 4,500 years old.
Two areas containing Lophelia pertusa, a deep-water coral, were also filmed off Norway in 1999, at depths of 200 metres, to look at the effects of fishing there. Dr Hall-Spencer notes that, in the past decade, both Norway and Tasmania took action when the effects of coral-reef damage were identified, and he says it is time the EU took similar action.
On a typical 15-day fishing trip, he says, trawls can seep about 33 square kilometres of continental-shelf-break habitat. Although skippers try to avoid dense coral reefs, as it limits their catch, there is collateral damage.
He recommends that legislation be introduced as soon as possible for sensitive areas such as north-west Rockall and the Darwin Mounds, on the north-east Rockall Trough. Managing conservation should be easier, given that satellite tracking for all fishing vessels more than 24 metres in length has been agreed by the EU in co-operation with the Faroes, Iceland, Greenland, Russia and Norway.
Marine special areas of conservation have already been proposed by the Irish Coral Task Force, chaired by Dr Anthony Grehan of the Martin Ryan Marine Science Institute, at NUI, Galway. He believes much of the damage is accidental, although allegations of deliberate use of destructive trawling techniques were made at a consultative workshop at the university in June 2000, which was organised as part of the Atlantic Coral Ecosystem Study.
The main goals of the Irish Coral Task Force included obtaining scientific proof of serious damage, identifying legal instruments available to protect Irish corals and informing policy-makers.
As part of this, the Franco-Irish mission, supported by the EU, was organised last summer, and more than 100 hours of high-resolution video was shot over tens of miles in the most important coral areas on the Porcupine Seabight and Rockall Trough.
"While we found some evidence of the use of static fishing gears, such as tangle and gill nets, we were delighted to find no evidence of the destructive trawling technique used in Norway," Dr Grehan says. He warns that this doesn't rule out the practice elsewhere.
"We know that corals have been damaged accidentally by trawling, when reviewing deep-water trawl fishery survey-by-catch records, so there is still an urgent need to put in place the necessary management measures." Discussions are taking place with the relevant agencies, he says.
Trawling Damage to the North-East Atlantic Ancient Coral Reefs, by Dr Jason Hall-Spencer, Valerie Allain and Jan Helge Fossa, is published by the Royal Society