TRAWLING has destroyed large parts of a unique coral formation at the bottom
of the North Atlantic, according to British marine biologists. Unless urgent
action is taken to protect the formation, known as the Darwin Mounds, all its
coral may be smashed within a few years.
The Darwin Mounds were discovered 100 kilometres northwest of the Scottish
mainland in 1998. Spread over 60 square kilometres under 1000 metres of water,
they comprise over 100 seabed hummocks up to six metres high. The mounds are
home to large cauliflower-shaped thickets ofLophelia pertusa, a
cold-water coral that provides a habitat for at least 800 species of deep-sea
animals. Unusually high numbers of huge single-celled protozoans called
xenophyophores also huddle downstream of the mounds.
An expedition that surveyed the mounds last month has uncovered evidence of
widespread damage caused by trawling the seabed. Sonar images reveal parallel
grooves left by trawlers crossing the mounds, while underwater video footage
shows fragments of lifeless Lophelia coral scattered nearby.
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鈥淚t is almost certain that the area has been extensively damaged by deep-sea
trawling,鈥� says Alex Rogers, a marine biologist at the Southampton Oceanography
Centre. 鈥淚t is very frustrating and upsetting, because this is a rare habitat
that needs to be conserved.鈥� The worst damage has been inflicted on the eastern
sector of the mounds, but coral in the western sector could disappear in a
matter of years, according to Rogers鈥檚 colleague David Billett.
The British government鈥檚 scientific advisers are now considering whether part
of the western sector should be brought under the protection of European
conservation law. Deep-sea corals, including Lophelia, are already
covered by the European Union鈥檚 habitat directive. Lophelia was at the
centre of Greenpeace鈥檚 objections to oil exploration in the North Atlantic,
although it was later found growing on the legs of a North Sea oil rig
(快猫短视频, 6 November 1999, p 16).
Dwindling shallow-water fish stocks are increasingly forcing fishermen to
chase deep-sea species. During their voyage, the Southampton researchers saw
French trawlers fishing for roundnose grenadier close to the mounds. Trawlers
from Scotland, Ireland, Spain, Norway and the Faroes may also operate in the
area.
Pascal Lorance from the French Institute for Research and Exploitation of the
Sea in Boulogne-sur-Mer confirms that 15 large French trawlers fish the North
Atlantic. Evidence from the South Pacific shows that trawling can damage the
seabed, but the industry is poorly aware of the problem, he says.
The World Wide Fund for Nature (WWF), which released a report on the state of
the marine environment this week, calls for fishery exclusion zones to help
protect the Darwin Mounds. The WWF鈥檚 marine specialist, Alistair Davison, warns
that time may be ticking away for the coral, given the current haphazard
approach to marine management.