Scientists discover coral reef off west coast

An NUI Galway photograph of long limbed squat lobsters surrounding a coral bush. Researchers have found a 200sq km rugged area of seabed covered in 100m high underwater hills and coral plants more than three times the usual size. Photograph: Anthony Grehan/PA Wire

LORNA SIGGINS, Marine Correspondent

IRISH AND French scientists have discovered a coral reef “province” off the west coast which has been described as the “most pristine” identified so far in these waters.

The 200sq km deepwater area on the southern end of the Porcupine Bank encompasses some 40 coral reef carbonate mounds or “underwater hills”, reaching up to heights of 100m from the seabed.

A remotely operated vehicle deployed from the Marine Institute research vessel, Celtic Explorer, confirmed existence of the subsea habitat, which is expected to be nominated as Ireland’s fifth offshore special area of conservation (SAC).

Four offshore SACs were nominated two years ago for special protection from activities such as trawling, given the potential threat posed by European vessels working in the area under the Common Fisheries Policy.

The expedition was led by Dr Anthony Grehan of NUI Galway, working with colleagues and students from NUIG and the French research agency, Institut Français de Recherche pour l’Exploitation de la Mer.

“These are by far the most pristine, thriving and hence spectacular examples of cold-water coral reefs that I’ve encountered in almost 10 years of study in Irish waters,” Dr Grehan said.

Use of high-resolution bathymetric maps, provided by the Irish National Seabed Survey led by the Geological Survey of Ireland and the Marine Institute, enabled the scientists to identify new areas that were likely to support coral reefs.

Vulnerable marine ecosystems such as coral reefs represent “one of the last untapped reservoirs of potentially useful bio-compounds that might support the development of new anti-viral or anti-bacterial pharmaceuticals,” Dr Grehan added.

NUIG post-graduate student Anna Rensdorf , from the university’s earth and ocean sciences department, said that living coral thickets standing up to 2m high were confirmed on many of the mounds surveyed. Deepwater coral such as lophelia pertusa has been identified on over 1,000 reefs over the past decade in these waters, spanning some 2,500sq km. A French-Irish expedition yielded some of the first images in 2001.

A further international expedition in 2003 confirmed that 60 per cent of European deepwater corals lay off this coastline.

Last year, Irish scientists led a multinational expedition on the Celtic Explorer from Galway to collect samples of cold-water coral as far west as 660km from the Connemara coast.

The aim of the expedition, led by Dr Andy Wheeler of University College Cork, was to provide a “missing link” in international climate change research.