Spectacular Deep-water Coral Province Discovered Off Ireland's West Coast

NUI Galway researchers, during a recent deep-water expedition, have confirmed the existence of a major new coral reef province on the southern end of the Porcupine Bank off the west coast of Ireland. The province covers an area of some 200 sq. km and contains in the order of 40 coral reef covered carbonate mounds. These underwater hills rise as high as 100m above the seafloor.
The deep-water research expedition took place earlier this month aboard the Marine Institute research vessel, the RV Celtic Explorer. The research used the new national Remotely Operated Vehicle (ROV) Holland I to survey the seafloor and capture unique video footage. The expedition, led by Dr Anthony Grehan, was a collaboration between NUI Galway and the Institut Français de Recherche pour l’Exploitation de la Mer (IFREMER) and involved researchers and students from both institutions.

Dr Anthony Grehan, NUI Galway, said: “These are by far the most pristine, thriving and hence spectacular examples of cold-water coral reefs that I’ve encountered in almost ten years of study in Irish waters. There is also evidence of recent recruitment of corals and many other reef animals in the area suggesting this area is an important source of larvae supply to other areas further along the Porcupine Bank”. Dr Grehan suggested that given the rugged terrain, its unsuitability for trawling and its well defined boundaries, that the area would be an excellent additional candidate to the four existing off-shore coral Special Areas of Conservation (SAC). He said that NUI Galway’s Department of Earth and Ocean Sciences would in due course provide a copy of all video footage to the National Parks and Wildlife Service to facilitate them in their work of further SAC designations to comply with the European Union's Habitat Directive.

The expedition began in French waters with a series of ROV dives in previously unexplored canyons in the Bay of Biscay which confirmed the presence of coral and geogenic reefs that will be notified to the new French Marine Protected Area Agency. Dr Brigitte Guillaumont from the newly established agency, said: “The video and images obtained from the high definition video camera of the Irish ROV are very impressive and will greatly assist us in our work of designating areas for the protection of corals”.

Moving into Irish waters, the use of high resolution bathymetry charts, provided by the Irish National Seabed Survey, a collaboration between the Geological Survey of Ireland and the Marine Institute, enabled the identification of new areas likely to support coral reefs. The ROV was then used to dive on one of these areas, the Archipelagos Mounds (or Arc Mounds), to reveal a seascape of spectacular coral reefs. Anna Rensdorf, a Griffith Geoscience PhD student in the Department of Earth and Ocean Sciences, NUI Galway, who had previously worked on tropical corals, said: “I can’t believe that coral reefs like these can be found in the cold waters of Ireland. On many of the mounds surveyed, living coral thickets stood up to 2m high where ordinarily they are less than half a metre in height”.

The NUI Galway study is part of a larger pan-European project funded by the European Commission’s 7th research Framework Programme, called ‘CoralFISH’ that is studying in detail the interactions between corals, fish and fisheries. Dr Grehan, coordinator of the European study, said: “At the recent International Council for the Exploration of the Sea (ICES) deep-sea symposium delegates expressed increasing concern about the level of bottom fishing related damage sustained by vulnerable marine ecosystems (VMEs) in the High Seas (i.e. areas beyond national jurisdiction). Because cold-water corals remain the best example of VMEs, much research is focused on them. One of the key areas in the management of fisheries now appears to be improving our understanding of how fish use habitat. We need to understand what effect damage or removal of that habitat will have on fish stocks and communicating that knowledge to fishermen”.

Dr Grehan noted that 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. Currently, there is a major biodiscovery programme underway at NUI Galway funded through the Marine Institute under Sea Change – A Marine Knowledge, Research and Innovation Strategy for Ireland 2007-2013.