Marine Institute

High-tech offshore exploration reveals the true extent of the Irish deep-water coral province

New discoveries about the extent of Ireland's deep sea coral reef and carbonate mound structures were obtained over the last three weeks using advanced offshore technology. The European marine research survey 'CARACOLE', (CARbonate mounds And COLd coral Exploration) just completed in the deeper waters of the Porcupine SeaBight and Rockall Trough off the Irish west coast, provided a comprehensive and unique study of Irish corals reefs and carbonate mounds.

Led by the French marine scientist, Dr. Karine Olu from IFREMER, this interdisciplinary and international collaborative project included both French researchers and teams from institutes and universities in Ireland, Belgium, Holland and Germany participating in the EU-funded projects ACES, ECOMOUND and GEOMOUND. The survey team used the IFREMER state of the art remotely operated vehicle VICTOR, in only its first full year of operation, to carry out unique underwater surveys at depths of up to 1000m. This was possible due to the advanced technological capabilities of VICTOR which includes precise bottom location of sonar and video transects as well as the robotic deployment of in situ sampling equipment.

Since departing Cork Harbour on 31st July, the VICTOR has made ten dives from the French Research Vessel, Atalante. Operated remotely by the scientists on board the ship for up to 24 hours a day, the VICTOR was used to carry out extensive surveys at several locations. These surveys have revealed an underwater wonder world of coral gardens teeming with life according to Dr. Olu. "Previously thought to be confined to summit areas of carbonate mounds we now know that living coral and associated fauna can be found both on mounds and on the adjacent seafloor", said Dr. Olu. "Strong erosional currents in this extreme environment compete with coral growth to create these impressive features. In a bizarre interaction between biology and geology, erosional features are colonised by new growth and have contributed over geological time to the spectacular development of these underwater hills," explained Dr. Andy Wheeler, University College Cork, Ireland.

The IFREMER-led survey was supported and co-funded by the Marine Institute. "The success of this project was made possible through ongoing European co-operation and the application of advanced marine technology," said Yvonne Shields, Director of Science, Technology and Innovation, Marine Institute. "The Marine Institute is currently engaged in a range of projects which will improve national marine research and technology capability. Of particular significance the new national research vessel the 65m Celtic Explorer will provide an excellent national platform for future deep sea studies when completed next year," explained Ms Shields.

The project team of high level European marine scientists included Irish researchers from National Universtiy of Ireland Galway (NUIG), National University of Ireland Cork and University College Dublin. The varied expertise of the Irish scientists involved made a major contribution to this important deep-sea project in Irish waters. "As well as increasing our knowledge about the distribution and diversity of the Irish deep-water fauna, the survey will provide the first comprehensive data to help assess environmental impacts on the coral ecosystem." said Dr. Anthony Grehan, National University of Ireland,Galway.

One of the immediate positive results of the cruise was that no evidence of extensive damage to reefs was found in any of the areas surveyed by CARACOLE. Dr. Grehan who is Chairman of the Irish Coral Task Force said, 'While this can not rule out damage in all areas, this is extremely good news for Irish coral'. Compared with Norway where up to 50% of known reefs have been damaged, the coral habitats we surveyed were largely pristine, he said. We are in the fortunate position of still having time to develop and implement management strategies to ensure the health and survival of this spectacular deep-water ecosystem. The key Irish agencies will be working actively to develop and implement management strategies to ensure the long-term health and conservation of this spectacular deep-water ecosystem.