North-West Irish Sea Mounds (2003, 2006 and 2007)

Boulders with common brittlestar (Ophiothrix fragilis) © AFBIFine silt with Dublin Bay prawn (Nephrops norvegicus) © AFBIBedrock outcrop with sediment veneer composing dead man’s fingers (Alcyonium digitatum), anemones (Urticina eques) with short hydroid and bryozoan turf © AFBI
The North-West Irish Sea Mounds are a group of bedrock outcrops between Northern Ireland and Scotland. The aim of this project was to survey and map the bedrock outcrops to enable JNCC to assess the areas suitability for selection as a Special Area of Conservation. To date, data from four research cruises have contributed to this project.
A previous acoustic survey had been undertaken under the Irish Sea Pilot Project in June 2003 which confirmed that the bathymetric peaks previously identified by the UK Hydrographic Office and the British Geological Survey were bedrock outcrops, or bedrock 'reef'. In order for a habitat map to be created for the area and potential Annex I bedrock reef to be delineated, further surveys were undertaken by AFBI in June 2006, when a multibeam survey was conducted. Further grab sampling was undertaken in November 2006, with additional video and grabs being collected in January 2007. Due to the bad visibility experienced in January 2007, additional video footage was collected in February 2007. Data from these surveys were supplemented with grab and video samples collected on a survey pre-dating the start of the project in February 2003.
Video footage, classified according to substrata type and obvious fauna was overlain on the predicted physical zones from the multibeam data. All grab samples were analysed to give a species list and sediment particle size information. Statistical analysis was undertaken to group similar samples and identify biotopes. Combining video, grab and multibeam data enabled the production of a broadscale habitat map. The biotopes CR.MCR.EcCr.UrtSed, CR.L.SMx.Omx, SS.SMu.OMu.MonPfal, SS.SMu.OfiMu.TwmS and SS.Ssa.OfiSa were recorded.
Click to download a pdf of the map

Further Reading

  • Mellor, A., Mitchell, A., Strong, J., Rooney, L., Service, M. 2008. North-West Irish Sea Mounds: hard and soft substrata habitats. JNCC Report 410.

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