Mid-Irish Sea Reefs (2006-2007)

Small boulders with barnacles (Balanus crenatus) and serpulids (Serpula vermicularis) © JNCCSand with mixed shell and stone gravel with Dahlia anemone (Urticina felina) © JNCCCobbles, pebbles and gravel with Echinus sp. © JNCC
The aim of this survey was to investigate and characterise the habitats and biological communities of an area of potential Annex I reef in the mid-Irish Sea, within waters in the offshore marine area, between the Llyn Peninsula in North Wales and County Wicklow in Ireland.
Survey cruises were conducted in November 2006 and January 2007 on board the RV Aora. An acoustic survey was conducted in November 2006 but due to inclement weather, drop down video and photographic sampling was postponed until January 2007. Sufficient data was collected to successfully allow the classification and mapping for the northern part of the survey area. However, due to inclement weather and technical difficulties with the camera equipment insufficient acoustic and groundtruthing data were gathered for the central and southern survey areas to enable the seabed habitats to be mapped with confidence.
The surveyed depths ranged from 60m on the western side of the southern survey area, deepending gradually to the east and north. The deepest area was found in the south-eastern corner of the northern survey area, where a trough 2km wide was fuond at a water depth of 90m. This trough deepened to 155m water depth at its centre.
The biotopes SS.SSa.OSa, SS.SCS.CCS.PomB and SS.SMx.CMx.FluHyd were recorded during the groundtruthing survey. Patches of cobbles and boulders of 25 to 50m2 were observed at several locations which were indicative of Annex I stony reef habitat, although additional high resolution acoustic data would be required to delineate these effectively.
Click to download a pdf of the map

Further Reading

  • Dalkin, M. 2008. Mid-Irish Sea reefs habitat mapping report. JNCC Report 411.

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