Submarine Structures in the Mid-Irish Sea and Solan Bank (2008)

 
The survey carried out on behalf of JNCC by Cefas had two objectives:
  1. To map the extent and condition of an area of potential Methane Derived Authigenic Carbonate which has formed reef-like structures in the mid-Irish Sea;
  2. To map the extent and condition of bedrock and stony reef around Solan Bank off the north-west coast of Scotland.
 

Submarine Structures in the mid-Irish Sea

 
Survey work within the "Submarine structures in the mid-Irish Sea" Area of Search took advantage of previous work undertaken by the SEA6 surveys commissioned by the Department of Trade and Industry, and gathered additional high resolution acoustic data. High quality underwater imagery (video and still images) were also obtained, along with seabed samples, to help interpret the acoustic data.
 
Boring sponge (Cliona celata) and dead man’s fingers (Alcyonium digitatum) at the Submarine Structures in the mid-Irish Sea © JNCCCommon sunstar (Crossaster papposus) and whelk (Buccinum undatum) at the Submarine Structures in the mid-Irish Sea © JNCCLong clawed squat lobster (Munida rugosa) under MDAC outcrop and Dahlia anemone (Urticina sp.) at the Submarine Structures in the mid-Irish Sea © JNCC
 
"Submarine structures made by leaking gases" are an Annex I habitat under the EC Habitats Directive. These seabed structures are often formed from Methane Derived Authigenic Carbonate, or MDAC. MDAC occurs where seabed sediments become bound together by carbonate cement - a bi-product of the microbial oxidation of methane rising up through the seabed, forming reef-like structures that provide a unique habitat for a wide range of marine life. In March 2011 this site was recommended to Government as Croker Carbonate Slabs.
 
Click on the image to download a pdf of the map
 

Solan Bank

The Area of Search which has now become Solan Bank pSAC was found to have extensive areas of bedrock outcrops with high topography, with linear cliffs rising up to 10 metres from the surrounding seabed running in ENE-WSW and SE-NW orientations. Away from the cliffs the substrata ranged from well sorted sands through to highly fissured bedrock reefs. The majority of reef sites were characterised by encrusting fauna, in particular encrusting bryozoans and encrusting corallines in shallower waters. Species of note were an unidentified cup coral, a sponge which has only previously been recorded from fishing trawl records and not seen in situ before (Oceanapia robusta) and another species of sponge classified as rare (Poecillastra compressa).
 
Bedrock reef at Solan Bank © JNCCRed cusion star (Porania pulvillus) and red gurnard (Aspitrigla cuculus) at Solan Bank © JNCCEdible sea urchin (Echinus esculentus) and brittlestars (Ophiocomina sp.) at Solan Bank © JNCC
 
Click on the image to download a pdf of the map
That data from this survey was assessed against established SAC site selection criteria to determine whether the Solan Bank Area of Search could contribute to the UK marine Natura network, and subsequently Solan Bank was formally advised to Government in December 2011.
 

Further Reading

 

Project Contractors

 

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