No. 16 Offshore seabed survey of the Fladen Grounds Scottish possible MPAs - Final Report
(016 - 2017)
Eggleton, J., Jenkins, C. & Schinaia, S.
This report presents the findings from analyses of the acoustic data and groundtruth samples gathered during the seabed survey of the Fladen Grounds pMPAs during January, 2013. The main aim of this survey was to confirm the presence of Priority Marine Features, namely ‘burrowed mud’ and its component habitats and species, within the pMPAs and provide evidence to allow comparison of benthic assemblages between the sites.



In the formal advice submitted by SNH and JNCC to Scottish Government, three Scottish nature conservation Marine Protected Areas (MPAs) were proposed in the Fladen Grounds area. Central Fladen was proposed for the ‘burrowed mud’ MPA search feature, and Western and South East Fladen were proposed as science based alternatives for the representation of the ‘seapens and burrowing megafauna in circalittoral fine mud’ component of the ‘burrowed mud’ habitat. All three possible MPAs (pMPAs) were assessed as being of equivalent ecological value for this feature. Central Fladen, however, was assessed as making a better contribution to the MPA network, as it was the only known location for the tall sea pen (Funiculina quadrangularis), which is a component species of the ‘burrowed mud’ MPA search feature off the east coast of Scotland. JNCC concluded that representation of the ‘burrowed mud’ search feature could be achieved either by taking forward the Central Fladen pMPA in its entirety; or by taking forward just the southern part of the Central Fladen pMPA (Central Fladen (core)), containing the tall sea pen. In addition, one of the two alternative locations, Western or South East Fladen pMPA, would be taken forward for the ‘seapens and burrowing megafauna in circalittoral fine mud’ component habitat.

The Fladen Grounds pMPAs are located within a muddy sand and sandy mud sediment plain in the Northern North Sea, approximately 80 nautical miles east of Orkney. Western Fladen and Central Fladen comprise sub-glacial tunnel valleys, classified as the ‘Fladen Deeps Key Geodiversity Area of the Quaternary of Scotland Block’. The South East Fladen includes the ‘Scanner-Scotia-Challenger pockmark complex key geodiversity area’, which is located within the Scanner Pockmark site of community importance (SCI).

The results of this survey showed that the Fladen Grounds pMPAs are dominated by the broadscale habitat, ‘subtidal mud’. Only Central Fladen pMPA and Central Fladen (core) showed any heterogeneity in terms of broadscale habitat. A deep tunnel valley was observed in the multibeam bathymetry data at Central Fladen pMPA; with the deepest point recorded to be at 293m below chart datum. The tunnel valley was characterised by coarser sediment (‘subtidal mixed sediments’) and as such was characterised by a significantly different infaunal community to the surrounding area. At the edge of the valley, nearing the shallowest region of the Central Fladen pMPA, the southeastern tip was found to comprise ‘subtidal sands’.




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ISSN 2051-6711
Please cite as: Eggleton, J., Jenkins, C. & Schinaia, S., (016 - 2017), No. 16 Offshore seabed survey of the Fladen Grounds Scottish possible MPAs - Final Report, ISSN 2051-6711