Publication Abstract

Developing a EUNIS seabed habitat map for the Dogger Bank

Developing a EUNIS seabed habitat map for the Dogger Bank

Markus Diesing*, Suzanne Ware*, Bob Foster-Smith, Heather Stewart, David Long, Koen Vanstaen*, Rodney Forster*, Angela Morando, Neil Golding

The Dogger Bank is a shoal located in the southern North Sea. It was formed by glacial processes before being submerged through postglacial sea-level rise some 7500 yrs before present. The Dogger Bank has recently been recommended to UK Government as a draft Special Area of Conservation (dSAC) by the JNCC (http://www.jncc.gov.uk) for its Annex I sandbank habitat (‘sandbanks which are slightly covered by sea water all the time’) under the European Commission’s Habitats Directive. Part of the process of recommending the Dogger Bank as a dSAC involved further investigations to identify a scientifically robust boundary for the dSAC, along with gaining a better understanding of the marine environment and habitats incorporated within it. Ultimately this resulted in the creation of a EUNIS seabed habitat map for the Dogger Bank.

The production of the Dogger Bank EUNIS habitat map involved a number of processes, analysing data from a recent survey commissioned by the JNCC as well as modelled and remotely sensed data. The Dogger Bank is exclusively composed of sublittoral sediment. The first step involved dividing this up into sublittoral coarse sediment and sublittoral sand, based on multibeam bathymetry, acoustic backscatter and particle-size data from surface sediments. Sandy substrates were subsequently split into fine sand and muddy sand with a cut-off at 5% mud-content. Photic and aphotic seabed was derived from analysis of MODIS satellite data. Together with data of the maximum wave base modelled for UKSeaMap (http://www.jncc.gov.uk/default.aspx?page=2117), this served as an input for the delineation of biological zones (or étages), namely infralittoral (photic and above wave base), circalittoral (aphotic and above wave base) and deep circalittoral (aphotic and below wave base). Finally, all relevant data layers were combined to yield a EUNIS (level 4) habitat map for the Dogger Bank. Comparison with the predictive EUNIS habitat map developed for the MESH (Mapping European Seabed Habitats, http://www.searchmesh.net/) study area revealed that coarse sediment habitats cover less area of seabed than previously thought. Such habitats are restricted to small-scale patches of 10s to 100s of metres in width and 100s to 1000s of metres in length and are also known as sorted bedforms. The dominant EUNIS habitats on Dogger Bank are infralittoral fine sand and circalittoral fine sand.

This work results from a survey undertaken by Cefas, BGS and Envision Mapping on behalf of the JNCC, as part of its Offshore Natura Seabed Survey Programme.

Reference

Markus Diesing*, Suzanne Ware*, Bob Foster-Smith, Heather Stewart, David Long, Koen Vanstaen*, Rodney Forster*, Angela Morando, Neil Golding  (2009) Developing a EUNIS seabed habitat map for the Dogger Bank. NGF Abstracts and Proceedings, 2: p. 25.

Markus Diesing*, Suzanne Ware*, Bob Foster-Smith, Heather Stewart, David Long, Koen Vanstaen*, Rodney Forster*, Angela Morando, Neil Golding

NGF Abstracts and Proceedings, 2: p. 25.