The Study Area

Geographic & Bathymetric Scope

The concept of the geographic range of the British marine molluscan fauna was established by the recording activities of Conchological Society of Great Britain and Ireland. Included were the coast and shelf around Britain, Ireland and the Channel Isles and is the basis of the their Atlas published in 1982¹. Additional data expanded to include the whole of the North Sea, English Channel, Faroes and a sector west of Ireland was published in 1990² but again primarily included only species from 200m or less. The scope of the “Species Directory” was again limited to 200m but did not include the Norwegian sector of the North Sea, nor the Faroes or Rockall Bank. The scope of Smith & Heppell’s checklist is similar to that of the “Species Directory” but includes species not recorded from British waters but found within 1° latitude or longitude; consequently equivalent to the 1990 publication.

This project has been funded by the UK government and the first priority is to include the whole of the Exclusive Economic Zone of the UK. This extends from 64°N to 48°N, in a westward arm to 24°W and to the adjoining sectors of the Republic of Ireland, France, Belgium, Holland Germany, Denmark, Norway and the Faroes. The EEZ does not include the Channel Islands but these have traditionally been included in any treatise on the British marine fauna and are included here. The bathymetric range includes all depths from the intertidal to the abyss, which here extends to about 5000m deep. Additional species have been added since the above publications notably as a result of the Atlantic Frontiers Environmental Network (AFEN) explorations to the north and west of Shetland as well as those from the Porcupine Bight and abyssal plain (Olabarria³)

Given the extent of the UK EEZ this guide will function for the fauna of Ireland as a whole, the fauna of the North Sea and the English Channel south to the north coast of Brittany.

¹ Seaward DR (editor) 1982 Sea Area Atlas of the Marine Molluscs of Britian and Ireland. Conchological Society and Nature Conservancy Council. 53 pp + 743 maps.
² Seaward DR (editor) 1990 Distribution of the Marine Molluscs of North West Europe. Conchological Society and Nature Conservancy Council. 114 pp.
³ Olabarria C 2005 Patterns of bathymetric zonation of bivalves in the Porcupine Seabight and adjacent abyssal plain, NE Atlantic. Deep-sea research I. 52: 15-31.

The Maps

Distribution maps based on sea area census data are available in Seaward (1982) and on the website of the Conchological Society of Great Britain and Ireland (http://www.conchsoc.org). Record-based maps are also available on the websites of the Marine Life Information Network for Britain & Ireland (http://www.marlin.ac.uk) and the National Biodiversity Network site (http://data.nbn.org.uk).

The maps presented by us give the projected range based on our interpretation of the record-based maps. Our maps may therefore differ from the above especially where we surmise that the identifications are erroneous, based on dead shells or do not reflect current data.

Example distribution maps :