The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Habitat & Distribution
This very large plankton-feeding pelagic shark, reaching 11m in length occurs in temperate waters circumglobally. In the UK it is mainly recorded in surface waters between April and September, when mostly immature females are seen. It is possibly migratory with seasonal population movements inshore to feed on high abundances of zooplankton near tidal fronts in coastal areas. In late summer, in the north-east Atlantic, basking sharks are thought to disperse off-shore, their winter distribution being unknown for sure, but is probably in deep water. Although widely distributed in both hemispheres, basking sharks appear to be most regularly recorded in coastal areas of the UK with seasonal, persistent tidal fronts that occur off the coast of western Scotland (Clyde area and Hebrides), the central Irish Sea and the western approaches to the English Channel. Here they may be seen, often in large numbers, feeding at the surface.
The attraction of these large and appealing creatures for ecotourism in the UK may well benefit their conservation, although there is some concern that the propellers of the boats carrying sightseers may occasionally cause damage to the sharks. The Basking Shark is protected under Schedule 5 of the Wildlife & Countryside Act (1981) to which it was added in 1998, it is also on the UK and OSPAR Lists of Priority Species and has its own Species Action Plan (SAP). Its global status is assessed as Vulnerable (A1a,d,A2d) in the IUCN Red List.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.