Environment Food and Rural Affairs written question – answered at on 3 March 2004.
To ask the Secretary of State for Environment, Food and Rural Affairs what estimate she has made of the (a) dolphin and (b) porpoise populations within (i) British waters and (ii) European Union waters; what the estimate was for these species 20 years ago; and if she will make a statement.
Obtaining population estimates for cetaceans is difficult. There is a wide margin of error around most abundance estimates and the geographical limits of most biological populations of dolphin species are not known.
To date, major surveys of cetacean distribution or abundance have not been carried out at regular intervals. The following table gives figures from the 2002 report of the Advisory Committee on Ecosystems of the International Council for the Exploration of the Sea (ICES) illustrating the latest information on the populations and abundance of small cetaceans occurring in UK waters. The populations are given in terms of ICES areas or geographical locality. A map showing the ICES areas has been placed in the Libraries of the House.
A consortium of international researchers, co-ordinated by the Sea Mammal Research Unit, is planning to carry out a survey of the distribution and abundance of small cetaceans—particularly harbour porpoises (Phocoena phocoena), bottlenose dolphins (Tursiops truncatus) and common dolphins (Delphinus delphis)—in 2004–05. The survey area is intended to cover the shelf waters of the Atlantic margin, the North Sea and adjacent waters. International funding is being sought in support of this work and the UK has already pledged £275,000 towards it.
Reliable estimates for dolphin abundance in British and European Union waters in 1984 are not available.
Species Year | ICES Area or geographical locality | Abundance estimate | 95 per cent. Confidence limits | Method | Reference |
---|---|---|---|---|---|
Harbour porpoise | |||||
1994 | IVa | 98,564 | 66,679–145,697 | Ship-based line transect | Hammond et al., 2002 |
IVb+c | 169,888 | 124,121–232,530 | |||
Vllf+g+h+j | 36,280 | 12,828–102,604 | |||
Bottlenose dolphin | |||||
1992 | Moray Firth (southwestern lVa) | 129 | 110–174 | Photographic mark-recap Photographic identification or direct observation. | Wilson et al, 1999 |
2001 | French coasts Vile Villa | 250–300 | n/a | ICES, 2002 | |
1991–1993 | Cornwall | 15 | n/a | ICES, 1996 | |
1994–1995 | Dorset | 5 | n/a | ||
2001 | Cardigan Bay, Wales | 135 | 85–214 | White and Webb, 1995 Baines et al.,2002 | |
213 | 183–279 | Ship-based line transect | |||
White-beaked and Atlantic white-sided dolphins | |||||
1994 | IVa | 1,685 | 690–4,113 | Ship-based line transect | Hammond et al., 2002 |
IVb | 9,242 | 5,344–15,981 | |||
VIIf+g+h+j | 833 | 159–4,360 | |||
Atlantic white-sided dolphin | |||||
1998 | Faroes-Shetland channel | 21,371 | 10,000–45,000 | Ship-based line transect | Macleod, 2001 |
1998 | V1a (N) | 74,626 | 35,000–160,000 | ||
2000 | Parts of V1 a&b V11 b/c, V11j&k | 5,490 | 1,134–10,015 | O'Cadhla et al., 2001 | |
Common dolphin | |||||
1994 | Vllf+g+h+j parts of VI a&b | 75,449 | 22,900–284,900 | Ship-based line transect | Hammond et al., 2002 |
2000 | VII b/c, Vllj&k | 4,496 | 2,414–9,320 | O'Cadhla et al., 2001 | |
1993 | Bay of Biscay | 61,888 | 35,461–108,010 | Goujon et al, 1993 | |
Striped dolphin | |||||
1993 | Bay of Biscay | 73,843 | 36,113–150,990 | Ship-based line transect | Goujon et al., 1993 |
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