Abstract
During the period September-December in 2001-2003, ship based surveys of grey seal (Halichoerus grypus) pups, including tagging, counting and staging of pups, were conducted along the Norwegian coast. All known and other potential breeding areas were surveyed from Rogaland county in the south to Finnmark county in the north. Most of the breeding sites were surveyed only once, but some sites were surveyed 2-4 times. The investigations resulted in a total minimum estimate of 1,159 grey seal pups born in Norwegian waters. Nordland county was the most important breeding area where about 50% of the pups were born. Total population estimates were derived from the recorded number of pups born using a range of multipliers (4.0-4.7), based on observed annual growth rates of approximately 7-12% in other grey seal populations. This gave a total estimate of about 5,800-6,600 grey seals including pups in Norwegian waters. However, the total pup production was probably underestimated due to only one pup count in most of the breeding sites. Observed mean pup mortality was 1.1% during the breeding season along the Norwegian coast.
Highlights
There are three main groups of grey seals (Halichoerus grypus) in the North Atlantic. One of these is distributed from the British Isles northwards along the entire coast of Norway and the Murman Coast of Russia (Bonner 1981, Wiig 1986, Haug et al 1994)
The species is resident in Norwegian coastal waters where Wiig (1986) suggested a discontinuous distribution with the largest abundance in mid Norway
Øynes (1964, 1966) concluded that no grey seal pup production occurred in the southern parts of Norway in the early 1960s
Summary
There are three main groups of grey seals (Halichoerus grypus) in the North Atlantic. To obtain a better basis for management, more extensive studies of grey seals from Stad to Lofoten (Fig. 1) were initiated in 1974, and continued throughout the 1980s and early 1990s, when the geographical range of the surveys was extended to include the entire Norwegian coast (Wiig 1986, 1987a, 1987b, 1988, 1989, Wiig and Øritsland 1987, Haug et al 1994) These studies indicated that the number of grey seals inhabiting Norwegian coastal waters at that time was probably much larger than previously reported for the early1960s by Øynes (1964, 1966)
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