Pup production and sustainable yield of white sea harp seals

Pup production and sustainable yield of White Sea harp seals.FiskDir. Skr. Ser. HavUnders., 16: 551-559. Pup production from 1962 to 1965 was estimated by a survival index method from age composition of Norwegian samples of moulting harp seals collected in the southeastern Barents Sea from 1964 to 1972. Pup production decreased from 130 thousand in 1962 to 98 thousand in 1965. From these estimates production was projected forward to give an estimate of 172 thousand pups produced in 1978, corresponding to a total stock of one year old and older harp seals of about 800 thousand. Both the projection and the number of adult females in the whelping patches estimated from Soviet aerial surveys give an annual increase of about 5% since 1968. The sustainable yield for 1978 is estimated at 98 thousand pups and 8 thousand one year and older animals