Pup production of hooded seals (Cystophora cristata) in the Northwest Atlantic

• Main Authors: Stenson, G.B., Myers, R.A., Warren, W.G., Ni, I.H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1996
• Subjects: Abundance; Hooded seals; Northwest Atlantic; Pup production; Cystophora cristata; Newfoundland
• Online Access: http://repository.ust.hk/ir/Record/1783.1-25977; http://lbdiscover.ust.hk/uresolver?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rfr_id=info:sid/HKUST:SPI&rft.genre=article&rft.issn=0250-6432&rft.volume=&rft.issue=26&rft.date=1996&rft.spage=105&rft.aulast=Stenson&rft.aufirst=G.B.&rft.atitle=Pup+production+of+hooded+seals+%28Cystophora+cristata%29+in+the+Northwest+Atlantic&rft.title=NAFO+Scientific+Council+Studies; http://www.scopus.com/record/display.url?eid=2-s2.0-0030428009&origin=inward

Pup production of hooded seals (Cystophora cristata) in two whelping concentrations along the northeast coast of Newfoundland (the 'Front') during March 1990 was estimated using systematic visual surveys. In addition, independent estimates of production in one of the concentrations and the number of pups born outside the whelping concentrations were obtained from photographic surveys. Photographic estimates were corrected for incorrectly identified pups by comparing black and white photographs with ultra-violet imagery. Estimates were also corrected for pups absent from the ice at the time of the survey using distinct age-related developmental stages. Approximately 91% of the pups born in the first whelping concentration, and 92% born in the second, were present during the surveys. Based on visual surveys, the corrected pup production in these patches was estimated to be 48 684 (SE = 2 747). Photographic surveys resulted in an estimate of 33 498 (SE = 12 450) pups born outside of the whelping patches, although this estimate could not be corrected for the absence of pups due to the temporal distribution of births. Thus, total pup production was estimated to be 82 182 (SE = 12 636). Comparison with estimates made in the mid-1980s suggest that pup production may have increased although they are not statistically different due to the imprecise nature of the estimates.