New Zealand Journal of Marine and Freshwater Research abstracts
New Zealand sea lion, Phocarctos hookeri, pup production—1995 to 2006
B. L. Chilvers1
I. S. Wilkinson1,2
S. Childerhouse1,3
1 Marine Conservation Unit
P.O. Box 10 420
Department of Conservation
Wellington, New Zealand
email: lchilvers@doc.govt.nz
2 Department of Environment and Conservation
Locked Bag 914
Coffs Harbour
NSW 2450, Australia
3 Department of Marine Science
University of Otago
P.O. Box 56
Dunedin, New Zealand
Abstract The New Zealand sea lion (NZ sea lion), Phocarctos hookeri, is New Zealand’s only endemic pinniped. Classified as vulnerable, it is one of the world’s rarest pinnipeds. During the 1994/95 austral summer, a long-term population-monitoring programme of the Auckland Island colonies was initiated using standard procedures to estimate annual pup production. This paper reports the pup production estimates for the known NZ sea lion population over the last 12 years (1994/95 to 2005/06), and the variation in pup production estimates for the Auckland Islands. Sixty-four percent of the pup production for the entire NZ sea lion population occurred at Dundas Island, followed by Enderby Island (19%), and Figure of Eight Island (3%). These three sites are all at the Auckland Islands, making this area the primary breeding site for this species with 86% of all pup production occurring here. The remaining 14% were born at Campbell Island, with Otago Peninsula representing <0.1%. The pup production estimates for the NZ sea lion population varied considerably by year and breeding area. The most significant change recorded was at the primary breeding site for this species, the Auckland Islands, which had a 31% decline in pup production between 1997/98 and 2005/06 owing to a combination of disease events and incidental by-catch from commercial fishing activity.
Keywords pinniped; pup production; sub-antarctic; Campbell Island; Auckland Islands
New Zealand Journal of Marine and Freshwater Research, 2007, Vol. 41: 205–213
0028–8330/07/4102–0205 © The Royal Society of New Zealand 2007
M06054; Online publication date 31 May 2007. Received 29 August 2006; accepted 18 February 2007
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