Early post-release survival of stranded Cape fur seal pups at Black Rocks, Algoa Bay, South Africa

Abstract

The small and isolated Cape fur sealArctocephalus pusillus pusillus rookery at Black Rocks, Algoa Bay, South Africa, is an important component of the marine biota of the Addo Elephant National Park. Although little is known of the demographics of this rookery, it is believed to be declining in abundance. The pupping season for this population coincides with summer storms that often wash pups from Blacks Rocks. In the past, many that washed up on the mainland were rescued and returned to their colony. However, the necessity and value of  this exercise has been questioned. The displacement of 200 pups from their rookery following a severe storm in December 2008 presented an opportunity to follow the early survival of rescued pups that were returned to Black Rocks. Tag  resightings of those that were adequately tagged (n = 52) were obtained during five visits to Black Rocks over a period of 3½ months. The results indicated that about one-quarter of tagged pups survived. This is the first study to demonstrate substantial short-term survival of otariid pups following rehabilitation and return to the wild.

Keywords: Arctocephalus pusillus pusillus, catastrophic events, mortality, rehabilitation, stranding

African Journal of Marine Science 2011, 33(3): 463–468