A 20 per cent drop in sea lion pup numbers is one of the biggest problems the species faces in the remote sub-Antarctic Auckland Islands, a group of six researchers has found.
Research project head Ian Wilkinson has told Prime Minister Helen Clark, Conservation Minister Sandra Lee and a small group
of media that the average weight of male pups was also down.
Sea lion pups had to contend with a natural mortality rate of 25 per cent, Dr Wilkinson said.
Parasites and a bacteria infection causing arthritis were also found to be problems for sea lions on the island. Helen Clark and Sandra Lee visited the island at the weekend as part of a three day trip to the group of six islands which are 320km south of Stewart Island.
Enderby Island and Dundas Island have 90 per cent of New Zealand's sea lion population.
Massey University vet and New Zealand Wildlife Health Centre director, Padraig Duignan, was also on the island studying the sea lions.
He said about half the deaths had probably been caused by a parasite that lived in the intestines of sea lions. The parasite seemed to be stimulated in adult female sea lions when they fed their young.
Sea lions had also been hit by a bacteria infection causing arthritis and joint inflammation, similar to the human disease, Mr Duignan said.
Dr Wilkinson said despite low pup numbers, sea lion families had not declined on the island.
Samples had been sent to Massey University in the hope it would give some answers to why the species was decreasing.
- NZPA
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