Department of Conservation Press Release 4 February 1998 "More Sea Lion Deaths a Concern: This is the first in a series of written updates on the New Zealand sea lion mass mortality event. The updates will be issued by the Department of Conservation on a regular basis as new information comes to hand, and will also be available on its website, <http//www.doc.govt.nz>.
The number of dead sea lion pups and adults found on sub-antarctic islands is increasing, the Department of Conservation reports.
Reporting from the Auckland Islands,
DOC-contracted vet Nick Gales said total sea lion pup mortality was now
45 percent, or 1353 pups, out of a total pup population of 3033 pups at
the Auckland Islands group. While the pup deaths on Figure of Eight Island
was above normal, Dr Gales had not observed any symptoms of the disease.
| Location. | Total pups born. | No. dead pups. | % mortality |
| Dundas Island | 2374 | 1145 | 48 |
| Sandy Bay (Enderby Island) | 488 | 154 | 31 |
| Figure of Eight Island | 120 | 34 | 28 |
| South East Point (Enderby Island) | 51 | 20 | 20 |
| TOTAL: | 3033 | 1353 | 45 |
At Davies Point on Campbell Island, 24 dead pups had been found and two of six adult females there appeared to have symptoms.
About 95 percent of the sea lions breed on two small islands, Dundas and Enderby, which are part of the Auckland Islands group.
DOC marine mammal expert Mike Donoghue said the deaths of adult sea lions, especially the females or cows, was a greater concern as it meant the remaining sea lion pups will die from starvation if their mothers did not return with food for them, in addition to losing potentially pregnant females. Cows usually left their pups while they foraged for food for up to three to five days, so it was difficult to know when or if the mothers would return.
Mr. Donoghue said an unknown number of adults might have died at sea so the exact extent of adult mortality might never be known. Update figures on the estimate of dead adults were expected tomorrow morning.
Dr Gales fitted seven Enderby Island cows with satellite tags about two weeks ago but only three had returned, suggesting the remaining four cows had died. Seven sea lion pups were also tagged at the same time, and four pups had since died.
Minister of Conservation Nick Smith said the latest information on adult sea lion deaths was tragic. "The New Zealand sea lion had already been pushed to the brink of extinction in the early 19th century and we were beginning to have success with small increases in the population over the last few years. The news about adults dying is very sad and we will need to keep a close eye on the remaining animals over the coming days and weeks." Dr. Smith said a decision to review the sea lion bycatch from the squid fishery, will be made when further information on the cause of the deaths is known later in the month.
Post-mortem examinations of dead sea lion pups and other samples brought back from the Auckland Islands were being conducted by the Massey University Cetacean Investigation Centre in Palmerston North, in conjunction with MAF. No results were expected immediately, and DOC would release final results when they were received.
Mr Donoghue said the three most likely possible causes of the deaths were a virus, a bacterium or a biotoxin, although it could be weeks before any definite results were available.
New Zealand sea lions, previously known as Hooker's sea lions, are one of the world's rarest sea lion. Classified as threatened, the estimated population is between 11,000 and 15,000 and they are confined to the southern waters of New Zealand. They have been legally protected since late last century and are New Zealand's only endemic seal species.
For further information, please contact Nicola Patrick, Department of Conservation Public Awareness Unit on 04-4713117 or 025-571503.
[And from various newspaper sources:] "The Massey University team has ruled out the distemper virus that killed 17,000 harbour seals in Europe 10 years ago. But after initial studies of samples from Auckland and neighbouring islands, Cetacean Investigation Centre director Per Madie said they were no closer to knowing what was killing the mammals.
Massey University scientists trying to find the cause of the deaths of hundreds of Hookers sea lions say while the present epidemic would dent the population, it was likely to recover over time. Cetacean investigation centre director Per Madie said yesterday it was "highly unlikely" the entire population would be wiped out an organism because it would wipe itself out by killing off its host. Mr. Madie said an autopsy of two pups had found a slight lung infection but that could be unrelated to the deaths. It was initially believed a virus might be responsible for the deaths but so far there had been no evidence to confirm that.
The team was now culturing tissue samples in the hope the micro-organism causing the deaths would become apparent. However, that was likely to take weeks." --Elayne Ravji <boss@clear.net.nz> on ProMED-mail <promed@usa.healthnet.org>