New Zealand sea lion conservation heading for failure: scientists

Scientists warned Tuesday that the New Zealand government needs to refocus its conservation efforts if it is to stave off the extinction of the endangered New Zealand sea lion.

A study led by the University of Otago found that the focus on the survival of sea lion pups to reverse population decline would probably fail.

The New Zealand sea lion has been listed as endangered by the International Union for Conservation of Nature based on a 50- perent decline in pup numbers since 1998.

The government's management of the species focused on improving pup survival, including options of vaccinating pups against disease and making the environment safer for them.

But the new modelling study found that adult female survival was the key to reversing the species' decline.

"We provide statistical evidence that even the smallest improvement in adult female survival will have a positive effect on population growth, whereas much more effort and money will be required to improve pup survival to a level for it to have an important impact on population growth," lead author Stefan Meyer said in statement.

Improvements to trawler catches were mistakenly believed to have curbed the number of New Zealand sea lions killed in fishing nets, and many of the sea lions killed that way were females.

The problem of sea lion by-catch had to be addressed, said Meyer.

The research also studied disease-related mass deaths, and found the disease events had no negative effect on population growth.

"It seems that disease has killed only those pups that were already impacted by other factors, such as starvation," said Meyer.

"We should focus on the factors we can successfully influence. Because our research provides good evidence that fishing is likely still having a negative impact on the New Zealand sea lion population, a simple option would be to remove fishing from parts of the Auckland Islands," he said.

"This would allow some of the sea lion breeding colonies to have a break from fishing impacts and would give us the opportunity to examine the ongoing impact of sea lion by-catch."

The New Zealand sea lion population is estimated at about 10, 000, making it the world's rarest seal species.

It is found around the far south of the South Island and in the Subantarctic islands, such as the Auckland Islands. Endi