Low count triggers new plan for endangered New Zealand sea lion

  • Nathan Guy
  • Nick Smith
Primary Industries Conservation

A Threat Management Plan for the New Zealand sea lion is to be developed in response to this season’s low pup count on the Auckland Islands, Conservation Minister Dr Nick Smith announced today from the HMNZS Wellington at Port Ross in conjunction with Primary Industries Minister Nathan Guy.

“The New Zealand sea lion is the rarest in the world and New Zealand’s only endemic seal. The 1575 pups counted on the Auckland Islands this year is down 18 per cent on last year and is cause for concern. It is the third lowest since monitoring began in the mid-1990s and shows an on-going trend of decline over the last decade. We need to step up our efforts to ensure these sea lions survive,” Dr Smith says.

The New Zealand (or Hooker) sea lion once numbered in the hundreds of thousands, with their habitat extending throughout New Zealand. However, in the nineteenth century the species was decimated for its blubber and skins, and in August 1997 when he was last Minister, Dr Smith declared the sea lions to be a threatened species under the Marine Mammals Protection Act.

The New Zealand sea lion mainly breeds on the Auckland Islands (70 per cent of the species) and Campbell Island (30 per cent), with small numbers found on Stewart Island. The more encouraging advice is that breeding numbers on Campbell Island are showing improvement and in the last decade, the sea lion has started breeding on the South Otago coast line.

“The cause of the decline in the Auckland Island sea lion population is not clear. A wider investigation was initiated in 2012 that indicated that environmental change and prey abundance were likely to have played a role in the population decline. There is also evidence that a bacterial disease has reduced pup survival rates over the last two decades,” Dr Smith says.

“A decade ago, fishing for squid, scampi and southern blue whiting was catching and killing an estimated 100 sea lion per year. This number has declined significantly with the Sea Lion Exclusion Devices (SLEDs) developed by the fishing industry. Despite high levels of observer coverage, only a small number of incidental captures have been observed in recent years. SLEDs are a great innovation but we need to continue to monitor the use and effectiveness of these devices,” Mr Guy says.

“The purpose of developing a new Threat Management Plan for the New Zealand sea lion is to review all the risks and explore all possible measures to ensure their survival. Options include active field management such as intervening to reduce the several hundred deaths from misadventure and disease, extending or creating new marine mammal sanctuaries under the Marine Mammals Protection Act, or additional measures to reduce impacts of fishing,” Dr Smith says.

“We are bringing forward the development of this new plan because we want DOC and the Ministry for Primary Industries to get the work underway promptly. The existing operational plan was for this to be triggered if pup numbers dropped below 1500. The two agencies need to work together on this new plan so as to better protect our sea lions, while also recognising that these fisheries generate over $100 million per year in export earnings for New Zealand,” the Ministers say.