Getting the seal of approval

Cape Pallliser Coast, New Zealand. PHOTO/STOCK.ADOBE.COM

Cape Palliser seal pups have been living in luxury for a week while the Department of Conservation and Auckland Zoo ran a shelter trial. Environment reporter GRACE PRIOR took a trip down the glistening coast.

An A-frame structure, constructed by Auckland Zoo and DOC, has the goal of being used by sea lions on the sub-Antarctic Auckland Islands and Campbell Island.

Cape Palliser seals pups were put to the test to see if they’d use the structure – and it seems to have had some success.

After the test, the A-frame shelter will be transported to Campbell Island’s Davis Point to shelter sea lion pups from the elements.

Campbell Island sits 700km south of Bluff – about 40 hours by boat.

DOC said Campbell Island was covered in steep and rugged terrain, hitting a peak of 569 metres in elevation at Mount Honey in the south.

“Most of the island is surrounded by cliffs which rise to over 300m in places on the south and western sides.”

Campbell Island hosts a cold, cloudy, wet, and windy climate, receiving only 650 hours of bright sunshine a year.

Rain falls about 325 days of the year, and wind gusts reach more than 96kmh on at least 100 days a year.

The island has an average temperature of 6 degrees Celsius, and it rarely rises above 12C.

Despite the torturous weather, this part of the world is favoured to the endangered New Zealand sea lions.

A DOC report showed sea lion pup mortality reached 81 per cent across Campbell Island from late December 2019 to January 2020, the highest recorded mortality rate since 2007.

Davis Point, home to one of the sea lion colonies on the island, had a mortality rate of 89 per cent.

Some factors causing the high mortality rates at Davis Point included mud, bad weather conditions, lack of shelter, and the presence of rock pools and bog holes.

“Unlike the breeding site at Shoal Point, which is drier and more sheltered, the Davis Point colonies are exposed. In wet conditions the site at bog colony transforms from a firm dry pan, into quagmire. Natural depressions in the terrain quickly become deep boggy holes that trap pups,” DOC said in its report.

The report said during bad weather, pups were frequently seen shivering in cold, wet, and muddy conditions. Pups were often huddling together trying find shelter or laying on the bodies of other deceased pups raising themselves out of the mud.

It wasn’t uncommon to see the same pups that were huddled for warmth dead in the same spot the next day, the report said.

New Zealand sea lions were deemed as endangered in 2015 by the International Union for the Conservation of Nature red list of threatened species.

Auckland Zoo seal keeper Odin Neil said the trial shelter had been built to hold up to 450kg – the weight of a large adult male sea lion.

The A-frame shelter was built using re-constituted plastic that lasts up to 100 years, is bacteria resistant, and is unable to be chewed by animals.

Auckland Zoo designer and project manager Roger Drew said the shelter that was trialed at Palliser would likely be the same one that would be used on Campbell Island.

He said if successful, the project could have a much wider implication for wildlife conservation across the world.

Neil said the sea lions on Campbell Island didn’t have the same shelter of rocks and shrubs as the seals at Palliser do.

DOC marine science adviser Laura Boren said the shelter and the trial took about a year to plan.

She said the idea started with the New Zealand Sea Lion Threat Management Plan, which outlined some of the problems the sea lion population faces.

Boren said DOC had launched a design challenge and liked the A-frame design Auckland Zoo had come up with.

She said the project and design had gone through many discussions, getting feedback from other sea lion biologists and making any adjustments as needed.

Neil said their team did some load testing with a 450kg sandbag – the shelter held up fine.

Iwi representative Teresa Aporo said the area was of great significance to the people, with Haami Te Whaiti blessing the area before the project began.

She said the area had changed a lot over the years and was pleased to see ongoing conservation efforts at Palliser.