Elephant Seals lived ‘from Cape Reinging to Bluff’ before the arrival of humans – study

A modern elephant seal in Southern Georgia.
Photo: 123rf

New research suggests that a distinct line of elephant seals was well established in New Zealand at the time of human arrival.

Senior Associate Professor Nic Rawlence, director of the Otago Paleogenetics Laboratory, said the history of marine mammal history in Aotearoa offers a vision of how our ecosystem can react to future climate change and human impact.

Rawlence said the seals of the South Elephant were the “canary in the coal mine” to the Antarctic Ocean and a large indicator of the region’s environmental health.

Southern elephant seals are not a common vision on the continent of New Zealand, but they certainly used to be “from Cape Reinging to Bluff” on our prehistoric beaches, according to the new research.

“They are an integral part of the southern ocean ecosystem – elephant seals respond quickly to human impact and climate change. If they start responding in a harmful way, they are acting like this canary, and we should pay attention to warning,” Rawlen said.

“Apex predators like elephant seals keep the rest of the ecosystem under control, but if you are losing these, the health of the ecosystem is deteriorating.

“The southern elephant seals are at the top of the food chain. If we start losing them, it means that what is affecting elephant seals means that it does not only affect them, is not an isolated incident and will affect the food chain.”

The southern elephant seals are the largest marine mammal that are not cetaceans (whales, dolphins and porpoises). Men, with their distinct muzzles, can weigh up to 3700 kg, while females usually have about 1000 kg.

They can be found throughout the Antarctic Ocean, parts of the Antarctic continent and subanthal islands.

Changes in Antarctic Sea Ice are impacting the distance between the breeding sites and where southern elephants go to food.

Rawlence said a unique line of Australian elephant seals was probably pressed to New New Zealand, expanding the sea ice during the ice era. However, this expansion of the interval would not become permanent due to indigenous subsistence hunting and European industrial sealing.

But Rawlen said his existence points to a healthier moment for our prehistoric backs that would seem “an alien world.”

“At the time of the human arrival, you would have seen the seals of Cape Elephants Reinging to Bluff. They would be reproducing here – we know this because we find remains of puppies.

“The beaches would have been covered by seals of elephants, lions -marinhos and penguins… you would have stumbled into a penguin or a pinned (seals) in the first five minutes of reaching New Zealand.

“We had a prehistoric marine lion of New Zealand, very different genetically to seal the lion here now, a unique line of the New Zealand and another exclusive lineage of the Chatham Islands.

“There was a penguin named Waitaha Penguin, a Hoiho Penguin cousin or the yellow -eyed penguin, living in New Zealand.”

While the southern elephant seal species showed quickly responding to human exploitation and climate change, Rawlen said actions to protect his habitat needed to be taken.

“They can only respond to a certain point, there is what you can call ecosystem buffer and, once they reach this cliff edge or point without return, they are out of it.”

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