Jamie Morton is the NZ Herald's science reporter.

Kaikoura Quake: How has wildlife fared?

A sperm whale breaches off the coast of Kaikoura. Photo / File
A sperm whale breaches off the coast of Kaikoura. Photo / File

How has Kaikoura's world-famous wildlife responded to the 7.8 earthquake? Science reporter Jamie Morton looked at what we know so far.

Marine mammals

Recent sightings of whales, as well as Hector's and Dusky dolphins, off the coast of Kaikoura have brought immense relief to locals and tour operators.

Forest and Bird marine advocate Anton van Helden was optimistic about the welfare of Kaikoura's many deep-diving species - among them sperm whales, humpback whales, Southern right whales, orca and several dolphin species.

While the submarine Kaikoura Canyon provided a productive ecosystem for whales and dolphins, there were similarly productive habitats elsewhere that could have served as alternatives.

But he expected that, even with considerable uplift around the canyon area - and the potential of landslides - the systems would have been easily large enough to sustain the quake's effects.

"The other thing, with sperm whales, it is only males that would effectively be there at the moment, so this is the time of year when there would be fewer of them in the region."

However, early indications showed Kaikoura's resident fur seals would have fared worse.

At Ohau Point, a large slip had caused heavy damage to a specially protected seal sanctuary, and it was likely some animals would have perished.

"It's too soon to be able to know the full impact that the earthquake will have had on the local population," Department of Conservation science adviser Laura Boren said.

Baby fur-seals laze on Barney's Rock, South Bay, Kaikoura. Photo / File
Baby fur-seals laze on Barney's Rock, South Bay, Kaikoura. Photo / File

Some seals would likely have been out at sea foraging and so may not have been impacted by this or other slips.

"There are still places north and south of Ohau point where seals can still haul themselves out to rest."

Seal pups play in the water at Ohau Point, where a landslide has destroyed much of the breeding ground. Photo / File
Seal pups play in the water at Ohau Point, where a landslide has destroyed much of the breeding ground. Photo / File

Fur seals generally needed to be very resilient, she said, and during major storm events females had been known to take their pups out into the open water to "ride it out" before returning to shore.

Seabirds

Boren said seabirds were also often found breeding or resting in exposed areas, such as a cliff or seashore, and so may be prone to further slips or landslides.

Because of safety risks to researchers, a full assessment of the impact of the earthquakes on wildlife could take several weeks, she said.

Early indications have shown some seabird colonies fared worse than others.

Forest and Bird seabird advocate Karen Baird said one landslide had taken out half of the largest colony of endangered Hutton's shearwaters, at a time when birds were nesting.

It was possible that up to a quarter of the population may have been wiped out.

Hutton's shearwater. Photo / Facebook / NZ Birds Online
Hutton's shearwater. Photo / Facebook / NZ Birds Online

"While we don't know the extent of the damage yet, it couldn't have come at a worse time, with the birds likely to have been on eggs, and their burrows would have been destroyed."

Conservation officers would now need to ensure what was left of the colony was well protected.

The species' estimated breeding population has dwindled to more than 100,000 pairs, and in New Zealand the bulk of the population stays between Cape Campbell and Banks Peninsula when breeding.

The area was home to many other seabirds, including albatross, petrels, shearwaters, shags and terns, whose fate also remained unclear.

Baird had been told a population of red-billed gulls on the Kaikoura Peninsula had escaped intact.

Little blue penguins at Kaikoura. Photo / Facebook / Kaikoura Ocean Research Institute
Little blue penguins at Kaikoura. Photo / Facebook / Kaikoura Ocean Research Institute

The Kaikoura Ocean Research Institute reported two little blue penguin chicks had died, but Kaikoura's main penguin colony remained mostly unscathed.

Shellfish and crustaceans

Canterbury University marine ecologist Dr Sharyn Goldstien, who has been carrying out early surveys on Kaikoura's around freshly uplifted seabed, said paua, crayfish and all marine organisms of the area will now be acclimatising to a "very different world".

"Just as we in Christchurch had to adjust to new road layouts, new living conditions and competition for our resources, the paua and the crayfish will also have these issues to sort through."

A crayfish on a rock lifted above sea level by the 7.8 quake. Photo / Supplied
A crayfish on a rock lifted above sea level by the 7.8 quake. Photo / Supplied

It was possible many of the crayfish were offshore and may well have survived in high numbers.

"However, upon return they will need to find new habitat to live in and their neighbours may be closer as their living space has been reduced."

Seafood New Zealand stated the quake had exposed large areas of important paua habitat, which would lead to the loss of large number of adult and juvenile paua.

It had also damaged a great deal of the special habitat that paua larval settlement and juvenile growth took place in.

In the new intertidal zone, the area between the new low-tide and high-tide mark, there were still a number of surviving adult paua, but the paua exposed permanently above the new high tide level have died off.

It was the paua in the new inter-tidal zone that would become the breeding stocks driving the future rebuild of the fisheries.

Rock lifted above sea level by the 7.8 quake. Photo / File
Rock lifted above sea level by the 7.8 quake. Photo / File

Goldstien had also observed seaweeds hauled out of the water, which were now hanging from rocks and platforms and had become brittle from drying out in the sun.

"Kaikoura coast is a diverse region and the shift in the marine community will be closely followed by scientists to investigate the successive processes as new communities form."

- NZ Herald

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