Helicopter herding seals away from quake rebuild red zones near Kaikoura.
Low-flying helicopters are being used to herd seals away from contractors clearing earthquake-damaged State Highway 1 north of Kaikoura.
The innovative method of "hazing" is understood to be a New Zealand first and conservationists say it's having no adverse effects on the legally-protected marine mammals.
Agencies and contractors working with heavy machinery to clear rockfall and landslides from State Highway 1 north of Kaikoura by a strict deadline of Christmas this year, have been issued a Department of Conservation permit that grants immunity from killing, injuring, or disturbing seals during the massive road and rail rebuild.
There have been around 180 fur, or kekeno, seal deaths since the massive magnitude 7.8 November tremor, with most likely succumbing to rockfall or natural causes.
But the local population of around 2000 at Ohau New Zealand Fur Seal Sanctuary and breeding colony appears largely unperturbed by the habitat disruption.
Every night, seals migrate back into the dangerous construction zones.
To move them on the following morning, and to keep them clear from trucks, diggers and falling debris, an experienced chopper operator buzzes over them, using the rotor wash to marshal them into the sea or safe areas.
A helicopter flies low to herd fur seals away from earthquake repair red zones near Kaikoura. Photo / Supplied
"The helicopter pilot has it down to a fine art," said DOC northern South Island director of operations Roy Grose.
"They are not tripping over as they lumber along and it's pretty low stress. They come back in the evening and don't seem concerned at all, sunning themselves right amongst all the activity."
The method is similar to those employed by Australian outback farmers mustering cattle.
NCTIR, the alliance of the New Zealand Transport Agency (NZTA), KiwiRail and other contractors to repair the quake-smashed road and rail corridor, also use electric fences to keep the seals away.
Construction crews can phone a "seal hotline" and request expert marine mammal assistance, including a team of seal wranglers from NCTIR's environmental team, to help usher the inquisitive sea creatures away from worksites.
Seals have been moved about 3150 times over the last six months, NCTIR says. Around 670 pups have been picked up by hand and carried to safer ground - some on more than one occasion.
Grose has been "heartened and impressed" by the care that NCTIR and its contractors have taken with local biodiversity during the unprecedented project.
"Sure there has been disruption, but the seal population has actually gained habitat and settled in nicely to the environment change," he said.
Steve Mutton, NZTA's earthquake recovery manager, said that heli-hazing, the technical term for herding by helicopter, is an international practice, but the extent of seal management required by the combination of the breeding colony, massive landslides and transport corridor rebuild is "unprecedented".
"It's a well-understood method of herding seals and our helicopter pilots have become very good at it. To be honest, we've been more concerned about the seals becoming used to the helicopters and refusing to move - but so far, so good," he said.
"As part of the earthquake recovery efforts, NCTIR has been working closely with DOC to ensure the seals are looked after in these most unusual circumstances."
