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Clarke Gayford and Kina Scollay were caged during filming. File Photo / 123RF
By RNZ
Seeing a great white shark stalk a crew member off the coast of Stewart Island while filming a documentary was one of the scariest incidents marine filmmaker Clarke Gayford has witnessed.
The global lockdown caused by the Covid-19 pandemic has calmed the oceans and may be pulling some of New Zealand’s great white sharks out of hiding.
Gayford teamed up with shark expert Kina Scollay, just off Stewart Island, to find out where sharks – some up to five meters long – are found and what they’re doing there.
The end result, Shark Lockdown, airs tonight at 7.30pm on Discovery as part of their coverage of Shark Week.
Clarke told RNZ’s Sunday Morning show that she spent two weeks on the mission that grew out of Covid.
The American crew scheduled to go were unable to enter New Zealand with the border closed, so at the end of the first national lockdown they accepted an offer to film a rare sight.
“It’s an incredible phenomenon down there in a very specific area near Stewart Island and it happens in very few places in the world; it’s a huge aggregation of white sharks …
“The idea is that the big females go there, they have never been seen, but they go there to mate.”
When asked about their size, Clarke says: “they get really big”, at about 4.5m, whereas a “big beast” that he observed was about 4.9m.
“But they get bigger than that, we’re talking about the five or six meter great targets and that’s when they really change shape, that’s when they really widen and look like a submarine under water.”
It is unknown why great whites are attracted to New Zealand waters, however they do have feeding stations, perhaps where there were once sealing areas, and they also have their mating aggregations.
They could have been following the call for thousands of years, Clarke says.
There are two distinct towns that meet on Stewart Island “to have a good time.” One moves from South Australia and the other from the tropics, usually Fiji.
It is believed that the great whites of the tropics coincide in their migration with the humpback whales that come from Antarctica. One in five whales does not survive, probably providing two tons of protein at a time for great whites.
Sharks use all of their senses to track prey, so during filming, the crew used an underwater speaker to reproduce the sounds of bottlenose dolphins.
This led to “an unsettling moment” after Clarke had been lowered to the bottom of the ocean in a cage with Kina Scollay, who was in a separate cage. The sharks slipped out of sight, fell, and then used a rocky outcrop to hide and stalk Scollay.
“I was in a prime position to see this shark physically stalking him across the ocean floor and it gave me a real chill because it made you realize that this is how they hunt seals, this is how they hunt dolphins, so maybe that dispersion The effect was that they cleared, got down and tried to make a more stealthy approach. “
It was like a way to hide and search the ocean, he says.
In another terrifying incident that appears in the film, two great white sharks surrounded Scollay in his cage and a shark that had been suddenly calm decided that he had had enough, went in to investigate, struck the side of his cage, ripped the airbags, and “he mistreated the cage.”
“It was a very dramatic moment in the water watching it … it happened very quickly.”
In another scene, an angry shark tries to snatch a huge Buller albatross from the surface of the water.
“The bird was fine, it pulled away at the last moment, but the makos are known to bring birds off the surface.”
Deaths in Australia
Clarke says the higher number of shark deaths in Australia this year may be due to an increase in the number of humpback whales in its waters.
Hervey Bay in Queensland is full of humpbacks under the age of two at certain times of the year and the shark’s feeding habits may have changed.
Rather than staying primarily in deep water, they spend more time closer to shore feeding on the young whales.
For New Zealand, “They are definitely there, they are close, but I would hate for that to put someone off from doing something in the ocean. As a spear fisherman I go and get on shark grounds regularly and it all depends on the type of sharks.
“I deal with a lot of sharks, like bronze whalers and makos, occasionally seven gillers if I’m in the south, but I’ve never seen a great white – knock on wood.”
White sharks have evolved over the years and are “super long-lived apex predators,” which is why they are so vulnerable, he says.
“I don’t think they reproduce until around 33 years of age, so they have to survive 33 years to get to that stage before they can even improve the chances of their population.”
– RNZ