Q&A: The world of NZ's great white sharks revealed in new book

The first great white shark Alison Ballance ever saw in the wild made her feel "very small" - but she's since come to find herself much closer to the remarkable predators. This week, the award-winning broadcaster and host of Radio New Zealand's Our Changing World, releases her new book on the species: New Zealand's great white sharks - how science is revealing their secrets. She talks to science reporter Jamie Morton.

What compelled you to write this book?

Over the last decade, shark scientists have revolutionised our understanding of New Zealand great white sharks - and I've been an excited bystander.

I wanted to share the adventures (they've) had studying these amazing creatures, as well as the incredible discoveries they've made about where these sharks go.

I also wanted people to realise how much work it takes to glean even the smallest bit of information about these creatures - there's not many of them, and you hardly ever see them.

What facts about great white sharks do you find most remarkable?

Great white sharks must be one of the most well-known animals in the world in terms of name recognition, but for such an iconic top predator we know very little about them.

So there are a lot of facts that we don't yet know.

Recent research shows they can live at least 70 years - that's much longer than we thought previously and is very interesting.

I'm fascinated by the fact that New Zealand great whites spend so much of their time around islands such as New Caledonia and Tonga, and off the coast of Australia.

They're real citizens of the South Pacific, and it's becoming clear from genetic work that the east coast of Australia and New Zealand share one big happy shark family which, curiously, sharks from the west of Australia are not part of.

So how far does the history of our country and that of great whites actually stretch back?

Sharks date back 400 million years, and the ancestors of great white sharks will have been here ever since New Zealand began to split off from the super-continent Gondwana about 80 million years ago.

We don't know exactly when modern great whites evolved, but maybe a couple of million years ago.

In contrast, modern humans only evolved 200,000 years ago.

You're a veteran - and Crown-honoured - science broadcaster, but is it fair to say your partner, NIWA scientist and shark expert Dr Malcolm Francis, has had a big influence on your interest in sharks?

In a word? Yes.

No one can spend time with either Malcolm or his Department of Conservation colleague Clinton Duffy and not become fascinated with sharks.

Their knowledge is immense, and their enthusiasm is contagious.

The New Zealand great white shark research project unfolded slowly over a few years, and it was fun because Malcolm would share information with me as it came in.

NIWA shark scientist Dr Malcolm Francis tags a great white shark. Photo / Warrick Lyon, NIWA

He'd get excited when he got an update from a shark that was travelling at sea, and it was like following a soap opera.

The sharks had names, and as they often behaved quite differently they began to develop personalities.

And then there were the quirky things about living with a shark scientist, like a fridge full of electronic shark tags - because it stops their batteries going flat so fast, apparently.

How have these tagging programmes changed our understanding of great whites?

Malcolm and Clinton's work has revealed that New Zealand great whites spend about four months of the year in New Zealand, before heading north to the tropics, usually in winter.

They spend about two months swimming there and back, and while they are travelling they dive to great depths - well over a kilometre.

Most of the time, though, they are swimming at the surface.

Quite a number of the tagged sharks also visited the subantarctic Auckland Islands and spent time there before heading north.

NIWA scientist Dr Malcolm Francis spots a shark off Stewart Island. Photo / Dave Allen, NIWA

In New Zealand, you most often see great whites at a few seal colonies, at Stewart Island and the Chathams, but the shark identification work that Clinton has done has shown that these sharks are mostly sub-adult males and females, with just a few adult males.

Young sharks tend to be in warmer waters up north, such as the Kaipara Harbour, and we still don't know where big adult sharks hang out and breed.

In New Zealand, particularly with some of the conflict we've seen between fishers and cage diving operators, do you see a greater need for protection?

Great white sharks have been fully protected in New Zealand waters since 2007.

That's also when great white shark cage diving began as a tourist venture at Stewart Island.

The two companies that offer diving with white sharks are regulated by the Department of Conservation.

The legislation for marine protected areas is being reviewed at the moment, and one suggestion put forward by Minister for the Environment Nick Smith is for species-specific sanctuaries.

He talked about the possibility of making a known shark hotspot at Stewart Island into a shark sanctuary, and this might be one way of keeping sharks and fishers away from each other.

You've been up close with great whites yourself. How did that shape your perspective of them?

I was awe-struck when I saw my first great white shark - and I hadn't expected to be quite so impressed by them.

I joined Malcolm and Clinton on a research trip at Stewart Island, when they were trying to attach electronic tags to the sharks to find out where they go.

Marine ecologist and DoC shark expert Clinton Duffy dissects a great white shark for research at the Auckland War Memorial Museum in 2009. Photo / File

It was a fine, calm day and the research team were berleying, putting fish oil and minced fish in the water to attract the sharks close to the boat.

The first shark I saw was over four-metres long, and looking down on it from the deck of the boat made me feel very small.

It wasn't just long, either.

The thing that struck me most about it - and everyone I speak to says the same thing about great whites - was the enormous girth.

Other sharks I've seen are quite slinky, but great whites are bulky.

It wasn't only their sheer size that was impressive.

They seemed very curious about us, swimming at the surface along the side of the boat and staring up at us.

We're so used to seeing film images of them breaching out of the water as they chase seals that we imagine they are always bold and aggressive, but Clinton told me that great whites are often quite shy around boats, and it can take a while for them to pluck up the courage to come close.

I should point out that I've never been in the water with a great white - I've just seen a few from the surface.

Statistically, the rate of encounters between sharks and Kiwis pales in comparison to the number of Kiwis injured each year by seemingly harmless activities like dancing (there were 8125 related ACC claims in 2014) and luge riding (373 claims). Yet there's an enduring fear factor around sharks, which media headlines no doubt contribute to. Why do you think the hype continues?

We like to scare ourselves silly, and I think sharks are just another one of those intriguing animals, like spiders and snakes, that we love to hate, even though most of us will never come across one.

It's the same reason we love horror films.

It's probably also a primal hangover from the days when our ancestors had to be hypervigilant about creatures that could genuinely harm them.

And there is still so much misinformation out there about sharks which fuels our fears.

As you say, the chances of being attacked by a shark are totally miniscule - and as far as sharks go, we humans are much more of a threat to them.

A great white shark with an acoustic tag attached, photographed off Stewart Island. Photo / Clinton Duffy, DoC

So what are some of the other myths that endure about great whites? A big one is that the species stick exclusively to colder waters.

That's what we used to believe, but great white shark research around the world has blown that one well out of the water.

Every white shark shark population that has been studied turns out to be full of international travellers that move between the hot tropics and cooler, temperate waters.

If there's a single message from your book you'd like to people to download, what is it?

I hope that knowing more about sharks and their behaviour, and that thinking about sharks as individuals rather than an amorphous scary concept, will encourage people to respect sharks, rather than be fearful of them.

We hunted sharks for many years, and it's only now that great whites are fully protected in New Zealand and a few other countries that their numbers are slowly starting to recover.

All sharks, including great whites, play an important ecological role, and a healthy ocean includes good populations of sharks.

New Zealand's Great White Sharks: How science is revealing their secrets. Potton & Burton, RRP $29.99.