Simple ways to avoid shark encounters

Sharks are present in larger numbers over summer months but following a few simple measures can reduce the chance of encounters to "almost nil", says one marine expert.

The ocean's apex predators follow warmer waters and food species to the Bay of Plenty at this time of year but renowned nature photographer Kim Westerskov says there is little to fear.

"Be careful on the roads, they're really dangerous. I'm more scared on the motorway than I am swimming in the ocean," said the man who has a PhD in marine sciences and has been diving and photographing for more than 40 years."

Seven species can be termed "common" in Bay of Plenty waters during summer, say experts.

Offshore these are mako and blue sharks while, closer to land, bronze whaler, school and rig sharks as well as juvenile hammerhead and thresher sharks predominate.

Encounters with any of the species are rare.

"I like sharks but I had to go to the tropics to find them in sufficient numbers," said Westerskov who has written 18 books on nature and won the BBC Wildlife Photographer of the Year five times.

"I'd happily swim with most sharks and have done. Anytime there's a shark around, I'll photograph it."

"I've met bronze whalers while diving in the Bay of Plenty a few times. Once at Mayor Island in dirty water, I saw one and it saw me and it buggered off quicker than I did. It was twice my size but just got spooked."

Westerskov had an encounter with a blue shark while photographing humpback whales in Tonga.

"A blue shark about two metres long was just swimming round in a slow, relaxed fashion, then saw me, turned and swam straight at me. He would've bumped into me but I held my camera up in defence and he literally bounced off it, evidently thought 'that felt a bit hard', circled round me again then cleared off."

However, a great white shark is a different matter. "The one I would be a bit nervous about is the white pointer or great white shark, which we get here occasionally.

"They attack from below. They see something on the surface which looks like a seal or is of interest and they come up at high speed and grab whatever it is.

"If it's a human, as far as we can tell, they think 'bugger I've got the wrong one we don't eat those' and let go.

"There are very few people that actually get eaten by one but they quite often die because that first bite is a lethal strike and they hit you with such force."

Clinton Duffy is technical adviser marine at the Department of Conservation (DoC) and describes himself as a "sharkaholic".

"It's unlikely anyone visiting a Bay of Plenty beach this summer will even see a shark," said Mr Duffy, who has studied numerous species including mako, blue and great whites in 22 years with DoC.

He has dived with more than 25 different shark species around the world.

"Shark attacks are rare in New Zealand. We usually have a couple of bite incidents a year where people are bitten on their arms or legs and end up with fairly minor puncture wounds or slash injuries.

"In New Zealand, you really have to work to see a shark in the water by doing something to actively attract them. So encounters between sharks and humans are relatively uncommon except for spearfishermen.

"Spearfishermen tend to have the most run-ins. They're in their environment and they're killing fish, so there's blood in the water and there's vibrations from the struggling fish.

"That attracts sharks into the area and it's stimulating them to feed."

Tauranga spearfisherman Kim Bade met an inquisitive bronze whaler at Great Mercury Island, off the Coromandel peninsula on Sunday. The persistent three-metre shark gave Mr Bade a nip on the hand which resulted in what he called the "smallest bite from the biggest shark". Mr Bade's story featured in yesterday's Bay of Plenty Times.

Mr Duffy said a few simple measures could reduce any risk of a shark encounter to "almost nil".

"Avoid swimming at dawn and dusk, especially night-time. Most sharks are primarily nocturnal hunters.

"Avoid deep channels, or near obvious areas where there is feeding activity going on, schools of fish being attacked by diving birds, as the likelihood is there will be sharks around. And avoid areas where people regularly discharge fish offal into the water."

Mr Duffy is a keen game fisherman and said spending many hours on the ocean had given him firsthand experience with sharks.

Offshore the most memorable of these encounters have been with mako sharks.

"Makos are very aggressive especially when there's any feeding stimulus in the water.

"They are one of the few sharks which if you behave aggressively to them, they won't back down.

"There are no recorded mako attacks on humans in New Zealand but attacks on boats are not uncommon.

"Boats which are burleying or catching fish, they will attack. I've seen that happen plenty of times and hooked mako sharks which have been released spin around and have a go at the boat.

"I was in an inflatable once when that happened," he said. "That wasn't a good look."

Mr Duffy said this overt aggression meant fishing off small vessels such as kayaks and jet skis a long way offshore carried a potential risk.

"Attacks on kayak fishermen are really rare.

"There has only been one in New Zealand and that was quite a few years ago. But, as kayak fishing becomes more popular and fishermen go further offshore, that increases the risk.

"Especially if you're far enough offshore to be catching tuna from your kayak, as some people have been doing. Where there are tuna, there are mako sharks. If you run into a 300kg-400kg mako shark, which are not uncommon in New Zealand, you're quite vulnerable in a kayak. It's a small risk but it's a risk."

Twenty-four-year-old Maurice Bede Philips was reported drowned after his kayak sank at Whangamata in December, 2009. However, a large bite was discovered on his upper thigh, which had caused huge tissue and blood loss.

Photographs of the injury were sent to Mr Duffy and he identified the bite marks as being consistent with that of a 3m great white attacking from below.

A coroner found it was unclear whether the mauling occurred after or before death.