The Great, Great White

Forest and Bird, Issue 311, 1 February 2004, Page 12

The Great, Great White

SARAH MANKELOW

The monster from Jaws is in need of protection in New Zealand waters,

according to

bullet-shaped head looms out of A* gloom towards you, row after row of sharp, jagged teeth propelled by a five-metre body of pure muscle. It’s the stuff of nightmares. Thanks to the Jaws movies of the 1970s, the great white shark (Carcharadon carcharias) is probably one of the best known and most feared of predators — and also the most misunderstood. Since he first wrote Jaws in 1974, author Peter Benchley has learnt that great white sharks are quite different from his fictional fiend that made people afraid to go into the water. In his latest book, Shark Trouble, he writes: ‘We knew so little back then, and have learned so much since, that I couldn't possibly write the same story today. I know now that the mythic monster I created was largely a fiction. I also know now, however, that the genuine animal is just as — if not even more — fascinating. Yet the legacy of Jaws lingers. The recent appearance of a great white shark in the headwaters of Akaroa Harbour on Banks Peninsula caused much excitement and anxiety. Alistair Hutt, Akaroa field manager for the Department of Conservation, says it was probably the same shark that caused a stir among residents last summer. ‘For all we know, it could have been there all along. The thing’s best left alone. It’s just going about its business, he says. Alistair Hutt is a mate of Peter Benchley, and shares his enthusiasm for these monsters of the deep.

‘It’s a real positive that it’s there, says Alistair Hutt. ‘It’s an opportunity of a lifetime to see one. ‘We're just about the only country in the world that doesn’t have some sort of protection for great white sharks. Biologist Clinton Duffy, also from DoC, agrees. ‘New Zealand is recognised as one of the world’s hot spots for great white sharks, along with the waters off California, South Africa, Australia and Japan, he says. "But they are nowhere near as abundant as many of the other large sharks found around New Zealand. We have no way of knowing exactly how many there are, but they are naturally rare. This is consistent with them being an apex predator. As an apex predator, the great white shark sits at or near the top of the food chain. It acts as an indicator species which means its status is a sign of the sea’s health — if great white populations run into problems, it’s likely that the marine world they live in is threatened, too. ‘Great whites generally occur as solitary creatures, quite often in pairs, says Clinton Duffy. "But they have been spotted in loose groups of up to half a dozen, usually thought to be due to a local abundance of prey, he says. Great whites are skilled hunters. Around

New Zealand small great whites, less than three metres long, feed on a variety of fish, including other sharks. Larger sharks also prey on fur seals, sea lions and elephant seals, dolphins and even small whales such as pygmy sperm whales. As seen in Akaroa’s waters, they also eat dead animals found floating in the water. ‘My data suggests that they breed around northern New Zealand, and move south

into colder waters as they grow, presumably because that’s where the main seal colonies are, says Clinton Duffy. Despite popular belief, the great white shark is not a bloodthirsty, mindless killer. On average there is a shark attack in New Zealand every two years, but they are seldom by great whites, and seldom fatal. New Zealand has the lowest attack rates in the world, with only13 known fatalities in

the last 150 years. ‘The last known attack by a great white was off Stewart Island last February, when a diver was bitten on the arm while waiting to be picked up by a boat, says Clinton Duffy. Backed by these statistics, Alistair Hutt says they don’t deserve the tag ‘man-eaters — a better description would be "manbiters"’ ‘Sharks decide whether something is good to eat by biting it, he says. "They consider humans too bony to make a good meal — fatty seals are much better. That’s why most humans attacked by great whites are spat out. ‘T don’t want to underplay it. There’s definitely a risk. If youre in the water with sharks around, you're moving into high risk. People just need to show a bit of common sense, Alistair Hutt says. Clinton Duffy agrees. ‘Swimming near marine mammals increases your chances of being attacked by sharks. It’s something that everyone that gets in the water with dolphins and seals should know. ‘It’s like going down to a waterhole in Africa at dusk and wandering amongst the lions and crocodiles, Clinton Duffy says. Adult great white sharks have only one natural enemy — the killer whale or orca — but their greatest threat comes from humans. In some areas they are now seen only rarely, after years of being hunted for trophy sport, or under a philosophy of ‘eat or be eaten. They are long-lived, slowbreeding creatures, producing small numbers of offspring, which makes them very vulnerable in terms of sustaining their population. Great whites are protected along the coasts of Australia, California and South Africa, but not yet in New Zealand. However, moves are afoot which could change this. New Zealand has recently joined the Convention for the Conservation of Migratory Species of Wild Animals, which currently includes over 80 countries. The first New Zealand delegation attended the seventh conference of parties to the Convention on Migratory Species in Germany last September. Mike Donoghue, senior international relations officer for DoC explains: ‘New Zealand joined the Convention on Migratory Species primarily motivated by a desire to support greater protection for albatrosses and petrels that are accidentally killed in long-line fishing operations. ‘But at the last meeting of the Convention held in Germany in September 2002, Australia put forward a proposal to add great white sharks to Appendices I and II of

the convention. This proposal was passed by acclamation, he says. These appendices list migratory species that are endangered, or have a conservation status that would benefit from international agreements for their conservation and management. ‘As a signatory to the Convention on Migratory Species, there are implications for New Zealand, says Mike Donoghue. ‘Our current regulations mean that great whites can be fished for, and their body parts — most commonly jaws and fins — can be sold commercially. In the spirit of the convention, this will have to change.’ Alistair Hutt hopes it’s the dawn of a new

era for great whites. ‘Let’s face it, the media sensationalism and widespread ignorance that followed the Jaws phenomenon has given the great white shark an undeserved bad rap, he says. ‘The great white is an amazing fish, worthy of our respect and protection. The ocean is the world’s last uncharted wilderness, where the great white shark reigns supreme. If you ever get to see one, it’s something you will never forget.

— SARAH MANKELOW

is a community awareness

officer with the Department of Conservation in Christchurch.

Sharks in New Zealand

¢ Sharks and rays belong to the same class of fish — the Chondrichthyes — fish with skeletons of cartilage. ¢ About 95 species of sharks and rays are found in New Zealand, which includes 61 types of sharks. ¢ About 20 percent of New Zealand’s sharks and rays are endemic (found nowhere else in the world). A further 15 species occur elsewhere only in Australia. ¢ New Zealand sharks are diverse — they range in size from the tiny pygmy shark which grows up to 27 centimetres long, to the 12-metre long whale shark. ¢ The two largest species of New Zealand shark — the basking and the whale shark — feed on the smallest animals: plankton. In contrast, great white sharks prey on the largest animals: large fish and marine mammals. e By far the greatest cause of shark and ray mortality is commercial fishing, mostly for their meat. ® Genetic studies have shown that great white sharks move between Australia and New Zealand but are genetically different from South African stocks. ® Great white sharks and basking sharks are listed in New Zealand’s threat classification systems as in ‘gradual decline. On the IUCN red list of threatened species they are classified as ‘vulnerable’. ® Great whites are taken accidentally as by-catch by commercial fishers, so most of these captures go unreported. Most great whites caught by recreational fishers are accidentally drowned in set nets. Few game fishers target great whites in New Zealand waters, with most recent reported catches being tagged and released. Some great whites are shot or harpooned by people who see them as a threat. We know very little about the impact fishing is having on the population of great whites in New Zealand waters.

Fascinating facts about the great white shark

® Only the belly of a great white shark is actually white. Its top surface is usually slate-gray or olive-brown, which blends in well with dark water, enabling it to approach its prey from below, unobserved. Underwater, its white belly reflects light downwards, making it harder to see from side on. ¢ The world’s largest meat-eating fish, they average 3.7 to 4.9 metres in length. The biggest great white shark on record was over seven metres long, and weighed up to 3200kg. Females are larger than males. ¢ The great white shark has triangular, serrated and razor-sharp teeth, up to 7.5cm long. They are located in rows, which rotate into use as needed. As teeth are lost, worn or broken, new teeth rotate into their place. ® Great whites don’t chew their food; their rows of teeth cut prey into mouth-sized pieces, which are swallowed whole. They can survive for two or three months on one big meal. ® Great whites are one of the only sharks that hold their heads up out of the water, a talent that allows them to look for potential prey at the surface. ¢ It has been recently discovered that great white sharks can jump out of deep water, in order to catch fast-swimming seals. ¢ The great white’s nostrils can smell one drop of blood in 100 litres of water. @ Great white sharks can sprint through the water at speeds of up to 69 kilometres an hour. They are propelled through the water by their powerful tails, using their fins for balance only. @ Until ‘Star Wars’ came along in 1977, the 1975 movie of Jaws was the all-time box office champion, grossing $260 million in the US. Author Peter Benchley was thrown off the set after objecting to the climax.