As they glide effortlessly through the water, sharks and rays strike fear into humans. Yet the chances of being attacked are slim; in fact humans threaten these animals, particularly sharks, much more than the reverse, to such an extent that some species risk extinction. Sharks are not protected by law in New Zealand.
Sharks, skates, rays and chimaeras are closely related, and belong to the class of vertebrates known as Chondrichthyes. They differ from other fish in that their skeletons are made of cartilage (the same flexible material in human noses and ears), not bones.
Of a world total of eight shark orders, New Zealand has six:
Three orders of ray live in New Zealand waters:
New Zealand also has:
In 2004 there were 70 known species of sharks, 26 skates and rays, and 12 chimaeras or ghost sharks in New Zealand. The total of 108 compares with 95 recorded in the mid-1990s, and only 62 in the early 1980s. There are at least four undescribed species. New shark and ray species are continually being discovered, especially in very deep waters. Previously unknown species are found as fishing techniques become more sophisticated and research vessels range more widely and deeply.
Between 15 and 20 sharks and rays are endemic to New Zealand – they live nowhere else. It is difficult to determine an exact number because these creatures are very mobile. Most of the endemic species are rays or skates, which do not travel as far as sharks.
Sharks have existed for more than 400 million years, and rays for 200 million years. By 140 million years ago they had evolved into close equivalents of their present-day forms.
Some early sharks were relatively large. The three-million-year-old remains of the extinct giant shark Carcharodon megalodon were discovered by fossil expert Joseph McKee among cliffs in south Taranaki. Fossilised sharks are not common, as their cartilage does not endure in the same way as bones. McKee was lucky enough to find calcified vertebrae. Scientists have used them to estimate that the shark was between 4.5 and 6 metres long.
More usually, a shark’s distinctive triangular teeth are the only fossil remains. A full set from Carcharodon angustidens, also extinct, was unearthed in North Otago in the late 1990s. It was an extremely rare find – usually only single teeth are discovered. Closely related to the living great white shark, this specimen may have measured up to 9 metres long.
Polynesians, the ancestors of Māori, thought of sharks as guardian spirits. Many Hawaiian families had an aumakua, or shark protector.
In Māori mythology, the demi-god Māui placed the shark Te Māngōroa in the sky, forming the Milky Way. Sharks and rays, along with other animals living in the sea, were considered to be the children of the ugly god Punga.
Several Māori legends relate to sharks. In the far north, the ocean taniwha Ruamano took the form of a mako shark. If a waka (canoe) overturned, the crew called upon Ruamano to deliver them safely to land. In another legend, when the canoe captained by Tamatekapua was voyaging towards New Zealand, it met Te Parata, an ocean creature who almost swallowed the canoe and its crew. They were saved by a shark, and in its honour the crew renamed the canoe and their tribe Te Arawa (shark).
Māori likened their warriors to sharks, invoking them in battle cries such as: ‘Kia mate uruora tātou, kei mate-ā-tarakihi’ (let us die like white sharks, not tarakihi fish).
Sharks were an important part of the Māori diet. Fishing expeditions used to bring in thousands of sharks, which were dried on racks as long as 400 metres. The stench was tremendous – some European explorers remarked that fishing villages could be smelt up to 13 kilometres away.
Each year, the northern Te Rarawa tribe set aside two days for shark fishing. The first day was close to the full moon in January; the second was two weeks later. People catching sharks outside of these days were stripped of their property.
In order to catch the fierce mako shark, Māori would first catch a ray or skate to use as bait. Once a mako took the bait, a lasso was placed around its tail so as not to damage its precious teeth. The shark was then made to tow the canoe until it was exhausted.
Small species, such as school sharks, were usually taken. Large numbers would swim into harbours at high tide, where they were intercepted and caught with hooks before they could escape. Observing one shark-fishing expedition in 1855, the European naturalist R. H. Matthews counted 1,000 people in a fleet of 50 canoes, catching about 7,000 sharks.
Māori used sharks’ teeth in necklaces or earrings. Particularly prized were the teeth of the mako and great white shark, which were valuable trading items. The teeth of broadnose sevengill sharks, or tuatini, were set in wooden handles and used as knives. Shark liver oil was mixed with red ochre to make the distinctive paint used on carvings. Blended with scented shrubs such as raukawa or manakura, the oil was rendered into a cosmetic for the body and hair.
In New Zealand sharks are eaten in fish and chips – the fillets are in high demand because they are tasty and free of bones. Exports of shark products, which include fins, liver oil and cartilage, increased rapidly between 1988 and 1991, and since then have fluctuated from 3,000 to 6,000 tonnes per year. Korea, Australia and Japan buy most of New Zealand’s shark products, with smaller quantities going to France, the United Kingdom and the United States. Korea buys spiny dogfish, Australia school and rig sharks, and Japan chimaeras (ghost sharks).
Not all the sharks which are caught have been targeted by the fishing industry; sometimes they are by-catch from tuna fishing or bottom trawling.
Found around New Zealand and Norfolk Island, the abundant and harmless rig shark (Mustelus lenticulatus) is 1.5 metres long, and grey or bronze with spots and a white underbelly. They take their food from the sea floor, no deeper than 860 metres, preying on crustaceans, especially crabs. Like many sharks, they do not lay eggs, but incubate them inside their body and give birth to developed young.
Rig sharks are the fish most often served up in fish and chips. They are caught mainly by set nets, and also by trawling. Reported landings peaked at 3,826 tonnes in 1983. In 2002–3 the annual catch limit was set at 2,034 tonnes, but recorded landings were only 1,449 tonnes. Casualties of rig fishing include Māui's and Hector's dolphins, which become trapped and drown in set nets.
Rig sharks are also known by the common names lemon fish, spotted dogfish and gummy sharks, and by the Māori names kapetā, mangō and pioke.
Probably the most abundant living shark, the spiny dogfish (Squalus acanthias) is a small species measuring just over 1 metre. The small spines on their dorsal fins can inflict a nasty wound. The fish are dark grey with white spots and a white underbelly. Spiny dogfish can live for at least 26 years in New Zealand, but populations in the Strait of Georgia, in Canada, can live up to 70 years. They hold the record for the longest gestation period of any animal – 24 months. Females mature at 10 years in New Zealand, and as late as 24 years elsewhere.
Although extensively fished for fish and chips, spiny dogfish have nevertheless increased, replacing species such as hoki or barracouta in areas where these have been overfished. Fishermen reported landing 11,530 tonnes of spiny dogfish in 2001–2.
The name dogfish was coined by anglers who observed them chasing smaller fish in large packs, like dogs. The sharks are also known as spinebacks, and by the Māori names koinga, kāraerae, mako-huarau, mangō-hapū and mangō-pekepeke.
School sharks (Galeorhinus galeus) grow to 1.7 metres in New Zealand, and 2 metres elsewhere. They have a life span of more than 50 years. They are grey on top and white underneath. Found worldwide in temperate waters, in New Zealand they are most common in the north. They inhabit both coastal waters and the open ocean, and are capable of swimming very long distances – 10% of all the tagged school sharks recaptured by scientists had swum 1,700 kilometres from New Zealand to southern Australia; one had travelled 4,940 kilometres.
In the early 1940s school and other sharks were harvested for the vitamin A in their liver oil, until the production of synthetic vitamins began in the 1950s. High mercury levels were detected in large school sharks, leading Australia to ban New Zealand imports temporarily in 1972.
In 2002–3, 3,151 tonnes of school sharks were caught, down from a peak of 4,776 tonnes in 1984, just before the introduction of a quota system. Because they are slow-breeding, school sharks are vulnerable to overfishing.
As their name suggests, these sharks frequently swim in schools. They are also known as grey sharks, and by the Māori names makohuarau, tupere and kapetā.
Chimaeras – also known as ratfish or ghost sharks – are the closest living relatives of sharks and rays, although they differ in a number of ways. They have large heads, bulging eyes, smooth skin without scales, and whip-like tails. Some chimaeras, such as the dark ghost shark (Hydrolagus novaezealandiae) and the elephant fish (Callorhincus milii), are fished commercially.
Using their trunk-like snouts to detect buried shellfish, elephant fish live in coastal waters and around the continental shelves of New Zealand and southern Australia, to depths of at least 200 metres. About 1.2 metres long, they are silvery white with a golden sheen, with dark patches on their backs.
Elephant fish are caught in commercial set nets or by trawling when they migrate into large estuaries and bays to breed in spring. In 2002–3 a total of 1,124 tonnes were landed, most of it trawled in fisheries off Banks Peninsula.
Elephant fish are also known by the Māori names makorepe and reperepe.
A number of sharks live hundreds or even thousands of metres deep, and never come near the surface. Among these bizarre species is the rare goblin shark (Mitsukurina owstoni), which has an outlandish overhanging snout, and jaws which protrude when feeding, then retract. Another odd creature is the frill shark (Chlamydoselachus anguineus), an eel-like animal living down to 1,300 metres. It has around 300 three-pronged teeth.
The cookie-cutter shark (Isistius brasiliensis) is a small, luminescent animal with a glowing belly that attracts fish from below. They usually inhabit depths to 3,500 metres, although they have been seen at the surface at night, and are believed to make daily vertical migrations of up to 3,000 metres. Their name comes from the cookie-shaped wounds they leave on whales, dolphins, tuna and other fish. Forming a suction cup with their mouths, cookie-cutter sharks latch onto their prey and rotate, carving out a chunk of flesh.
The world’s largest fish is the harmless whale shark (Rhincodon typus), reaching 12–15 metres in length. They can be recognised by their great size and distinctive blue-grey or red-brown colouring, with grid-like patterns of white spots and stripes.
They swim in tropical and subtropical coastal waters and the open ocean, and some venture into New Zealand waters on their annual migrations during summer. Between 1980 and 2001, 36 whale sharks were reported between the Three Kings Islands and south to the Bay of Plenty. Following the East Auckland Current, which flows past the east coast of Northland south to East Cape, whale sharks feed on anchovies and other small fish. They swim slowly near the surface, occasionally opening their cavernous mouths to consume the prey in their path.
The 10-metre-long basking shark (reremai, Cetorhinus maximus) is the second-largest fish in the world. Gentle giants, they can sometimes be seen from the coast swimming slowly near the surface of the ocean. Basking sharks open their mouths wide to catch plankton.
On 25 April 1977, Japanese fishermen 500 kilometres east of Christchurch hauled aboard a rotten and stinking carcass. After taking photos and keeping some of the decayed animal, they returned it to the depths. Speculation that it might have been a plesiosaur – a long-necked marine reptile known only from fossils – sparked monster fever in Japan. Stamps and toys were produced to commemorate the find. Finally, it was decided that the remains were those of a basking shark.
Between 1986 and 1999, 203 basking sharks were accidentally caught in trawl nets off New Zealand; 93 were caught off the east coast of the South Island in the spring–summer period.
Basking sharks are found around the world in temperate and sub-polar seas, excluding the Indian Ocean. Although considered a coastal species, they have been caught at depths of 900 metres during winter, where they could be feeding on the vast bonanza of hoki eggs available at that time.
Some sharks can pose a risk to humans in the water: great whites, bronze whalers and mako have occasionally attacked people off New Zealand shores. These sharks can be found in waters close to the coast or in the open ocean.
Most sharks are cold blooded, so they live in warmer waters. But several species of the Lamniformes (mackerel shark) order, including the great white, mako and thresher sharks, have successfully invaded cool waters by developing special heat-exchange tissues in their circulatory systems, allowing them to retain the heat they generate from muscular and metabolic activity. This makes them capable of great bursts of speed. But in order to maintain their body heat they have to eat up to 10 times more than the cold-blooded sharks which live in the tropics.
The 4.6-metre thresher shark (Alopias vulpinus) has a tail fin with an extremely long upper lobe. The Māori name, mangō ripi (slashing shark), refers to the way these sharks, working in groups or pairs, use their tails to herd and prey, usually small schooling fish, but occasionally seabirds. The purple-brown and white thresher is found worldwide in warm, temperate and tropical seas, around continental shelves and in the open ocean. In New Zealand their stronghold is off Northland.
The most feared of the world’s sharks, the 7-metre great white or white pointer (Carcharodon carcharias) is responsible for most of the unprovoked attacks by sharks on people, including a number of New Zealanders.
Great whites are dark grey to black, with a white underbelly. They can be found worldwide in cool, temperate and subtropical coastal and continental shelf waters. According to a 1999 study that compared great whites from Australasian and South African coastal regions, males ranged widely across ocean basins, while females remained in a particular region, perhaps returning to the site of their birth to have their young. Great whites live in the waters all around New Zealand, but are more populous around Otago because of the abundance of seals, on which they prey.
Great whites are also known in Māori as mangō taniwha, mangō ururoa and, to people of the Ngāi Tahu tribe, tupa.
The Māori name mako has universal currency for this 4-metre-long shark. Indigo with a white belly, warm-blooded short-fin mako (Isurus oxyrinchus) range widely in tropical and temperate waters, from coastal waters through to open seas.
Short-fin mako are champion speedsters among sharks, and are prized by game fishers for their fighting qualities, earning them the name ‘blue dynamite’. Their teeth were valued by Māori, who daringly caught the sharks from canoes. Zane Grey, who wrote about big-game fish in the Bay of Islands, noted that mako could leap as high as 6 metres out of the water. When hooked on a line they have been known to attack boats, or land in them, causing considerable damage.
Slim, graceful and bright or dark blue, the 3.8-metre blue shark (mangō pounamu, Prionace glauca) is among the swiftest of swimmers. They have been clocked at almost 40 kilometres per hour, making them second only to mako sharks in speed.
Blue sharks can be found worldwide in the cooler depths of tropical seas and nearer the surface in continental shelf or open temperate waters. They eat mainly fish and squid. Although generally docile, they have been known to kill people. They are one of the most abundant oceanic sharks.
The distinctive skull of the hammerhead shark (Sphyrna zygaena) is believed to help detect prey, and to add lift like a hydrofoil, counteracting the downward push of the tail. Hammerheads are olive to dark grey, with a white underbelly, and grow to 4 metres. Large individuals can be dangerous to people.
Known in Māori as kakere or mangōpare, hammerheads are regular summer visitors to North Island waters, venturing as far south as Cook Strait. Juveniles as small as half a metre are sometimes seen in the Hauraki Gulf – it is possible that the species gives birth around New Zealand. They are found worldwide in temperate and tropical waters, from the coast to continental shelves.
The relatively uncommon bronze whaler (Carcharhinus brachyurus) can be seen close to shore in late spring and early summer, when they may be pupping. They inhabit temperate and tropical waters, both close to shore and in the open ocean. These 3-metre sharks have a reputation in Australia for unprovoked attacks on people, and in New Zealand there have been at least two attacks, both non-fatal. As their name indicates, they are bronze, and have a cream underbelly.
Bronze whalers are also known in Māori as horopekapeka, matawhā, tōiki and ngerungeru.
New Zealand has a relatively high incidence of shark attacks. Record keepers differentiate between provoked and unprovoked attacks: sharks which have been speared or taken on a line will naturally defend themselves by attacking the person on the other end. Since 1852 there have been 44 recorded unprovoked attacks in New Zealand (compared with 39 in the whole of Europe since 1847). A third of New Zealand attacks occurred between Ōamaru and the Otago Peninsula, probably because sharks are attracted by the high numbers of seals, dolphins and pilot whales in that area.
Great white sharks have been responsible for most of the 11 fatal attacks in New Zealand where the shark has been identified. Other species known to have caused fatalities are mako and bronze whalers. More than half of the victims were swimming, a quarter were snorkelling, and the remaining quarter were either surfing or standing in shallow water.
However, the chances of being killed by a shark in New Zealand are slight: since 1852 there has been one fatal attack every 13 years. You are far more likely to drown than be mauled by a shark.
After a spate of attacks off Dunedin beaches in the 1960s, patrol boats and planes have been used to warn swimmers and surfers. From 1969, nets were also laid at local beaches; the programme was still in effect in 2004 at St Clair, St Kilda and Brighton beaches. In the early to mid-1970s, about six great whites were netted each year. Since then most of the sharks caught have been harmless.
Opinion is divided as to the efficacy of the nets. Gary Barton, who was rammed by a great white shark off St Clair in 1968, said in 2004 that he believed the nets were still useful. However, Mike Barker of the University of Otago Marine Science Department argues that netting is not in keeping with international practices, which aim to conserve sharks. He considers the nets too small to be effective – they merely provide swimmers with the illusion of safety. Even so, popular opinion is in favour of the nets, even at the cost of $28,000 a year.
Increasingly sophisticated techniques since the late 20th century have led to the massive harvesting of sharks and rays. Previously invincible species such as mako and basking sharks are killed for their fins only; the remainder is thrown overboard. In parts of Asia, shark-fin soup is consumed as an aphrodisiac.
A worldwide movement aims to stop such wasteful practices and conserve some of the vulnerable larger sharks. The 2000 World Conservation Union Red List categorises 19 species as vulnerable, 17 as endangered, and four as critically endangered. Four New Zealand sharks – the basking, spiny dogfish, whale and great white – are listed as vulnerable.
In Australia, South Africa and parts of the United States, the great white is a protected species. The grey nurse shark is also protected in Australia. Great white sharks have been fully protected in New Zealand since April 2007.
Formed in 1957, the New Zealand Big Game Fishing Council has 61 affiliated clubs with 33,000 anglers throughout the country. Many of these anglers catch sharks – the most sought after are mako because they fight fiercely and are good eating.
In recent years, however, there has been a change of approach. Rather than take sharks home, many anglers prefer to release them to fight another day. They will land a shark only if it could be of record-breaking size.
Long believed to have health-giving properties, shark cartilage and liver oil are manufactured by several companies in New Zealand. There is a widespread belief that sharks do not get cancer or other diseases. However, no systematic research has been carried out to prove this.
In 2002, New Zealand researchers at Industrial Research Ltd and the Wellington School of Medicine tested the anti-cancer properties of shark muscle. Their studies showed that, when fed to rats with cancer, the extract prevented new blood vessels from forming. Because cancer spreads through the body through these vessels, shark muscle may help in the fight against cancer. However, the product does not actually stop cancers from forming; it may simply delay the progression of tumours.
Swimming with an elegant, undulating motion of their broad front fins, New Zealand’s 26 species of rays and skates move like large birds in flight.
Rays and skates are wide, flattened fish belonging to the same family as sharks, and sharing some of the same features: they have skeletons of cartilage, not bone, and open gill slits.
Rays and skates also differ from sharks. They have blunt rather than sharp teeth, and their gill slits are on the belly rather than along the sides.
Although skates and rays have similar, kite-shaped bodies, skates are usually not as large or as venomous. Rays are not aggressive animals, but if attacked or accidentally stood on they can inflict painful and serious wounds.
Skates lay leathery eggs, known as mermaid’s or sailor’s purses, on the sea floor.
Other rays carry their offspring inside them and give birth to live young.
These rays generate electric charges from muscle tissues in two kidney-shaped glands on either side of their heads – the currents can be strong enough to knock down an adult person. Electric rays stun fish and crabs, which they prey on at night. Ancient Romans and Greeks called electric rays numbfish because of their effect on people who touch them.
A species of electric ray, the New Zealand torpedo (Torpedo fairchildi), is endemic to the country. They are 1 metre long, grey-brown above and white underneath. They are found on or near the ocean floor, at depths from 5 metres to more than 1,150 metres. Māori know them as mātā and whai repo.
The most common skate around New Zealand, where it is endemic, is the rough skate (Dipturus nasutus). This species was first described scientifically by the naturalists accompanying Captain James Cook on his first visit to the country in 1769–71. Growing to 1.1 metres, rough skates are mottled brown with white and black spots and white undersides. Like other skates, they have thorny tails, but are essentially harmless. They inhabit the ocean floor at depths from 10 to 1,500 metres.
Rough skates are commercially harvested. In 2001–2 reported landings were 1,566 tonnes. The wings of skates are usually eaten grilled, fried or baked. Although they are not to everyone’s taste, some people consider them a delicacy.
Rough skates are also known by the Māori names uku, whai, waewae and pākaurua.
The longtail stingray (Dasyatis thetidis) grows to 4 metres, including the tail which is twice the length of its disc-shaped body. They are dark olive green, grey or black, and white underneath. They are also called whiptail stingrays, or whai in Māori. They can be found in New Zealand, southern Australia and south-eastern Africa, in the shallows and down to about 400 metres.
Longtail stingrays are feared because of the serrated, poisonous spines at the base of their tails, which they thrust into anything that tries to catch them. If a person accidentally stands on them they will be injured, but these stingrays do not seek out victims. Growing to a maximum of 214 kilograms, they feed on crabs, mantis shrimps, molluscs, worms and conger eels.
The eagle ray (Myliobatis tenuicaudatus) lives on the sea floor around New Zealand and Norfolk Island, in shallow waters and to depths of 160 metres. Growing to 2 metres, they are olive green or yellow brown, with pale blue or grey markings. Eagle rays are known in Māori as whai keo.
Their pointed fins make them excellent swimmers. Their teeth work like nutcrackers to crush their prey, which include crabs and other crustaceans from the sea floor. Eagle rays have a poisonous spine on their tails, but, unlike stingrays, they cannot swing their spine around and can be safely handled from the front.
Although not as large as some manta rays, the spinetail devil ray (Mobula japonica), which visits New Zealand waters during summer, is nevertheless a sizeable 3 metres long. They are dark blue to black above, with a white underbelly. In common with other members of the manta ray family, they cruise the open oceans straining the water for plankton. Found worldwide in tropical and subtropical seas, spinetail devil rays are harmless unless harassed.
Acknowledgements to Malcolm Francis (National Institute of Water and Atmospheric Research)
Andrew, Neil, and Malcolm Francis, eds. The living reef: the ecology of New Zealand’s rocky reefs. Nelson: Craig Potton, 2003.
Batson, Peter. Deep New Zealand: blue water, black abyss. Christchurch: Canterbury University Press, 2003.
Cox, Geoffrey, and Malcolm Francis. Sharks and rays of New Zealand. Christchurch: Canterbury University Press, 1997.
Paulin, Chris, and others. New Zealand fish: a complete guide. Wellington: Te Papa Press, 2001.
Tricas, Timothy, and others. Sharks and rays. Sydney: Reader’s Digest, 1997.