Many species of sharks and rays live in shallow coastal waters at least for part of the year. The most familiar of these are the school shark, rig, spiny dogfish, shorttail stingray and eagle ray. Many of the larger species are wide-ranging, open-ocean fish such as the mako, whale shark, pelagic stingray and manta ray.
The greatest diversity of New Zealand’s sharks and rays occurs on the upper continental slope between 200 m and 1800 m depth. This zone is characterised by many species of often bizarre looking dogfishes and skates.
Encounters with large sharks in coastal waters usually happen over spring and summer when many species move inshore to pup and feed. These include the broadnose sevengill shark, common thresher shark, mako, bronze whaler and smooth hammerhead shark.
During summer the normally oceanic blue shark is occasionally seen close to shore off surf beaches and will even enter large harbours.
Fascinating shark facts
- Sharks and rays belong to the class of fish called Chondrichthyes – fish with skeletons of cartilage, not bone.
- About 110 species of chondrichthyans are found in New Zealand waters, of which 73 are sharks, 25 are rays and 12 are chimaeras (a.k.a. ghost sharks); like other types of marine life these numbers will change as scientists continue to discover or recognise new species of sharks and rays from our waters.
- New Zealand sharks are diverse – they range in size from the tiny pygmy shark which grows up to 27 cm long; to giant basking and whale sharks.
- The two largest species of shark, the basking and the whale shark, feed almost exclusively on krill (small shrimp-like animals) and small bait fishes.
- It has been estimated that a 4.5 m great white shark can survive for a month and a half and swim over 3500 km on 30 kg meal of whale blubber.
- The cookie cutter shark feeds on large fish and marine mammals by taking a single circular, cookie-shaped bite from their flesh or blubber.
- Sharks continuously replace their teeth throughout their lives; some sharks generate new teeth every eight days.
- Great white shark/white pointer/mangō taniwha
- Oceanic whitetip shark
- Basking shark/mangō reremai
- Whale shark
- Mobulid rays (manta and spine-tailed devil rays)
Mobulid rays have diamond-shaped bodies with distinctive cephalic fins projecting forward on each side of the mouth. These fins resemble horns when rolled up and are the source of the name devil ray. Mobulid rays occur off the northern North Island during summer and early autumn.
Manta rays are often reported inshore or near offshore islands and reefs, whereas the spine-tailed devil ray is usually seen well away from land. Spine-tailed devil rays grow up to 3 m across, while manta rays as large as 7.9 m across have been seen in New Zealand.
Despite most species being totally harmless to humans sharks frighten many people. Worldwide, shark attacks kill about 25 people a year. Over the last 170 years, there have only been 13 fatal shark attacks documented in New Zealand.
Commercial fisheries on the other hand, kill up to 100 million sharks worldwide each year. Many species of sharks and rays are vulnerable to over fishing because of their low biological productivity (i.e. slow growth and small number of offspring).
In New Zealand fisheries impacts on sharks are managed by the Ministry of Primary Industries under the National Plan of Action Sharks (NPOA Sharks). Rig, school shark, spiny dogfish, blue shark, porbeagle, mako shark, elephantfish, rough skate and smooth skate are managed under the quota management system.
Great white sharks (white pointers) are absolutely protected within the Territorial Sea and Exclusive Economic Zone (within 200 nm of New Zealand) and aboard New Zealand vessels fishing in international waters.
Targeted commercial fishing of basking sharks and bronze whalers is prohibited under fisheries regulations but they may be landed as by-catch. Recreational bag limits restrict the recreational catch of most large shark species.
Significance to Māori
Kapeta/school shark and mangō / rig were important seasonal foods of Māori and were taken with nets and lines in large well organised fisheries. The flesh once dried kept for a long time and was an important form of koha at hui and tangihanga. Whai/skates and rays were taken with nets, lines, and harpoons.
Shark liver oil was also mixed with red ochre to make paint. Items of jewellery (necklaces, pendants and ear rings) were made from the teeth of larger species particularly mako and occasionally great white sharks / mangō taniwha. In some cases pendants resembling shark teeth were fashioned out of bone.
Sharks appear in many Māori creation stories and legends, and many important or tapu / sacred places had kaitiaki/guardians that took the form of sharks or rays. One story of the origin of sharks is that they are the progeny of Te Pu-whakahara and Takaaho (one of the children of Rangi and Papa), who appointed them, along with whales and dolphins, inhabitants of freshwaters. However they refused and persisted in roaming the oceans.