Everyone knows they’re out there, but how well do you know your sharks? NIWA looks at four of the most common sharks you’re likely to spot this summer.
Blue shark
A cousin of the tiger shark, these sleek creatures are regularly seen in harbours and along our coasts over summer. Their sinuous movements and streamlined forms rank them among the fastest of sharks. Also known as the blue whaler or blue pointer, the blue shark's upper body is a striking cobalt blue and the underside is bright white.
Their large black eyes have a protective membrane to shield them from struggling prey.
A young 2m blue shark weighs less than 40kg and despite their slim build, a female can give birth to up to 135 pups, each about 50cm long.
Named for their habit of swimming in schools, the school shark is also known as grey boy, tope or kapeta. School sharks are grey on top and white underneath.
They are Identified by their long snout, which is translucent from below.
School sharks live for up to 50 years but are slow growers and only reach 175cm long. A 90cm school shark is about 5 years old but by 10 years old is about 120cm. Females will give birth to between five and 40 pups but only every two years and usually in shallow sheltered waters.
School sharks are found throughout New Zealand's mainland coastal waters. In summer, they move inshore, where they feed on small fish and squid. School sharks tracked by Niwa covered distances between 1735 and 4940km. The greatest distance travelled each day was 23km.
Bronze whaler
Found around the northern half of the North Island when they move into shallow coastal waters to feed on kahawai, mullet, snapper, kingfish and eagle rays.
Bronze in colour with cream underbellies, these sharks take about 30 years to reach a maximum length of three metres but most are between 1.5m and 2m. Female bronze whalers will have 16 to 20 pups at a time.
One of the most abundant large shark species in our coastal waters, the species is the one most likely to be encountered by divers. Not normally aggressive to humans, although spear fishers have been bitten by them. These sharks eat live or dead fish, so spear fishers should remove their catch from the water as soon as possible.
Spotted dogfish
Spotted dogfish. Photo / Malcolm Francis
One of the smaller, common species of shark is the spotted dogfish or rig, which is served at fish 'n' chip shops. Endemic to New Zealand waters, females grow to a maximum of 1.5m long and males to 1.2m. Bronze or grey on top, they have a white belly and small white spots on their upper body.
Rig sharks spend the summer in estuaries and coastal waters and are of little threat to humans. Their teeth are small grinding plates, good for eating crabs - their main food source.
Most female rigs reproduce from late October to early December delivering about 10 pups, each 10 to 20cm long.
Rigs are good swimmers and travel very long distances. One tagged rig clocked up 1159km, going from south of Stewart Island to Golden Bay.
