Protecting the world’s smallest marine dolphin

The Hector’s dolphin is one of the world’s rarest, and one found only in New Zealand waters.

The species which grows to just 1.4 metres is divided into two subspecies. The South Island Hector’s dolphin lives around the east, west and south coast, while the Maui’s dolphin lives off the North Island’s north-west coast. The South Island Hector’s dolphin, with an estimated population of around 7,600 individuals, is ranked as nationally endangered by the Department of Conservation. The North Island Maui’s dolphin, with an estimated 100 individuals, is listed as nationally critical.

Human activities such as pollution, propellers from boats, and fishing can pose a danger. Even low rates of death threaten Hector’s dolphins as they reproduce slowly and have a low potential for population growth.

Fishing is the greatest known human threat to Hector’s dolphins. It is responsible for around 75 percent of reported deaths with a known cause.

Threats from fishing include the risk of dolphins becoming entangled in fishing gear. There have been reports of dolphin captures in trawl nets, however, of the different fishing methods, set nets are considered to pose the greatest threat.

The government began introducing protection measures in some areas earlier in the decade.

Further measures set to be introduced include a more comprehensive mix of regional bans and other restrictions on set netting, trawling and drift netting in the coastal waters where the dolphins are most often found. As well as this, observer monitoring will be significantly increased. These measures will sit alongside marine mammal sanctuary measures  announced at the same time. For more information see the MFish website.