Kōrero: Marine conservation

Whārangi 3. Marine mammals

Ngā whakaahua me ngā rauemi katoa o tēnei kōrero

Whales and seals

Europeans and Māori plundered the ocean around New Zealand, hunting seals and whales in massive numbers. By the 1830s extinction was looming for seals, and it was becoming uneconomic to send out gangs of sealers from Australia, Britain and other countries.

Concern about plummeting seal numbers resulted in a law in 1875, which banned sealing between 1 October and 1 June. After 1894 even this open season was closed except in 1914 and 1915, when hunting was allowed with a licence.

Open seasons were again allowed in 1924 and 1926 on Campbell Island, and in 1946 in Otago, Southland and Fiordland. Protection in these cases was lifted as fishers argued that seals were taking too many fish. During the last open season in 1946, 6,187 seals were killed from June to September.

Seals and sea lions are protected under the Marine Mammals Protection Act 1978. In 2003 a 12-mile marine reserve was established around the Auckland Islands to safeguard the sea lion from squid nets.

Accidental slaughter

Even though they are totally protected by law, seals and sea lions die in large numbers each year when they are caught in commercial fishing nets. Between 1988 and 2003, 7,759 seals died in hoki fisheries, and at least 2,000 New Zealand sea lions have been killed in the Auckland Islands squid fishery since 1980.

The Fishing Industry Association has produced a code of conduct to minimise seal deaths. Even so, they still occur. In 1991 the government set an upper annual limit of 65 sea lion deaths resulting from squid fishing; if this was exceeded then the fishery would be closed. In the early 2000s conservation groups were lobbying for zero sea lion deaths.


Despite its history of whale exploitation, New Zealand has led the way in modern whale protection. In 1946 it was a founding member of the International Whaling Commission, established to manage the world's whale resources. The last harpooning by a New Zealand vessel in New Zealand waters occurred off the Kaikōura coast in 1964. Having been a whaling nation for over 100 years, by the late 1970s the country was taking a strong stance against the industry.

In 1982 the commission voted for a moratorium on commercial whaling, and in 1994 established the Southern Ocean Whale Sanctuary. This covers over 11 million square miles of ocean, including all of New Zealand's Exclusive Economic Zone south of 40° south. Japan does not recognise this sanctuary and continues to hunt for minke whales in the Southern Ocean.

All whales within New Zealand’s 200-nautical-mile Exclusive Economic Zone are totally protected under the Marine Mammals Protection Act 1978. Under this act areas could be declared marine mammal sanctuaries. 

Whale watching, 1960s style

In the early 1960s New Zealand’s navy and air force carried out population surveys of sperm whales, and spotted them so that whalers could harpoon them. For the same purpose, the government also employed whale lookouts – pilots and navigators of the National Airways Authority, lighthouse keepers, coastal and trans-Tasman ships, and weather-station personnel on Campbell Island and the Kermadecs.


All dolphins are also totally protected in New Zealand waters by the 1978 act. Most species are maintaining their numbers, but others need further protection. In 2010–11 it was estimated that there were 48–69 Māui's dolphins over one year of age. In 2003 set-netting was banned between Kaipara Harbour and Mōkau to protect this subspecies. In 2008 the West Coast North Island Marine Mammal Sanctuary was established, and the area closed to set-netting was also extended. In 2012 an area in Taranaki from Pariokariwa Point to Hāwera was closed to commercial and recreational set-netting up to 2 nautical miles off the coast; commercial set-netting was allowed between 2 and 7 miles offshore only if an observer was on board. In 2013 the area between Pariokariwa Point  and the Waiwhakakaitio River was closed to all set-netting up to 7 nautical miles offshore.

Hector's dolphins, which are found around the South Island, have a larger population, estimated at around 7,000 in 2013. The first marine mammal sanctuary of 114,000 hectares was established off Banks Peninsula in 1988 to protect this species. In 2008 it was extended from the mouth of the Waipara River to the mouth of the Rakaia River and 12 nautical miles off the coast, an area of around 413,000 hectares. Catlins Coast, Clifford and Cloudy Bay and Te Waewae Bay marine mammal sanctuaries were set up in 2008 to protect Hector's dolphins. There are also various set-netting restrictions in place around the South Island. 

Other protected species

Under the Wildlife Act 1953 and the Marine Mammals Protection Act 1978, certain other marine species are protected irrespective of where they are found. All marine reptiles (including turtles and sea snakes), black coral and red coral are fully protected. In these cases protection is not only for the living creature, but any part of it.

Me pēnei te tohu i te whārangi:

Gerard Hutching and Carl Walrond, 'Marine conservation - Marine mammals', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/mi/marine-conservation/page-3 (accessed 25 May 2024)

He kōrero nā Gerard Hutching and Carl Walrond, i tāngia i te 12 Jun 2006, updated 1 Sep 2015