Protecting Hector's and Māui dolphins

To help protect Hector's and Māui dolphins we have closed extensive areas to fishing. It's vital that we ensure the long-term survival of these unique marine mammals.

The world's smallest and rarest dolphins

Hector's and Māui dolphins are only found in New Zealand’s waters, and look very different to other dolphins. They're significantly smaller, with distinct grey, white and black colouring, and a rounded black dorsal fin.

While Hector's and Māui dolphins look identical, they are physically and genetically different.

Hector's dolphins

  • Most commonly found around the South Island in 3 main areas – the east, west and south coasts.
  • Classified as nationally endangered, with research from the Cawthron Institute in August 2016 estimating the total South Island population at almost 15,000 – which is more than double what was previously thought. The research has recently been peer-reviewed and endorsed by scientists from the International Whaling Commission Scientific Committee.

Māui dolphins

  • A subspecies living off the North Island's west coast. 
  • Classified as critically endangered with a 2015-16 population estimate of about 63 individuals (aged one year and older). 

Both dolphins are commonly found within 7 nautical miles of the coast, but the recent population research on Hector’s dolphins observed them out to 20 nautical miles offshore.

Find out more

Closing areas to fishing

Public and government concern over human impact on these dolphins led to the development of a Threat Management Plan in 2008. The plan was a joint effort between MPI and DOC, describing the nature and extent of fishing and non-fishing related threats to the dolphins. It also identified strategies to reduce these threats. The plan looked at all human-induced threats such as fishing, mining, seismic activities, vessel traffic, pollution and other contributing factors like disease.

Fishing is the greatest known human threat to Hector's and Māui dolphins. Set nets pose the biggest risk to the dolphins, as they can become entangled and drown. Hector’s dolphins have also been caught in trawl nets, but to a much lesser degree.

MPI has put extensive set net and trawling restrictions in place – closing around 8,000 square kilometres to trawling and 15,000 square kilometres to set netting around the North and South Islands.

Marine mammal sanctuaries established

The Department of Conservation has also established 5 marine mammal sanctuaries in key Hector's and Māui dolphin habitats. In these sanctuaries, restrictions have been placed on various activities including seabed mining, acoustic seismic survey work, and fishing to reduce threats to the dolphins.

Further research and monitoring

We are currently working to understand more about where fishing may affect Hector’s and Māui dolphins. A risk assessment approach is currently underway to identify fishing activities and areas that pose the greatest risk to the dolphins. This work, along with our monitoring programmes, will feed into a review of the Threat Management Plan, which is scheduled for 2018 (although any significant findings could bring the review forward).

MPI has monitoring programmes in place to help assess the effectiveness of current fishing restrictions and whether additional measures are required. Independent monitoring programmes help to reduce uncertainty and improve information on where the dolphins are, and how they are interacting with fishing activities.

Along the North Island's west coast, there is mandatory observer coverage on any commercial set net vessel operating between 2 and 7 nautical miles off the Taranaki coast between the Waiwhakaiho River and Hawera.

MPI has also been increasing observer coverage on trawl vessels operating north of this area between Maunganui Bluff and Pariokariwa Point.

Who to contact

If you have questions about protecting dolphins, email

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