Protecting Hector's and Māui dolphins

We want to ensure the long-term survival of these unique marine mammals. Find out about the threat management plan, closed fishing areas, monitoring, and other protection efforts.


We are involved in several measures to protect Hector's and Māui dolphins, including:

Threat management plan

Fisheries New Zealand and the Department of Conservation (DOC) are responsible for a threat management plan for these dolphins.

The plan looks at all known threats to the dolphins, including:

  • fishing
  • oil and gas exploration
  • boat strike
  • pollution and plastic bags
  • climate change
  • tourism
  • mining
  • noise
  • toxoplasmosis.

The plan was launched in 2007 and the Māui dolphin portion was updated in 2012. In June 2020, a revised plan was released to further address fishing and non-fishing threats.

Decisions and consultation on the latest measures

Non-fishing related threats

The Department of Conservation (DOC) manages mainly non-fishing threats to Hector's and Māui dolphins.

The world's smallest and rarest dolphins

Hector's and Māui dolphins are only found in New Zealand's waters and look very different from other dolphins.


  • are much smaller
  • have a rounded, black dorsal fin
  • have unique grey, white and black colouring.

While Hector's and Māui dolphins look almost identical, they are physically and genetically different. The dolphins only live for around 20 years and breed slowly. Females don't have their first calf until they are about 7 or 8 years old. They have a new calf only every 2 to 4 years. This means the species may be threatened by even occasional deaths caused by human activity.

Hector's dolphins

  • Most often found around the South Island.
  • Classified as nationally endangered. Research from the Cawthron Institute in August 2016 estimated the total South Island population at almost 15,000. This is more than double previous estimates. The research has been peer-reviewed and endorsed by scientists from the International Whaling Commission Scientific Committee.

Māui dolphins

  • A sub-species living off the North Island's west coast.
  • Classified as critically endangered, with about 63 individuals over 1 year old, based on an estimate from a 2015 and 2016 survey.

Both dolphins are mostly found within 7 nautical miles of the coast. However, recent population research on Hector's dolphins observed them out to 20 nautical miles.

Closing areas to fishing

Of the fishing-related threats these dolphins face, set-nets are the biggest threat – the dolphins can get tangled in them and drown. Hector's dolphins have also been caught in trawl nets, but this happens less often.

We have set-net and trawling measures in place around the North and South islands to reduce the chances of entanglement.

  • 17,530 square kilometres have trawl closures and restrictions.
  • 31,500 square kilometres are closed to set-netting.

Spatial data for closed and restricted areas

Access spatial data layers through our Marine Geospatial Catalogue:

Marine mammal sanctuaries established

DOC has established 5 marine mammal sanctuaries in Hector's and Māui dolphin habitats. In these sanctuaries, DOC has restricted many activities, including:

  • fishing
  • seabed mining
  • acoustic seismic survey work.

Further research and monitoring

Fisheries New Zealand has monitoring and research programmes in place to help assess the effectiveness of current fishing restrictions. These programmes help inform whether more measures are needed.

Independent monitoring and research programmes are also carried out by external groups – like marine scientists.

Monitoring on the North Island's west coast

Since November 2019, on-board cameras have been in use on some commercial fishing vessels operating off the west coast of the North Island.

Find out about on-board cameras in Māui dolphin habitat

Observer coverage will continue on trawl vessels operating between Maunganui Bluff and Pariokariwa Point to test the effectiveness of on-board cameras and their ability to detect protected species interactions.

Māui dolphin sightings – DOC

Related topic

Strengthening fisheries management

Data on seabird and protected marine species caught by commercial fishers

Who to contact

If you have questions about the information on this page, email

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