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.

The world's smallest and rarest dolphins

Hector's and Māui dolphins are only found in New Zealand's waters. Compared to other dolphins, they:

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

The dolphins only live for around 20 years and breed slowly. Females don't have their first calf until they're 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.

Both dolphins are most commonly observed within 7 nautical miles of the coast. However, recent population research on Hector's dolphins observed them out to 20 nautical miles in some locations. Dolphin distribution appears strongly influenced by:

  • water turbity
  • presence of suitable prey.

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

Hector's dolphins

  • A subspecies most often found around the South Island.
  • Classified as nationally vulnerable. 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.

Hector's dolphin – Department of Conservation

Māui dolphins

  • A subspecies 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.

Māui dolphin – Department of Conservation

Find out more

South Coast South Island Hector's dolphin abundance and distribution [PDF, 3.2 MB]

West Coast South Island Hector's dolphin abundance and distribution [PDF, 3.2 MB]

East Coast South Island Hector's dolphin abundance and distribution [PDF, 3.3 MB]

Supplementary material [PDF, 1.7 MB]

West Coast North Island Māui dolphin abundance – Department of Conservation

Threat management plan

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

The plan looks at all known human-induced threats to the dolphins, such as:

  • fishing
  • toxoplasmosis
  • oil and gas exploration
  • mining
  • tourism.

The plan was launched in 2008 and the Māui dolphin portion was reviewed in 2012. In June 2020 a revised plan was announced to further address fishing and non-fishing threats.

Decisions and consultation on the 2020 measures

Managing fishing-related threats

Set nets are the biggest fishing-related threat for dolphins. 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've introduced measures and restrictions on set nets and trawling to help protect the dolphins from these threats.

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

Hector's and Māui dolphins TMP – North Island fisheries measures [PDF, 761 KB]

Hector's and Māui dolphins TMP – South Island fisheries measures [PDF, 555 KB]

If you're a recreational fisher, make sure to check the restrictions that apply to you.

Fishing rules

View maps of where set netting is banned

These documents have detailed maps showing exactly where set netting is banned.

North Island set net closures [PDF, 9.2 MB]

South Island set net closures [PDF, 5.3 MB]

Spatial data for closed and restricted areas

Access spatial data layers through our Marine Geospatial Catalogue:

Spatial data for all commercial fishing regulations

Spatial data for set netting prohibitions

Managing non-fishing threats

DOC mainly manages non-fishing threats to Hector's and Māui dolphins.

Māui Dolphin – Department of Conservation

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:

  • seabed mining
  • acoustic seismic survey work.

Other marine protection tools – Department of Conservation

Toxplasmosis action plan

Toxoplasmosis is a significant threat to Hector's and Māui dolphins. The disease is caused by cats when they shed parasites in their stools.

DOC has developed an action plan to respond to the threat.

Toxoplasmosis action plan – Department of Conservation

Further research and monitoring

Fisheries New Zealand and DOC have monitoring and research programmes in place to help assess the effectiveness of current management measures.

These programmes help inform whether more measures are needed.

Independent monitoring and research programmes are also carried out by external groups, including:

  • Crown research institutes
  • universities
  • non-government environmental organisations.

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 – Department of Conservation

Related topic

Strengthening fisheries management

Who to contact

If you have questions about our work to protect Hector's and Māui dolphins, email

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