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

In August 2007, the Ministry of Fisheries (now Fisheries New Zealand) and the Department of Conservation (DOC) released a Threat Management Plan (TMP) for these dolphins. This was in response to public and government concern over human-caused deaths among these species.

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

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

In 2012 and 2013, MPI completed a review of the Māui dolphin section of the TMP. 

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 to other dolphins. They:

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

While Hector's and Māui dolphins look 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 one 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

Fishing is the greatest known human threat to Hector's and Māui dolphins. Set nets are the biggest threat to the dolphins – they 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 restrictions in place around the North and South islands to reduce the chances of entanglement.

  • 8,000 square kilometres have trawl restrictions.
  • 15,000 square kilometres are closed to set netting.

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

A review of the Threat Management Plan is scheduled for 2018.

We are working to understand more about where fishing may affect Hector's and Māui dolphins. We are carrying out risk assessment reviews to identify:

  • fishing activities that pose the greatest risk to the dolphins
  • areas that pose the greatest risk.

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

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

Monitoring on the North Island's west coast

There must be a government observer on any commercial set net vessel operating within 2 to 7 nautical miles from the Taranaki coast. This rule is in place between the Waiwhakaiho River and Hawera.

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

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Who to contact

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

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