Maui’s dolphins are a sub-species of Hector’s dolphins, the world’s smallest dolphin. They are found on the west coast of the North Island of New Zealand and nowhere else in the world. It is one of the world’s rarest dolphins.
The dolphin is listed internationally as 'critically endangered', which means there is a high risk of it becoming extinct in the near future. A recent abundance estimate for Maui's dolphin indicates as few as 55 individuals over one year of age remain (95% confidence interval of 48 - 69).
We need your help
Your help is urgently sought to look out for Maui’s dolphins around New Zealand and to report sightings immediately. What to do if you think you have seen a Maui’s dolphin.
On the edge of extinction
New Zealand’s rarest dolphin, the Maui’s dolphin, is on the edge of extinction. With fewer than 100 left in the wild, this small, round-finned dolphin needs all our help to survive.
A ban on set netting and trawling along part of the North Island’s west coast, together with more stringent controls over petroleum and mineral prospecting and mining, are big steps forward to help protect Maui’s dolphin.
Research is being undertaken to find out more about these dolphins. You can help by keeping an eye out for Maui’s dolphins and reporting sightings.
Get information on what DOC is doing to save Maui's dolphin. This includes: a research advisory group, surveys, sightings, incident database, abudance estimates, research and threat management.
Why are Maui's dolphins so special?
Maui’s dolphins (Cephalorhynchus hectori maui) are found on the west coast of the North Island of New Zealand and nowhere else in the world.
This small population of dolphins is thought to have been isolated from their more numerous relatives, South Island Hector’s dolphin, for thousands of years. They are separate subspecies that look identical but are physically and genetically distinct from each other - see Geographical variation in Hector's dolphin. Maui's dolphin used to be known as North Island Hector's dolphin but since 2002 they have been classified as separate subspecies.
Maui’s dolphins are classified as Nationally Critical, the highest ‘at risk’ classification in the New Zealand Threat Classification System. The dolphins are also listed as Critically Endangered by the International Union for Conservation of Nature (IUCN). This means there is a high risk of the subspecies becoming extinct in the near future.
Like the kiwi, the Maui’s dolphin is an important part of New Zealand’s natural heritage. If we don’t take care of them, this endemic dolphin will be lost forever.
Features of Maui's dolphins
Maui's dolphin and common dolphin dorsal fins compared
Maui’s dolphins are the smallest of the world’s 32 dolphin species.
Maui's and Hector's dolphins look different to other dolphins. They are the only New Zealand dolphins with a rounded black dorsal fin and a black tail, flippers and eye patches. Other dolphins usually have a sickle-shaped fin.
Other characteristics include:
Distinctive grey, white and black markings and a short snout.
Females grow to 1.7 m long and weigh up to 50 kg. Males are slightly smaller and lighter.
They are known to live up to 20 years.
Females are not sexually mature until 7 - 9 years of age. They produce just one calf every 2 - 4 years, making population increase a very slow process.
Like other dolphins, Maui’s use echolocation to find their food. They send out high frequency ‘clicks’ that bounce off surrounding objects and fish, giving the dolphins a detailed picture of their surroundings. This sonar is not used all the time, which may be why the dolphins get caught in nets.
Maui’s dolphins feed opportunistically, both at the bottom and throughout the water column, on a variety of species of fish.
Range of Maui's dolphins
Maui’s dolphins are generally found close to shore in groups or pods of several dolphins. They are often seen in water less than 20 m deep but may also range further offshore.
They use the mouths of the Manukau and Kaipara harbours, and are often seen just outside many of the other harbours on this coast.
Studies suggest that the dolphins use about 30 km of shoreline, and some individuals have been recorded moving nearly 80 km in under three weeks.
Declining numbers of Maui's dolphins
Maui’s dolphins are known to live up to 20 years. Females are not sexually mature until 7-9 years old, and produce just one calf every 2-4 years. This means any population increase is slow.
Recent studies suggest the number of Maui’s dolphins has reduced since earlier surveys and may still be declining. Their range has also reduced, with most sightings of dolphins now between the Manukau Harbour and Port Waikato.
Interestingly, DOC surveys in 2010 and 2011 found that there were at least two South Island Hector’s dolphins swimming among the Maui’s dolphins. While there is no evidence yet of interbreeding, if they did interbreed this may provide Maui’s dolphins with a much-needed boost by increasing genetic diversity.
Maui's dolphin mother and calf
Threats to Maui's dolphins
There are human-induced and natural factors that impact Maui's dolphins and all of these need to be better understood. Some of these threats may cause the death of the dolphins directly, whereas others may impact on the population by reducing the health of individuals and therefore their ability to breed.
Threats caused by people
Unfortunately the close inshore distribution of Maui’s dolphins overlaps with many coastal activities that pose a threat to their survival.
Maui’s dolphins can be affected by human activities in the following ways:
- Becoming entangled in fishing gear and drowning, including from set netting, trawling and drift netting
- Being hit by boats and their propellers
- Becoming entangled in or ingesting marine litter (especially plastics)
- The effects of marine mining and construction, including seismic surveys.
Get more information on threats caused by people.
Threats not caused by people
Some other threats are beyond our control but could have significant effects due to the small population size of Maui’s dolphins. These include:
- Predation from sharks and orcas (killer whales)
- Extreme weather, which can cause mothers and calves to be separated, resulting in the death of the calf.
Get more information on threats not caused by people.
Research and protection events for Maui's dolphins
The Review of the Maui’s dolphin Threat Management Plan Consultation Paper provides further details on threats facing Maui's dolphins and how the Department of Conservation and the Ministry for Primary Industries are seeking to mitigate threats against them.
In November 2013, The Minister of Conservation, along with the Minister of Primary Industries, announced a variation to the West Coast North Island Marine Mammal Sanctuary (after public consultation) to be implemented in full alongside a package of protection measures as a part of the Maui’s Threat Management Plan review.
View a timeline of research and protection efforts for Maui's dolphin since their recognition as a subspecies in 2002.
Set netting bans
Set netting poses a threat to Maui’s dolphins. Fisheries regulations now ban set netting along part of the west coast of the North Island. See the Auckland and Kermadec Fishery Management Area recreational fishing rules for more information on these closed and restricted areas.
Amateur fishers found fishing with set nets in the closed area can be fined up to $20,000 and fishing equipment can be seized. Fines for commercial fishers are up to $100,000. If you see set nets within the closed areas please phone 0800 4 POACHER (0800 47 62 24).
If Maui's dolphins are caught in set nets they drown
Research on Maui's dolphins
There is still a lot that we don’t know about Maui’s dolphins, including:
Can the population recover, and how quickly?
What species are most important to them for food?
How will they be affected by increasing human use of their home range (marine mining, seismic surveying, marine construction and coastal development)?
The Department of Conservation, together with university researchers and conservation groups, is seeking answers to these questions using a range of research methods and techniques. You can help with this research by reporting sightings of Maui’s dolphins.
How you can help Maui's dolphins
If you see Maui’s dolphins when out on the water:
- Avoid approaching Maui’s dolphins and never swim with them.
- Ensure there are no more than three vessels (including jet skis and kayaks) within 300 m of a pod.
- Keep your speed to a minimum - no wake allowed within 300 m.
- Do not feed Maui’s dolphins or dump rubbish, and keep noise to a minimum.
- Report any sightings to 0800 DOC HOT (0800 362 468). Include the location, number seen, time and date. Email any photos you were able to take to email@example.com.
- If you see set nets within the closed areas phone 0800 4 POACHER (0800 47 62 24).