On this page:
- The world's smallest and rarest dolphins
- Threat management plan
- Managing fishing-related threats
- Managing non-fishing threats
- Toxoplasmosis action plan
- Further research and monitoring
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 turbidity
- presence of suitable prey.
While Hector's and Māui dolphins look almost identical, they are physically and genetically different.
- 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.
- A subspecies living off the North Island's west coast.
- Classified as critically endangered, with about 54 individuals over 1 year old within the survey area, based on the estimate from a 2020 and 2021 survey.
Find out more
Supplementary material [PDF, 1.7 MB]
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:
- oil and gas exploration
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.
Additional consultation was undertaken in 2021 on further fisheries measures to protect South Island Hector’s dolphins. Decisions on that review were announced in October 2022.
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.
- 12,825 square kilometres have trawl closures and restrictions.
- 31,500 square kilometres are closed to set netting, which will increase to 32,675 square kilometres by the end of 2022.
South Island Hector’s Dolphin Bycatch Reduction Plan
In October 2022, the Minister for Fisheries and Oceans agreed on further measures to mange the effects of fishing-related mortality on South Island Hector’s dolphins and support the delivery of the TMP. Those measures include a Bycatch Reduction Plan.
The Bycatch Reduction Plan is a suite of regulatory and voluntary measures designed to incentivise and support fishers to reduce Hector’s dolphin bycatch towards zero.
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:
If you're a recreational fisher, make sure to check the restrictions that apply to you.
DOC mainly manages non-fishing threats to Hector's and Māui dolphins.
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.
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.
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
- 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.
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.
Who to contact
If you have questions about our work to protect Hector's and Māui dolphins, email firstname.lastname@example.org