- 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.
- 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.
- 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.
Threats to Maui Dolphins
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.
Non human-induced threats
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.
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.
What to do?
2014: New measures
After a lengthy public consultation on the protection of Maui’s dolphins, in 2013/2014 the government decided to –
- Retain the set-net ban around Taranaki
- Extend the protection slightly south of Pariokariwa point
- Increase observer coverage on fishing vessels to see if any dolphins are caught as by-catch to prioritise research.
This is a step in the right direction but it falls well short of stopping Maui’s dolphins from becoming extinct.
What Forest & Bird wants Within the next 3 years:
- immediate protection of the full range of Maui’s dolphin habitat
- from Maunganui Bluff to the Whanganui river, including all five harbours along the west coast of the North Island, and extending offshore to 20nm and
- removing all threats within this area including set nets, trawling, marine mining and seismic surveying
In addition to this, we want the Government to help fishers transition to more sustainable fishing methods that can be used within this protected area
- We strongly support the International Whaling Commission Scientific Committee’s June 2014 recommendation that the Government take urgent action.
- It recommends that they cease seeking further scientific research on Maui’s dolphins and instead concentrate their efforts on to eliminate by-catch of Maui’s dolphins.
Long-term goals We want to see a priority on Maui’s and Hectors dolphin research and population targets developed and progress monitored to help ensure the recovery of the rarest dolphins in the world.