On the edge of extinction
In the 1970s between 21,000 & 29,000 Hector and Māui dolphins lived around our coastline. Today, their population stands at just 7,000 dolphins.
Māui dolphin used to be known as the North Island Hector's dolphin but since 2002 they have been classified as separate subspecies.
Hector’s and Māui dolphins are only found in shallow water less than 100 meters deep. Because they are found only around the west coast of the North island these dolphins are protected from Maunganui Bluff in Northland to Whanganui, and you’re most likely to spot one between Manukau Harbour and Port Waikato.
A 2010/11 survey estimated the latest population of Māui at just 55 dolphins over the age of one. Accordingly they are listed as critically endangered.
At the current estimated rate of decline these dolphins are likely to go extinct without drastic intervention on their behalf.
Hector’s dolphins are listed as endangered.
Features
- Māui dolphin are the smallest of the world’s 32 dolphin species.
- Māui and Hector's dolphins look different to other dolphins. They are the only New Zealand dolphins with a rounded black dorsal fin. Other dolphins usually have a sickle-shaped fin.
- Māui and Hector’s dolphins look identical, although they are physically and genetically different.
- Māui dolphin have 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.
Māui dolphin are particularly vulnerable to decline as they have short lifespans, and are slow to reproduce.
- They only live up to 20 years. This is a short lifespan compared to other dolphins and whales.
- Females have their first calf (baby) between 7 – 9 years of age.
- They produce just one calf every 2 - 4 years, making population increase a very slow process.
- Māui dolphins may only be able to grow their population by 2% a year. That means that a population of 55 can only increase by 1 individual per year.
Threats
DOC say the greatest threat to Māui dolphin is the effect of human activites such as
- 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)
- pollution
- the effects of marine mining, drilling, and construction, including seismic surveys.
It’s estimated that around five Māui dolphins die each year from human activities – and they can only survive one human related death every 10 – 23 years.
Hope for Māui dolphin
Big steps forward have been taken to help protect Māui dolphin. There has been a ban on set netting and trawling along this part of the North Island’s west coast, and more stringent controls over petroleum and mineral prospecting and mining.
Locally the bans and restrictions placed upon human activities within the Protection Zone is extremely controversial, especially among commercial and recreational fishers. Particularly so since there have been no confirmed sightings of Māui dolphin off the Taranaki coastline since the introduction of the government's Threat Management Plan in July 2012.
DOC request you immediately report sightings of Hector’s/Māui dolphin in the North Island, south of Awakino - in the vicinity of this cache near the Taranaki / Waikato boundary (and on the East Coast).
Call DOC's 24 hour emergency hotline 0800 DOC HOT (0800 362 468) to report a sighting.
The cache is behind the sign. Parking may be at a premium, and stealth might be necessary.