Maui's Dolphins

Maui's dolphins (popoto) are the world’s rarest marine dolphins and are found only off the north-west coast of the North Island.

Maui's: Quick Facts

• The Maui’s dolphin is a North Island sub-species of Hector's dolphins. It is  is genetically distinct from the South Island Hector's dolphin
• Maui's dolphins look just like their cousins the South Island Hector's dolphin. 
• Maui’s dolphins are very slow breeders and typically only have one calf every two or three years.
• They are easily spotted by their rounded dorsal fin, which looks similar to a Mickey Mouse ear.
• They have a short snout and white “flames” up their body.

They are so small they could fit into a bathtub, and have a distinctive round dorsal fin, so they are easy to tell apart from more common dolphin species.

Listed as critically endangered by the International Union for the Conservation of Nature - www.redlist.org - Maui’s dolphins have an estimated population of 55 individuals.

As well as being slow breeders the pool of potential mates for Maui’s dolphins is very small, meaning that inbreeding may occur.

Inbreeding reduces the gene pool and creates a higher chance of birth defects and genetic problems.  Maui’s dolphins are on the brink of extinction and urgently need our help.

 

19th Century population & now

In the 19th Century Maui's dolphins were found around the North Island coastline, from Tuaroa Point in Northland to mid-Bay of Plenty (see map).

In the 1970s most strandings (the main indicator of historical distribution) were around the lower North Taranaki Bight. A decline in the reported deaths in this area indicates the rapid shrinking of their distribution.

Maui’s dolphins are now found only from Maunganui Bluff (near Dargaville) to just south of New Plymouth - most commonly between Manukau Harbour and Port Waikato (see map).

 

Threats – set nets and trawling

Maui’s dolphins prefer shallow waters, which brings them into direct contact with humans and makes them particularly vulnerable to their main threat: fishing.

What is being done?

In June 2007 Forest & Bird launched a proposal to establish a Marine Mammal Sanctuary for Maui’s dolphins off the west coast of the North Island. Following extensive consultation, a formal proposal was presented to the minister of Conservation in February 2008.

 

Click here for a copy of the Forest & Bird proposal for a Marine Mammal Sanctuary to protect Maui's dolphins.(PDF)

In May 2008, new measures to protect Maui’s dolphins were announced. These came into force on 1 October 2008 and include –

Solution Problem

Gill Net Ban

Gill netting is banned within seven nautical miles of the west coast of the North island (from Maunganui Bluff to North Taranaki).

  • The Maui’s dolphin’s range extends further south than the set net ban (see VIDEO), so they still remain unprotected in these waters.
  • This ban does not include harbours, despite sightings in three of the five harbours. Studies of Manukau Harbour confirm that Maui’s dolphins regularly use the harbour and range further into the harbour than the protected area.

 

Trawling Ban

Trawling is banned within two nautical miles of the coast, and within four nautical miles in core Maui’s dolphin habitat (Manukau to Port Waikato).

 

  • Maui’s dolphin’s range extends further south & offshore beyond the set net ban, so they remain unprotected in these waters.

 

Marine Mammal Sanctuary

A new West coast North Island Marine Mammal Sanctuary:

  • Maunganui Bluff (near Dargaville) to Oakura Beach (near New Plymouth)
  • All coastal waters out to 12 nautical miles, including all harbours

The MMS includes restrictions on acoustic seismic surveys plus a 2 nautical mile ban on mineral mining (4 nautical mile ban on mining in core Maui’s area - north of Manukau Harbour to south Raglan harbour)

  • The offshore boundary of the Marine Mammal Sanctuary does not extend far enough to ensure protection of their entire range.
  • Fishing restrictions do not match the boundaries of the MMS, so whilst some dolphins are protected, not all dolphins inside the MMS will be protected.
  • There is no management plan for the sanctuary.

 

Solutions

>The critically endangered Maui's dolphin cannot withstand deaths caused by fishing methods if it is to survive and recover to a safe population size. In fact in a report by scientists from NIWA, the fishing industry and the Ministry of Fisheries, it is estimated that Maui’s dolphins could not sustain more than 1 human caused death in any 5 year period. Fishing regulations should therefore be extended immediately, particularly along the southernmost boundary, around Taranaki.

> Protection of waters between the North and South Island is also needed to allow the expansion of the dolphins’ range and to encourage the expansion of their genetic pool.