New Zealand is home to the world’s smallest and one of rarest marine dolphins – the Hector’s dolphin.
In the 1970s they numbered between 21,000 and 29,000. Today, fewer than 8000 dolphins remain, with sub-populations fragmented to a degree that threatens their survival.
Maui’s dolphin vs Hector's dolphin
Hector’s dolphins in the North Island and the South Island have been separated to such a degree the species has become genetically distinct – the dolphins found off the North Island coast are recognised as a sub-species, the Maui’s dolphin
Threats to Hector’s dolphin
Both Hector’s and Maui’s dolphins are listed on the IUCN’s (International Union for the Conservation of Nature) Red List of threatened species. Maui’s dolphins are listed as critically endangered with an estimated population of just 111, and Hector’s dolphins are listed as endangered.
Not only are Hector's dolphins slow & fickle breeders, they are coastal dwellers so they’re frequently in contact with human activity, such as fishing, which puts them in greater danger.
There are several human-induced threats to Hector’s dolphins, including boat strikes, trawling and pollution, but the main threat is set netting.
Set netting
Set nets (used in commercial, recreational and customary set net fishing) are the single most significant threat to the survival of Hector's dolphins, responsible for more than 60 per cent of all known deaths where the cause of death is known.
These nets are used to catch fish in coastal waters where Hector's dolphins live - the dolphins get entangled in these nets and drown. Set nets are indiscriminate, killing a wide range of non-target fish, other dolphin species, seals and seabirds. They are banned or heavily regulated in many countries.
A study by NIWA, the Ministry of Fisheries and fishing industry representatives (March 2008) shows that an estimated 110-150 Hector’s dolphins are killed in commercial set nets every year. The study found that without restrictions placed on commercial fishing, the risk of extinction of Hector’s dolphins would be very high.
Trawlers
Trawling involves pulling large nets behind boats, and, like set nets, may indiscriminately catch unwanted species. Some are so large they could hold the Cook Strait ferry.
Although a less significant threat to Hector’s dolphins than set netting, trawling does effect dolphin populations. On 3 April, 2006, three Hector’s dolphins were caught by one single commercial trawl vessel around the Marlborough Sounds.
What is being done?
In May 2008 the Government announced new measures to protect Hector’s and Maui’s dolphins that recognises the impact of set netting and also addresses a number of other threats.
The protection from fishing is not as comprehensive as that called for by Forest & Bird, but the new measures are still a very significant step towards halting the decline of Hector’s and Maui’s dolphins.
In addition to restrictions on set net fishing and coastal trawling, the government extended the Banks Peninsula Marine Mammal Sanctuary and established 4 new sanctuaries.
What’s missing?
There are still a number of areas where Hector's dolphins are unprotected (see map).
| Problem | |
|---|---|
|
Maui's
|
As well as failing to cover harbour areas, the ban does not extend into areas where Maui’s dolphins commonly range. For example Maui's dolphins were recently sighted (VIDEO) around Taranaki - outside their protected area. |
| Hector's
|
South Island Hector’s dolphins are still unprotected off the west coast of the south island, where 70% of the population lives. As well as facing threats from flounder nets in the Marine Mammal Sanctuary, Hector’s range near Banks Peninsula extends to 20 nautical miles. Since the protection measures were announced, Hector's dolphins have been found in unprotected waters around Wellington and Kaikoura. In Kaikoura, A Hector's dolphin was found dead in a commercial set net. Greater protection measures around these areas should be employed. |
Legal Challenge
After the government announced the fishing restrictions in 2008, a number of commercial fishing groups collectively commenced judicial review proceedings to try and overturn the new regulations.
As part of the proceedings, interim relief was sought in September 2008. This allowed fishing to continue off the West Coast of the North Island and parts of the East and South coasts of the South Island until the more substantive proceedings in the High Court were completed.
The case was heard in the High Court in Wellington on 15-17 May 2009. However, despite the judge promising a ruling by 1 September 2009, we are still waiting for a decision.
As a result, fishing has continued in the exempted areas for nearly 2 years and Hector’s and Maui’s dolphins have continued to be put at risk.
No Hector’s dolphin has been reported killed in these areas during this time, however there has been very low number of observers on fishing boats and the periods of high entanglement have been poorly covered
