Hector’s dolphins
THE PROBLEM
Hector’s and Maui’s dolphins are among the world’s rarest and smallest dolphins. They are an inshore coastal species with a limited home range. They are found only in New Zealand’s waters.
The Hector’s dolphin species is estimated to number fewer than 8,000. It is divided into two sub-species—the Maui’s and South Island Hector’s dolphins.
The Maui’s dolphin sub-species lives around the North Island’s west coast. It is estimated there are only about 110 dolphins left. The Department of Conservation (DoC) classifies them as “nationally critical”.
The South Island Hector’s dolphin sub-species lives in three geographically distinct groups around the South Island. On the south coast estimates of dolphin numbers range from about 90 to 400. It is estimated about 1,800 dolphins live on the east coast and about 5,400 on the west coast. DoC classifies them as “nationally endangered”.
Hector’s and Maui’s dolphins live for only around 20 years and breed slowly. Females don’t have their first calf until they are about seven or eight years old, and have a new calf only every two to four years. This means the species may be threatened by even occasional deaths caused by human activity.
Fishing is the greatest known human threat to Hector’s and Maui’s dolphins—responsible for about 75 per cent of reported deaths with a known cause. Set nets are the main fishing threat. Dolphins can get entangled in the fine nylon nets and drown. However, there have also been reports of dolphin captures in trawl nets.
Other human threats include marine tourism, vessel traffic, mining, construction, coastal development pollution, sedimentation, oil spills, plastic bags, marine farming and climate change.
CURRENT AND FUTURE MANAGEMENT
New fishing prohibitions and restrictions to manage the effects of fishing-related mortality on Hector’s and Maui’s dolphins came into force on 1 October 2008. The prohibitions and restrictions apply to commercial and recreational fishers and affect set netting, trawling, and drift netting.
Please note: High Court judgement on legal challenge against new rules issued on Tuesday 23 February 2010.
In 2008 the New Zealand Federation of Commercial Fishermen and other industry parties lodged a legal challenge against the new rules and sought interim relief to stop some of the rules coming into force in some areas. On Friday 26 September 2008, the High Court granted the interim relief that industry sought. This meant that for some areas the new set net rules did not apply to commercial fishers, or applied as modified by the Court.
A judgement from the Wellington High Court on the legal challenge was issued on Tuesday 23 February 2010. The Court upheld four out of the six restrictions that were the subject of the legal challenge and referred two back to the Minister for reconsideration. The two measures that have been referred back to the Minister are:
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the extension of the set net closure for commercial fishers on the West Coast of the North Island to include the area between 4 and 7 nautical miles from shore; and
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the inclusion of targeted butterfish fishing in the closure for commercial fishers of part of the East Coast of the South Island.
The interim relief measures previously granted by the High Court will continue to apply to commercial fishers only in relation to the above measures and in relation to ring netting in part of the Manukau Harbour, as outlined in the table below. All other interim relief in relation to measures that the High Court upheld no longer applies and the original measures are now in force in those areas (e.g. South Coast of the South Island). Please check this website regularly for up to date information.
For additional information refer to the Minister’s press release.
See table below for descriptions and maps of the measures in place, including interim relief for commercial set and ring net fishers where applicable. The High Court action does not affect any rules applicable to recreational fishers.
To view the actual regulations for the new prohibitions and restrictions follow this link.
In addition to the new fishing prohibitions and restrictions, the government is investing in more monitoring of commercial fisheries that overlap with the dolphins. Over the next few years the Ministry of Fisheries (MFish) will place more observers on inshore trawl and set net boats to monitor any fishing interaction with Hector’s and Maui’s dolphins as well as with other protected species like seabirds.
Hector’s and Maui’s dolphins are one of the best studied cetacean (marine mammal) species in the world, but there are still information gaps. MFish, working with DoC, will continue investing in research to help inform future management decisions and to examine the success of the new fishing prohibitions and restrictions.
Monitoring and research signal that the new fishing prohibitions and restrictions are not the end, but rather part, of a process. MFish, working with DoC, tangata whenua and stakeholders, will use monitoring and research as a framework for ongoing discussion about the management of threats to the dolphins.
The new fishing prohibitions and restrictions replace other fishing rules that the government had introduced to protect the dolphins. These included:
- a smaller set net prohibition on the North Island’s west coast
- fishing prohibitions and restrictions in the Banks Peninsula Marine Mammal Sanctuary
- a seasonal set net closure in between the Waiau and Waitaki Rivers in Canterbury
- a rule that recreational fishers had to stay with their nets in Te Waewae Bay.
THREAT MANAGEMENT PLAN
The new fishing prohibitions and restrictions are part of a Threat Management Plan (TMP) coordinated by MFish and DoC.
Public and government concern over the effect of human-induced mortality on Hector’s and Maui’s dolphins led to the development of a draft TMP that MFish and DoC released for public consultation in August 2007. The draft TMP:
- examined all known threats to the dolphins, including fishing, boat strike, noise, pollution, mining, climate, and tourism (experts on dolphins and people from all interest groups were involved in the development of the draft TMP)
- outlined strategies to reduce human-induced threats – including fishing threats.
This link – draft Threat Management Plan – takes you to the series of consultation and advice documents that led to the government’s decision to introduce new fishing prohibitions and restrictions to protect Hector’s and Maui’s dolphins. This link also provides access to the regulations for the new prohibitions and restrictions.
The Department of Conservation is focusing on managing non-fishing threats identified in the draft TMP. Go to the Department of Conservation website for more information.
The Ministry of Fisheries and the Department of Conservation will eventually combine the new fishing prohibitions and restrictions, as well as the non-fishing measures, into a comprehensive Threat Management Plan that will be available to the public.