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110-150 Hector’s, Maui’s Dolphins die in gill nets

News Release 8 April 2008

NIWA Report on Hector’s and Maui’s Dolphins estimates 110 – 150 Die in Commercial Gill nets Every Year

A new Government commissioned report by the National Institute for Water & Atmospheric Research (NIWA) confirms that Hector’s and Maui’s dolphins are being fished to extinction. The report substantiates urgent calls for action from Care for the Wild International (CWI), a wildlife charity that promotes the conservation and welfare of wild animals around the world through direct projects, education, research and science-based advocacy.

Commenting on the NIWA report, which analyses the risk commercial set netting poses to Hector’s and Maui’s dolphins, CWI’s Chief Executive Dr Barbara Maas said, “Experts have warned about the failure to fully protect these highly endangered animals against this key threat for more than two decades. Banning all gill-netting is crucial to the survival of Hector’s and Maui’s dolphins.”

The report calculates that each year between 110 and 150 Hector’s dolphins die in commercial gill nets, and concludes that under current management Hector’s dolphin numbers will continue to decline to the point where extinction is the most likely outcome. South Coast South Island Hector’s dolphins and the North Island subspecies, the Maui’s dolphin, have been particularly hard hit. Complete protection against human impacts, including commercial and recreational gill-netting as well as trawling, would allow numbers to slowly double to some 15,000 over the next 50 years.

Maui’s dolphins are already listed as ‘Critically Endangered’ on the International Red List of Endangered Species (World Conservation Union –, the highest category, and face an extremely high risk of extinction in the immediate future. Hector’s dolphins are ‘Endangered’ and face a high risk of extinction in the near future.

Dr Maas says that 110 – 150 Hector’s deaths a year is scandalous, given that the species will not survive if more than ten dolphins are killed.

Associate Professor of Zoology at Otago University, Dr Liz Slooten, has studied Hector’s and Maui’s dolphins for a quarter of a century and is the world’s leading expert on these species. She points out that “despite the report’s gloomy predictions, NIWA’s analysis is in fact optimistic, because it excludes dolphin deaths caused by recreational gill-netting and trawling. It also fails to consider fisheries mortality in North Island harbours, although Maui’s dolphins are caught there as well,” she says.

Dr Maas says, “The ‘zero net fishing’ measures considered in the NIWA report go well beyond any of the management options proposed in the Draft Threat Management Plan (TMP) and consequently are much more effective. The best option the TMP offers the dolphins would still allow gill-netting in several areas where the animals live, including Tasman Bay and Golden Bay, and does not effectively address the threat posed by trawling.

“While we have some reservations about the NIWA report; it stresses the urgent need to protect these animals far better than the TMP provides. The best the TMP would do is to give Hector’s dolphins less than a 50/50 chance of recovering to half their original numbers by 2050. This is in conflict with the Government’s statutory mandate to base its decision on the best available evidence and to ensure for Critically Endangered, Endangered or Vulnerable species become non-threatened as soon as possible, but at least within 20 years.

The Government is expected to announce its response to the TMP next month and has invited public submissions based on the information presented in the NIWA report [See Analysis of Final NIWA Report, Maas & Slooten attached (PDF)] by 20th April (

The NIWA report was presented on the 17th September last year, just three weeks after the publication of the TMP on 29th August. It is regrettable that these figures were not made public for six months.

“Relative to other international conservation problems, ensuring the survival of the Hector’s and Maui’s dolphins is easy. But unless the Government acts decisively and stands firm against industry pressure, it will only be a matter of time before the Hector’s and Maui’s dolphins become extinct,” Dr Maas says.


Analysis of Final NIWA Report, Maas & Slooten attached (PDF)


Notes to editors:
1. Care for the Wild International (CWI)
CWI is a conservation and animal welfare charity that funds practical projects around the world. We make areas safe from poachers, rehabilitate sick or injured animals and provide sanctuary for those who can not return to the wild.
We also act as a global voice for wildlife through research, education and advocacy, and expose animal cruelty and wildlife crime.

2. Hector’s Dolphins Facts

- Hector’s dolphins are classified as Endangered by the Red List of Endangered Species. This means that Hector’s are “facing a high risk of extinction in the near future”.
- Numbers have declined from 21,000-29,000 in the 1970s to less than 8,000 today.
- Commercial and recreational fishing is responsible for almost 70% of Hector’s dolphin deaths. Because not all deaths are reported, this is a minimum estimate.
- Other threats include boat strikes, pollution, sand-mining, coastal development and harassment.
- Existing protection measures have failed to halt the species decline. Hector’s dolphins will only be safe into the future if all threats of commercial and recreational fishing are removed.

3. Maui’s Dolphins Facts

- Maui’s dolphins are classified as Critically Endangered by the Red List of Endangered Species. This means that Maui’s dolphins are “facing an extremely high risk of extinction in the immediate future”.
- Only 111 Maui’s dolphins survive.
- There are just 25 breeding females left amongst about 60 breeding adults.
- Females only have one calf every 2-4 years and do not reach breeding age until they are 7-9 years old. These species’ potential for recovery is therefore extremely slow.
- Maui’s dolphins prefer shallow waters up to 100m deep and are therefore highly vulnerable to nets.

4. Images and footage
Images and footage is available at

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