2018 was a bad year for Hector’s dolphins. Twelve of 16 reported deaths with a known or likely cause of deaths were the
result of fishing. In January 2018, five Hector’s dolphins died in a single gillnet off Banks Peninsula. The following
December, a trawl net killed a further three in the same area, and a fourth off Timaru.
“The number of dolphin deaths that are reported are of course only the tip of the iceberg. Over the past 40 years,
fishing nets have killed all but a third of all Hector's dolphins and more than 95 percent of their closely related
North Island cousins, the Māui dolphin.
“We have known what kills Māui and Hector’s dolphins for many years, yet overall a staggering four fifth of their
habitat is unprotected against trawling and the use of gillnets,” says Thomas Tennhardt, Chair of NABU International.
“Gillnetting and trawling are the main causes of dolphin bycatch around the world,” explains Tennhardt. “However, the
fishing industry has always denied that trawl nets kill Hector’s and Māui dolphins for decades. Together with scientists
in New Zealand and elsewhere, we urge the government in the strongest possible terms to finally protect its only endemic
dolphins from these fishing methods, so they can survive.”
“Looking at where the dolphins live, and where gillnetting and trawling are still permitted, there is nothing surprising
about these devastating but all too predictable deaths,” says Otago University dolphin expert Prof. Liz Slooten, who has
studied Hector’s and Māui dolphins and charted their decline for over 30 years. “It is literally matter of when, not
if.”
“Like in Māui dolphins, Hector's dolphin populations are becoming more and more fragmented and isolated, says Slooten.
“One after the other has dwindled, endangering the species as a whole. Several populations have become incredibly small.
Only about 45 Hector's dolphins live in Porpoise Bay in the Catlins, 42 off Otago, two or three hundred in Te Waewae Bay
on the south coast, and about 200 off the north coast of the South Island.”
“Hector's dolphins used to be very common off Brighton, south of Dunedin,” adds Slooten, “but are very rarely seen there
now. Likewise, Raglan surfers used to see Māui dolphins almost every time they went out, often in large groups of 30 or
more. Nowadays they are very rarely seen, and if so, only in small groups. Whanganui, the Kapiti Coast and the east
coast of the North Island have very occasional sightings, but the dolphins used to be much more common there.”
The first Hector’s and Maui Dolphin Threat Management Plan (TMP) was published 12 years ago, in 2017. It offered three
protection options for public consultation, none of which included habitat-wide bycatch protection. The TMP was to be
reviewed after a period of five years but is now six years late.
“We strongly encourage the government to finally, bring Hector’s and Māui dolphin protection into line with
international scientific advice and with reality during the current TMP review,” says NABU International’s Head of
Endangered Species Conservation, Dr Barbara Maas. “This means creating a contiguous protected area across their habitat
to a water depth of 100 metres, in which commercial and recreational gillnetting and trawling are prohibited.”
“The international scientific and conservation community is at a loss as to what the Ministry of Primary Industry and
the Department of Conservation are waiting for. There is only one way to ensure New Zealand’s and Hector’s dolphins have
a future,” adds Maas. “If the government is determined to wait for support from the fishing industry, the dolphins’
extinction is inevitable.”