New Hector’s dolphin deaths no surprise
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.
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
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.”