The Department of Conservation’s updated Māui and Hector’s Dolphin Incident Database reveals a Māui dolphin and a Hector’s dolphin, both dead in February. These deaths are devastating for the dolphins and their human supporters.

The Hector’s dolphin killed by a commercial fishing net near Kaikoura was a female, and her body was thrown overboard. This was the fourth female Hector’s dolphin reported killed off Kaikoura since the roll out of cameras began in October 2023.

The Māui dolphin death will hit the population particularly hard, as Māui dolphin numbers are thought to be lower than 50 individuals over one year of age. The cause of death is not known though the dolphin’s body “had a series of intersecting linear lacerations of varying length, forming a 'criss-cross' pattern.”

When dolphins are killed in fishing nets, they often suffer from lacerations of this nature, but the decomposed body means scientists are not yet concluding a cause of death.

Emeritus Professor Liz Slooten is a world expert in Māui and Hector’s dolphins. She says “The linear lacerations could be gillnet marks, which are very distinctive (at least in a dolphin that is not severely decomposed). Or they could be tooth marks from the mother trying to disentangle her calf from a gillnet. Or they could be knife marks from the person who found the dolphin in their net and either had trouble removing it from the net or tried to hide the evidence. Or they could have another cause altogether.”

Christine Rose is the founder and Chairperson of the charity Māui and Hector’s Dolphin Defenders. She says “DOC will need to make the photographs public, so that people like Professor Slooten and other experts at distinguishing these kinds of markings can determine the cause.

Every dolphin’s life matters and no dolphin should be killed in a net.”

Māui dolphins, including calves, were seen in Port Waikato swimming around legally set nets several times last summer. Rose says “We might never know if the juvenile male (last year’s calf?) was killed by those nets. But we do know that must be avoided in the future. Māui and Hector’s dolphins need protection throughout their range, and that includes river mouths such as Port Waikato, as well as in Kaikoura.”

At least 24 Hector’s dolphins have been reported killed by the fishing industry since the roll out of onboard cameras began in October 2023. They include females pregnant with female calves. “So the fishing industry is killing future generations as well”, says Mrs Rose.

“Māui and Hector’s dolphins must be protected throughout their range. That’s out to 100m deep or 20 nautical miles offshore and including harbours” says Dr Slooten. That’s a view shared by leading international bodies. The International Whaling Commission has called for full protection for Māui dolphins in particular.

Yet the Government is proposing even weaker fisheries laws. That’s why imports of fish from NZ into the US should also be banned, according to a Dolphin Defenders court case currently underway.

“New Zealand isn’t doing enough to ensure Māui and Hector’s dolphins survive the extinction crisis caused by the fishing industry. These deaths would be unacceptable under US laws. This country must do better. Action is needed now”, says Mrs Rose.

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