New Zealand’s Hector’s dolphins are the rarest dolphin species on earth. Entanglement in gill and trawl nets has depleted numbers by about three quarters and caused them to fragment into four genetically isolated populations. The North Island population, a subspecies known as Maui’s dolphins, numbers just 111 animals, is critically endangered and, with less than 30 surviving adult females, perilously close to extinction.

An estimated 110-150 Hector’s dolphins die in commercial gill nets each year. This level of mortality is ten times more than the species can sustain from all causes. New research from the University of Otago just confirmed that that despite new regulations introduced last year, fishing nets continue to kill Hector’s dolphins faster than they can breed.

After more than two years of public consultation, the newly introduced measures partially restrict gill netting and trawling in known dolphin habitat. British wildlife charity Care for the Wild International’s (CWI) Chief Executive, Dr Barbara Maas a former employee of New Zealand’s Department of Conservation says, “In view of the dolphins’ precarious status, marine scientists and conservation groups had called for full protection from entanglements to facilitate recovery. Fishing industry bodies, on the other hand, strongly opposed these restrictions and deny that Hector’s dolphins are in decline as a result of entanglement. In an effort to overturn the new protection measures they even challenged the new fishing laws in court.”

To test the effectiveness of the new measures and to assess whether currently unprotected area may have to be considered as no-fishing zones, the government also required some fishing boats to carry independent observers. “NIWA scientists calculated that robust estimates of dolphin net deaths demand around 80% observer coverage”, says Dr Maas. In reality however, the government’s observer programme only reached about four percent. New research from the University of Otago has now confirmed that if 110-150 dolphins die as a result of entanglement, only between zero and one dolphin death would be observed at this low level of observer coverage. There is therefore no evidence to suggest that the number of dolphins killed this year is lower than before the new protection measures were introduced. This means that the number of Hector’s dolphins killed is still ten times higher than what is biologically sustainable.”

In May, government observers witnessed one entangled Hector’s dolphin off the cost of Kaikoura. “The animal died in an area where dolphins are not protected, because the industry insisted that entanglements were highly unlikely here”, says CWI’s Barbara Maas. “Despite this error of judgement, the industry maintains that this death is proof that only few dolphins are dying. The new protection measures, it argues, are therefore unnecessary. But with low levels of observer coverage, this is exactly what we would expect to find and the industry’s conclusions are therefore not supported by fact.”

“The fishing industry is once again trying to block urgently needed conservation measures for a species that is teetering on the brink of extinction. It does so to save New Zealand’s gillnetting industry, which contributes less than half of one per cent to the country’s fishing revenue. In doing so, it threatens to bring down New Zealand’s “100% Pure” reputation as an environmentally responsible nation and a reputable tourism destination.”

The court’s decision on the fishing industry’s challenge of the new protection measures is expected before 1st September.

ENDS

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