New Zealand's Unique Dolphins Dying in Fishing Nets

WELLINGTON, New Zealand, May 4, 2006 (ENS) - Endangered Hector’s dolphins, found only in the coastal waters of New Zealand, have been dying in fishing nets during the past few months, the Department of Conservation reports.

As New Zealand's austral summer comes to a close, the agency says 19 Hector’s dolphin deaths were reported over the course of the season. Eleven of those were confirmed by pathology reports as being caused by fishing practices, or were reported by fishers who caught them accidentally while fishing.

“We are extremely grateful to the fishers who have reported these incidents to the Department of Conservation,” said Department of Conservation (DOC) Research and Development General Manager John Ombler.

Hector's dolphins, Cephalorhynchus hectori, are killed as by-catch in the New Zealand rig shark and elephant fish set net fisheries. Rig is one of the commonest species served as fish-and-chips in New Zealand, where it is sold under the name lemonfish.

Unique to New Zealand, Hector's dolphins are vulnerable to the fishing industry. About 7,000 animals are still found in New Zealand waters. (Photo courtesy DOC)

New Zealand's largest environmental group, the Royal Forest and Bird Protection Society, says the number of Hector's dolphins killed this summer was probably greater than 19.

“The actual number of deaths was much higher than the 19 reported, because many commercial and recreational fishers do not report deaths of dolphins caught in their set nets,” said Forest and Bird Advocacy Manager Kevin Hackwell.

Forest and Bird is urging the government to put in place its long-promised species management plans. “This is the world’s rarest marine dolphin. It is critical that urgent action is taken to improve management practices and implement conservation measures, such as marine mammal sanctuaries, before it is too late,” Hackwell said.

The Hector’s dolphin is the world’s smallest marine dolphin, as well as being the rarest marine dolphin on Earth. It has an extremely low reproductive rate, with females only reaching breeding age at about seven or eight years. Each female produces one calf every three to four years.

A subspecies of the Hector’s dolphin, the Maui’s dolphin exists on the West Coast of the North Island and it is now listed as critically endangered as classified by the IUCN-World Conservation Union. The South Island population remains classified as endangered.

“Maui’s dolphin is one of the few mammals found only in New Zealand. It is one of the world’s rarest dolphins making it is as precious a part of our natural heritage as the black robin or the kakapo.” said Ombler. Only an estimated 111 of these unique dolphins survive today.

Hector’s and Maui’s dolphins are seen close to shore and in summer they frequent shallow waters less than 20 meters (65 feet) in depth. They are characterized by their distinctive grey, white and black markings, short snout and rounded black dorsal fin.

New Zealand fishing vessel hauls about four tons of mixed fish species aboard. Dolphins can be caught in these nets although they are not a target species. (Photo courtesy Allan Ronald Dunford)

The government is working on a Threat Management Plan for Maui’s and Hector’s dolphins, that would be run jointly by the Department of Conservation and the Ministry of Fisheries with guidance from an advisory group consisting of a range of stakeholders.

Last week, an expert panel, involving a range of scientists and marine mammal experts, met to assess and evaluate threats to the Hector’s dolphins.

The overall aim of the plan is to better define threats to all Maui’s and Hector’s dolphin populations and how to best manage those threats, including those posed by recreational and commercial fishing.

Forest and Bird wants marine mammal sanctuaries to provide statutory protection to Hector's dolphin populations off Kaikoura, Curio Bay, Te-Wae Wae Bay, and the South Island West Coast. The group also recommends an extension of the existing Banks Peninsula sanctuary protecting Hector’s dolphins.

Maui’s dolphins off the North Island northwest coast should be protected with a sanctuary in that area, the group says.

The conservation organization is asking the government to impose a set net ban in areas of high importance for Hector’s dolphins in addition to those already in place at Banks Peninsula and northwest of the North Island.

Numbers of Hector’s dolphins are estimated at about 7,000, but have fallen by more than two-thirds since monofilament set nets were introduced in the 1970s. In 1970 there were over 26,000 Hector’s dolphins in New Zealand waters.

Nine species of dolphin are found around the New Zealand coast. All marine mammals in New Zealand waters are covered under the Marine Mammal Protection Act of 1978, administered by the Department of Conservation.