Answers sought to dolphins’ deaths

The deaths of four vulnerable Hector’s dolphins – three of them calves – will be investigated after they were discovered on South Island beaches over the past two weeks.

The Department of Conservation (DOC) says three of the carcasses will be sent to Massey University in Palmerston North for the cause of the deaths to be determined.

The smallest dolphins in the world, Hector’s dolphins are only found in New Zealand waters and are considered nationally vulnerable, with a population of about 15,000.

Their North Island subspecies, the Ma¯ui dolphin, is critically endangered, with experts estimating that less than 60 of them are left.

DOC aquatic director Elizabeth Heeg said three of the dead dolphins were found in the last week.

A member of the public encountered the carcass of a Hector’s dolphin calf at Marfells

Beach in Marlborough on November 27, and reported it to DOC the next day.

On November 28, an adult Hector’s dolphin was found decomposing on a beach just north of Hokitika on the West Coast.

The third discovery was made on November 30 at O¯ ka¯ rito, also on the West Coast. This dolphin – another calf, Heeg said – was quite fresh, indicating it had likely been found and reported not too long after it had died.

A third calf had been found dead earlier on November 16 near the West Coast town of Hector.

Heeg said while it was too early to say what caused the deaths of the four dolphins, DOC was grateful for the public reporting them.

‘‘From the necropsies done by the Massey team, we can glean really valuable information about these species and the threats they face. When people are quick to alert us to discoveries of dead dolphins, however sad, it increases the volume and value of the information we can obtain.’’