Ships told to slow down for whales

Ships will be asked to slow down and boaties put on watch to save a whale species that calls the Hauraki Gulf home.

Marine scientists have confirmed that the waters off our biggest city have a resident population of Bryde's whale.

But there may be as few as 50 and their status is threatened by vessel strikes - chiefly big ships coming and going from the Port of Auckland.

New Zealand's Bryde's whale population is concentrated in and around the country's busiest shipping lane and the Department of Conservation lists its status as nationally critical - its highest threat ranking.

Research by Auckland University masters student Stephanie Behrens suggests ship collisions are the biggest killer of the Bryde's although more information is needed about the size of the population.

Ms Behrens established that ship strikes were the probable killer of at least a third of the 39 Bryde's found dead in the gulf in the past 20 years.

"If the population at any one time is only around 50 animals then two deaths a year is not very good."

Ms Behrens' supervisor, marine biologist Dr Rochelle Constantine, says it's likely that many more whales have been killed than the recorded deaths. In more than half of those found, no autopsy was carried out to establish the cause of death.

International Whaling Commission conservation committee chairman Alexandre de Lichtervelde attended an Auckland meeting this week to discuss the plight of the Bryde's.

He says the presence of a whale population on the doorstep of a large city is of international significance. The meeting heard that the chances of a whale being killed by a ship reduces to 50 per cent if ships travel below 12 knots, and 25 per cent below 10 knots.

But attempts overseas to force ships to reduce speed where whales are present have met resistance from shipping companies.