Heavy fuel oil continues to leak from the stranded ship Rena with a 5km slick heading northwest towards the Department of Conservation marine and birdlife reserve Mayor Island.
National on Scene Commander Rob Service has despatched a light aircraft to monitor the slick and its threat to the island.
Rena remains stuck fast at Astrolabe Reef.
“A plane is up as we speak assessing where the fuel is and where it isn't,” he said during a press conference held this afternoon at the Mount Maunganui Cosmopolitan Club.
“Rena has been declared a hazardous ship. As far as I know the heavy fuel oil is coming from a breach in the pipework.”
Rena ran aground on Astrolabe Reef at about 2.20am on Wednesday and has leaked fuel since.
“It is uncertain at this stage how much fuel has leaked,” says Rob.
Initial estimates of how much fuel was onboard stated about 1700 tonnes, but at today's press conference this was revised to about 1500 tonnes.
The slick is a narrow band.
Rob says stopping the leak is difficult as it is intermittent and likely sourced from multiple places.
He says the fuel tanks are secure and the leaks are from pipework.
The focus of the combined response team, which includes Maritime New Zealand, Department of Conservation and Bay of Plenty Regional Council, is containment of the oil.
"The aim of the response is to minimise the impact of spilled oil in the Bay of Plenty.