Attempts to disperse the oil slick from a grounded container ship off Tauranga using chemicals have proved ineffective.
Maritime New Zealand national on-scene commander Rob Service said initial tests had indicated that chemical dispersants were working to dilute a 5-kilometre slick spreading from the 235-metre vessel Rena.
However, further analysis showed that was not the case and officials were now considering other options.
That might include different dispersants, but could also mean an “on-water” recovery operation, where specialist equipment is used to scoop the oil from the surface of the water.
“We will have shoreline assessment teams on Papamoa Beach tomorrow, doing pre-clean surveys, which means identifying vulnerable areas and assessing clean up options,” Mr Service said.
The Rena has been stranded since crashing into the Astrolabe Reef, about 7km north of Motiti Island, about 2.30am yesterday.
Earlier today, Transport Minister Steven Joyce said the situation was worse than first thought.
There was a “significant amount of oil” and the vessel could break up due to its “precarious” position on the reef.
Earlier Service said that an aerial survey had confirmed an oil leak from the ship was deeper than expected.
”It’s a thicker layer than first thought,” Service said.
Four birds have been found dead near the slick. It is not yet known what species the birds are.
Service said the spill had spread in a narrow band about 5km from the ship to the northwest.
The leak was from extensively damaged fuel pipes rather than a fuel tank although the equivalent of one tank’s worth of fuel was thought to have leaked from the ship.
It was unknown exactly how much this might be as there was no standard fuel tank size on such vessels, although the Rena was carrying 1700 tonnes of fuel when it struck the reef.
“We are not aware of any actual breaches in the fuel tanks. However, because of the extensive damage to the vessel, it is difficult to determine accurately what the scale and scope of the damage is. The crew are working to prevent further leakage.”
Maritime NZ also today issued legal notices to the Rena’s owners under the Maritime Transport Act 1994 classifying it a hazardous ship and instructing its owners, shipping line MSC, to appoint a salvor.
This does not put MNZ in charge of the salvage but gives it the ability to take control if necessary.
Salvage company Svitzer will manage the salvage operation and went aboard the ship earlier this evening.
Service said he had spoken to the captain of the vessel, but not discussed how the grounding had happened. He said the crew were ”under a great deal of stress and pressure” and plans were being made to evacuate them from the ship if necessary.
A wildlife response team will tonight set up two bases in an attempt to rescue further contaminated birds near the stranded cargo ship.
Oiled Wildlife Response Coordinator Kerri Morgan, from Massey University, said the team has now activated its response plans.
The team’s equipment arrived in Tauranga this afternoon. An oiled wildlife response centre will be set up at the Tauranga Wastewater treatment plant and a further base will be set up on Motiti Island.
Morgan said around 20 people were expected to be settled on the island tonight, ready to begin work at first light tomorrow. The team on the island will include veterinarians.
A team with experience in the capture and treatment of oiled birds would be undertaking beach searches on Motiti Island and the Maketu Peninsula tomorrow morning.
At-risk species near the spill include little blue penguins, shearwaters, New Zealand dotterals and diving petrels. A seal colony was also at risk.
Massey University’s Brett Gartrell, part of the oiled wildlife team, said birds that were covered by the oil had to be rescued and washed or they would die.
“The oil breaks down the thermal qualities of the feathers. The birds normally have a down jacket to keep them warm but the oil stops that from happening so they become very cold,” Gartrell said.
“It also waterlogs the feathers, meaning the birds start to sink and can drown.”
It could also make the birds sick, as they tried to clean their feathers and ended up swallowing the oil, which affected their livers and kidneys.
“The birds cannot survive without intervention. They will die if left in the wild,” Gartrell said.
Mr Service said reports of oil heading towards Tuhua (Mayor) Island, which is a marine reserve, were incorrect.
– Angela Cuming, Kirsty Johnston and Paloma Migone