Tank ruptures on grounded ship off Tauranga

10:06 pm on 7 October 2011

A tank containing 100 tonnes of oil on a stricken container ship off Tauranga ruptured on Friday, spilling more fuel into the ocean and prompting warnings of a major environmental disaster.

Oil continues to stream northwards from the 47,000-tonne Rena which struck the Astrolabe Reef, about 12 nautical miles off the coast, about 2.20am on Wednesday.

The 21-year-old vessel was heading towards Tauranga from Napier carrying about 1700 tonnes of fuel. Among its cargo are four containers of the hazardous substance ferro-silicon.


Transport Minister Steve Joyce visited the ship on Friday and told Radio New Zealand's Checkpoint programme some oil has gone into the ship's keel, but some has also spilled into the sea.

The ship is half wedged on the reef and the other half is over deep water. Mr Joyce says there is a very real possibility the Rena will break up and the situation is likely to get worse before it gets better.

The minister says the ship is not in good shape and that, combined with the weather over the next few days, will make it very challenging to try to contain the situation. He warned more oil is likely to leak and residents should expect some to come ashore.

Maritime New Zealand on-scene commander Rob Service says a salvage operation is underway and expects attempts to pump fuel from the Rena to start on Monday. In the meantime, ships and equipment are being assembled on shore in case more of the oil on board spills.

The authority says there are hopes the dispersant Corexit 9500 may be proving more effective than initial assessments indicated and is undertaking further tests.

It is not known how far the oil has spread on Friday and the 1km exclusion zone around the ship may have to be extended.

The Bay of Plenty Regional Council is providing Maritime New Zealand with any resources needed and is very concerned at the oil threat.

Environmental threat

Maritime New Zealand pollution response service manager Andrew Berry told Radio New Zealand's Morning Report programme on Friday he was very worried about the environmental threat posed by the oil slick.

"It has the potential to be very, very serious indeed simply because of the age of the ship, the damage that she's sustained and the 1700 tonnes of heavy fuel oil on board.''

Teams of wildlife rescue staff have been sent to Motiti Island and Maritime New Zealand is also preparing to launch a shoreline clean-up in the event that oil reaches land. Shoreline assessment teams are also at Papamoa Beach to identify vulnerable areas and wildlife.

Mr Berry says four little blue penguins and two shags affected by the oil were rescued from Motiti Island on on Friday afternoon. The birds are being stabilised and treated by trained wildlife officers.

Maritime New Zealand says staff have done spot checks of beaches where members of the public have reported seeing oil, but none has been found so far.

It says reports of oil heading towards Tuhua (Mayor) Island marine reserve were incorrect.

Chris Battershill of Waikato University leads the Coastal Science research group in the Bay of Plenty and visited the ship on Friday. He warned there is a very real risk the situation will turn into an environmental disaster, particularly if the weather gets worse.

Professor Battershill says it appears there is quite a lot of internal leakage in the vessel and oil is coming out of the ship but "not at an alarming rate". However, he says that could change, depending on the tides.

But Tourism operator Graeme Butler, who runs a swimming with dolphins business, says the leak is already an environmental disaster.

Mr Butler says the breeding season is underway, there will be newly-born calves in the harbour and there are big colonies of blue penguins around Mount Maunganui near where the ship has run into the reef.

"Anything in spread over the surface is just going to severely compromise the plankton and then it'll compromise all the fish that feed ... on the surface."

Salvage 'a delicate operation'

Multinational firm Svitzer Salvage has been put in charge of refloating the ship. Spokesperson Matthew Watson says the work cannot be rushed, and getting the oil off the vessel would be a very delicate operation.

A naval architect was due to arrive in New Zealand from Holland on Friday and would calculate such things as whether the load on the ship needs to be lightened.

Significant oil spill incidents since 1990

  • Don Wong 529, Stewart Island, 1998 (400 tonnes of automotive gas oil)
  • Rotoma, Poor Knights Island, 1999 (approx 7 tonnes of oily bilge discharge)
  • Sea Fresh, Chatham Islands 2000 (60 tonnes of diesel)
  • Jody F Millennium, Gisborne 2002 (25 tonnes of fuel oil spilled)

Source: Maritime New Zealand