More oil could wash ashore at Papamoa Beach from the Rena as the ship faces its biggest storm yet since grounding on the Astrolabe Reef on October 5.

The ship is in a vulnerable state with a crack in its hull having widened during the last week – notably during the stormy weather.

The crack on the Rena is considerable. See video from the press conference today of MNZ salvage unit manager Kenny Crawford talking about it. Photo: Maritime New Zealand/Ross Brown.

Salvors are working to pump the last remaining oil from the vessel after late last year pausing pumping operations after they had removed over 1000 tonnes of heavy fuel oil.

Most of the oil to leak subsequent to this pumping operation was of a lighter nature and not the thick, black oil generally associated with marine spills.

The second environmental threat posed by the storm to the Rena wreck is what will occur should the vessel completely separate in two and a piece float off the reef.

At a press conference held at the MNZ incident control centre on Cameron Road today, the organisation's salvage unit manager, Kenny Crawford, said his team is ready for this.

'We do have a plan in place and are ready to respond.

'We have had a number of other bad weather events and we remain ready to respond, but we have to wait and see.”

The tug Go Canopus remains on standby to tow part of Rena to shallow waters if the ship breaks up.

MNZ salvage unit manager Kenny Crawford says the condition of the ship has deteriorated during the last week and it will depend on where the ship breaks up as to how his unit will be able to respond.

'You can see the condition of the vessel is deteriorating – a week ago you could step from one part of the ship to the other, now you can't do that.”

However, Kenny says both parts of the ship are firmly grounded on the reef.

It is now three months to the day since the ship ran aground on Astrolabe Reef on October 5 carrying 1368 containers.

Water is leaking into the ship from the top deck. Photo: Maritime New Zealand/Ross Brown.

So far 372 containers have been lifted off the ship, leaving 898 still onboard and a further 98 lost overboard during storms.

The Oiled Wildlife Centre in Te Maunga, which once housed more than 400 oiled birds, has been demobilised and the remaining 25 oiled birds are now being treated at Massey University in Palmerston North.

Wildlife responder Helen McConnell says a small team remains working on Motiti Island and in Tauranga to stabilise any new oiled wildlife before they are transported to Palmerston North.

Since January 1, Helen says they have received six oiled penguins and two oiled petrels.