Anyone wishing to volunteer should call 0800 645 774 or email iccrena@gmail.com with ‘Volunteers – 1 for all’ in the subject line, full name, contact number and relevant experience.
What you need to know:
* A large crack has been spotted in the side of the stricken container ship
* PM says ship could break up
* Soldiers called out to clean up beaches
* Ship's captain granted name suppression in court
* About 70 containers have fallen off the ship
* Masks may be issued to Tauranga residents near toxic oil leak
* Port of Tauranga is on standby to shutdown operations
* Environment Minister Nick Smith says this is NZ's "worst maritime environmental disaster"
A large fracture has spread all the way around the hull of the stricken cargo ship Rena and officials say it is now just a matter of time until the ship breaks into two pieces.
A Maritime NZ spokesman said the Rena is now only being held together by its internal components.
"We have to look at reality. It is obviously being moved in the sea, the back half of the ship has been under extreme pressure for days."
Aerial footage taken by TVNZ shows the hull of the vessel grounded on Astrolabe Reef off the coast of Tauranga has cracked open.
Prime Minister John Key this afternoon said the substantial fractures in the vessel made it much more likely to break up on the reef.
He defended the amount of time it had taken the Government to respond to the disaster, saying the operation had been carried out as swiftly as possible.
"I can understand people wanting to believe that this could be fixed more quickly. But the Government doesn't hold a magic wand...
"We are moving as quickly as we can."
Salvage team captain John Walker said the condition of the ship was deteriorating.
Three tugboats were ready to head to the Rena in an attempt to pump more oil out if weather conditions allowed the operation, he said.
A Maritime New Zealand spokesman said it was possible a fuel tank could be ruptured if the Rena broke up - allowing more oil to leak into the sea.
However, salvage teams had capped the tanks before leaving the vessel and it was possible no more oil would escape, he said.
The aerial footage also showed a container from the vessel emitting bright blue smoke as it floated in the ocean.
Hundreds of dead birds have been found dead on the beaches around Tauranga as the oil from the container ship continues to cause environmental havoc.
Maritime New Zealand is considering issuing face masks to people living near beaches affected by the oil and New Zealand soldiers are now clearing up the Tauranga beaches affected by oil from the stricken container ship Rena.
The "world's best" navy architects are preparing reports on the damage to the Rena, while the ship's captain - who turned 44 on the day of the accident - has had his name supressed during a brief appearance in court.
Wildlife killed
Environmental response teams have found 200 birds killed in oil spilled from the stricken Rena cargo ship off the coast of Tauranga.
They are expecting that death toll to rise again sharply later today.
Department of Conservation spokesman Mike Patt said dead seabirds, including blue penguins and shags, were still picked up by teams trawling through oil on Bay of Plenty beaches.
Many had died of hypothermia brought on by being soaked in the oil, he said.
"It's like being in the mountains and losing your coat really."
A wildlife treatment facility at Te Maunga is treating 26 oiled birds, Mr Patt said.
Defence Force goes to work
Soldiers from the Defence Force have swung into action, with the start of beach cleaning work at Papamoa this morning.
The group of 80 soldiers, working in teams of 10, began this morning after undergoing training in how to safely handle the oil washing up on the beach.
The Defence Force planned to have more than 150 soldiers working on the beaches this afternoon.
Ship deforms
Further out to sea, metal plating on the stricken cargo ship Rena - which is listing at 18-19deg with its bow firmly wedged firmly on the Astrolabe Reef - has begun deforming.
New Zealand salvage manager Bruce Anderson this morning told media the hull of the Rena had started to bend amid rough seas and high winds.
Top naval architects were preparing reports on how badly the vessel had been damaged, he said.
He would not confirm whether the vessel was expected to break up until those reports were prepared.
An overflight this morning revealed the ship was moving around in 4m swells but there were no new signs of oil leaking.
Salvage crews would board it as soon as they could but that would not be until it had stabilised.
"The last thing that we will do is put people at risk by putting them on to a vessel which is in a dangerous state,'' Mr Anderson said.
"The vessel still hasn't stabilised because the weather is so rough and the swell is still lifting and dropping the vessel.''
MNZ had been criticised for not keeping residents well enough informed but Maritime NZ director Catherine Taylor said it had launched a stronger community liaison programme.
That included keeping the public informed on health risks, and a public health team was working in the incident command centre.
"This is a very, very fast-moving game for everybody,'' she said.
Masks may be needed
Maritime New Zealand is considering issuing face masks to people living near beaches affected by oil from crippled cargo ship Rena.
Ms Taylor was this morning asked about the smell of oil in sea spray on the beaches.
"The way in which the oil has moved through the water, and how quickly it has moved, will be causing that,'' she said.
"We are concerned and we will be considering issuing masks to people.''
Containers reach Motiti Island
Meanwhile containers spilled from the Rena have reached shore at Motiti Island off the coast of Tauranga.
About 70 containers fell from the vessel amid heavy seas last night.
Maritime New Zealand said some containers had washed ashore on Motiti Island this morning, but could not confirm how many.
The agency said the eleven containers containing hazardous substances are still on the vessel and are not among the up to 70 estimated overboard.
The ship was listing at 18deg - sparking a navigation warning about the possibility of falling and submerged containers - after being at 11deg for much of the past week.
Maritime New Zealand this morning confirmed the Navy ship Endeavour had reported the loss of the containers.
More containers were expected to fall off as five metre swells and 30 knot winds continue to batter the stricken vessel today, a Maritime spokeswoman said.
"They more it's tilting the more they're just going to keep tipping off... The ones at the top are coming off first."
Simon Boxall, from the National Oceanography Centre at the University of Southampton, said the fallen containers would be a hazard to shipping.
They often float just below the surface of the water and are difficult for ships to track, he said.
"There should also be concern as to the contents of the containers. This could range from household good to chemicals."
Mr Boxall said the main concern for authorities should be securing the containers.
Police warn public over containers
Police have threatened to prosecute anyone found taking goods from containers that spilled off the grounded cargo ship Rena overnight.
Inspector Karl Wright-St Clair said the containers remained the property of the ship owners.
He said people have a statutory responsibility to notify authorities about their location.
They would be dealt with by police if they were caught interfering with the containers, he said.
"I can't reiterate enough, please do not attempt to open any of the containers. Not only do they remain the property of the original owners or insurers, they may contain hazardous material and need to be dealt with carefully and appropriately."
The Rena started moving in 4m swells yesterday - forcing an emergency evacuation of the crew.
It was revealed yesterday that maritime officials turned down an early offer to have two barges help remove oil from the ship.
Hundreds of tonnes of oil leaked from the hull yesterday.
Our reporter at the scene has described the beaches he's seen today as "coated black".
Port of Tauranga ready to shut
Port of Tauranga is ready to shut down its operations ahead of a busy cruise ship season if containers spilled from the stricken cargo ship Rena threaten incoming vessels.
The Bay of Plenty harbour master has warned vessels against travelling in the area between the stranded ship and nearby Motiti Island.
That has raised fears for the operations of Port of Tauranga, which is set to host 58 vessels, including six cruise ships, this week.
Its chief executive Mark Cairns said the containers could be dangerous to incoming vessels if they moved to a different area or if officials "lost track of them".
The oil spill was a "nightmare" scenario for the port and the wider Bay of Plenty, he said.
"It's just an absolute nightmare. I feel sick about it. It's really heartbreaking to look out at the beach."
Most of the containers spilled so far had fallen into an area south east of the Rena, near Motiti Island, Mr Cairns said.
He said the position of the containers could change quickly with changing weather conditions and currents.
"It's a really dynamic situation. It all depends on where the containers go."
The first large cruise ship of the upcoming summer season arrived at the Port of Tauranga at 8am.
Rena is grounded about 22 kilometres from the Mount Entrance to the port.
Opinion: A major bank suggests there's a 60% chance of a US recession soon.