The work of cleaning oil-smothered birds is more heartbreaking than satisfying, say volunteers, as the recorded death toll outweighs the survivors by four to one.
The Oiled Wildlife Response Unit in Mt Maunganui was set up within 12 hours of the container ship Rena striking the wildlife-rich Astrolabe Reef, as marine scientists anticipated a large-scale ecological disaster.
A week after its opening, the unit is holding 92 animals, the majority of them seabirds, but also five fur seals.
A volunteer at the centre, doctoral student Baukje Lenting, has cleaned the viscous ship oil from around 20 birds.
"It's hard on all of us," said the 27-year-old. "I get to start with a black, sticky penguin and turn it into a little blue penguin ... but the hard work is being done in the post-mortem tent.
"We know that these [deaths] are just the tip of the iceberg."
As the oil-covered animals are brought into the unit, a collection of vets, ornithologists, and students single out the ones which are physically strong enough to survive.
"Any handling is stressful for them, but it's not something we can avoid. So we have to pick the strongest ones. So far, those birds have done really well."
Ms Lenting said the oil was too thick to remove from the birds by simply scrubbing, so she bathed little blue penguins in warm canola oil, which broke down the fuel. They were then washed with a detergent in water heated to their body temperature.
She said the birds took three to five days to preen the detergent from their bodies and return to their natural state. But because their habitat is tainted by oil, they will have to remain at the wildlife centre for months.
"Most of them have really strong homing instincts. So they would just fly straight back into the slick," Ms Lenting said.
While tents were now teeming with petrels, shags, penguins and shearwaters, lines of oil-choked dead birds were also a common sight at the centre. Nearly 400 birds have been found dead, a figure which Forest and Bird believes to be a fraction of the actual death toll.
Seabird conservation advocate Karen Baird said many of the oil-covered birds would have sunk at sea, and some of the lightly oiled birds could have flown back to their colonies.
Many seabirds were breeding on offshore islands in the Bay of Plenty and any impact on the parent birds would also affect their chicks.
Ms Baird said that if the parent birds had swallowed oil, both they and any chicks they fed were likely to die or be harmed.
Thirteen dotterel have been removed from estuaries in Tauranga after the highly endangered birds - only 1700 remain - were found with oil on their legs and breast.
Five oiled seals were being treated at the centre, and Forest and Bird cited concern for whales, dolphins and coastal fish in the Bay of Plenty.