At least 90 birds may already have been affected by oil spilling from a cargo ship stuck on a Bay of Plenty reef and rehabilitating them could ultimately cost millions of dollars for the shipping company responsible.
The wildlife treatment facility at Te Maunga has nine oiled birds, but with oil already washing up on Mount Maunganui beaches the number is expected to rise.
Wildlife centre director Brett Gartrell said the nine birds taken in by the facility were unlikely to be the only ones affected.
He said some estimates suggested only 10 per cent of oiled birds were rescued. This could mean that 81 other oiled birds might already have died.
"There are lots and lots of seabirds in the area. This is a really rich area. There's a very high possibility we'll be dealing with a large scale,'' he said.