A fishing boat aground on rocks near Banks Peninsula is leaking diesel and hydraulic oil close to a marine reserve.
The 25-metre-long Austro Carina activated its emergency beacon at 9:38pm on Sunday.
The four crew members made it to shore and were winched aboard a helicopter to safety.
Maritime NZ has opened an investigation.
The area is home to protected tāonga species such as kororā/little blue penguin, hoiho/yellow-eyed penguin, kekeno/NZ fur seal, upokohue/Hector's dolphins, and several other seabird species.
The Canterbury Regional Council is working to contain the spill - its on-scene commander is Emma Parr.
Parr spoke to Ingrid Hipkiss.