A fishing vessel that struck rocks off Stewart Island on Friday night, spilling diesel from a ruptured fuel tank, has berthed in Timaru for assessment.
Environment Canterbury will monitor the Sureste-700 during its stay.
Regional harbourmaster Jim Dilley says oil spill booms will be placed around the damaged area in case of any further discharge.
About 20,000 litres of diesel has been pumped out of its tank.
Mr Dilley says once the extent of damage is known, the trawler will be sent to Lyttleton for repair.