Authorities have warned heavy fuel oil spilt in Tauranga Harbour earlier today could come ashore on beaches, as rain and high winds hamper a clean-up effort.
The spill occurred earlier today as a ship was bunkering at the Port of Tauranga.
An oil slick was spotted by Tauranga Bridge Marina staff, who contacted Bay of Plenty Regional Council's Pollution Hotline and the Port of Tauranga.
Adrian Heays, the regional council's oil spill on scene commander, said severe weather was hampering oil retrieval, with some booms proving ineffective in the high winds and heavy seas.
It is believed an oil line on a berthed ship had leaked and oil spilled near berths further along.
Once the spill was spotted, the bunkering was stopped and responders were attempting to get under the wharf to fix the leak.
"At this stage we don't have any idea how much oil was lost," Mr Heays said.
"This means there could be oil coming ashore on beaches, and on boats."
The spill occurred on an incoming tide, and the tide had now turned, which could mean the oil would be taken out to sea.
However, the threat is understood to be incomparable to that which came from the
grounding of the MV Rena off the coast of Tauranga in 2011.
So far, four streams had been spotted heading towards the railway bridge."We have staff working on it, and have notified Maritime New Zealand," Mr Heays said.
"We would appreciate people who spot oil on their boat or on beaches to contact the Regional Council's Pollution Hotline on 0800 884 883 so we can determine where the oil is spreading to."
The incident comes after the vessel Sea Star Emperor spilled 20 litres of heavy fuel oil into the Port of Tauranga in August.
Most of the oil was collected around the bunkering connection, and only about one litre of oil went into the water.
A few months earlier, the German owners of the container ship Liloa have been fined $30,000 for spilling 1000 litres of heavy fuel oil into Tauranga Harbour.