A Highland community is united in its opposition to a plan to transfer nearly nine million tonnes of crude oil a year between tankers in nearby waters, which are home to a precious colony of dolphins.

They fear the ‘catastrophic’ impact of an oil spill on tourism, the local economy and important environmental sites in and around the Cromarty Firth.

The Highland Council is also raising serious concerns.

As the Herald revealed last month Cromarty Firth Port Authority’s (CPFA) has applied for a licence to conduct the transfers just outside the mouth of the Cromarty Firth. No community council around the Cromarty and Moray Firth was informed, apart from by a small newspaper advert.

Highland Council officials say that despite being an official consultee, the first they heard of it was on December 28 when a consultation document was received to be returned by the end of this month.

The consultation has since been extended till February 8. The final decision will be taken by the Maritime and Coastguard Agency (MCA), not the Scottish Government.

Plans for ship-to-ship oil transfers in the Firth of Forth were ruled out by the area's harbour authority in 2008, but in the north it is the authority which is pursuing it. .

All 122 residents of Cromarty who attended a packed public meeting last night organised by the community council, voted against the plan. They can’t understand the need, when ship to ship oil transfers (STS) between tankers tied up at the nearby Nigg Oil Terminal jetty have been carried out safely for years.

The authority says there is uncertainty over the future of the Nigg terminal which is tied to the decommissioning of the Beatrice oil field.

But local councillors are to table a motion at the Highland Council, and the community council will object.

The port authority refused an invitation to attend the meeting, although met members of the community council privately.

Five mooring points for tankers have been earmarked beyond the Sutors headlands at the Cromarty Firth entrance. The closest is about a mile from the shore. This area is just in the larger Moray Firth but under CFPA control.

It is regularly visited by the North Sea’s last resident colony of bottlenose dolphins. Wildlife spotting boat trips, local fishing boats, leisure craft and cruise liners would also have to observe a 500m exclusion zone round the tankers, projected to be there for 24 hours, four times a month.

More than 3,600 people worldwide have signed two petitions opposing the port authority’s strategy.

Bob Buskie, the port authority's CEO said: "During the past two weeks we have had a number of very constructive meetings with representatives from various local communities, as well as other interested parties. We understand their concerns and have explained the many environmental safeguards that would be put in place if the licence was granted.

Changes in the law in 2011 meant that STS needed a licence to ensure they were strictly regulated.

But Dr Greg Fullarton, and environmental consultant who lives locally and is advising the community council, said “The people of Cromarty clearly have no confidence in the port authority’s modelling which takes no account of the risk of ships colliding; of the fact that the wind can blow from the east up the firth for days; or of the strong tides. It bases its calculations only one to tonne of oil escaping despite 180,000 tonnes are planned for every visit.”

Highland Council’s Director of Development and Infrastructure Stuart Black said the council's draft response raises a number of concerns. The final response would be returned before the extended deadline but it could only go before councillors on February 17

“We have also been liaising with Scottish Natural Heritage the MCA and Marine Scotland over the last week or so and the Leader and senior members are meeting with the Port Authority on Monday." The widespread concerns raised in the local community had been noted.