Members of the public have been urged to avoid using the water and beaches within Poole Harbour in Dorset after an oil leak led to a major incident being declared.

Poole Harbour Commissioners (PHC), which regulates activities in the harbour, said a leak occurred at a pipeline operated by gas company Perenco, under Owers Bay, on Sunday.

Perenco, the UK’s largest onshore oil field, said a “small” amount of reservoir fluid (consisting of 85% water and 15% oil) escaped from its pipeline and that, as of late on Sunday night, some of it had already been recovered.

PHC said: “Early indicators are that the surface slick is already dispersing.”

Poole Harbour, Dorset
The pipeline leak occurred at Poole Harbour in Dorset (Alamy/PA)

The commissioners added that Perenco had reported “no risk” of further leakage after the pipeline was shut down and booms were placed on either side of the leak to minimise pollution.

A further assessment will be made early on Monday morning regarding the clean-up operation, PHC said.

Jim Stewart, PHC chief executive, said that it was carrying out an examination of the harbour involving 60 people, helicopters and drones with the aim of understanding the extent of the spill with a situation update expected later in the morning.

He told the PA news agency: “All of the teams will be feeding information into the harbour commissioners and then we will know how serious the spill is and where we should allocate our resources.

“We are collecting reports and we haven’t had many reports in so far of any serious pollution in any parts of the harbour but it is early days and it is a huge harbour.

“It appears some of the spill has dispersed and Perenco feel they stopped a lot of it with the booms at the point of the leak.”

Mr Stewart said the PHC would be liaising with the Maritime and Coastguard Agency about the use of its pollution containment equipment if required.

He added: “We have an oil spill resource centre with lots of equipment in Poole which we are able to utilise.

“Once we have the situation report later this morning we will make a decision on what assets we want to deploy.”

Anyone who came into contact with the spill was being urged to “wash immediately with soap and water”.

Group of wigeon, Mareca penelope, feeding on saltmarsh in Poole Harbour, Dorset
A group of wigeon, Mareca penelope, feeding on saltmarsh in Poole Harbour (Alamy/PA)

Approximately 200 barrels of reservoir fluid were released into Poole Harbour after the leak occurred at the Wytch Farm oil field in Dorset on Sunday.

Conservative MP for Poole Sir Robert Syms said he and neighbouring South Dorset Tory MP Richard Drax have asked the Government to take an urgent question in the Commons on Monday about the incident.

According to Poole Tourism, Poole is Europe’s largest natural harbour and a site of nature conservation, with many international protections in place.

The harbour is also a Ramsar site which recognises wetlands of international importance, particularly for wildfowl, a Site of Special Scientific Interest (SSI) and a Special Protection Area (SPA).

Franck Dy, Perenco UK’s Wytch Farm general manager, said: “Any spill is an extremely serious matter and a full investigation will be launched to ascertain what happened in Poole Harbour.

“It is important to stress that the situation is under control, with the discharge of fluids having been stopped and the spill is being contained.”

The firm confirmed a clean-up operation is under way.

Philip Broadhead, leader of Bournemouth, Christchurch and Poole Council, said in a statement: “The Wytch Farm oil field in the Purbecks has been operating since 1979 and is one of the largest onshore oil fields in Europe.

“We have today been advised by the operators that there has been a leak from the facility. Whilst this has been contained, we are told that oil has escaped into the water and surrounding area.

“We are liaising closely as part of long-established mechanisms with a variety of parties as this situation unfolds.”

Speaking on BBC Radio 4, he added: “I am clearly angry and disappointed, this the second-largest natural harbour, award-winning beaches, very delicate ecosystem… The natural reaction is to be very worried.

“What we are hearing is that it’s a small leak of reservoir fluid which is about 85% water and 15% oil which was caught, fortunately, quickly.

“They stopped any further leaks and they are already trying to get some of it back.

“One hopes that at the moment we have avoided any real disaster but the early indications are that the surface slick is already dispersing.”

An Environment Agency spokesman said: “We have received reports of a large amount of oil in Poole Harbour and we are supporting the port authority and other partners in responding to this incident.”

Alice Harrison, fossil fuels campaign leader at Global Witness, said: “Whilst the extent of the damage is still unknown, there is no doubt that a huge spill like this will have a devastating impact on the local population and environment in Dorset.

“Despite all the safety promises fossil fuel companies make, they simply cannot guarantee against these kinds of incidents. Sooner or later, this is the unavoidable reality of the oil industry.

“It’s baffling that there are still MPs in the UK Parliament who complain about wind and solar farms spoiling the British landscape, when the alternative is toxic oil polluting our waters and killing our wildlife.

“The sight of our waters turning black shouldn’t be possible in 2023 and the responsibility lies squarely at the door of those who are blocking a green energy transition that both people and planet desperately need.”