A charity that works to protect rare seahorses says plans for an oil well off Studland Bay are an environmental disaster.

Proposals to drill an exploratory well six kilometres east-northeast off the Studland coast, and just south of Poole Bay’s Wytch Farm oilfield - the largest onshore oilfield in western Europe - are being considered by the Government.

Neil Garrick-Maidment, executive director of The Seahorse Trust, said: “I have just checked our records and the nearest seahorse sightings we have to the proposed well are half a mile in one direction, just under a mile in another direction and in the third direction two miles away.

“Within five miles we have hundreds of sightings.

“This proposal sits smack bang in the middle of known seahorse habitat and should not go ahead, especially as this region is the most important area for seahorses in the UK.”

Mr Garrick-Maidment says an oil well off Studland Bay would be “devastating” and a “major environmental disaster.”

He added: “Studland Bay has to become a Marine Conservation Zone (MCZ) because of the environmental impact the anchoring has caused and now we have the threat of an oil spill on the doorstep.

“What has stunned us about the environmental assessment carried out on behalf of the company is how little the seahorses have been mentioned and there is almost no mention of the fact they are legally protected.”

Corallian Energy submitted a bid to drill an exploratory well at the site last year.

If agreed, the well would be 1,800m long, drilled vertically into an area dubbed the ‘Colter Prospect’ by a jack-up rig roughly 100m above the water at its highest point.

It would remains in place for several weeks.

A consultation is under way until February 19, after which a decision is expected from the Secretary of State for Business, Energy and Industrial Strategy.

A spokesman for the department said: “There is no set timeframe for a decision, it depends on whether more information is needed.”

“It is likely to be months rather than weeks.”

The Oil and Gas Authority said the firm had recently extended its licence for P1918 - a swathe of seabed extending eastwards from the Purbeck peninsula.

Meanwhile, spokesman for the Crown Estate, which owns the seabed, said: “The Crown Estate is working with Corallian to finalise an exploration drilling agreement, which would grant them consent to undertake exploration drilling, just off the Swanage coast.

“This follows the decision of the Oil and Gas Authority, the regulatory body for the sector, to grant a licence for the Colter Prospect project.”

Numerous bodies, including local authorities, will be consulted before any decision is made.

Corallian says it plans to extract oil from the site by drilling horizontally from Wytch Farm, so a long-term platform will not be needed.