DORSET Council has shot down claims from local residents that smog seen over Weymouth Bay is caused by the cruise ships anchored there during lockdown.

Jason West, co-founder of Weymouth community group Weyforward, said residents had become concerned about seeing what he claimed was smog caused by cruise ship pollution. He said: "A great number of residents and a local GP and councillor are extremely concerned about the number of large cruise ship vessels that have been residing in Weymouth Bay since the start of lockdown.

"None of us has ever seen smog over Weymouth Bay before and we are extremely concerned that it is, especially at this time with a respiratory disease pandemic, posing a severe and current unnecessary risk to the health of the residents of Purbeck, Portland and Weymouth."

Mr West also complained to the Maritime and Coastguard Agency (MCA) about cruise ships breaching the Purbeck coast Marine Conservation Zone (MCZ). This protected area stretches from Ringstead Bay in the west to Swanage Bay along the Jurassic Coast World Heritage Site. This MCZ protects critical black sea bream nesting grounds, rare maerl beds, and vital habitat for species such as the stalked jellyfish and peacock’s tail seaweed.

Following his complaint the MCA confirmed that vessels that were previously situated within the protected area had been moved from the area.

Mr West added: "They shouldn't be in a protected area, something that size is going to cause damage to it because they still emit something even if they aren't running at full power."

A Dorset Council spokesperson said: "The ships at anchor within Weymouth Bay are subject to the regulations laid down by the International Maritime Organization (IMO). Dorset Council does not have any powers to enforce, or ensure that the ships comply with any regulations set out by the IMO.

"The vessels at anchor will be running their auxiliary engines, to enable power for the skeleton crew’s basics on board – in effect sanitation, power for cooking, possible water purification etc. These engines are not therefore labouring at as full a capacity as those underway into and out of Portland Port, or Weymouth Bay.

"The summer weather we have been experiencing is causing temperature inversions – these are responsible for producing smog, trapping the pollutants produced by all vehicles, fires and industrial activities. You sometimes see this as you travel over the Ridgeway and look towards Dorchester – as a yellowy haze – it’s not uncommon. With this inversion layer present, emissions remain suspended.

"We are monitoring for nitrogen dioxide at many locations and there are no anomalies with respect to this pollutant – only the very great reduction when lockdown commenced in March and April."

Andy Smith, Extinction Rebellion coordinator, said: "I have massive concerns about the cruise industry as a whole. It's horrendously polluting. When fully operational each ship creates approximately the equivalent amount of pollution as a million cars.

"We see people looking at these cruise ships in admiration and awe and yet these are the very things which are contributing to the death of the planet and all life on it. It's about making those connections and being aware of the impact on the world around you."

A Maritime and Coastguard Agency spokesman said: "The UK monitors emissions from vessels very closely. International maritime air pollution regulations are strictly enforced in UK waters and are monitored as well as regulated. Vessels must use fuel within approved limits to make sure they comply with these regulations. Under Port State Control, the Maritime and Coastguard Agency closely monitors fuel content and environmental standards to ensure vessels are operated in line with international regulations."