Falmouth seabed more contaminated than Tyneside, analysis finds

Falmouth is celebrating its oysters this week. Some of the people who catch them are worried about what is sitting in the mud beneath their boats.

New analysis by Cornwall Wildlife Trust suggests the seabed sediment in Falmouth harbour, where a major dredge is planned, is more contaminated with Tributyltin (TBT) than some of the UK’s biggest industrial ports. The trust’s comparison puts the Fal ahead of Teesside, Tyneside, Liverpool, Plymouth and Portsmouth.

The findings land as the Falmouth Oyster Festival gets under way, and as a local campaign group launches a new petition asking for the dredge not to be licensed without proof it is safe.

📷Credit: Cornwall Wildlife Trust

What the sediment samples show

TBT was widely used in antifouling paint on boat hulls. It is now banned internationally, and campaigners say that even at low concentrations it poses a severe threat to human health and is lethal to marine life.

According to the release, analysis of sediment samples taken by the developers found three-quarters of them too toxic to be disposed of at sea. In some cases the levels were more than 17 times safe limits.

Other contaminants found in the sediment include mercury, zinc, lead and copper.

📷TBT contamination by port: maximum sediment values. UK national dredge dataset (Cefas, 1998-2019).

What campaigners fear could happen

For now, those toxins are trapped in the seabed. The concern raised by campaigners is what happens when it is disturbed.

They say a dredge could devastate Falmouth’s marine life, from shellfish such as oysters, mussels, scallops and crabs to maerl beds, seagrass meadows, dolphins and seals. Local fishers have said they are deeply worried about their livelihoods.

The campaign also points to risks to people if TBT enters the food chain or swimming areas, listing metabolic disruption, immune system suppression, neurotoxicity, and threats to fertility and prenatal development.

Rachel Parkes, community organiser with Stop the Dredge, said: “Thousands of people from the local community do not want this dredge to go ahead. Many support the redevelopment of the docks, but oppose harmful dredging and inadequate consultation. They are also deeply concerned about the impacts of ‘mega’ cruise ships docking in Falmouth.”

“Falmouth is a beautiful town with a rich heritage, a thriving ocean economy and protected wildlife, we cannot rush ahead with any decision that risks ruining that.”

📷Credit: Cornwall Wildlife Trust

A petition to the Marine Management Organisation

More than 700 objections have already been lodged on Cornwall Council’s Planning Portal. Now the campaign group, recently renamed Stop the Dredge. Redevelop Responsibly, has launched a 38 Degrees petition addressed to the Marine Management Organisation (MMO). It has also published a new statement of its position on the current proposal.

The petition asks the MMO not to grant a marine licence unless:

• independently verified safeguards are in place to protect fisheries and marine life
• less harmful approaches to redeveloping the docks have been fully explored
• the public consultation is reopened, so local people can respond to environmental evidence submitted since it closed

📷Credit: Cornwall Wildlife Trust

The £150 million plans

The £150 million redevelopment would dredge almost 650,000 cubic metres of sediment. That is the equivalent of more than 250 Olympic-sized swimming pools.

The aim is to deepen berths to 10.5 metres, partly so that much larger cruise ships and commercial vessels can dock. The plans envisage the number of cruise passengers disembarking in Falmouth quadrupling to 200,000 a year.

Campaigners say cruise ships in dock would need to run their engines continually for power, and that thousands of passengers would head straight out of town on coach excursions. They say many in the community are concerned about the effect on local services, air pollution and traffic congestion.

The original consultation ran from 24 July to 4 September 2025. Further environmental information has been submitted since, including an updated Habitats Regulations Assessment and comments from Natural England, published in September 2026.

📷Credit: Cornwall Wildlife Trust

Fishers say they were left out

Local fishers, who say their knowledge is essential for a safe dredge, say they were not fully consulted by the MMO.

Patrick Vinnicombe, a local oyster fisherman who is taking part in the Oyster Festival, said: “This weekend, thousands of people have arrived in Falmouth to celebrate its oysters, bringing thousands of pounds to the local economy. Any new development must ensure there is still an oyster fishery to celebrate in 10 years time. This dredge could completely wipe us out. After a much smaller dredge in 2001, it was years before local fish stocks recovered.”

“We have expert knowledge of tidal currents and winds, gained over many years, and we know how easily toxic sediment could drift well beyond the dredging site. But we’ve not been allowed to feed into a decision that could severely impact our livelihoods. That is simply wrong.”

📷Credit: Cornwall Wildlife Trust

Swimmers want answers too

Adam Radage, a local swimmer and free diver, said: “Hundreds of us swim off Greenbank, Flushing and Gylly all year round, and nobody has explained what this means for the water we swim in and our health. We’re not asking for much. Test it properly, prove to us the right measures are in place to protect local people and wildlife, and let us have a say before a decision is made.”

📷Credit: Cornwall Wildlife Trust

Engineers question the offshore wind case

Earlier in the week, a group of engineers with floating offshore wind and marine backgrounds, including a former Pendennis Shipyard project manager, wrote an open letter to Jayne Kirkman MP. They question whether floating offshore wind justifies the capital dredging proposed at Falmouth Docks.

The engineers say they are concerned renewables are being used to front a scheme that is also serving cruise ships and national defence.

📷Credit: Cornwall Wildlife Trust

Find out more during the Oyster Festival

Residents and festival-goers are invited to hear more from community members about the plans and their possible impacts.

• Stop the Dredge stall, Church Street (near the Cornish Bank): chat to community volunteers, sign the petition and buy new Stop the Dredge merchandise designed by local children.
• Film screening, this Saturday (10 October) at 6pm, Pendennis Community Centre: All Rivers Spill their Stories, a documentary following a fisherman who led a grassroots campaign after a mass die-off of crabs and lobsters following dredging on the River Tees. Tickets for the Falmouth screening are available online.

The MMO has yet to decide on the marine licence.

📷Credit: Cornwall Wildlife Trust