New life from old barges: National Trust undertakes ultimate recycling mission to create island haven for endangered seabirds

The project—believed to be the first of its kind in the UK—marks the latest chapter in more than 30 years of cutting edge coastal adaptation work in the estuary where the conservation charity has been trialling innovative, nature based solutions to protect Northey Island against rising sea levels and the rapid loss of saltmarsh.

Working with the Environment Agency, Natural England, Maldon Harbour Improvement Commissioners, specialist engineering and environmental consultants Royal Haskoning DHV and specialist marine contractors Landbreach Ltd, the Trust has repurposed three flatbottomed barges, dating back to the 1950s, to create a stable structure that will soon become a new habitat and roosting refuge for red-listed birds including dunlin, curlew, lapwing and ringed plover, as well as vulnerable seabirds such as little terns and avocets. The Blackwater Estuary is home to around 10% of the UK’s population of Brent geese.

Once used to transport building materials, coal and food from the Port of London, the retired lighters have spent more than 30 years moored in Essex. Measuring between 20 and 32 metres long, they now sit on the inter-tidal mudflats of the estuary creating a new land mass on the edge of the existing saltmarsh at Northey Island and have begun their second life as part of pioneering conservation efforts.

Creating a brand-new island has been a challenging yet exciting task. Katy Gilchrist, Coastal Project Manager for the National Trust, explains: “This is the ultimate act of marine recycling—transforming retired industrial vessels into a sanctuary for wildlife. We’re basically turning history into habitat, and as far as we know, no one has attempted anything quite like this before.

“The lighters have been decommissioned for some time, so work was needed by specialist contractors to make them clean and seaworthy again before they could be towed into place and set onto a platform of sediment. Holes were cut into the hulls to sink the vessels and they were then filled with sediment, mostly mud, to weigh them down to secure them. Once the island is fully established with gravel on top, it will sit safely above the highest tides to offer a safe refuge for some of our bird species which are in decline.”

Up to 8,000m³ of sediment—roughly the volume of more than three Olympic swimming pools—is being used to fill and surround the barges before the final gravel surface is added.

Nigel Cardy of Landbreach Ltd, the specialist contractors carrying out the engineering work, said: “I have been working on the river for more than 50 years and been involved in some interesting jobs, but this one is a bit special as it ticks so many boxes: it makes good use of the old barges, helps keep the channel clear in the Maldon Harbour area and also creates a new habitat for the birds in the estuary which is good to see. Plus river users benefit from the dredging.

“In total it will take around 170 trips from the harbour to the new island. Our dredge barge holds approximately 65m3 of mud which is then transferred into and around the old barges to create the island, which will hopefully create some salt marsh as well.

“We can only carry out this work on high tides to get close enough to the new island.

“It is nice to be involved in such an interesting project that benefits wildlife and people in the local area."

Nick Cooper, Technical Director at Haskoning, specialist consultants working with the Trust to design, plan and implement the works said “We’ve been working with the National Trust at Northey Island for the past nine years on innovative, nature-based solutions to habitat loss and the impacts of climate change in the Blackwater Estuary. The initial idea of using the lighters as the structure for the island was devised by the National Trust. Our expertise has helped design the island, secure the necessary planning permission and marine licence and bring it to life. It’s exciting to see the island now taking shape.”

Once the work is complete, the island will add 0.55 hectares (1.4 acres) of vital new habitat—almost the size of a football pitch—within the Blackwater Estuary, one of the most ecologically important wetland systems in the UK.

Matt Wilson, Countryside Manager for the National Trust, said: “The new island, located just off the eastern shore of Northey will provide a refuge for birds above the highest tides and away from disturbance on shore, acting as a lifeline for birds that are running out of safe spaces to nest and rest.

“Depending on the time of year, the different birds we hope to see include oystercatchers, Brent geese, redshank and curlew.

“We will be continuing to top the island with sediment for a little while and then we’ll just have to wait to see when the birds will start to use their new sanctuary.

He added: “As well as creating a new habitat for birds, the island will also help to reduce erosion of the existing saltmarsh at Northey Island.

“As the tide comes into the estuary, the force of the water erodes the saltmarsh which acts as a natural flood defence, massively impacting the wildlife that depends on it.

“Saltmarsh is one of the biggest natural carbon stores in our marine landscape. By sheltering the marsh from wave energy, the new island will also help us slow erosion and protect this precious, habitat.”

Northey Island is open to the public from April to September and closed in winter to protect overwintering birds. More information can be found at www.nationaltrust.org.uk/northey-island