Conservation experts are to allow rising sea levels to flood a huge stretch of reclaimed Essex coastline. The RSPB intends to puncture sea defences around Wallasea Island, near Southend, and turn 728 hectares (1,800 acres) of farmland into a mosaic of saltmarsh, creeks and mudflats.
Farmers have worked the land there for 500 years, since Dutch settlers first built a wall around the remote strip of coast. The RSPB wants to transform the area into a wildlife reserve. As the sea returns, so should otters, wild plants, fish and birds, some of which have not nested in the UK for more than 400 years. Graham Wynne, RSPB chief executive, said: "Wallasea will become a wonderful coastal wetland full of wildlife in a unique and special landscape. We will be restoring habitats that were lost more than 400 years ago and preparing the land for sea level rise. This is land that was borrowed from the sea that now the sea is reclaiming."
Mark Dixon, project manager, said: "We will have a landscape of marshes, islands, lagoons and creeks, little more than 20 inches deep at high tide. Wallasea is one island now but was once five separate pieces of land. We will restore these ancient divisions and each new island will have its own tidal control." The full force of the uncontrolled high tide would wash much of the restored landscape away, because the land inside the existing sea wall has been gradually lowered since it was reclaimed.
The Wallasea project borders a similar, smaller scale, saltmarsh restoration project carried out by Defra, the environment department, last year. In that case, 300 metres of the sea wall was bulldozed and the tide allowed to wash in. The region is already transformed, and saltwater plants and wildlife have moved in. Similar projects are under way in Germany, the United States, Denmark and Holland.
Of 30,000 hectares (74,000 acres) of intertidal saltmarsh that surrounded the Essex coast 400 years ago, only 2,500 hectares remain, and 100 hectares more are destroyed across England each year. Mr Dixon said: "Many birds will starve to death if we don't restore Wallasea. Fish are under incredible pressure too, not just because of overfishing but because of the loss of their saltmarsh nurseries." The restored wetland will also be a refuge for people living in the new Thames Gateway development, he said, with artificial beaches, cycle paths and a visitor centre planned. "We want to recreate a lost landscape. More people in this country know about the destruction of the rainforests than about the destruction of their own coastal heritage."
The RSPB hopes the wetland will attract spoonbills, which have not nested in Britain since the 1600s, Kentish plovers, absent for 50 years, and black-winged stilts, which have only bred in Britain three times.