Ed visits a 5,000-year-old ‘ghost’ river and anticipates the reintroduction of a charismatic animal extinct since the 16th century.
We live in a society with an acute awareness of the environment and the human impact on the planet. Our individual perspectives differ but it feels that the peril of our time is growing. Never has the natural world been under so much pressure.
This edition of the Wildlife Diary is about a glacial landscape that lies hidden in Shrewsbury and exciting plans to re-introduce a river animal that became extinct in the UK in the 16th Century. It is a story about taking a glimpse from the past and translating it into a bold vision for the future.
The story begins near the village of Leighton, in a roadside layby. From this viewpoint, the serpentine beauty of the Middle Severn can be fully appreciated. Set against a backdrop of lush pasture and field-grown oaks, the river flows through an S-shaped series of meander loops. Those readers who studied Geography at school may remember that the erosional power of water can eventually cut off such a loop.
Old Man River
The Old River Bed in Shrewsbury is an example of this. Before the last period of glaciation, the Severn flowed through this site. The river followed a more northerly route and joined the Dee before flowing into the Irish Sea. Around 5,000 years ago, there was a change in the direction of flow. The river began to flow in a more southerly direction along the course that we are now familiar with. Various theories have been postulated about what caused this dramatic shift. These include the presence of a vast waterbody called Lake Lapworth which eventually over-topped. Meltwater then surged down the river, carving the steep-sided Ironbridge Gorge and forming the valley as we know it. The Old River Bed was left marooned, around a mile from the river.
Housing developments and highways now encircle the Old River Bed which is designated as a Site of Special Scientific Interest. In the lockdown summer of 2020, I was granted permission to visit the site. It was Midsummer’s Day and there was not a cloud in the sky. On the grassy bank below the gate, several six-spot burnet moths were already on the wing. This glossy black insect is resplendent with scarlet red markings that signal poison, in this case hydrogen cyanide which deters would-be predators.
There are no footpaths on the site. I traced vague animal tracks through the vegetation and stepped onto the quivering skin of the fen. Wetland plants like water horsetail, soft rush and lesser pond sedge began to dominate. If I stood still, water pooled around my feet. It is as if the ghost of the river has never really left this place, an ancient flow slowly percolating through the nutrient-rich soil. Wild angelica towered over me, with disc-shaped white umbels held in perfect orbit on this sparkling day.
Return of the native
A lone marsh orchid glowed a deep violet as I neared the Bagley Brook. If plans are successful, this small stream will be the home to the first Shropshire Beaver population in over 400 years. The project is being delivered by Shrewsbury Town Council (the manager of the site) and Shropshire Wildlife Trust. A huge, fenced enclosure will be constructed, into which a number of Eurasian Beavers can be released.
Works could start this winter with animals being released as early as September 2022. A boardwalk will improve public access around the perimeter of the reserve, giving the chance for visitors to observe these charismatic mammals in an almost natural habitat.
Beavers can weigh up to 38kg and have a broad flattened tail that they use as a rudder. They are herbivores and their most famous attribute is an ability to fell trees to create dams. In time, areas of slack water form behind the dams in which beavers can make their home, called a lodge. The action of the beavers will improve the diversity of the wetland habitat at the Old River Bed. Dams will filter sediment from the water. On the morning of my visit, the sound of sedge warblers drifted through the scrub willow trees that are scattered across the reserve. In time, these same willow trees will spread and begin to change the nature of the fenland habitat. The gnawing action of the beavers will control scrub encroachment and ensure that the wetland remains diverse and healthy.
I have seen a photo on social media of the Old River Bed completely under water. Occasionally during periods of intense winter rainfall, the ancient river is briefly re-imagined. This has always been a place of change. The re-introduction of beavers is part of the continual evolution of the site. The project is ambitious and exciting. It offers the chance for the people of Shropshire to experience a wilder landscape, once again full of mystery and joy.
Do one thing for wildlife
Loopholes in the law mean that, under certain conditions, water companies can discharge raw sewage into our rivers. This shocking practice is killing aquatic life and threatening our health. Why not take some time this month to lobby your MP, asking them to support the Sewage (Inland Waters) Bill which will introduce new regulations to control the actions of the water companies. There is a handy tool to speed up the process at: https://www.sas.org.uk/EndSewagePollution-SewageBill