Lampreys are among a long list of species to have benefited from a grant to enhance the ecology of the rivers flowing within North Meadow National Nature Reserve near Cricklade in Wiltshire. Famous for its stunning snakes-head fritillaries few people are aware that within the sinuous water courses the serpentine brook lamprey dwells.
The restoration work, made possible by a £37,000 Biffa Award, has improved the Rivers Churn and Thames by reducing sediment loading, diversifying the channel and reducing excessive shading.
The Cotswold Water Park Trust, that carried out the work, was delighted to receive the funding as it meant that much needed repairs and preventative measures could be put in place to protect The Thames and Churn. These rivers are subject to significant damage of their banks and river beds from both livestock and dogs. The resulting areas of eroded soil are left exposed all winter which results in flood water and rain washing sediment into the rivers. This pollutes the water, smothering both the aquatic vegetation and gravels that fish, including lampreys, need for spawning.
Damage to the river banks has now been limited and repaired and temporary electric fencing introduced for the duration of grazing periods to prevent livestock having unregulated access to the water.
In addition to bank repairs, densely shaded areas of scrub have been cut back, or sections removed. Many of the mature willow trees which dominated the banks have been pollarded. This will re-invigorate the trees and also allow more sunlight to reach the river. In time the newly established aquatic and marginal vegetation will provide food for invertebrates and water voles allowing them to extend their range.
Large Woody Debris deflectors have also been constructed and installed in historically straightened sections of the rivers. These will encourage diversification of both river form and flow to enhance micro habitat variation. By reducing sediment loading and allowing more sunlight to reach the watercourse water quality should be improved. Biodiversity will increase as aquatic and marginal vegetation recolonises and exposed gravels will be kept cleaner by areas of higher flow rate. All in all, it’s looking better than ever for lampreys in North Meadow National Nature Reserve.
And here’s a short video showing a brook lamprey found during the works –