Fencing can significantly improve habitat that is being damaged by livestock, such as cows or sheep. Livestock kept in fields adjacent to the river trample the river banks and in some instances defecate in the watercourse impacting water quality. This causes erosion to the river banks and widening of the river channel; it also contributes high quantities of fine sediment into the water course which smothers river bed gravels and potential fish spawning locations. An effective measure to prevent the impact of livestock is the installation of fencing. Fencing protects the river banks from livestock trampling, reduces s sediment input and livestock waste from entering the watercourse and allows plants to flourish which help filter sediment, nutrients and runoff. Cattle poaching and subsequent bank erosion have also led to serious declines in populations of the European water vole which depend on bank structure for its refuge.