Infra-Red style shot of Hen Beck, Wath Brow near Cleator Moor in Cumbria.
The river supports the largest viable population of freshwater pearl mussel left in England. The majority of which are adults. Surveys indicate that juvenile mussels are present but they are very rare. The River Ehen is designated as a European Special Area of Conservation (SAC), designated for Freshwater Pearl Mussels (FWPM) and Atlantic salmon and also as a Site of Special Scientific Interest (SSSI). The river flows from Ennerdale Water, discharging 16.5 miles downstream into the Irish Sea.