 The recovery of the river since that time owes much to the regulatory effort of the NRA, and more lately the Environment Agency Wales, and to the massive capital investment made by Dŵr Cymru / Welsh Water.As the pollution of the river abated, so fish populations slowly returned to the river from the many small tributaries.Roach, Brown trout, perch, chub, eel, grayling, sea trout and salmon and more recently some barbel.