Angling Trust shows how river pollution affects fish
River and fishing groups have rounded on Wales' environmental regulator, branding Natural Resources Wales "no longer fit for purpose".
Budget cuts have meant it is failing in its duty to protect and improve fisheries, the charities claim.
Levels of pollution, particularly from farms, are now "out of control", according to Afonydd Cymru and the Angling Trust.
Mark Lloyd, chief executive of the Angling Trust and Fish Legal, explains to BBC Wales environment correspondent Steffan Messenger why clean rivers are so important.