Craig Coch Field Surveys Group meeting, Malvern February 1976: UWIST Paper 5. Invertebrate studies: Ystwyth & Rheidol

The Rivers Ystwyth and Rheidol have a history of metal pollution (Carpenter 1924, 1925: Newton 1944): many reaches still receive substantial volumes of water contaminated with heavy metals, principally zinc and lead, although there has been considerable improvement in water quality and biological status in recent years, particularly in the R. Rheidol (Jones & Howells 1969). As a consequence of proposals to divert uncontaminated water from the headstreams of both rivers in order to provide a refill source for the enlarged Craig Goch Reservoir, a surveillance programme was instituted to provide base-line data for water quality, fisheries and invertebrates. U.W.I.S.T., under contract to W.N.W.D.A., has implemented a programme which will provide information on the variety, distribution and relative abundance of aquatic invertebrates: the study of other aspects has been undertaken by South West Wales River Division (1976)