Biological indicators of water quality. (Based on papers given at a Conference on the Biological Indicators of Water Quality, held in Newcastle, 12-15 Sep 1978)

aguas fecales algae aquatic organisms bacteria calidad del agua fishes hidrobiologia hydrobiologie hydrobiology indicator organisms methode methods organisme aquatique organisme indicateur organismos indicadores peces poisson (animal) pollution de l'eau sewage test biologique water pollution water quality