The River Don in South Yorkshire has suffered abuse from a legacy of pollution that dates back to the Industrial Revolution. Population growth and urban development have resulted in the use of the river for the discharge of mining, sewage, and industrial effluents. Despite considerable efforts to reverse the ecological impacts of these abuses, the river still suffers from continuing pollution from these sources. As a consequence, fish and macroinvertebrate fauna of the river remain restricted due to water quality problems. The macroinvertebrate fauna comprised only 12 taxonomic families and generally consisted of pollution-tolerant species with low species diversity. The fishery consisted of stocked brown trout and grayling, and there appeared to be little or no recruitment of these fishes through reproduction. Other native fishes occurred in low numbers.