[en] The concentrations of copper in the abiotic and biotic compartments of freshwater ecosystems, and the effects on biota of increased amounts of copper in the water and sediments are reviewed. Data compiled and discussed include the quantities and physicochemical forms of copper in the water column, the concentrations of copper in the bed-load sediments and interstitial waters, and the concentrations of copper in primary producers, molluscs, crustacea, aquatic insects, other invertebrates, and fishes. In addition, the acute and sublethal effects of copper on the same groups of biota are presented, as well as data on copper concentration factors. This information can be used to: (1) determine the ranges of copper concentrations that occur in nature for different types of ecosystems; (2) identify ecosystems that are or may be impacted by copper released from industrial and urban sources; and (3) assess the effects of biota of the use of copper alloys in nuclear power station cooling systems