Historical Changes in Large River Fish Assemblages of the Americas

Historical Changes in Large River Fish Assemblages of the Americas: A Synthesis

Robert M. Hughes, John N. Rinne, and Bob Calamusso

doi: https://doi.org/10.47886/9781888569728.ch29

Abstract.—The objective of this synthesis is to summarize patterns in historical changes in the fish assemblages of selected large American rivers, to document causes for those changes, and to suggest rehabilitation measures. Although not a statistically representative sample of large rivers, the book chapters indicated that physical and biological stressors usually had a greater impact on fish assemblages than chemical stressors (where point sources were treated). In particular, flow and channel regulation combined with alien species were key factors affecting large river fish assemblages. And these factors were most pronounced for southwestern U.S. rivers. We hope that such information will aid interested citizens and government agencies in river rehabilitation and river protection or conservation. There will never be a better time to do so.