I am looking for examples of unintended consequences that stem from human activities, both proposed and realized. For example, the Aswan Dam was heralded as a success from the standpoint of water supply for agriculture along the Nile. However, it reduced the inflow of inorganic nutrients into the Eastern Mediterranean, with unintended (and unpredicted?) negative consequences for fisheries.

There must be many examples along these lines. My primary interests are ecological and environmental impacts, and the marine environment. However, I'll gladly accept (and learn from) any other examples.

Gall, John, Systemantics. New York: Simon & Schuster,1975. may be worthwhile your attention. Do A google on A. Judge and his review of this book which is an eye opener...
tommy