Documentation of the Impacts of Introduced Species
•Horwitz 1982
•Philip 1983
•Murphy and Terre 1984
•Barel et al. 1985
•Hocutt et al. 1986
•Deacon 1988
•Echelle and Connor 1989
•Waples et al. 1990
•Minckley and Deacon 1991
•Moyle and Leidy 1992
•Courtenay 1993
•Tyler et al. 1999
Because we know so little of the natural workings of native aquatic ecosystems, most potential impacts by introduced species are based on presumptions as to cause and effect.  But an increasing number of studies have been done that demonstrate negative effects on native species as a direct result of introduced fishes.    Some introductions may take decades to realize their full potential as an invasive species.  Some scientists believe every introduction should be treated as a potential “biological time bomb”.