This publication provides an historical review and evaluation of documented ecological effects associated with salmonine introductions to the Laurentian Great Lakes. The introduction of salmonines to the Great Lakes date back to the 1870s, when natural populations of native salmonines in the Great Lakes were in severe decline. Using established evaluation protocols, it was determined that there is evidence of significant ecological effects in six different categories: (1) diseases and parasites, (2) predation on native species, (3) competition for limiting resources, (4) genetic alteration, (5) environmental alteration and (6) community alteration. Taken together, this body of evidence supports the conclusion that the ongoing introduction of non-native salmonines poses an ecologically-significant risk to the Great Lakes ecosystem and its native organisms, and that the introductions should be terminated.