Just a slight correction. The great lakes never wanted the alewives as a forage fish. They came into the great lakes via the St. Lawrence seaway and were one of the first invasive species to enter the great lakes. They were a nuisance for a while dying by the millions and clogging beaches to the point bulldozers had to be used to clean them up. Then the Michigan DNR figured out (after others failed) by planting salmon in the great lakes as a way to reduce the alewives numbers. This all came with a great side effect for some of the best salmon fishing anywhere.