Based on the number and size distribution of the gobies observed by the divers, it seems likely the population has been established for some time. Lake vessels are commonly brought for repair at the shipbuilding facilities near Sunset Park. Both gobies and white perch may out-compete more desirable native fish like yellow perch for food and habitat. White perch, which have inhabited Green Bay for several years, are known to be aggressive invaders and may have contributed to the decimated populations of yellow perch in Lake Michigan during the nineties, according to Binkowski. We know from Sea Grant-sponsored research in Green Bay that they eat young yellow perch, both larvae and fingerlings.
White perch are the junkyard dogs of the fish community.
Despite their common name, white perch are not related to yellow perch. White perch are actually members of the same family as white, striped, and yellow bass, which they more closely resemble. The white perch, an East Coast native, first found its way into the Great Lakes in the 1980s. In its native range it is anadromous, spending its adult life in ocean but swimming up coastal streams to spawn. The white perch has a mottled coloration on the sides and back, lacks the dark colored, horizontal black bars along the body seen on white bass, and does not get as large.