Round gobies are difficult or impossible to age by scales, but Ohio State biologists think it can be done if one looks at many scales from a specimen. There is concern that the lake subspecies of mottled sculpin may be driven to extinction. Other species that may be affected include logperch and lake sturgeon. There is concern about predation on lake trout eggs and fry, but ongoing research by the Illinois Natural History Survey indicates that the mottled sculpin may be a more effective predator on lake trout than the goby. If round gobies colonize the Mississippi River Basin, there is concern about their impacts on darters, several of which are listed on the Federal List of Threatened and Endangered Wildlife.
Round gobies are behaviorally aggressive in defending optimal space.
They are larger than most competing species, feed in total darkness by sensing prey with their ultra sensitive lateral line system, and they tolerate poor water quality. All of these factors give them competitive advantages over native species. Task Force that the round goby be declared an aquatic nuisance as defined by law, and that a control program be developed. The ANS Task Force responded that more information is needed, and there is a clear process that must be followed.