Fisheries crews followed a tracking device embedded in a carp and found two more fish in Bayport.
The non-native fish jump out of the water when boats pass, endangering safety as well as the ecosystem.
Invasive fish and other species demand vigilance and eradication efforts to preserve natural ecosystems.
Third meeting about draft plan to control invasive plants and animals will be held this week in Spooner.
Float sought to call attention to threat posed by the invasive fish.
Anglers hooked into at least a few of the big, ugly fish near the Xcel Energy power plant in recent days.
Recent water sampling indicates that Silver carp, one of the invasive Asian carp species, are present in the St. Croix River, potentially as far up the river as the dam at St. Croix Falls.