zebra mussels in the Great Lakes zebra mussels invasive freshwater mussels "Invasive Mussels" reports zebra mussels in the Great Lakes Invasive Mussels less food for native fish wreaking ecological havoc ballast water of large seagoing ships Invasive Mussels Invasive Mussels zebra mussels, an invasive species Invasive Mussels zebra mussels, an invasive species "Invasive Mussews" "Invasive Mussels" zebra mussels "Invasive Mussels" They have now spread to over 29 states. nwf.org