The zebra mussel has been a poster child for invasive species ever since it unleashed economic and ecological havoc on the Great Lakes in the late 1980s. Yet despite intensive efforts to control it and its relative, the quagga mussel, these fingernail-sized mollusks are spreading through U.S. rivers, lakes and bays, clogging water supply pipes and altering food webs.
Click here for original story, The westward spread of zebra and quagga mussels shows how tiny invaders can cause big problems
Source: Phys.org