The westward spread of zebra and quagga mussels shows how tiny invaders can cause big problems

NPS/Flickr” width=”800″ height=”394″/> A boat propeller encrusted with zebra mussels. Credit: NPS/Flickr The zebra mussel has been a poster child for invasive species ever since it is 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 … Read more