By Loren Anne Barnett
LUCIDITY INFORMATION DESIGN
Non-native species from all over the world have invaded the Chesapeake Bay watershed.
Profiled on the following pages are nutria, English ivy, Japanese stilt grass,
mute swans, Zebra mussels, and hydrilla.
ver 170 species from other areas now live and reproduce in the Chesapeake Bay watershed. Some have been brought here accidentally—through
ballast water or as hitchhikers on boat bottoms—and others have been
introduced to serve a specific purpose. Although some have proven beneficial, others are a nuisance, and a few threaten our ecosystem. Some thrive out-of-control with no natural predators or disease, choking out our native plants and animals. Millions of dollars are spent each year across the country trying to control the
invasive species that threaten the balance of the ecosystems they invade. Which are
our enemies? And which are our friends? Following are profiles of six of the most
well-know, and sometimes misunderstood, aliens in our watershed.