NATIONAL SCIENCE EDUCATION STANDARDS CORRELATIONS Science as Inquiry Ability to do scientific inquiry (5-8, 9-12) Understanding of scientific inquiry (5-8, 9-12) Life Science Populations and ecosystems (5-8) The interdependence of organisms (9-12)

They've been called non-indigenous species, exotic species, alien species, invader organisms, nuisance organisms.......no matter what you call them, they're trouble. The zebra mussel, the Asian clam, the comb jelly, the Rapa whelk, the European green crab, and the Northern Pacific seastar are just some of the marine organisms which have found themselves in new homes, but aren't exactly welcome there. These creatures can effectively alter ecosystems and upset food chains. They can introduce new diseases, outcompete native species for food, or even consume native species. Billions of dollars are spent each year trying to control exotic species.

How are these organisms ending up in environments so far from their homes? How can this be prevented? Read about it in MIT Sea Grant's information on ballast water, and find more background and related links on their main Exotic Species Page. Get up-to-date information from the USGS' Nonindigenous Aquatic Species, and research the species of your choice.

One of the most notable non-indigenous introductions is the zebra mussel, a native of eastern Europe. Zebra mussels were first discovered in 1988 in Lake St. Clair, Michigan. They have caused havoc by settling in and solidly clogging intake pipes for water treatment plants, as well as destroying entire colonies of native mussels. Follow the alarming spread of zebra mussels in the United States over the last decade with U.S.G.S. distribution maps. You can also do queries by state and see reports of zebra mussel sightings by county. Have they been sighted near you?

If you live on the East Coast of the United States, you can help MIT Sea Grant scientists track and contain the spread of a new species of crab. Stop the alien invasions!