Invasive Species
Go to the U.S. National Atlas web page, nationalatlas.gov/natlas/natlasstart.asp. (This page displays best if you have a large or high-resolution monitor; if you don't, use the scroll bars to move left and right on different parts of the page.) On the right side of the page, scroll down until you see the list of invasive species, and select one of the species listed. Hint: select only one species at a time, and click on the Redraw button below the map to display your choices. Which of the species shown is most widespread? Which regions of the country have the most problems with the invasive species shown here?
Zebra Mussel Invasion
Look at the National Atlas animated map of zebra mussel spread at nationalatlas.gov/zmussels1.html. You will need Shockwave to display this movie; you can download Shockwave at the link on this page. Click the Play button below the map (the right-pointing arrow) to play the movie. You can loop the movie by clicking the Loop button in the lower right corner of the map, and you can move the slider to go through the movie more slowly. Where did zebra mussels first invade U.S. waterways? How far had they spread by 1999?
