Explores the basics of freshwater ecology--the workings of lakes, ponds and streams--as learned while traveling by canoe or kayak, or while hiking or snorkeling. Answers questions such as, ``Of what good are mosquitoes?'' and ``Of what harm is acid rain to lakes and streams?'' Includes more than 100 illustrations of aquatic life and associated environments. One chapter covers a hypothetical three-day solo journey. A list of select national wildlife refuges featuring freshwater environments is also included.