Wade into rivers and lakes - watery underwater worlds teeming with plant and animal life. These biomes provide a home filled with all the elements their inhabitants need for survival. Peel back a corner of these amazing ecosystems to discover the incredible organisms that function within them and around them, from microorganisms and plants to fish and the mammals that feed on them. Explore rivers and lakes all over the world and find out what you can do to help protect the riches of these wonderful waterways. Teacher's guide available.