Britannica Educational Publishing 
Lakes and Wetlands [PDF ebook] 

Lakes and wetlands are significant ecosystems that nourish, sustain, and house many of the planet’s plant and animal species. Though both of these regions are defined by water-both fresh and saline-each lake and particular type of wetland also has characteristics all its own. This detailed volume considers the formation, composition, and maintenance of these intricate ecological units and the various life forms they support. Dramatic full-color photographs and in-depth profiles of Earth’s major lakes highlight the beauty and complexity of these regions.