This title consists of a book and a DVD. During the considerable periods of time trout spend feeding exclusively on underwater food forms, nymph fishing can be the most productive, if not the only way to catch fish. But understanding what occurs below the water's surface can be a challenge for even the most experienced angler. In "Nymph-Fishing Rivers and Streams", aquatic entomologist and long-time fly fisherman Rick Hafele shares the information necessary to successfully decipher the mysteries of trout life. He starts by explaining their feeding patterns - where trout feed, when they feed, and what's available for them to eat. Sections on tackle and pattern selection help anglers sort through equipment and imitations to find the best outfit for their needs. The DVD complements the photos in the book that show various methods for nymph fishing. Also included is an angler's field guide to nymphs with details on their habitat, importance to trout, and the most effective patterns and fishing tactics to imitate them.