Sockeye salmon (Onchorynchus nerka), sometimes called red or blueback salmon, are one of the 5 species of Pacific salmon-the other four Pacific species are Chinook (king), Silver (coho), Chum (dog), and Pink (humpy). "Sockeye" is an English adaptation of a Salish (native British Columbian) term meaning "red fish.".

Sockeye live between 3 and 5 years, although sometimes longer, according to a highly variable spawning cycle. All sockeye are anadromous, which means they migrate from saltwater back to fresh water. After one, two or sometimes 3 years in fresh water, sockeye migrate 1200 to 1500 miles (sometimes as far as 2000 miles) to North Pacific and Arctic saltwater. After one to four years at sea, sockeye return to precisely the lake or stream where they were born-to spawn and subsequently die.

Maturing sockeye salmon are filter feeders, subsisting on a variety of plankton. As sockeye grow older, they continue to feed on zooplankton, as well as larval and small adult fish, and, occasionally, small squid. Sockeye flesh gains its brilliant orange-red color from an antioxidant called astaxanthin (pronounced "asta-ZAN-thin"). Astaxanthin, a naturally-occurring pigment found in the zooplankton that salmon eat, is the same substance that gives cooked crustaceans-shrimp, crawfish, crabs and lobster-a brilliant red color.