Salmon are marine fish of the family Salmonidae that spawn in fresh water. The herring-like Salmonidae are characterized by soft, rayless, adipose fins and live in cold, oxygen-rich waters. They are generally a uniform silver in color. The Atlantic salmon (genus Salmo), once abundant, is threatened by pollution, damming, and over fishing. Salmon feed on crustaceans at sea and small fish while spawning and reach 15 pounds (6.8 kilograms). The Pacific salmon (genus Oncorhynchus), comprising five species, is commercially the most important. The largest, the chinook, may reach 100 pounds (45 kilograms); the blueback forms the bulk of canned salmon. Pacific salmon are famed for their grueling journeys of hundreds of miles to their headwater breeding grounds. The genus Salvelinus includes the European chars and the North American brook trout.
