Chinook SalmonAugust 19, 2015
The Chinook salmon (Oncorhynchus tshawytscha) is the largest species in the Pacific salmon genus Oncorhynchus. The common name refers to the Chinookan peoples. Other vernacular names for the species include king salmon, Quinnat salmon, spring salmon, and Tyee salmon. The scientific species name is based on the Russian common name chavycha (чавыча).
The adult is between 84 and 147 cm in length and weighs between 25 and 60 kg. It is blue-green on the back and head, silver flanks and white on the belly. It has black spots on the tail and on top sel body; his face is dark gray.
The record catch in fishing is 44.1 kg) registered by the fisherman Les Anderson in the Kenai River, Alaska, in 1985. In commercial fishing the record is 57 kg recorded near Petersburg, Alaska on a catch 1949.
Chinook may spend one to eight years in the ocean (averaging from three to four years) before returning to their home rivers to spawn. Chinook spawn in larger and deeper waters than other salmon species and can be found on the spawning redds (nests) from September to December. After laying eggs, females guard the redd from four to 25 days before dying, while males seek additional mates. Chinook eggs hatch, depending upon water temperature, 90 to 150 days after deposition. Egg deposits are timed to ensure the young salmon fry emerge during an appropriate season for survival and growth. Fry and parr (young fish) usually stay in fresh water 12 to 18 months before traveling downstream to estuaries, where they remain as smolts for several months. Some Chinooks return to the fresh water one or two years earlier than their counterparts, and are referred to as “jack” salmon. “Jack” salmon are typically less than 24 in long, but are sexually mature and return at an earlier age.
The Yukon River has the longest freshwater migration route of any salmon, over 3,000 km (1,900 mi) from its mouth in the Bering Sea to spawning grounds upstream of Whitehorse, Yukon. Since Chinook rely on fat reserves for energy upon entering fresh water, commercial fish caught here are highly prized for their unusually high levels of heart-healthy omega-3 fatty acids. However, the high cost of harvest and transport from this exceptionally rural area limits its affordability. The highest in elevation Chinook migrate to spawn is in the Upper Salmon River and Middle Fork of the Salmon River in Idaho. These anadromous fish travel over 5,000 ft in elevation past eight dams on the Columbia and Lower Snake Rivers.
The species has been introduced in the coast of Patagonia in Chile and Argentina where it has colonized rivers and established stable spawning grounds. It was also successfully brought to New Zealand.