Tuesday, June 1, 2010

Chinook Salmon

Alaska's state fish, the Chinook Salmon, goes by a plethora of other names, including the King Salmon, Spring Salmon, Tyee Salmon, and Blackmouth Salmon. It is the largest of the pacific salmon, often exceeding 40lbs, and is and extremely important fish for commercial and sporting uses. They are found all along the Pacific coast, from the Bering Strait to Southern California.

Image from Pacific Northwest National Library
Male and female salmon differ in appearance, with the males possessing a hooked upper jaw and nose, some reddish coloration, and a ridged back. Females have a sleeker shape, blunt faces and grey coloring. Coloring in the males and females changes during spawning. The males also develop the hooked face at that time.

Salmon are well known for their breeding practices. In the late summer/early fall, the normally ocean dwelling salmon make for deep, freshwater streams in order to spawn. Young fish (fry) remain in the freshwater environments for around a year before becoming smolt (juvenile fish) and heading out to the saltwater estuaries. The salmon then spend anywhere from 1-8 years in the ocean, before travelling back up river to the place of their birth to spawn. Males and females pair up to breed, and then the female will dig a nesting hole where she will deposit between 3,000 and 14,000 eggs. The males then fertilize the eggs, and both parents stand guard over them to keep them safe from predators. Unfortunately the long migration, sometimes constituting hundreds, if not thousands of miles, followed by the taxing process of spawning, saps all of the adult's remaining energy. Because of this, all Chinook Salmon die during their spawning migrations.

Chinook are valuable not only because of their commercial impacts, but also because of their role as a role source for numerous other species. Whales, bears, seals and birds of prey all consume Chinook Salmon. Habitat loss, over fishing, and waterway development (such as the creation of dams) are all human made threats to the Chinook Salmon. They are endangered in the lower 48 states, but the stocks in Alaska remain healthy.

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