Scientific name: Oncorhynchus Tshawytscha
Other names: Chinook, Quinnat salmon, Tyee salmon. Small Chinooks (2-8 pounds) are also called Jacks.
Introduction: It is one of the most important native species of the northern hemisphere. They named this species after the common language from the locals of Columbia´s River basin. That population depended on salmons and anadromous trout for hundreds of years. King Salmons are the largest species in the pacific salmon family; however, there is a bigger species of salmon in Asia named Siberian Huchen (also known as “Taimen”) that can weigh up to 91 kg (200 pounds).
Distribution: It can be located on the west coast of North America, from San Francisco Bay in California (USA) to the north, including the entire coastline of Canada and Alaska. In order to control invasive fish species, King salmons were introduced by man in the Great Lakes of North America. Across the Pacific Ocean, it is found in Russia and the islands of Japan. As regards the southern hemisphere, it was introduced in the Chilean coast and in New Zealand for commercial purposes. Many of those salmon escaped from captivity, and gave rise to wild populations spawning in different rivers in these regions.
Weight and measures: In 1949, the largest specimen ever registered was caught near Peterburg – Alaska, weighing 57 kg (154 pounds). Largest fish had been reported over the last years but none has been verified yet. The current sport-caught world record is 45 kg (99 pounds), and fly fishing is 30 kg (66 pounds).
Appearance: During the ocean phase, Chinook is blue-green or purple on the back and top of the head with silvery sides and white ventral surfaces. It has black spots on its tail and the upper half of its body. Once they come back to fresh water and mature sexually, their skin turns copper.
Life cycle: It is a semelparous and anadromous fish born in freshwater. Afterwards it migrates to the Pacific Ocean where it grows to sexual maturity. Then it returns to its natal river to reproduce once and die. The transformation in its physiognomy before spawning is less pronounced than in other species of salmon.
Chinook salmon may spend 2 to 5 years in the ocean feeding before returning to their home rivers to spawn. The longest salmon migration run recorded, 3000 km, was in the Yukon River from the Bering Sea to Whitehorse.
This species spawn in larger and deeper waters than other salmon species and can be found on the spawning redds (nests) from September through to December. There are exceptions due to the number of subspecies, for example the four species of King present in the Sacramento River on the west coast of the United States are named after the time of year in which they return to the river to spawn: summer, autumn, spring and winter (i.e. in the same year there are four different runs). Another exception occurs in the River Nanaimo, Victoria Island, British Columbia – Canada-where Chinooks are differentiated by the time the young migrate to the sea. The first group of juveniles migrates just a few weeks after birth, in early summer; the second group migrates in late summer, and the last group remains in the river during the winter and migrate in spring.
For breeding, female Chinook chooses a male based on their physical dimensions, and seeks for a river area plenty of gravel to create the redd. The number of eggs deposited varies between 3,000 and 14,000, depending on the size of the female. The male fertilizes the eggs. The “fry” are born and gradually absorb the food in their yolk sac; in the next stage the “smolts” make their migration to the sea.
Diet: During their juvenile stage in fresh water, they feed on aquatic and terrestrial invertebrates, as well as salmon eggs. Once at the sea, its growth rate is very high, due to a diet consisting 70% of other fish and the other 30% of large crustaceans.
As regards maturity, female reach that stage after five to six years, while for male even though the average is four years, it can vary between specimens. Some reach sexual maturity after one year, weighing 3 kg to 4 kg, and there are other fish that take eight years to become mature, weighing up to 30 kg.
Sports: On their way back to natal waters to spawn, Chinook salmons stomach atrophies, creating space for their eggs (for females) and sperm (in the case of males). Consequently, flies are only attacked if they are irritated; and if so, given its weight, heavy equipment is necessary. Some anglers reported they had to follow the fish down river a couple of miles to get them out.