Chinook salmon sexually mature between the ages of 2 and 7 but are typically 3 or 4 years old when they return to spawn. Chinook dig out gravel nests redds on stream bottoms where they lay their eggs.
All Chinook salmon die after spawning. Young Chinook salmon feed on terrestrial and aquatic insects, amphipods, and other crustaceans. Older Chinook primarily feed on other fish.
Fish such as whiting and mackerel and birds eat juvenile Chinook salmon. Marine mammals, such as orcas and sea lions, and sharks eat adult salmon. Salmon are also primary prey for Southern Resident killer whales, an endangered species. After salmon spawn and die, salmon carcasses are a valuable source of energy and nutrients to the river ecosystem. Carcasses have been shown to improve newly hatched salmon growth and survival by contributing nitrogen and phosphorous compounds to streams.
Managed under the Pacific Coast Salmon Plan : Every year, the council reviews reports of the previous fishing season and current estimates of salmon abundance. Using this information, they make recommendations for management of the upcoming fishing season. Their general goal is to allow fishermen to harvest the maximum amount of salmon that will support the fishery while preventing overharvest of the resource and ensuring that salmon populations with low abundance can rebuild.
Specific management measures vary year to year depending on current salmon abundance, and include size limits, season length, quotas, and gear restrictions. Management of Chinook salmon must also comply with laws such as the Endangered Species Act. One of the threats to recovery of endangered Southern Resident killer whales on the West Coast is the availability of their preferred prey, Chinook salmon.
Every year the fishery management council considers the prey needs of this endangered population before setting commercial fishing catch limits for Chinook. State and tribal managers use council management recommendations to shape their policies for inland fisheries, to ensure that conservation objectives are met.
Managed under the Fishery Management Plan for Salmon Fisheries in the EEZ off the Coast of Alaska : All management of the salmon fisheries in federal waters is delegated to the State of Alaska , which is also responsible for managing the commercial, recreational, and subsistence fisheries for salmon in state waters.
Managers regulate the fishery based on escapement goals to ensure harvests are sustainable. They want enough salmon to be able to escape the fishery and return to fresh water to spawn and replenish the population. Salmon fishery management largely relies on in-season assessment of how many salmon return to fresh water to spawn. Managers set harvest levels based on these returns. When abundance is high and the number of fish returning is much higher than that needed to meet escapement goals, harvest levels are set higher.
In years of low abundance, harvest levels are lowered. During the fishing season, scientists monitor catch and escapement, comparing current returns with those from previous years, to keep an eye on abundance and actively manage the fishery.
Commercial fishery: In , U. Most of the Chinook in the U. Gear types, habitat impacts, and bycatch: Chinook salmon are harvested using a variety of gear types. Troll vessels catch salmon by "trolling" their lines with bait or lures through groups of feeding fish. To retrieve hooked fish, the lines are wound on spools by hand or hydraulically, and the fish are pulled aboard when alongside the vessel. CHF Technical Specifications. Rotor Diameter H Chinook Gallery.
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When not spawning, they appear blue-green with silvery sides, and they have black spotting on their backs and dorsal fins and on both lobes of their tail fin. Chinook often prefer larger river systems for their freshwater stays, but they can also be found in small tributaries and headwaters. They are famous for their strong swimming endurance and for the fantastic leaps they make when migrating. Chinook vary in their migratory habits, with some displaying a strong urge to move oceanward within weeks of hatching.
Others are content to remain in freshwater for up to two winters. Tipping the Scales The largest Chinook on record was a pound specimen caught in a fish trap near Petersburg, Alaska in
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