Species: Oncorhynchus tshawytscha

Chinook Salmon
Species

    Numerous scales; one dorsal fin plus one adipose fin; no spines in fins; irregular black spots on back, both lobes of tail fin, dorsal fin, and adipose fin; gums black at base of teeth. In the ocean, chinook salmon are blue, green, or gray on the upper side, silvery-white on the flanks and belly. During the spawning season, chinook salmon are olive brown, red, or purplish, the color change being more pronounced in males than in females. Young have 6-12 large parr marks on each side. Total length to around 150 cm.

    Science Review:

    Articles:

    Abundance of pink salmon may be harming orcas

    Pink salmon now comprise nearly 80 percent of all adult salmon in the North Pacific. This record abundance is coming at a cost to other salmon species such as threatened Chinook, which compete with pinks for spawning territory. A new study shows that the ecological toll may extend all the way to endangered southern resident killer whales.

    Underwater view of many fish swimming in one direction.
    The role of estuaries in the ecology of adult Pacific salmon and trout in Puget Sound

    The extensive loss or modification of estuaries throughout Puget Sound creates a significant challenge for adult salmon as they migrate to their natal streams to spawn. A 2024 report by University of Washington scientist Thomas Quinn looks at how different species of salmonids use estuaries to move from marine to freshwater environments. The report was commissioned by the University of Washington Puget Sound Institute with funding from the Environmental Protection Agency's National Estuary Program.

    Report cover with text and image of salmon swimming underwater.
    The role of estuaries in the ecology of juvenile Pacific salmon and trout in Puget Sound

    This overview describes the different ways that juvenile Pacific salmon and trout use estuaries, and why those differences are important for ecosystem recovery efforts. The report was commissioned by the University of Washington Puget Sound Institute with funding from the Environmental Protection Agency's National Estuary Program.

    Aerial view of Puget Sound showing multiple rivers and inlets. The text reads ‘The role of estuaries in the ecology of juvenile Pacific salmon and trout in Puget Sound’ by Thomas P. Quinn from the School of Aquatic and Fishery Sciences, University of Washington.
    A new beginning for threatened Chinook

    The Stillaguamish River is home to what may be the most imperiled stock of Chinook salmon in all of Puget Sound. What scientists are learning here at the Stillaguamish estuary on Port Susan Bay could help turn the tide for these fish and other salmon around the region. E

    An open motor boat sitting in sill water as to people place a fishing net across the channel.
    Rare tidal marshes set the table for salmon recovery

    Tidal wetlands are crucial to Chinook salmon recovery but are among the most threatened habitats in Puget Sound. In 2012, The Nature Conservancy began restoring a 150-acre section of tidal marsh on Port Susan Bay at the mouth of the Stillaguamish River. That project is entering a new phase and may soon connect with other adjacent restoration efforts put forth by the Stillaguamish Tribe.

    Three people wearing chest waders walking on a mudflat with blue sky above.
    The ups and downs of zooplankton in Puget Sound

    Zooplankton are critical to the marine food web, but until recently there have been few surveys of the zooplankton community in Puget Sound. Ongoing monitoring is now revealing a system full of complexity and surprises. The following article was commissioned by the Habitat Strategic Initiative Lead (HSIL), a cross-agency team co-led by the Washington Departments of Fish and Wildlife and Natural Resources.

    Two people standing on a boat hosing off two long, black sampling nets that have been pulled out of the water by a small crane.
    Southern resident orcas chase and sometimes kill porpoises. Why don’t they eat them?

    Puzzling encounters between endangered killer whales and harbor porpoises point to questions about prey availability and whale culture, scientists say. Are the whales playing, practicing their hunting skills, or is something else going on? 

    A killer whale surfaces with its head above water holding a harbor porpoise in its mouth.
    Returning home: The Elwha's genetic legacy

    Following dam removal, migratory salmon have been free to swim into the upper Elwha River for the first time in 100 years. Their actual behaviors and reproductive success may well be driven by changes in their genetic makeup. Our seven-part series 'Returning home' examines how the fish are doing and whether the Elwha's genetic legacy remains intact. 

    View of the Elwha River above the site of the former Glines Canyon Dam in 2021. Photo: Sylvia Kantor
    Will the mighty spring Chinook rise again?

    Our series 'Returning home: The Elwha's genetic legacy' continues with a look at the possible return of spring Chinook to the upper portions of the Elwha River. We bring you part three of seven.

    Two fish swimming underwater with rocks below them.
    Making room for salmon

    How can Puget Sound generate more salmon? That question has been at the center of ecosystem recovery efforts for decades. But even as scientists and conservationists make progress on many fronts — from breaching dams to cleaning up the water — they have faced one especially complicated and frustrating limitation: Salmon need more estuaries. We look at how local tribes are working to restore this critical habitat.

    Winter scene of marsh at high tide two conifer trees reflected on water in the foreground; snow covered mountain in the background.
    Chinook Salmon Implementation Strategy

    This article provides an overview and a link to further information about the Chinook Salmon Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.

    Southern residents’ winter diet comes into focus

    A 2021 paper in the journal PLoS ONE provides a clearer picture of what endangered southern resident orcas eat throughout the year. Chinook salmon make up the bulk of the whales' diet, but the paper suggests that other salmon species and non-salmonid fishes can also play important roles depending on the season.

    Researchers in a boat near killer whales
    Combining bugs and chemistry in Soos Creek stormwater study

    Many creeks and waterbodies in Puget Sound may look pristine, but most face serious threats from stormwater pollution. A new study at Soos Creek shows how mud-dwelling bugs, traditional chemistry and digital "heatmaps" can be used to track stormwater impacts and identify the most polluted areas. Scientists and planners hope that this may one day lower the price tag on costly stormwater fixes. 

    Close up of a stonefly larva on river rocks.
    Orcas without borders

    The Salish Sea’s endangered southern resident orcas travel freely across the U.S.-Canada border, unconstrained by political boundaries. But while they don’t require passports, they can still face differing policies and conditions as they go back and forth between nations. We look at some of the ways that the United States and Canada compare in their efforts to protect the whales.

    Southern resident killer whales. Photo by Candice Emmons/NOAA Fisheries (CC BY-NC-ND 2.0)
    'Early migration gene' tied to unique population of Chinook

    Spring and fall Chinook salmon were thought to be alike until researchers discovered a gene for early migration. Now, federal biologists and legal experts are struggling to decide if spring Chinook should be granted their own legal protection under the Endangered Species Act.

    Caption: Chinook salmon (Oncorhynchus tshawytscha) swimming upstream. Photo: Ingrid Taylar (CC BY-NC 2.0) https://flic.kr/p/dmbyre
    The orca docs: Can medical interventions help?

    This three-part series explores opportunities and challenges of using medical interventions to save Puget Sound's southern resident orcas from extinction. Part 1 looks at how scientists might treat endangered southern resident orcas that face starvation and risks of disease; Part 2 considers how veterinarians have intervened with other animals in the wild, and how this might apply to orcas in Puget Sound; and Part 3 explores a federally approved vaccination program designed to ward of a deadly virus among endangered Hawaiian monk seals.

    Clockwise from top left: 1) Mountain gorillas. Photo: Andries3 (CC BY-NC 2.0) https://www.flickr.com/photos/andriesoudshoorn 2) J pod Southern resident orcas – Photo: Miles Ritter (CC BY-NC-SA 2.0) https://www.flickr.com/photos/mrmritter/42903242165 3) Scientists collect orca breath samples. Photo: Pete Schroeder 4) Hawaiian monk seal. Photo: Karen Bryan/Hawaiian Institute of Marine Biology (CC BY-NC 2.0) https://www.flickr.com/photos/papahanaumokuakea/38322932854
    When should medical experts intervene to save a killer whale?

    The death of a young female orca in September has sparked a discussion of how and whether scientists should step in with medical care for distressed animals in the wild. Medical intervention has become routine for some endangered mammals, but scientists say Puget Sound’s resident orcas present a series of unique challenges and ethical questions. In part one of our two-part series The Orca Docs we look at how scientists are preparing to treat endangered southern resident orcas that face starvation and risks of disease.

    Scientists in a boat use a long pole to capture the breath of an orca. Photo: Pete Schroeder
    Tidal forests offer hope for salmon

    Can scientists bring back the lost tidal forests of Puget Sound? It could take generations, but restoring this rare habitat will pay big dividends for Puget Sound’s salmon.   

    Tidal forest as viewed from an inner waterway of Otter Island in the Snohomish River estuary. Photo: Jeff Rice/PSI
    New studies on emerging threats to salmon

    Chemicals, disease and other stressors can increase a salmon's chance of being eaten or reduce its ability to catch food. We wrap up our series on the Salish Sea Marine Survival Project with a look at some of the lesser-known, but still significant factors contributing to salmon declines in the Salish Sea.

    Chinook salmon leaping at the Ballard Locks in Seattle. Photo: Ingrid Taylar (CC BY 2.0) https://www.flickr.com/photos/taylar/29739921130
    Could anchovies and other fish take pressure off salmon and steelhead?

    A recent influx of anchovies into Puget Sound may have saved some steelhead from predators, but researchers seek more evidence to prove the connection. Our series on the Salish Sea Marine Survival Project continues with a look at these and other potential impacts from predators on the region's salmon and steelhead.

    A harbor seal hunting anchovies. From Howe Sound Ballet video by Bob Turner: https://youtu.be/Ycx1hvrPAqc
    Opening the black box: What’s killing Puget Sound’s salmon and steelhead?

    An intensive research program in the U.S. and Canada is studying why so few salmon in the Salish Sea are returning home to spawn. They are uncovering a complex web of problems involving predators, prey and other factors that put salmon at risk as they migrate to the ocean. We begin a four-part series on the Salish Sea Marine Survival Project, including new findings presented at the 2018 Salish Sea Ecosystem Conference last spring in Seattle. 

    Spring Chinook Salmon. Photo: Michael Humling, US Fish & Wildlife Service
    Study would explore changes to protections for seals and sea lions

    As wildlife managers work to recover Puget Sound’s diminished Chinook population, a proposed white paper is expected to review the impacts of some of the salmon's chief predators. The study would include a section on potential management of seals and sea lions, prompting open discussion of a long taboo subject: Could officials seek to revise the Marine Mammal Protection Act — or even conduct lethal or non-lethal removal of seals and sea lions in some cases? Such actions are hypothetical, but we look at some of the ongoing discussions around the issue as prompted by a new resolution from the Puget Sound Leadership Council. 

    Harbor Seals sunning on intertidal rocks of Puget Sound. Photo: Tony Cyphert (CC BY-NC-ND 2.0) https://www.flickr.com/photos/tony717/14630242564
    Seals and sea lions may be slowing salmon recovery, hurting orcas

    Increased consumption of Chinook salmon by seals and sea lions in the Salish Sea “could be masking the success of coastwide salmon recovery efforts,” according to a new study published in the journal Scientific Reports. Endangered resident orcas are said to be declining in part due to a lack of available Chinook, the orcas' preferred prey.

    A young resident killer whale chases a chinook salmon in the Salish Sea near San Juan Island, WA. Sept 2017. Photo: (CC BY-SA 2.0) https://flic.kr/p/21wV8rV
    Are we making progress on salmon recovery?

    In recent decades, hundreds of millions of dollars have been spent to restore habitat for Puget Sound salmon. In this article, we look at how scientists are gauging their progress. Are environmental conditions improving or getting worse? The answer may depend on where you look and who you ask.

    Dean Toba, a scientific technician with the Washington Department of Fish and Wildlife, operates the agency’s screw trap on the Skagit River. The trap helps biologists estimate the number of juvenile salmon leaving the river each year. Photo: Christopher Dunagan, PSI
    State of the salmon in watersheds 2016

    A biennial report produced by the Governor's Salmon Recovery Office provides stories and data about salmon, habitat, and salmon recovery in Washington, including Puget Sound.

    Salmon smolts. Photo courtesy of Governor's Salmon Recovery Office
    Finding a strategy to accelerate Chinook recovery

    As threatened Chinook populations in Puget Sound continue to lose ground, the state is looking to new strategies to reverse the trend. In the Skagit watershed, the scientists — and the fish — are among those leading the way. 

    Fir Island Farms habitat restoration monitoring in Skagit County. Project provides rearing habitat for young threatened Chinook salmon along with other wildlife. Copyright: Bob Friel
    Study says predators may play major role in chinook salmon declines

    A new study shows that increased populations of seals and sea lions are eating far more of Puget Sound’s threatened chinook than previously known, potentially hampering recovery efforts for both salmon and endangered killer whales. 

    Sea lion sunbathing between meals in Seattle's Eliott Bay. Photo: Johnny Mumbles (CC BY 2.0) https://www.flickr.com/photos/mumbles/3283168713
    Concerns rise over rogue chemicals in the environment

    Drugs like Prozac and cocaine have been showing up in the region’s salmon. But these are just some of the potentially thousands of different man-made chemicals that escape into the Salish Sea every day, from pharmaceuticals to industrial compounds. Now the race is on to identify which ones pose the greatest dangers.

    Fluoxetine hydrochloride. Photo: Meg (CC BY-NC-ND 2.0) https://www.flickr.com/photos/disowned/1125134972
    Mystery remains in deaths of young salmon

    The Salish Sea Marine Survival Project has mobilized dozens of organizations in the U.S. and Canada to find an answer to one of the region's greatest mysteries. What is killing so many young salmon before they can return home to spawn? A series of talks at the 2016 Salish Sea Ecosystem Conference brought together some of the latest research. 

    Key hypotheses include bottom-up and top-down processes and additional factors such as toxics, disease, and competition.  Graphic: Michael Schmidt, Salish Sea Marine Survival Project
    Contaminants higher in resident 'blackmouth' Chinook

    Many of Puget Sound's Chinook salmon spend their entire lives in local waters and don't migrate to the open ocean. These fish tend to collect more contaminants in their bodies because of the sound's relatively high levels of pollution. 

    Chinook salmon (Oncorhynchus tshawytscha). Photo: WDFW
    New theory rethinks spread of PCBs and other toxics in Puget Sound

    Researchers are proposing a shift in thinking about how some of the region’s most damaging pollutants enter Puget Sound species like herring, salmon and orcas.

    Puget Sound's orcas are among the most contaminated marine mammals in the world. Photo: Minette Layne (CC-BY-2.0) https://en.wikipedia.org/wiki/Killer_whale#/media/File:Orca_porpoising.jpg
    Shoreline armoring's effect on the food web

    The removal of shoreline armoring in Puget Sound has become a priority for state and federal agencies, but until recently there have been relatively few scientific studies of armoring's local impact. New research looks at the pronounced biological and ecological effects of these common shoreline structures, especially for tiny beach-dwelling creatures that make up the base of the food web.

    Storm surges against the bulkheads protecting beach houses at Mutiny Bay, WA. Photo: Scott Smithson (CC BY-NC-ND 2.0) https://www.flickr.com/photos/dtwpuck/15725058917
    Will Ballard Locks withstand a major earthquake?

    For close to 100 years, Seattle's Ballard Locks has been one of the region's busiest waterways, drawing major boat traffic along with millions of tourists. But as it prepares to celebrate its centennial, the aged structure is also drawing the concern of engineers. They worry that an earthquake could cause the locks to fail, draining massive amounts of water from Lake Washington and Lake Union. In some scenarios, the two lakes could drop by as much as 20 feet, stranding boats, disabling bridges and causing big problems for salmon restoration.

    Ballard Locks from the air. Photo: Jeff Wilcox (CC BY-NC 2.0) https://www.flickr.com/photos/jeffwilcox/4805933588
    Salmon live in a topsy-turvy world upstream of the Ballard Locks

    Chinook, coho and sockeye salmon, along with steelhead trout, live in the Lake Washington watershed and navigate a treacherous route through the Ballard Locks on their way to Puget Sound.

    Returning sockeye salmon packed gill-to-gill in the viewing windows at the Ballard Locks fish ladder. Photo: Ingrid Taylar (CC BY-NC 2.0) https://www.flickr.com/photos/taylar/7511895940
    Are diseases playing a role in salmon decline?

    Chinook, coho and steelhead populations in Puget Sound have declined dramatically over the past 30 years. In some cases, counts of fish returning to the rivers are just a tenth what they were in the 1980s. While many possible causes of this decline are under consideration, some researchers are focusing on the combined effects of predators and disease. This article continues our coverage of the ecological impacts of disease in Puget Sound.

    Steelhead (Oncorhynchus mykiss). Photo: Eric Engbretson, U.S. Fish and Wildlife Service
    Contaminants of emerging concern (CECs) in the waters of the Pacific Northwest

    Contaminants of Emerging Concern (CECs) range from pharmaceuticals, personal care products and food additives to compounds used in industrial and commercial applications. These compounds are not typically removed from wastewater and are flushed into waterways throughout the world in significant amounts. This article describes how scientists are measuring the presence of these contaminants along with their potential impacts in Puget Sound, the Columbia River and elsewhere.

    Sucralose, an artificial sweetener, is a good tracer of wastewater. It is present at low levels throughout the Puget Sound [1].
    2014 state of salmon in watersheds executive summary

    This report documents how Washingtonians have responded to the challenges of protecting and restoring salmon and steelhead to healthy status. It also serves as a tool to summarize achievements, track salmon recovery progress through common indicators, and identify data gaps that need to be filled.

    2014 state of salmon in watersheds report cover
    2012 state of salmon in watersheds executive summary

    Salmon recovery demands both dedication among people with different interests, and sustained resources. This biennial report tells the story of the progress made to date and the challenges ahead.

    2012 State of Salmon in Watersheds Executive Summary report cover
    2014 Salish Sea Ecosystem Conference

    The 2014 Salish Sea Ecosystem Conference took place April 30-May 2 at the Washington State Convention Center in downtown Seattle. Over 1200 delegates attended the conference.

    Screenshot of archived SSEC 2014 website at http://www.wwu.edu/salishseaconference/archived/2014/
    Monitoring for adaptive management: status and trends of aquatic and riparian habitats in the Lake Washington/Cedar/Sammamish watershed (WRIA 8)

    King County conducted physical and biological monitoring between 2010 and 2013 in the Lake Washington/Cedar/Sammamish (WRIA 8) watershed using common survey protocols and a probabilistic survey design. Hydrologic monitoring was also conducted at several locations to supplement physical and biological monitoring. 

    Foraging differences between male and female harbor seals present challenges for fisheries management

    A 2015 article published in the Marine Ecology Progress Series identifies intraspecific differences in diet between harbor seals in the Salish Sea, suggesting implications for marine reserve management. 

    Harbor seal photographed by Andreas Trepte. Available through a Creative Commons Attribution Share Alike 2.5 license.
    Brighter future for salmon at downtown seawall

    The decaying seawall along Seattle’s waterfront is providing scientists with an opportunity to improve long-lost habitat for migrating salmon. It could also show the way for habitat enhancements to crumbling infrastructure worldwide. One University of Washington researcher describes the project.

    Seattle's central waterfront at sunset. Photo: Michael Matti (CC BY-NC 2.0) https://www.flickr.com/photos/michaelmattiphotography/9090323308/
    No salmon left behind: The importance of early growth and freshwater restoration

    The growth and survival of young salmon in streams, river deltas and floodplains are seen as crucial pieces of the salmon recovery puzzle. In part two of this two-part series, researchers at the Salish Sea Ecosystem Conference in Seattle say the complexities of the salmon life cycle require new coordination among scientists.

    Nisqually Reserve Fish Sampling March 2012. Photo: Michael Grilliot, DNR (CC BY-NC-ND 2.0) https://www.flickr.com/photos/wastatednr/6834386824
    What is killing young salmon in Puget Sound?

    Scientists say Puget Sound’s salmon are dying young and point to low growth rates in the marine environment as a possible cause. In part one of this two-part series, scientists consider threats facing young salmon in the open waters of Puget Sound.

    Chinook Salmon (juvenile) Photo Credit: Roger Tabor/USFWS. https://www.flickr.com/photos/usfwspacific/6093338474
    Lead Entities for salmon recovery in Puget Sound

    Lead Entities are local organizations in Puget Sound that develop salmon recovery strategies and priorities for the region on a watershed-based scale.

    Chinook salmon. Image courtesy of NOAA.
    Presentations: 2013 study panel on ecosystem-based management of forage fish in Puget Sound

    Download presentations from the Study Panel on Ecosystem-based Management of Forage Fish held August 25, 2013 at the University of Washington’s Friday Harbor Lab, San Juan Island.

    NOAA report establishes Chinook monitoring framework

    A new Chinook monitoring framework is designed to build cooperation among managers and policymakers working across the Puget Sound watershed. The report, prepared by an independent team of scientists and released by NOAA, includes a regionally specific, common classification system for Chinook habitats and key ecological attributes. 

    Drawing of Ocean Phase Chinook (king) salmon (Oncorhynchus tshawytscha)
    Puget Sound Chinook Salmon recovery: a framework for the development of monitoring and adaptive management plans

    The Puget Sound Recovery Implementation Technical Team has released a draft of a NOAA technical memorandum describing frameworks for adaptive management and monitoring of Chinook salmon in Puget Sound. Download the report.

    Juvenile Pacific Salmon in Puget Sound

    This technical report produced for the Puget Sound Nearshore Partnership on Valued Ecosystem Components (VEC) summarizes existing knowledge of salmon use of nearshore habitats in order to help protect and restore these habitats.

    School of juvenile chinook/king salmon. Photo: USFWS/Togiak National Wildlife Refuge (CC BY-NC-ND 2.0) https://www.flickr.com/photos/usfws_alaska/6479109041/
    Methods and Quality of VSP Monitoring Of ESA Listed Puget Sound Salmon and Steelhead: With Identified Critical Gaps 2012
    Download a November 2012 assessment of monitoring of viable salmonid population (VSP) criteria. 
    Chinook salmon (Oncorhynchus tshawytscha). Image courtesty U.S. Fish and Wildlife Service.
    Salmonids in Puget Sound

    Fish in the family Salmonidae (salmon, trout, and charr) play potentially integral roles in the upland freshwater, nearshore and pelagic marine ecosystems and food webs of Puget Sound.

    Chum salmon (Oncorhynchus keta). Image courtesy U.S. Fish and Wildlife Service.
    Kingdom
    Animalia
    Phylum
    Craniata
    Class

    Actinopterygii

    Order

    Salmoniformes

    Family

    Salmonidae

    Genus

    Oncorhynchus

    Classification
    Other Global Common Names
    King Salmon - saumon chinook
    Informal Taxonomy
    <p>Animals, Vertebrates - Fishes - Bony Fishes - Salmon and Trouts</p>
    Formal Taxonomy
    Animalia - Craniata - Actinopterygii - Salmoniformes - Salmonidae - Oncorhynchus - Has hybridized with pink salmon in the St. Marys River, Michigan (Rosenfield 1998).

    Numerous scales; one dorsal fin plus one adipose fin; no spines in fins; irregular black spots on back, both lobes of tail fin, dorsal fin, and adipose fin; gums black at base of teeth. In the ocean, chinook salmon are blue, green, or gray on the upper side, silvery-white on the flanks and belly. During the spawning season, chinook salmon are olive brown, red, or purplish, the color change being more pronounced in males than in females. Young have 6-12 large parr marks on each side. Total length to around 150 cm.

    Short General Description
    A large fish (salmon).
    Habitat Type Description
    Freshwater
    Migration
    <p>false - true - true - Anadromous; migrates up to several hundred km upstream to the stream in which they were spawned. Different races differ in the timing of adult migration and spawning. Oregon coastal chinook stocks vary in ocean migration; some stocks migrate north, some migrate south, and one stock has a mixed north and south migration (see Nehlsen et al. 1991). There are two basic behavioral forms, stream-type and ocean-type (see Salo 1991). Stream-type chinnok is typical of Asian populations and of northern populations and headwater tributaries of southern populations in North America; spends one or more years as fry or parr in fresh water before migrating to sea, performs extensive offshore oceanic migrations, returns to natal river in spring or summer, several months prior to spawning; occasionally males mature without ever going to sea. Ocean-type is typical of populations on the North American coast south of 56 degrees north latitude; migrates to sea during first year of life (normally within 3 months of emerging from spawning gravel), spends most of ocean life in coastal waters, return to natal river in fall, a few days or weeks before spawning.</p>
    Non-migrant
    false
    Locally Migrant
    true
    Food Comments
    In fresh water juveniles feed opportunistically on terrestrial and aquatic insects. In salt water they eat crustaceans as well as other bottom invertebrates. Adults eat mostly fishes.
    Reproduction Comments
    Overall, chinook salmon generally spawn at 2-7 years of age (typically 3-5) in fall, depending on the population. A small proportion of males (called jacks) mature after only spending about 6 months or 18 months at sea, and still others mature without having migrated to sea at all. Eggs hatch in about 2-3 months and alevins complete development in another 1-2 months (depending on temperature, hence related to latitude and elevation). Juveniles stay in fresh water for a few days or 1 year (rarely more). Adults die soon after spawning. Several distinct spawning populations may occur in one stream; these may differ in duration of juvenile rearing, size and date of ocean entrance, timing of adult return and spawning, age composition of spawners, fecundity, and egg size (see Nehlsen et al. 1991).
    Length
    80
    NatureServe Global Status Rank
    G5
    Global Status Last Reviewed
    1996-03-08
    Global Status Last Changed
    1996-03-08
    Conservation Status Map
    <img src="http://www.natureserve.org/explorer/servlet/GetMapGif?CA.BC=S4&CA.ON=SE&CA.QC=__&CA.YT=S2&US.AK=S4&US.CA=SNR&US.ID=S1&US.IL=SE&US.IN=SE&US.ME=SE&US.MI=SE&US.MT=SE&US.NV=SX&US.NY=SE&US.ND=SE&US.OR=S4&US.PA=SE&US.SD=SE&US.WA=S3&US.WI=SE" alt="Conservation Status Map" style="width: 475px; height: auto;" />
    Global Range
    Native range includes the Pacific Ocean and tributary drainages, in North America presently from the Sacramento-San Joaquin system (sometimes farther south) north to Point Hope, Alaska, and in northeastern Asia, from northern Japan to the Anadyr River. The species has been widely stocked elsewhere.<br><br>In the Columbia River basin, the Hanford Reach supports the largest population of fall chinook salmon; annual production is an estimated 20-25 million subyearling salmon (P. Hoffarth, Washington Department of Fish and Wildlife, unpublished data).
    ELEMENT_GLOBAL.2.102499