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Coho Salmon (Oncorhynchus kisutch)

Status | Species Description | Habitat | Distribution | Population Trends | Threats | Conservation Efforts | Regulatory Overview | Taxonomy | Key Documents | More Info

Status

ESA Endangered - 1 ESU
ESA Threatened - 3 ESUs
ESA Species of Concern - 1 ESU

California Central Coast coho salmon are one of NOAA Fisheries' Species in the Spotlight            

Species Description

Weight:
average 8 pounds (3.6 kg), but can weigh as much as 35 pounds (16 kg)
Length:
2 feet (61 cm)
Appearance:
dark metallic blue or greenish backs with silver sides and a light belly; spawning fish in rivers are dark with reddish sides
Lifespan:
unknown
Diet:
coho feed on plankton and insects in freshwater and switch to a diet of small fishes while in the ocean
Behavior:
migrate from a marine environment into freshwater streams and rivers of their birth; they spawn only once and then die

The size of an adult coho may measure more than 2 feet (60 cm) in length and can weigh up to 35 pounds (16 kg). However, the average weight of adult coho is 8 pounds (3.6 kg).

Coho salmon have dark metallic blue or greenish backs with silver sides and a light belly and there are small black spots on the back and upper lobe of the tail while in the ocean. The gumline in the lower jaw has lighter pigment than does the Chinook salmon. Spawning fish in inland rivers are dark with reddish-maroon coloration on the sides.

Coho salmon adults migrate from a marine environment into freshwater streams and rivers of their birth in order to mate (called anadromy). They spawn only once and then die (called semelparity).

Adults return to their stream of origin to spawn and die, usually at around three years old. Some precocious males known as "jacks" return as two-year-old spawners. Spawning males develop a strongly hooked snout and large teeth. Females prepare several redds (nests) where the eggs will remain for 6-7 weeks until they hatch.

As the time for migration to the sea approaches, juvenile coho salmon lose their parr marks, a pattern of vertical bars and spots useful for camouflage, and gain the dark back and light belly coloration used by fish living in open water. Their gills and kidneys also begin to change at this time so that they can process salt water.

In their freshwater stages, coho feed on plankton and insects, and switch to a diet of small fishes as adults in the ocean.

Habitat

Coho spend approximately the first half of their life cycle rearing and feeding in streams and small freshwater tributaries. Spawning habitat is small streams with stable gravel substrates. The remainder of the life cycle is spent foraging in estuarine and marine waters of the Pacific Ocean.

Critical habitat was designated on May 5, 1999 for the Central California Coast and Southern Oregon/ Northern California Coast coho salmon, and on February 24, 2016 for the Lower Columbia River coho salmon.

Distribution

The species was historically distributed throughout the North Pacific Ocean from central California to Point Hope, Alaska, through the Aleutian Islands, and from the Anadyr River, Russia, south to Hokkaido, Japan. Coho probably inhabited most coastal streams in Washington, Oregon, and central and northern California. Some populations, now considered extinct, are believed to have migrated hundreds of miles inland to spawn in tributaries of the upper Columbia River in Washington, and the Snake River in Idaho. Coho still occur in Alaska as well.

Population Trends

More information is available in the status review report [pdf] (2005).

Threats

Conservation Efforts

A variety of conservation efforts have been undertaken with some of the most common initiatives including:

The Pacific Coast Salmon Recovery Fund (PCSRF) was established by Congress in 2000 to support the restoration of salmon species. We oversee the Fund, and it is carried out by state and tribal governments.

Regulatory Overview

The threatened and endangered ESUs of coho salmon were listed on June 28, 2005. Some of them had been previously listed in 1996 or 1997, but, because of legal and other issues, all listings were reaffirmed in 2005. The Central California Coastal ESU was uplisted from threatened to endangered in the 2005 listing.

The Puget Sound/Strait of Georgia ESU was listed as a Species of Concern on April 15, 2004.

A final critical habitat designation was published on May 5, 1999 for Central California Coast and Southern Oregon/Northern California Coasts coho salmon, and on February 24, 2016 for the Lower Columbia River coho salmon.

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Osteichthyes
Order: Salmoniformes
Family: Salmonidae
Genus: Oncorhynchus
Species: kisutch

Key Documents

(All documents are in PDF format.)
Title Federal Register Date
Final Recovery Plan for Oregon Coast Coho Salmon 81 FR 90780 12/15/2016
Spotlight Species 5-Year Action Plan n/a 02/10/2016
Proposed ESA Recovery Plan for Oregon Coast Coho Salmon 80 FR 61379 10/13/2015
Klamath River Basin 2012 Report to Congress n/a 2014
Notice of intent to prepare a recovery plan for the Oregon Coast ESU 78 FR 38011 06/25/2013
Negative 90-day finding on an updated petition to delist Southern Oregon and Northern California Coast (SONCC) coho salmon ESU from the ESA 77 FR 55458 09/10/2012
5-year reviews   various
Endangered Central California Coast ESU now includes all naturally spawned populations that occur in Soquel and Aptos creeks 77 FR 19552 04/02/2012
Negative 90-day finding on a petition to delist Southern Oregon and Northern California Coast (SONCC) coho salmon ESU from the ESA 77 FR 1668 01/11/2012
Negative 90-day finding on a petition to delist coho salmon under the ESA 76 FR 62375 10/07/2011
Species of Concern Fact Sheet: Detailed n/a 06/10/2009
n/a 09/22/2008
Federal Register Notices for Coho Salmon various various
Recovery Plans and Related Documents n/a n/a

More Information

Updated: January 5, 2017