Oncorhynchus gorbuscha (Walbaum, 1792)

Common Name: Pink Salmon

Synonyms and Other Names:

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Identification: Oncorhynchus gorbuscha has two dorsal fins including one adipose fin with 13–17 rays in its anal fins. It has a dark mouth and gums and is mostly silver overall, with large oval black spots on the tail and back (Michigan DNR 2003). During spawning, its sides and back are pinkish, giving this species its common name (Halpern et al. 2002).  See also: Moyle (1976a); Scott and Crossman (1973); Wydoski and Whitney (1979); Morrow (1980); Eschmeyer et al. (1983); Page and Burr (1991).


Size: 76 cm


Native Range: Arctic and Pacific drainages from Mackenzie River delta, Northwest Territories, to Sacramento River drainage, California; occasionally as far south as La Jolla, southern California. Also in northeastern Asia (Page and Burr 1991).


Great Lakes Nonindigenous Occurrences: Pink salmon has been introduced into the Great Lakes and the surrounding states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin (Eddy and Underhill 1974; Becker 1983; Cooper 1983; Underhill 1986), and to the coasts of Maine (Kendall 1914a; Morrow 1980) and Maryland (Morrow 1980). This species was collected in Isle Royale National Park and Pictured Rocks National Lakeshore in Michigan (Tilmant 1999).


Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Oncorhynchus gorbuscha are found here.

Full list of USGS occurrences

State/ProvinceFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
20002000*
IL197319731Lake Michigan
IN197319731Lake Michigan
MI1959201719Au Sable; Betsie-Platte; Betsy-Chocolay; Black-Macatawa; Black-Presque Isle; Carp-Pine; Cedar-Ford; Cheboygan; Dead-Kelsey; Fishdam-Sturgeon; Keweenaw Peninsula; Lake Huron; Lake Michigan; Lake Superior; Lone Lake-Ocqueoc; Millecoquins Lake-Brevoort River; Sturgeon; Tahquamenon; Waiska
MN195620012Baptism-Brule; Lake Superior
NY197919863Lake Erie; Lake Ontario; Salmon-Sandy
OH197919863Ashtabula-Chagrin; Lake Erie; Sandusky
PA197919792Chautauqua-Conneaut; Lake Erie
WI1959201410Beartrap-Nemadji; Door-Kewaunee; Lake Michigan; Lake Superior; Lower Fox; Manitowoc-Sheboygan; Menominee; Oconto; Peshtigo; Pike-Root

Table last updated 3/28/2024

† Populations may not be currently present.

* HUCs are not listed for areas where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).


Ecology: Pink salmon are coldwater fish with a preferred temperature range of 5.6 to 14.6 °C, an optimal temperature of 10.1 °C, and an upper incipient lethal temperature of 25.8 °C. Once thought to require salt water to complete their life cycle, a population has become established in the Great Lakes which exhibits genetic variation from their anadromous counterparts that allows them to tolerate freshwater throughout their lives (Gharrett and Thomason, 2011). Lake Superior pink salmon are phenotypically similar to their Pacific Coast counterparts, the major difference being age structure and smaller size of adults. Approximately 90% of the adults mature as 2-year-olds while the remaining 10% mature as 3-year-olds. Pink salmon maturing as 3-year-olds have different growth patterns than those maturing at 2 years of age. Two-year-old pink salmon average 390 mm in length, which is about 30% smaller than 2-year-olds from the Pacific Ocean. Three-year-old females have a lower fecundity and a poorer egg quality than 2-year-old females (Bagdovitz et al. 1986). 

In the Great Lakes, pink salmon move from open lake into rivers to spawn in late summer or early autumn and not all return to their natal river (Kwain and Rose 1986). With a life span of only two or sometimes three years, pink salmon typically spawn biennially (Kocik et al. 1991). After spawning, the female guards the nest and dies within a few days or weeks. Spawning males defend territories, and adults die soon after spawning. Eggs hatch from late December to late February depending on water temperatures. When the young mature enough to leave their gravel nest in late April or early May, they journey downstream in large schools. The young salmon reach adulthood in about 18 months with a size of two to seven pounds and 17 to 19 inches in length (Michigan DNR 2003).


Means of Introduction: This species was introduced accidentally into the Canadian side of Lake Superior in Thunder Bay in 1956, when about 100 salmon escaped while being transferred from a hatchery to a seaplane (Schumacher and Eddy 1960; Eddy and Underhill 1974). Another reference states that about 21,000 surplus fingerlings from the hatchery at Port Arthur, Ontario, were disposed of into the Current River, a tributary of Lake Superior (Becker 1983). The hatchery was raising them to stock in Hudson Bay (Eddy and Underhill 1974). The first evidence of reproduction was noted in 1959, when two second-generation fish were caught in Lake Superior, Minnesota (Schumacher and Eddy 1960; Schumacher and Hale 1962; Eddy and Underhill 1974). The species was first observed in a northern tributary of Lake Huron in 1969 (Parsons 1973). By 1979, it had spread throughout the Great Lakes (Cooper 1983). Emery (1981) gave an account of their spread through the Great Lakes and included a map showing the dispersal. The species was also intentionally stocked on the coasts of Maine and Maryland (Morrow 1980). Also see Schumacher and Eddy (1960), Schumacher and Hale (1962), Parsons (1973), Wagner (1976), Emery (1981), and Kwain and Lawrie (1981).


Status: Established population present throughout the Great Lakes (Emery 1981; Trautman 1981; Phillips et al. 1982; Cooper 1983). Populations in Maine and Maryland survived until about 1973, then disappeared (Morrow 1980).


Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...

EnvironmentalSocioeconomicBeneficial



Oncorhynchus gorbuscha has a moderate environmental impact in the Great Lakes.

Realized:
Pink salmon may displace native chubs by way of food competition and may also compete with native cisco (Coregonus artedi) (Becker 1983). Individuals over one year old feed heavily on rainbow smelt (Osmerus mordax) and alewife (Alosa pseudoharengus), which are important components of the diets of other Great Lakes salmonids (Diana 1990, Kocik et al. 1991, Kocik and Taylor 1987). Pink salmon has also been identified as utilizing spawning habitats similar to those used by brook trout (Salvelinus fontinalis), potentially providing another mechanism of competition (Kocik and Jones 1999).

More research is needed on the role of this species in the food web, its interactions with prey and competitor species, and its impacts on the physical environment and water quality.

There is little or no evidence to support that Oncorhynchus gorbuscha has significant socio-economic impacts in the Great Lakes.

Realized:
Genetic analysis of populations in the St. Marys River, MI indicates that pink salmon is capable of hybridizing with recreationally important chinook salmon (Oncorhynchus tshawytscha) (Kirkpatrick et al. 2007). The first hybrid was identified in 1992 and populations were monitored in the study until 2002 (Kirkpatrick et al. 2007). The implications of this occurrence are unknown. Hybridization has the potential to create further competition for the parental species, especially since the hybrid appears to have growth rates that exceed those of pink and chinook salmon. It is also possible that introgression or suppression of population growth in the parental species could occur (Kirkpatrick et al. 2007).

Potential:
Certain commercial/recreational species could be negatively affected by pink salmon (see above).

Oncorhynchus gorbuscha has a moderate beneficial effect in the Great Lakes.

Realized:
Although pink salmon is not stocked in the Great Lakes like most introduced salmonids, it has spread to all of the Great Lakes, and plays a part in the lakes’ recreational fisheries (Kocik and Taylor 1987). However, it has reportedly been caught more frequently by anglers in spawning streams (MIDNR 2003).


Management: Unlike other Pacific salmon, pink salmon were not deliberately stocked for alewife biocontrol, nor are they deliberate stocked.  Nonetheless, pink salmon descendants of an accidental release have become a valued part of the Great Lakes recreational fishery and they are managed alongside the other Pacific salmonids.  Therefore, pink salmon management objectives are not geared towards the removal or eradication of the species like with most invaders.

Regulations (pertaining to the Great Lakes region)
Direct Regulations:
Great Lakes states and provinces have their own specific fishing regulations. Generally, the overall goals and objectives of Pacific salmon fishing regulations are the same throughout the region i.e., to maintain or enhance a healthy and sustainable salmonid fisheries. Pacific salmon fishing regulations include daily and season bag limits, size limits, permitted baitfish, manner of taking i.e., snagging or hook and line, and designated season dates (See New York DEC, Pennsylvania F&BC, Ohio DNR, Michigan DNR, Indiana DNR, Illinois DNR, Minnesota DNR, Wisconsin DNR, Ontario MNR, and Quebec MRNF websites for specific fishing regulations). 

Indirect Regulations:
Typically, Pacific salmon regulations are not species specific, but rather regulate the salmonid fisheries as a whole. Indirect Pacific salmon regulations include mandated salmonid pathogen screening tests and baitfish regulations.
Mandatory salmonid pathogen screening tests are implemented in all Great Lakes states and provinces. The importation, exportation, and transportation of Pacific salmon is highly regulated to control the spread of infectious diseases and parasites such as VHS, BKD, and whirling disease (See USGS nonindigenous diseases and parasites fact sheets for state and provincial regulations).
State and provincial baitfish regulations have aided in preventing the spread of infectious disease. Specific and or stricter regulations are placed on baitfish species that are known carriers of salmonid pathogens.

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Biological
Like other Pacific salmon, pink salmon prey heavily upon two non-native species in the Great Lakes, the alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax).   Alewives remain a key food source and crucial to the survival of Pacific salmon.  Over the past several decades, Pacific salmon populations have fluctuated with fluctuating alewife populations. Managing one species significantly impacts the other. Pacific salmon and alewives have significant environmental, socio-economic, and beneficial effects in the Great Lakes and therefore integrated management is essential. Rainbow smelt are also a major component of Pacific salmon diet. Similar to alewives, Pacific salmon and rainbow smelt management should be integrated.  Rainbow smelt have a high environmental impact and high beneficial effect in the Great Lakes. The presence or absence of this species significantly alters predator-prey relationships and competition between native species. Managers can also attempt to increase less harmful native prey species stocks while allowing harmful invasive prey species to decrease.  Implementation of this bio-control has potential significant beneficial effects in the Great Lakes with few negative impacts (See USGS fact sheets on alewife and rainbow smelt).

Of the 23 nonindigenous diseases and parasites in the Great Lakes, Aeromonas salmonicida, Renibacterium salmoninarum, Myxobolus cerebralis, and Novirhabdovirus sp. infections have been realized in Great Lakes Pacific salmon, while Heterosporosis sp. and Piscirickettsia cf. salmonis infections have been realized clinically or outside the Great Lakes. Glugea hertwigi, a microsporidian, is known to cause mortality in rainbow smelt. Therefore, Pacific salmon management must include the management of the above pathogens and parasites (See fact sheets on Aeromonas salmonicida, Renibacterium salmoninarum, Myxobolus cerebralis, Novirhabdovirus sp., Heterosporosis sp., Piscirickettsia cf. salmonis, and Glugea hertwigi for information on Great Lakes impacts and management).

Physical
Aquaculture facilities manage wild and cultured Pacific salmon stocks through wild stock assessments and other methods. Managers are then able to make informed decisions on stocking strategies. Research, pathogen screening, and pathogen treatment, etc. is conducted in aquaculture facilities (See state and provincial DEC, MNR, DNR, and corresponding agency and department websites for information on salmonid aquaculture and state hatcheries).

Chemical
Chemical controls for Pacific salmon are not intended to eradicate or kill the species but rather to protect it against infectious disease. Typically, depending on the target species, chemicals controls are only effective in aquaculture or similar systems. Examples of chemicals used and include cefuroxime, chlorination, and disinfectants.


Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.


References (click for full reference list)


Author: Fuller, P., J. Liebig, J. Larson, and A. Fusaro


Contributing Agencies:
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Revision Date: 12/20/2019


Peer Review Date: 6/26/2014


Citation for this information:
Fuller, P., J. Liebig, J. Larson, and A. Fusaro, 2024, Oncorhynchus gorbuscha (Walbaum, 1792): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?Species_ID=906&Potential=N&Type=0&HUCNumber=DHuron, Revision Date: 12/20/2019, Peer Review Date: 6/26/2014, Access Date: 3/28/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.