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).

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

Environmental	Socioeconomic	Beneficial

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).

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, Oncorhynchus gorbuscha prey heavily upon non-native species in the Great Lakes, in particular alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax). Alewives remain a key food source and are crucial to the survival of Pacific salmon.  Over the past several decades, Pink salmon populations have fluctuated with fluctuating alewife populations (Tsehaye et al. 2014). Managing one species significantly impacts the other. Similarly,  integration of management for Oncorhynchus gorbuscha and Osmerus mordax is recommended, due to the trophic linkage between the species and the significant impacts of Osmerus mordax in the Great Lakes.  A decline in Diporeia spp. has also caused Oncorhynchus gorbuscha to target the invasive spiny water flea (Bythotrephes longimanus) (Langan et al. 2026).  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
There are no known physical methods used to control Oncorhynchus gorbuscha in the Great Lakes.

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.