Pink salmon, Oncorhynchus gorbuscha, is a significant Pacific salmon species. Known for its predictable two-year life cycle and abundant populations, it plays an important role in marine and freshwater ecosystems. It contributes substantially to commercial fisheries and wildlife diets.
Distinctive Features
Pink salmon are the smallest Pacific salmon, typically 20 to 25 inches long. In the ocean, they are steel blue to blue-green on their back, with silver sides and a white belly. They have large, dark oval spots on their back and tail fin, distinguishing them from other salmon species.
During the spawning season, male pink salmon undergo a notable transformation, developing a pronounced humped back, earning them the nickname “humpies.” This hump is a secondary sexual characteristic, driven by hormonal changes, and serves a role in attracting females and asserting dominance among males. Males also become dark with reddish-brown blotches, while spawning females show similar but less distinct color changes and do not develop a dorsal hump.
Life Cycle and Habitat
Pink salmon are anadromous, meaning they hatch in freshwater, migrate to the ocean to mature, and then return to freshwater to spawn. They are unique among Pacific salmon for their consistent two-year life cycle. This leads to genetically distinct populations spawning in odd and even-numbered years, which do not interbreed.
After emerging from the gravel, young pink salmon, or fry, migrate directly to estuarine and marine waters, unlike other salmon species. This rapid ocean migration reduces their freshwater time. In the ocean, they feed voraciously on small crustaceans, zooplankton, squid, and small fish, growing rapidly over about 18 months.
Mature pink salmon return to freshwater to spawn, typically between August and October. They often spawn in the lower reaches of rivers, sometimes in intertidal zones or brackish water. Females construct nests, called redds, in the streambed gravel, depositing 1,200 to 1,900 eggs. Both male and female pink salmon die shortly after spawning.
Culinary and Commercial Significance
Pink salmon holds significant commercial importance due to its abundance and predictable two-year return cycles. It is the most numerous Pacific salmon species, with vast commercial harvests, especially in Alaska. Most commercially caught pink salmon is processed for canning, but also sold fresh, frozen, and smoked.
Pink salmon has a milder flavor and softer texture than other salmon varieties, due to its lower oil content. Its flesh, lighter in hue, gets its pink color from crustaceans in its diet. It is a versatile ingredient, often used in canned products, and suitable for dishes like salmon cakes or flaked salads.
Nutritionally, pink salmon provides a source of protein, niacin, vitamin B12, and selenium. It is also recognized for its omega-3 fatty acid content. The consistent availability and nutritional value of pink salmon make it a cost-effective and widely consumed food source globally.