Temperate to polar latitudes of the north Pacific Ocean
Spawn in rivers; feed in coastal seas
Near Threatened With Extinction
Order Salmoniformes (salmons and relatives), Family Salmonidae (salmons and trouts)
The pink salmon is an iconic species of the north Pacific Ocean and is one of the most important fishery species throughout its range. It reaches lengths of only 30 inches (76 cm) and weights of only 15 pounds (6.8 kg). It is much smaller than the Chinook salmon and other salmons that live in the Pacific Ocean. The pink salmon gets its common name from the classic pink color of its flesh. Like all salmons, this species is noted for undergoing long migrations and significant physiological changes during a transition in habitat from freshwater rivers, to coastal seas, and back to freshwater rivers.
Adult pink salmon live in coastal seas and feed mostly on pelagic invertebrates. During the oceanic portion of their life cycle, these fish are primarily concerned with growing and storing energy that they will require for successful reproduction. This period lasts only a couple of years. Once they reach reproductive age (at two years old), they begin a long migration to their preferred spawning ground, sometimes far inland, in freshwater rivers. Interestingly, though they mix into large populations at sea, each individual pink salmon typically returns to spawn in the river where it hatched. Thousands of individuals migrate to and reach the spawning grounds at the same time. Once they arrive, females dig nests in light gravel and lay their eggs on the river bottom. Males fertilize the eggs externally, and then the females bury the nests. Pink salmon do not feed during the long trip to spawn, and the difficult task of swimming upriver, jumping up rapids and waterfalls, and digging nests is too much to survive. Within a few days after spawning, all individuals die. After they hatch, baby pink salmon slowly make their way to the ocean, where they feed until they reach maturity and begin the cycle again.
Salmon are important oceanic prey for species such as the Steller sea lion and the killer whale. They are also an extremely important source of nutrients and food for species that live near their spawning grounds (where they all die). Those species include bears, predatory and scavenging birds, wolves, and countless other species. In fact, even trees growing along north Pacific rivers likely rely on dead salmon for vital nutrients required for growth. The pink salmon is also a very important fishery species throughout its range, and tens of millions (if not hundreds of millions) of individuals are captured by net fisheries each year. Unfortunately, overfishing, climate change, and damming of large, coastal rivers all threaten pink salmon, and some populations (particularly in the continental United States) are heavily depleted. The species as a whole, however, is not currently at risk of extinction. Dams that prevent this species from reaching its preferred spawning grounds are probably the most detrimental current human impact on pink salmon populations.