Pink salmon can be distinguished from other Pacific salmon by the presence of large dark oval spots on the back and the entire caudal fin and their general coloration and form. In the sea, pink salmon are steel blue to blue-green on the back, silver on the sides, and white on the belly. Breeding males become dark on the back and red with brownish green blotches on the sides. Breeding females are similar but less distinctly colored. Maturing males also develop a hump on their back.
The maximum size of pink salmon is about 2.5 feet (76 cm). The maximum reported weight for pink salmon is about 15 pounds (6.8 kg).
Rapid. Pink salmon are among the fastest growing Pacific salmon species.
From the Arctic coast in Alaska and territories in Canada to central California.
Pink salmon have a complex life cycle that spans a variety of freshwater and saltwater habitats. They are born in inland streams and rivers, migrate to coastal estuaries, and then disperse into ocean waters to grow. Once mature, they reverse their course, returning to fresh water to reproduce and die. Pink salmon require cool, clean water with appropriate depth, quantity and flow velocities, and upland and riparian (stream bank) vegetation to stabilize soil and provide shade. They must have clean gravel for spawning and egg-rearing, large woody debris to provide resting and hiding places, and varied channel forms.
About 2 years. Because the pink salmon life cycle is so regular, essentially independent populations spawn in even and odd years. In the southern part of their range, odd year returns are dominant, and in some systems exclusive. Throughout most of Alaska, there is no distinct run dominance, but even year runs predominate in the northwestern part of Alaska.
Pink salmon generally feed on small crustaceans, zooplankton, swimming mollusks, and small fish.
Reaches Reproductive Maturity
Pink salmon reach reproductive maturity when they weigh about 2 to 5 pounds (0.9-2.3 kg). After about 18 months in the ocean, maturing fish return to fresh water to spawn and die.
Pink salmon have the lowest reproductive potential of Pacific salmon, averaging 1,200 to 1,900 eggs per female, and also some of the smallest eggs. The eggs are fertilized when they are deposited in the nests. Males compete with each other to breed with spawning females. Females remain on their redds (nests) one to two weeks after spawning, to protect the area from another female laying her eggs on top. Upon emergence, pink salmon fry migrate quickly to the sea and grow rapidly as they make extensive feeding migrations.
Spawning season runs from August to October. Pink Salmon spawn closer to tidewater than most other Pacific salmon species, generally within 30 miles (48 km) of a river mouth. In areas such as Southeast Alaska and Prince William Sound, the majority of the populations have significant components that spawn in the inter-tidal zone. However, some populations might migrate up to 310 miles (500 km) upstream to spawn. Pink salmon usually spawn at depths of less than 1 foot to just over 3 feet (30-90 cm). In general, they pick sites in gravel with relatively fast currents.
They are anadromous fish, which means that they migrate up rivers from the ocean to breed in fresh water. The incubating eggs, and resulting fry, spend the winter in the stream gravel and as soon as they are about half the weight of a paper clip.
In fresh water, aquatic invertebrates, other fishes, especially sculpins, birds, and small mammals prey on pink salmon eggs, alevins, and fry. In the ocean, other fishes, including other Pacific salmon, and coastal seabirds prey on pink salmon fry and juveniles. Predators of adults include marine mammals, sharks, other fishes such as Pacific halibut, and humpback whales. In freshwater spawning habitats, bears are important predators of adult pink salmon, and wolves, river otters, and bald eagles will also occasionally take pre-spawning adults.
Information courtesy of NOAA.