Sockeye salmon, also known as red or blueback, inhabit the North Pacific and Arctic oceans as well as associated freshwater systems. They range as far as south as California’s Klamath River to as far north as Bathurst Inlet in the Canadian Arctic. Sockeye were an important food source for native Alaskans. Natives ate them fresh or dried them to use in the winter. They remain an important mainstay for commercial fisheries and are popular for sport fishermen. Historically, the sockeye has been one of Alaska’s best for canning due to its ability to retain its red color and its high oil content.
Most sockeye are tinted a bluish silver, and are the slimmest and most streamlined of the five species of Alaskan salmon. One can distinguish sockeye salmon from Chinook, Coho, and pink salmon by their lack of large, black spots. They are different from chum salmon by the number and shape of gill rakers on the first gill arch. Sockeye salmon have twenty-eight to forty long, slender, rough or serrated closely set rakers on the first arch. Chum salmon have nineteen to twenty six short, stout, smooth rakers. Sockeye salmon which are immature, or which spawn prematurely, are elongate, fusiform, and somewhat laterally compressed. Their appearance is a striking metallic green blue back and head, iridescent silver sides, and a white or silvery belly. Some sockeye sport fine black speckling on the back, but large spots are absent. Young sockeye, while in fresh water, exhibit the same general coloration as immature sockeye salmon in the ocean, but they are less iridescent.
Male sockeyes that breed develop elongated, hooked jaws filled with sharp teeth as well as humped backs. Both males and females turn a dark, vibrant red on their sides and back, a pale to olive green color on their heads and upper jaws and white on their lower jaws. When in fresh water, young sockeyes eat mostly zooplankton, including cladocerans, copepods, and ostracods. When in the ocean, they also feed on zooplankton as well as larval and small adult fish, including the sand lance.
Sockeye salmon live in the sea, but enter freshwater to spawn. After hatching, juveniles spend as much as four years in freshwater before migrating to the ocean. Once reaching the ocean, young sockeye mature quickly. They grow from a few ounces to as much as eight pounds in one to four years. Mature sockeyes swim thousands of miles to spawn in the same freshwater system in which they were born, using their olfactory sense as their guide. Like all Pacific salmon, sockeyes die a few weeks after spawning.
Maturing sockeye salmon migrate from freshwater systems to the ocean during the summer months. There is little deviation in when the sockeye arrive at their destinations. Freshwater systems with lakes seem to produce the greatest number of sockeye. Sockeye spawning usually occurs in rivers, streams, and upwelling areas along lake beaches, and is carried out in the same fashion as other salmon. Some sockeye will stay close to freshwater, while others will migrate to the open sea. Sockeye salmon return to their natal stream to spawn after spending one to four years in the ocean. Those mature sockeye, which have spent only one year in the ocean, are called jacks and are, almost without exception, males. Sockeye grow quickly in open ocean. Returning adults usually weigh between four and eight pounds. Sockeye weighing in excess of fifteen pounds have been reported. Some sockeye populations elect to live in freshwater for the duration of their lives. This landlocked form of sockeye salmon, called "kokanee," reaches a much smaller maximum size than the anadromous form and rarely grows to be over 14 inches long.