Sockeye Salmon

Name:

Sockeye Salmon

Other Names:

Blueback Salmon

Kokanee Salmon

Scientific Name:

Oncorhynchus nerka

Characteristics:

Sockeye salmon is an anadromous species of salmon found in the Pacific Ocean. The same species when it occurs in landlocked bodies of water is called the Kokanee. It is the third most common species of Pacific salmon, after Pink and Chum salmon. The name "sockeye" is thought to have been a corruption of the various indigenous tribes' word "sukkai."

It has an elongated, torpedo shaped body, with an adipose fin, and a bluntly pointed snout. The gill rakers located just behind the head are long and closely spaced. Its colouration changes as it migrates from saltwater to freshwater in preparation for spawning. In freshwater, its colour is bright red with a pale green head; females may have green and yellow marks or stains. Its colour in saltwater is bluish-green on top, silvery on the bottom, with uniform, shiny skin.

Distinguishing Characteristics:
Sockeye salmon can be distinguished from Chinook, coho, and pink salmon by the lack of large, black spots and from chum salmon by the number and shape of gill rakers on the first gill arch. Sockeye salmon have 28 to 40 long, slender, rough or serrated closely set rakers on the first gill arch, while chum salmon have 19 to 26 short, stout, smooth rakers. Immature and prespawning sockeye salmon are metallic green-blue on the back and top of the head, iridescent silver on the sides, and white or silvery on the belly. Some fine black speckling may occur on the back, but large spots are absent. Juveniles, while in fresh water, have the same general coloration as immature sockeye salmon in the ocean but are less iridescent.

Juveniles also have dark, oval parr marks on their sides. These parr marks are short (less than the diameter of the eye) and rarely extend below the lateral line. Upon maturing in fresh water, breeding males develop a humped back and elongated, hooked jaws filled with sharp teeth. Both sexes turn brilliant to dark red on the back and sides, pale to olive-green on the head and upper jaw, and white on the lower jaw.

Fish Habits:

Sockeye salmon spawn mostly in streams having lakes in their watershed. The young fish, known as fry, spend from zero to three years in the freshwater lake before migrating to the ocean, some stay in the lake and do not migrate to the sea. The fish that migrate spend from one to four years in the salt water, and thus are four to six years old when they return to spawn in summer (July-August). Migration back to the home river is thought to be done using the characteristic smell of the stream, and possibly the sun.

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Spawning season:
Sockeye salmon typically spawn in the summer or fall.

Spawning grounds:
Most sockeye salmon spawn in or near lakes, where the juveniles stay for 1 to 3 years before migrating to sea.

Migrations:
Sockeye salmon are anadromous fish that migrate from the ocean to spawn in fresh water. Mature sockeye salmon travel thousands of miles from ocean feeding areas to spawn in the same freshwater system where they were born. Maturing sockeye salmon typically return to freshwater systems from the ocean during the summer months, and most populations show little variation in their arrival time on the spawning grounds from year to year.

Predators:
Predators of juveniles include fish (including other salmon) and birds. Predators of adults in the ocean include sharks, lampreys, and marine mammals, and bears and occasionally wolves and eagles in fresh water.

Adult Size:

A sockeye can be as long as 840 millimetres (33 in) and weigh 2.5 to 3.5 kilograms (6 to 8 lb).

Fishing Tactics:

Trolling or hand lining are effective methods for catching kokanee. Trolling techniques vary from trolling with small spinners, using corn on a glow hook. Hand lining is popular in the northern part of the state. It is an effective technique wherever kokanee are abundant. Anglers may use trolling techniques to find a school of kokanee. Once they locate a school they may switch to a different technique.

Sockeye Salmon, unlike the other species of Pacific Salmon, feed almost exclusively on plankton. They are able to do this as a result of their many gill rakers, which strain the plankton from the water. It is speculated that this diet is the reason for the striking hue of their flesh, as well as their very low concentration of methyl mercury. They also tend to feed on small aquatic organisms such as shrimp.

Sockeye salmon are currently listed under the U.S. Endangered Species Act with the National Marine Fisheries Service as an endangered species in Snake River (Idaho, Oregon and Washington area) and as a threatened species in Lake Ozette, Washington. Other sockeye populations in the upper Columbia River and in Puget Sound (Washington) are not listed under the Endangered Species Act.

Distribution:

Its current range is as far south as the Columbia River in the eastern Pacific (though individuals have been spotted as far south as the 10 Mile River on the Mendocino Coast of California) and northern Hokkaidō Island in Japan in the western Pacific, and as far north as Bathurst Inlet in the Canadian Arctic in the east and the Anadyr River in Siberia in the west. Landlocked populations occur in the Yukon Territory and British Columbia in Canada, and in Alaska, Washington, Oregon, California, Utah, Idaho, Montana, Colorado,New Mexico, and Wyoming in the United States.