Sockeye Salmon | Oceana Canada

Canadian Marine Life Encyclopedia

Sockeye Salmon

Oncorhynchus nerka

Also known as

Blueback, Kennerly’s salmon, kokanee, little redfish, pygmy salmon, silver trout

Distribution

Throughout the North Pacific Ocean

Ecosystem/Habitat

Rivers and coastal seas

Feeding Habits

Active predator

Conservation Status

Endangered

Taxonomy

Order Salmoniformes (salmons); Family Salmonide (salmons, trouts & chars)

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The word sockeye comes from the Coast Salish name “sukkai,” once commonly used in southwestern British Columbia. It translates roughly to “fish of fishes.” Sockeye are the most iconic and sought after salmon species in British Columbia due to their bright red colour and emerald-green head during spawning, and their rich, bright pink, oily flesh. The rich colour and oil content of sockeye is thought to be because of their diet, which is high in zooplankton and shrimp. 

Sockeye salmon have a more bluntly-pointed head than the other Pacific salmon. They are also the slimmest and most streamlined of the Pacific salmon species and appear almost toothless. They are typically a silver-blue colour with some individuals having tiny black speckles along their body. When sockeye salmon return to their natal rivers to spawn, they undergo intense colour changes,  darkening to a silvery-purple. 

As males continues to mature, their heads become a pale emerald green, their bodies turn bright red and they develop a hump on their back. The male’s jaw also becomes darker, elongated and hooked. Females resemble the males in colour, but are slightly less bright, with green and yellow blotches on their bodies and an absence of a humped back and hooked jaws. On average, sockeye salmon grow to be about 45 to 60 centimetres long and weigh around three kilograms, but some have been recorded between six and seven kilograms. 

Sockeye salmon, like all salmonids, have a complex life cycle that involves life stages in both freshwater and marine environments. When Sockeye salmon reach sexual maturity at around four to five years old, they will begin a long migration to spawn, traveling from the ocean back to the river systems that they were born in. Depending on the population, adults will head inland to spawn at different periods of the year. Populations found further south migrate from June to September, and those found further north migrate from September to December. 

Once inland, females will select sites they deem appropriate to “dig” out nests in the gravel with their tails, called “redds.” Males will then swim over the redds and release sperm to fertilize the eggs, after which the female will immediately bury the eggs in the gravel. The eggs develop over the winter, with the larvae, also known as “fry,” emerging in the following spring. The fry will undergo several “smolts,” or physiological adaptations, in the freshwater environment before they reach their adult form and head back out to the ocean at around two years of age. 

Although the life cycle of Sockeye salmon is the same across all populations, the timing of each of these stages varies with separate spawning population, based on the conditions of the spawning site and corresponding temperature, hydrography (physical features of the water body), and biological features of the area. While in the marine environment, adults feed on zooplankton, insects and most fish that are smaller than them.

Sockeye salmon have been harvested for centuries by First Nations for food, social and ceremonial purposes, traditionally using nets, weirs and gaffs. They have been targeted by commercial and recreational fisheries since the nineteenth century, using purse seines, gill nets, troll gear and handlines. They were the first species of salmon in the Pacific to be harvested commercially, and also the first to be canned in quantity, starting in the late 1870s. 

Today, fishing is the greatest threat to Sockeye salmon populations, since most of the damage to population abundances across British Columbia arose in the early 1900s because of land use changes. Logging operations, damming of river systems, introduction of larger-scale agriculture, and residential development along waterways greatly altered the habitat of Sockeye salmon and has made it difficult for populations to rebound to healthy levels, especially with continued fishing pressure.

Sockeye salmon caught using gillnet, purse sein and troll are listed as a sustainable seafood choice. 

In 2003, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed both the Cultus Lake and Sakinaw Lake populations of Sockeye Salmon as Endangered. They were designated as such because both populations have seen variable declines since the 1950s and 1960s, and dramatic population declines throughout the mid- to late-1900s. 

Due to their freshwater and marine life cycle, they are vulnerable to threats in both environments, and particularly to those in freshwater spawning grounds, such as damming of rivers, logging operations along rivers, degradation of water quality, and human development around waterbodies. Conservation measures such as habitat protections, reduced fishery quotas and hatchery supplementations (raising salmon from eggs and releasing them) have been put in place with the hope of improving the status of Sockeye salmon in Canada’s Pacific ocean.

Oceana Canada is working to protect Canada’s oceans for species like the Sockeye salmon. Find out more about our campaigns and join us in helping to bring abundance back to the ocean.