WDFW LogoWashington Department of Fish & Wildlife
  HELP | EMPLOYMENT | NEWS | CONTACT  
WDFW LogoFishing & Shellfishing
Report a Poacher or Other Violation

Fishing Hotline
360-902-2500

Shellfish Rule
Change Hotline

1-866-880-5431

More Hotline Information...

For more information on
fishing, please contact the
WDFW Fish Program.
360-902-2700
Fish Program District Biologists

For fishing regulation
questions, e-mail us at:
fishregs@dfw.wa.gov

For all other questions and comments, e-mail us at:
fishpgm@dfw.wa.gov

 

 
Chum Salmon Life History
Buy Your License Online! Buy Your License Online!
Chum salmon

Timeline for Life Cycle, Growth, and Survival
The timeline below follows one complete generation of fall chum salmon, from egg to spawning adult.

Life Cycle: The dates given for each life stage represent the approximate norm for fall chum salmon. Each individual stock of salmon has adapted to the unique set of environmental and biological conditions that influence all stages of its life in freshwater and the ocean. These adaptations can cause the timing of the various life stages of each stock to vary substantially.

Growth: The sizes presented below for individual life stages are from two sources. The sizes for juvenile stages are from Salo (1991) and represent approximate rates of growth for Minter Creek fall chum salmon in the 1940s. Adult sizes are from Pratt (1974) and are based on samples from the 1970 Puget Sound chum salmon return. Sizes of chum salmon are highly variable for different stocks and in different years, and the values below are presented only for illustrative purposes. These sizes should not be used to represent the actual or approximate growth rates for any current chum salmon populations.

Survival: As with the growth rates, the survival rates for various chum salmon life stages are presented only to provide an indication of the nature of the mortalities that can occur throughout the life of these fish. The survival rates below are based on values reported by Parker (1962), and represent a chum stock from a small coastal British Columbia stream. Survival rates vary tremendously by stock and by year, and the following values should not be used to represent actual or approximate rates for any Washington chum stocks.

The numbers given for surviving progeny at various life stages begins from a theoretical single year's spawning population of 100 pairs of spawners (or 200 total fish). It is assumed that this is a healthy population of chum salmon, surviving at average rates and able to support fishery removals of 65% of the returning adults. The numbers are based on the population replacing itself, and the resulting total of the three-, four-, and five-year old chum salmon surviving to spawn equal the original population of 200 parent spawners.

YEAR ONE

November-March

eggs

Incubation - Eggs are deposited in the stream gravels during the November through December spawning season. The chum embryos develop within the eggs and hatch after approximately four months. At this time the young fish are called alevins, and they continue to reside in the gravel as they absorb their yolk sacks. After about a month and a half, the alevins emerge from the stream bottom as 1 to 1½ inch long fry. The potential total number of eggs for the 100 female spawners is 300,000 eggs. This number is reduced by factors like: eggs lost during spawning, predation, erosion of redds during floods, siltation, etc. The remaining progeny of 200 spawners when the fry emerge from the gravel total 23,400 fry.

February-July

fry

Migration to Sea - The newly emerged fry immediately begin downstream migration to marine waters. A very small number of chum fry may reside in freshwater until the end of summer. When the fry first enter saltwater they assemble in small schools and reside close to shore to avoid predators. As the young fish grow, they gradually move to deeper waters and generally migrate towards open ocean waters. Mortalities during this early marine life period are primarily the result of predation by birds and other fish species. By mid- to-late summer the juvenile chum have reached ocean waters. At this time they are approximately 4 to 6 inches long. Some chum salmon juveniles will remain in nearshore marine waters until late in their second year before migrating to the open ocean.

May-December

juvenile_may-dec

Ocean Growth - When the juvenile chum salmon leave nearshore waters they migrate generally northward along the Washington and British Columbia coastlines. Their ultimate destination is the Gulf of Alaska, where they will feed and grow for the next 2 to 3 years. The rate of mortality drops as the fish increase in size, with predation continuing to be the primary impact on survival. The remaining progeny of 200 spawners at the end of the first year total 1,265 juvenile chum salmon. These juvenile chum salmon average approximately 11 inches in length and weigh about 0.5 pounds.
YEAR TWO

January-December

juvenile_jan-dec

Ocean Growth - The second year of life is spent in the northeast Pacific Ocean, as the immature chum continue to feed and grow. Those chum salmon that remained in nearshore coastal waters migrate to open ocean waters in the second half of year two. The exact distribution of Washington chum salmon in the northeast Pacific and the Gulf of Alaska is unknown, however, it likely varies from year to year depending on environmental conditions. Mortality rates continue to drop as the fish increase in size, with losses primarily caused by predation by various fish species and marine mammals.
YEAR THREE

January-December

juvenile_jan-dec

Ocean Growth - The immature chum salmon continue to migrate, feed, and grow in the waters of the northeast Pacific. During the year, those the fish that will mature and spawn at age three begin their migration back to Washington waters. The chum that will mature in coming years (as 4- and 5-year old fish) continue their pattern of ocean feeding and growth. The portion of the progeny of 200 spawners that leave the ocean during year three total 215 three- year old maturing adults.

September-November

ocean_adult

Adult Return - As the maturing three-year old chum salmon return to coastal waters they are subjected to low levels of predation mortality, primarily from marine mammals and large fish species like sharks. The remaining progeny of 200 spawners entering nearshore marine waters total 200 three- year old adults. These chum salmon average about 26 inches in length and average about 8.2 pounds in weight.

The chum salmon returning to Washington waters are managed for harvest by recreational, commercial, and tribal fishers. Only those fish in excess of the numbers needed for spawning are subjected to harvest. This example assumes a healthy chum population that can accept a 65% harvest rate. The remaining progeny of 200 spawners after fisheries total 70 three- year old mature adults. A small percentage of the remaining fish will suffer pre-spawning mortalities from causes such as predation or environmental conditions.

November-December

spawners

Spawning - Most fall chum spawning occurs during November and December. Females select preferred sites for spawning and begin the construction of the nest or redd by displacing gravel with her body and tail. Males compete with one another for access to the female. Fertilized eggs are deposited in multiple pockets within the redd over a span of several days. When the redd is complete the female will guard the site until she weakens and dies. Males continue to compete for mates until they die. The spawning process averages about 10 days from start to finish. The progeny of 200 parent spawners that successfully complete spawning in the third year total 60 three- year old spawners.
YEAR FOUR

January-December

juvenile_jan-dec

Ocean Growth - The remaining immature chum salmon continue to migrate, feed, and grow in the waters of the northeast Pacific. During the year, the fish maturing at age four will begin their migration back to Washington waters. Those chum that will mature as age-five fish continue to feed and grow in the northeast Pacific. The portion of the progeny of 200 spawners that leave the ocean during year four total 465 four- year old maturing adults.

September-November

ocean_adult

Adult Return - As the four-year old fish enter coastal waters they are subjected to predation mortality by marine mammals and some large fish species. The remaining progeny of 200 spawners entering nearshore marine waters total 430 four- year old adults. These chum salmon average about 28 inches in length and average about 10.4 pounds in weight.

Those fish in excess of the numbers needed for spawning are harvested by recreational, commercial, and tribal fishers at a 65% harvest rate, suitable for a healthy chum population. The remaining progeny of 200 spawners after fisheries total 150 four- year old mature adults. A small percentage of the remaining fish will suffer pre- spawning mortalities from causes such as predation or environmental conditions.

November-December

spawners

Spawning - The four-year old chum spawners enter their natal stream and complete the spawning act as described above for the age-three fish. Typically, the four-year old fish make up the majority of the spawning population. The progeny of 200 parent spawners that successfully complete spawning in the fourth year are 130 four- year old spawners.
YEAR FIVE

January-October

Juvenile_jan-dec

Ocean Growth - The remaining immature chum salmon continue to migrate, feed, and grow in ocean waters. During the year, the final group of fish to mature begin their migration back to Washington waters. The portion of the progeny of 200 spawners that leave the ocean during year five total 35 five- year old maturing adults.

September-November

ocean_adult

Adult Return - The remaining fifth year fish return to coastal waters and are subjected to limited levels of predation by marine mammals and large fish species. The remaining progeny of 200 spawners entering nearshore marine waters total 30 five- year old adults. These chum salmon average about 29.5 inches in length and average about 11.8 pounds in weight.

Managed fisheries for recreational, commercial, and tribal fishers will harvest those fish in excess of the numbers needed for spawning at a 65% harvest rate. The remaining progeny of 200 spawners after fisheries total 12 five- year old mature adults. A small percentage of the remaining fish will suffer pre-spawning mortalities from causes such as predation or environmental conditions.

November-December

spawners

Spawning - The five-year old chum spawners enter their natal stream and spawn as described above for the age-three fish. The five-year old chum spawners typically make up less than 10% of the spawning population, and very rarely a sixth year fish returns. The progeny of 200 parent spawners that successfully complete spawning in the fifth year total 10 five- year old spawners.

At the conclusion of spawning by the five-year old spawners, the cycle has been completed. The progeny of the original 200 parent spawners returned as three-, four-, and five-years old fish and spawned, starting new generations of chum salmon. In total, 200 fish successfully returned to their streams and spawned, replacing their parents and renewing the life cycle.


LIFE HISTORY SUMMARY

This timeline followed the life history of the progeny of 200 chum salmon spawners. The 100 female spawners in the original population had a potential of 300,000 total eggs for deposition in the stream gravels. After mortalities during egg deposition and the period of incubation, a total of 23,400 fry emerged from the gravel and migrated to saltwater. At the end of the first year of feeding and growth in estuaries and marine waters a total of 1,265 juvenile chum salmon remained. The second year of life was spent feeding and growing in the northeast Pacific Ocean. During the third, fourth, and fifth years of life, individual chum salmon began to mature and return to Washington waters. Over the three years a combined total of 715 maturing adults returned from the ocean. Of this total, 660 adults survived to enter nearshore marine waters, 232 mature adults remained after fisheries, and a total of 200 chum salmon survived to successfully spawn. Over the three years of return, 60 three- year old, 130 four- year old, and 10 five- year old chum salmon returned to their natal streams, successfully spawned, and then died. These spawners replaced the original 200 parent spawners, and renewed the chum salmon cycle of life.

References

Parker, R.R. 1962. A concept of the dynamics of pink salmon populations, p. 203-211.. In Wilimovsky, N.J. (ed.), Symposium on pink salmon. H.R. MacMillan Lectures in Fisheries. U. Brit. Columbia, Vancouver.

Pratt, D.C. 1974. Age, sex, length, weight, and scarring of adult chum salmon (Oncorhynchus keta) harvested by Puget Sound commercial net fisheries from 1964 through 1970. Wash. Dept. Fish. Suppl. Prog. Rept. 78 p.

Salo, E.O. 1991. Life history of chum salmon (Oncorhynchus keta), p. 231-309. In Groot, C. and L. Margolis (eds.), Pacific Salmon Life Histories. Univ. B.C. Press, Vancouver, B.C., Canada.