FWP: Salmon Spawn Wrap-Up 10.23.26

-by Fort Peck biologist Heath Headley and hatchery manager Wade Geraets

Fort Peck hatchery and fisheries staff completed Chinook salmon spawning operations this past week by collecting a total of an estimated 763,000 eggs.

The numbers of salmon collected were lower than the previous couple of years; however, the size of salmon collected this season were some of the largest since spawning operations have begun.

Females collected and used during the spawn this fall averaged 20.2 pounds compared to 15.1 pounds in 2025. The male in the picture on the scale weighed 36.3 pounds!

Good numbers of adult cisco, salmon’s main forage base, that averaged 8-9 inches along with high numbers young-of-year cisco that averaged approximately 5 inches in length contributed to these phenomenal weights in 2026.

In addition, it appears a large portion of these fish collected and spawned were 4-year-old fish. Otoliths were collected from fish used during the spawning process and will be aged at a later date to confirm ages.

These larger females also held larger eggs and more eggs when compared to previous years. The larger egg size also filled the incubation jars sooner in 2026 than in 2025 when a total of 895,131 eggs were collected.

These large fish averaged 3.7 pound of eggs per female this fall compared to 2.6 pounds of eggs per female in 2025. The average number of eggs per female Chinook in 2026 was 5,156 eggs compared to 4,662 eggs per female in 2025.

As these “green eggs” (those eggs recently fertilized) develop, hatchery staff will continue to observe continued egg development.

Once the eggs develop eyes in the eggs (now “eyed eggs”), those eggs will be picked. Picking eggs is removing the dead/non-fertilized eggs from the live eggs and calculating the number of live eggs to determine the estimated survival to hatched “sac fry”.

Sac fry are fish that have a visible egg sac, that is used for further fish development and growth. After the egg sac is used up, these fish will be placed on specialized feed program for continued development, until they are released back into Fort Peck Reservoir in the spring of 2027.

^{Photos via Montana FWP | Feature image caption: 36.3 pound male Chinook salmon}