PROJECT BACKGROUND:
This project has focused on quantitative evaluation of the relative reproductive success of naturally spawning hatchery and natural origin spring Chinook salmon in the Wenatchee River since 2004. Hatcheries are one of the main tools that have been used to mitigate for salmon losses caused by the construction and operation of the Columbia River hydropower system. In addition to harvest augmentation, hatcheries have recently been used in attempts to protect stocks from extinction and to enhance natural production (supplementation). Surprisingly, little is known about how much the investment in hatcheries benefits or harms natural production. WDFW and NOAA have used recent technological advances in genetics to empirically monitor the reproductive success of hatchery and natural spring Chinook salmon using a DNA-based pedigree approach. Specific methods have included: (1) direct measurement of the relative reproductive success of hatchery and natural-origin Chinook salmon in both natural and hatchery settings, (2) determination of the degree to which any differences in reproductive success between hatchery and natural Chinook salmon can be explained by measurable biological characteristics such as run timing or size, and (3) estimation of the relative fitness of hatchery-lineage Chinook salmon after they have experienced an entire generation in the natural environment.

This project is a collaboration between NOAA-Fisheries (Northwest Fisheries Science Center) and the Washington Department of Fish and Wildlife. The combined budget total is in alignment with the approved budget for the project. Results and progress are reported on jointly.

CURRENT CONTRACT:
The field data collection associated with this project ended in 2023. However, this project has been extended for two years (until 2/28/26) to provide adequate time to analyze project data, produce draft manuscripts for publication, and develop a complete, final dataset that will be archived on a publicly available server. Specifically, the goal is to have a full, final pedigree of >50,000 adult Chinook salmon that have been sampled since 2004. Data from this final pedigree will be analyzed to compare hatchery and natural reproductive success over multiple generations and evaluate environmental factors that contribute to the variance in reproductive success among individuals. The final analyses and results will be written as several manuscripts to fully describe and document patterns of relative reproductive success for hatchery and natural Chinook salmon in the Wenatchee River and submitted for publication in a suitable scientific journal.

This is the final contract for WDFW in project 2003-039-00.