This project will quantitatively evaluate the relative reproductive success of naturally spawning hatchery and natural origin spring Chinook salmon in the Wenatchee River. 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.  We propose to take advantage of recent technological advances in genetics to empirically monitor the reproductive success of hatchery and natural spring Chinook salmon using a DNA-based pedigree approach.  Specifically, we will (1) directly measure the relative reproductive success of hatchery and natural-origin Chinook salmon in both natural and hatchery settings, (2) determine 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) estimate the relative fitness of hatchery-lineage Chinook salmon after they have experienced an entire generation in the natural environment.  The project is intended to last until 2018 in order to evaluate two entire spring Chinook salmon generations.

In 2011, much of the work to be performed will be similar to previous years.  However, based on past results more emphasis will be collecting data on redd morphology from throughout the spawning areas not simply the index areas.  If observed trends in productivity are real (i.e.,  redd location farther upstream = higher productivity), then we should be able to determine what factors (e.g., biological, habitat or environmental) are responsible for those trends.  Explaining observed differences in reproductive success is one of our primary objectives and has not been reported in the literature.    

This project is a collaboration between NOAA-Fisheries (Northwest Fisheries Science Center) and the Washington Department of Fish and Wildlife.  The combined budget total will be in alignment with the approved budget for the project.  Results and progress will be reported on jointly.  For example, a joint authored, single annual report will be generated for the contract period.

This project is an extension of the Chinook salmon supplementation and monitoring program in the Wenatchee River operated by WDFW and funded by Chelan County PUD.