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 2020 in order to evaluate two entire spring Chinook salmon generations and evaluate the effectiveness of hatchery reform actions on the population.

In 2014, WDFW removed 1,146 hatchery fish at Tumwater Dam in order to obtain a target an escapement goal in the Chiwawa River  of ~450 redds.  Only 1,152 hatchery fish were released upstream of Tumwater Dam at a male to female ratio of 0.75 to 1.0.  No age-3 hatchery fish (jacks were released upstream). The proportion of hatchery fish upstream of Tumwater Dam was 0.46 compared to 0.65 if no adult management activities had occurred. A total of 1,505 DNA sampled were collected from smolts in the lower Wenatchee smolt trap in order to estimate the relative reproductive success of the 2012 brood spawners.          

In 2015, work under this contract will consistent of trapping and collecting DNA samples and biological data from potential spawners at Tumwater Dam and progeny from the 2013 spawners at the lower Wenatchee smolt trap.  Additionally, 2015 will be the second year in which hatchery reform measures are implemented at Tumwater Dam which may result in a significant reduction in hatchery origin spawners compared to previous years.

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.