Date requested: 3/8/2017 3:23:08 PM

Requester: Debbie Milks

Requester email: deborah.milks@dfw.wa.gov

Request status: Implemented

Action and Files
Target group Site Action Tags for Action Total Tags Released Start Date End date Additional Info
Snake River Hatchery releases GRA Collect all 52 8/1/2017 11/30/2017 Our goal is to tag 52 but we will need to enter more fish into the sbyc database because some fish detected at dams below LGR may not convert to fish encounted at LGR (fish taken in fisheries and fish remaining in the reservoir downstream of LGR)
Title: Snake River Hatchery Fall Chinook Fidelity and Fallback Study 2017
Project Lead: Debbie Milks
Agency: WDFW
Project Number: 2012-013-00
Funding Agency: BPA
Project Objectives: The final year of this study will have one objective – 1) quantify fallback at LGD of adults returning from releases of yearling and subyearling smolts from Lyons Ferry Hatchery (this SbyC request). This project has four field components: (1) PIT tagging juvenile fish has already occurred under separate studies); (2) radio-tag adult fish a LGR Dam adult trap; (3) track fish throughout the Snake River and tributaries using a network of fixed station radio receivers; and (4) validate fixed site detections through mobile tracking and field observation. This study will continue through 2017.
Study Description: The Snake River fall Chinook Hatchery Genetic Management Plans (HGMPs) describe hatchery programs that were developed to mitigate for the effects of the Federal Columbia River Power System (FCRPS) and Idaho Power Company dams. These programs were developed by the US v. Oregon Parties who agreed to implement them according to the 2008-2017 US v. Oregon Management Agreement . The hatchery programs are intended to supplement the natural spawning component of Snake River fall Chinook and provide for continued fisheries within and outside of the Snake River basin. Uncertainty exists regarding the success or impacts of supplementation on the natural population. During consultation with NOAA Fisheries for ESA coverage for the programs, several critical data gaps were identified; agreement was reached to design and implement studies to answer these questions as a special condition of section 10 permits 16607 and 16615. The proposal below describes an effort to better understand the behavior of subyearling and yearling smolt releases when they return as adults. Spawning aggregates within the basin are not isolated and although the fish released from the Fall Chinook Acclimation Pond (FCAP) facilities have relatively strong fidelity to their release location there is a measurable amount of interchange of fish. Garcia et al. (2004) tracked 515 fall Chinook from 1997-2001 and determined that 32% of the supplementation fish overall spawned in areas other than their release reach. Specifically 11% of the males and 4% of the females from the Captain Johns Rapids acclimation pond spawned in the Upper Snake River Reach. All of this research was done on acclimated yearling age smolt release groups. Since the early 2000’s, increased releases of subyearling smolts have occurred throughout the basin from FCAP acclimation facilities (AF) and as direct releases from hatcheries in Washington, Oregon and Idaho. Fidelity of adults to release site areas is unknown for these sub-yearling release groups. In an attempt to understand spawner distribution associated with sub-yearling releases we propose to replicate the Garcia et al. (2004) study using returning adults Passive Integrated Transponder (PIT) tagged as juveniles under the U.S. Army Corp of Engineers’ (COE) Evaluating the Responses of Snake and Columbia River Basin Fall Chinook Salmon to Dam Passage Strategies and Experiences study (Consensus Study) as the known release site fish to radio tag. Sufficient numbers of specific release site PIT tagged adults should be available over the next 3-5 years (2013 to 2017). Beyond understanding the behavior of adults returning to the natural production areas of the basin, of particular interest to NOAA Fisheries is the spawning distribution upstream of Lower Granite Dam (LGD) of Lyons Ferry Hatchery (LFH) on-station release (‘stray’) groups. These adults have been documented passing LGD through systematic sampling at the adult trap facility at the dam and from detections of PIT tags passing the ladder. The NOAA staff are concerned that these adults are contributing a significant number of hatchery fish to the spawning population upstream of LGR Dam. If these LFH on-site released fish do intermix with wild fish in significant numbers, they could be depressing development of within population diversity that may arise from spawning in diverse habitats. However, Mendel and Milks (1997) documented upstream migration, passage at dams and the ultimate spawning location of fall Chinook released from Lyons Ferry Hatchery returning as adults in 1992 and 1993. They found that a significant number of those fish fell back over or through the dam and thus did not remain in upstream spawning reaches. Repeating their study with adults returning from subyearling releases should answer whether they behave similarly. Sufficient numbers of on-station yearling releases have been PIT tagged in recent years and will be included in the 2013-2017 radio tagging and additional subyearlings are being tagged to facilitate their capture as adults in 2015-2017.
Juvenile Description:
Smolt-to-Adult Ratio:
Collection Efficiency:
Adult Description: Fall Chinook, Adults, Snake River stock, ESA threatened, targeting 52 adults to radio tag of fish already PIT tagged as juveniles, Radio tags will be implanted at the LGR Adult fish trap and then they will be released from into the fish ladder to continue their migration.
Certify: True