Presentation Abstract
The highly altered lower Green river subbasin has been the focus of intense salmon habitat planning and restoration efforts since the listing of Puget Sound Chinook in 1999. Monitoring juvenile chinook migration and life history dynamics has been critical for tailoring habitat restoration in the Green River. In the lower Green subbasin, however, juvenile salmon population monitoring using screw traps has proven to be difficult due to low gradient and water velocities. Meanwhile, traditional monitoring methods (e.g., electrofishing and seining) cannot accurately quantify residence time or survival rates. Given the large financial investments of habitat restoration in the lower Green, it is critical to gain an understanding of these life history traits in a highly altered basin to ensure that salmon recovery dollars are being spent effectively. To achieve this, this project piloted a new PIT tag antenna for the first time in western Washington to measure juvenile Chinook migration patterns, residence time, and survival in the lower Green where previously this information was unknown. Natural origin juvenile Chinook salmon were PIT tagged at the WDFW screw trap near the upstream end of the lower Green subbasin, while hatchery juveniles from Soos Creek Hatchery were used to perform barge efficiency trials as well as release at the screw trap. Results from this demonstrated that the PIT tag barge technology was an effective tool, with a mean detection efficiency of 8.8%. Detections of tagged fish from the WDFW screw trap proved for the first time that juvenile Chinook are in fact rearing in the lower Green subbasin (up to 63 days), and that smaller fish stayed longer on average. These results also highlight potential mortality issues through this section of river, as detections rates of upstream releases were much lower than expected based on barge efficiency trials.
Session Title
Hatchery, Habitat, & Survival
Conference Track
SSE4: Fish Science and Policy
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-traditionals-143
Start Date
27-4-2022 1:30 PM
End Date
27-4-2022 3:00 PM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Utilizing new PIT tag technology to assess juvenile Chinook migration patterns, residence time, and survival in the lower Green River.
The highly altered lower Green river subbasin has been the focus of intense salmon habitat planning and restoration efforts since the listing of Puget Sound Chinook in 1999. Monitoring juvenile chinook migration and life history dynamics has been critical for tailoring habitat restoration in the Green River. In the lower Green subbasin, however, juvenile salmon population monitoring using screw traps has proven to be difficult due to low gradient and water velocities. Meanwhile, traditional monitoring methods (e.g., electrofishing and seining) cannot accurately quantify residence time or survival rates. Given the large financial investments of habitat restoration in the lower Green, it is critical to gain an understanding of these life history traits in a highly altered basin to ensure that salmon recovery dollars are being spent effectively. To achieve this, this project piloted a new PIT tag antenna for the first time in western Washington to measure juvenile Chinook migration patterns, residence time, and survival in the lower Green where previously this information was unknown. Natural origin juvenile Chinook salmon were PIT tagged at the WDFW screw trap near the upstream end of the lower Green subbasin, while hatchery juveniles from Soos Creek Hatchery were used to perform barge efficiency trials as well as release at the screw trap. Results from this demonstrated that the PIT tag barge technology was an effective tool, with a mean detection efficiency of 8.8%. Detections of tagged fish from the WDFW screw trap proved for the first time that juvenile Chinook are in fact rearing in the lower Green subbasin (up to 63 days), and that smaller fish stayed longer on average. These results also highlight potential mortality issues through this section of river, as detections rates of upstream releases were much lower than expected based on barge efficiency trials.
