was completed in 2014 however it was not approved by the FTC per the intended approval process established when the draft DAMP was prepared. It contains outdated background information and language pertaining to fish collection infrastructure updates that have since been made. Following completion of the draft DAMP, construction began on the current Cowlitz Falls North Shore Collector (CFNSC), which was completed in 2017. Proposed revisions to the draft DAMP would occur under the following categories: (1) removal of hypothetical and prescriptive language for future infrastructure upgrades written prior to completion of the CFNSC; (2) descriptions of the CFNSC in its current form, reflecting completion of construction and highlighting key features that pertain to TWG decision making; (3) summaries and results of directed studies conducted since 2017 that have investigated key decision points within the framework developed for the draft DAMP; and (4) description of the current acoustic telemetry study, well as next steps and future TWG investigations based on progress made since 2017. It’s important to note that the original decision-making framework that was developed for the DAMP will likely largely remain intact but will be reviewed by TWG and FTC to ensure it aligns with extended operations of the CFFF as part of the recently approved Satellite Rearing Facility actions. The proposed revisions constitute a refresh of background information and management actions that have been taken to contemporize the document and reflect 11 years of implementation. Now that the DAMP has been linked to the Satellite Rearing Facility action of increased CFFF operation, it will be updated accordingly. The updated draft will be presented to the FTC for review and approval via a Decision Document. 5. Juvenile coho aging validation at Mayfield Dam: In the spring and summer of 2025, Tacoma Power conducted an evaluation of existing fish passage data collection methods currently in use at both the Cowlitz Falls Fish Facility (CFFF) and the Mayfield juvenile bypass facility (Mayfield). A key discrepancy was found in methods that are used to age juvenile coho, resulting in mismatched data sets coming from each facility. In an effort to standardize these methods, TWG will be working with staff from both facilities to develop and recommend implementation of a standard aging protocol. To help refine this new protocol, juvenile coho age classifications will be validated by aging a subset of scales to be collected during the 2026 coho outmigration season. Scales will be collected from both 20 subyearling and 20 yearling individuals each week throughout four one week-long sampling periods beginning in late May and ending in early July. This amounts to a total of 160 fish, with several scales aged per individual (exact number TBD pending final contract and SOW with the WDFW scale aging lab in Olympia, WA). From the scale age data, accuracy of field calls (based on visual cues in the Mayfield counting house) will be analyzed along with several factors that may potentially influence visual aging accuracy. A multivariate mixed logistic regression model will be developed for accuracy of field call (correct vs. incorrect) with the following independent covariates: scale-determined age, sample week, body length, body weight, and Fulton’s condition factor (K). This analysis will identify which of these factors tend to influence visual-based aging accuracy and will allow us to further refine aging protocols and improve training and coordination for facilities staff. |