DESCRIPTION
This monitoring project will assess natural salmonid smolt abundance and productivity in the Puyallup River with an emphasis on Fall Chinook and Puget Sound Steelhead. This project will support the protection of presently functioning high priority salmon streams including South Prairie Creek, mainstem Carbon River and upper Puyallup River via higher population level monitoring from catches of mainstem migrants on the lower Puyallup River. Catch in the mainstem will include all salmon and Steelhead that spawned in the afore mentioned tributaries. This project will utilize a rotary screw trap that already exists in the mainstem of the Puyallup River. This project will monitor the "health and condition" of ESA listed species (Chinook, Steelhead and Bull Trout) by providing abundance estimates, run timing, size and other useful metrics. 2018-2019 has been funded, 2020 funding requested from SRFB in the 2019 Grant Round.
An eight-foot rotary screw trap (RST) was used to capture juvenile salmon on the main stem Puyallup River from February 15th to August 9th, 2022. Six full and part time staff worked the trap both day and night during the time period. The rotary screw trap (RST) was located upstream of the confluence with the White River at river mile 10.6 (17.1 rkm). Throughout the sampling period, the trap fished on 74% of total days. A majority of the work, money and hours for this project are spent here, maintaining and fishing the trap.
The primary objective(s) of this project were to estimate juvenile abundance and survival of natural-origin (NOR) Chinook salmon, while detailing run timing and collecting biometric data. Data was also collected on other ESA-list species, steelhead and bull trout. This year 900 Chinook were captured, below the five-year geometric mean of 2,047. Catch in the month of July accounted for 29% of total catch, this is unusual, typically May or June are peak months. Combined, June and July accounted for 57% of total catch. From daily abundance estimates, median migration date was June 1st. Chinook had the longest migration period of any salmon in the Puyallup River. To estimate total abundance of Chinook, daily capture efficiency (modeled) was applied to daily catch and summarized for the year, from this, we estimate 16,412 sub-yearling Chinook passed the trap in 2022. This is the third time in five-years abundance was below 20,000 recruits. The estimate is below the 18-year geometric mean of 35,045.
Based on potential egg deposition of 7.3 million eggs from 1,792 females, egg-to-migrant survival for the 2021 brood was 0.22%. Flow continues to explain the variation in egg-to-migrant survival during the incubation period of Chinook (August - February), similar to other Puget Sound rivers. The survival of this year’s brood was below the five-year mean of 2.1%.
Analysis for other species is still on-going but include abundance estimates of Coho (66,000 – above the 18-year geometric mean of 57,000) and Pink (1.3 million – above the three-year (even years only) geometric mean of 1.0 million).
Again, a majority of time, money and effort were spent on daily trap checks (at all hours of the day), but also performing mark re-capture experiments, on-going maintenance and maintaining fish health in hatcheries for experiments.
There were no amendments to the project and metrics were met as planned (abundance, FWS, run timing).
