Track-a-Cohort -- Winter Chinook

Provides in-season, real-time data in comparison to data in historical years. Post-season, Track-a-Cohort also provides the latest annual data summaries.

Winter Chinook:

Juveniles in River

Migration Timing — annual data

Today Percent

Average Percent by 01/09, with 95%CI, of annual emigrating population for juveniles of each species of interest captured at the following locations and salvaged at SWP and CVP Delta facilities
Species Red Bluff Diversion Dam Tisdale RST Knights Landing RST Sac Trawl (Sherwood) Catch Index Chipps Island Trawl Catch Index Salvage
Chinook, LAD Winter-run, Unclipped 97.8%
(96.3%,99.3%)
BY: 2015 - 2024		 74.3%
(59.6%,89.0%)
BY: 2015 - 2024		 73.1%
(53.9%,92.2%)
BY: 2015 - 2024		 38.0%
(12.1%,63.9%)
BY: 2015 - 2024		 2.1%
(-2.4%,6.6%)
BY: 2015 - 2024		 13.5%
(0.2%,26.9%)
WY: 2016 - 2025
Calculations generated by SacPAS Migration Timing and Conditions by Cohort and Salvage Timing. Data Courtesy of USFWS, Red Bluff; CDFW via StreamNet and CDEC; USFWS, Lodi.

Current Catch

Juveniles in Delta

Salvage Timing — annual data

Historical salvage timing for DNA race Winter-run Chinook, genetic sampling
Historical salvage timing for LAD race Winter-run Chinook

Juvenile Production Estimate JPE — annual data

Delta STARS Survival and Routing Probabilities

Percent Loss of Juvenile Production Estimate (JPE)

Genetic vs Length-at-Date (LAD) Historical Percent Loss of JPE
Cumulative Genetic Percent Loss of JPE

Loss

Genetic vs Length-at-Date (LAD) Total Loss per water year
The figure shows cumulative loss by BiOp Status and Hydrological Classification Index (HCI). Each quadrant of the faceted plot includes grey lines for historical years, colored lines (blue for wet years, red for dry years) for years within the BiOp status and HCI type, a black line for the current year, and a dashed horizontal line indicating the current cumulative loss maximum.

Daily Loss and Export with OMR

Daily LAD natural-origin winter-run Chinook salmon (CVP=gold bars and SWP=blue bars) with daily exports at both the CVP (gold line) and SWP (blue line). Vertical black bars are approximate dates when OMR/OMRI controlling factors change.

Loss Single Year Thresholds

Cumulative Genetic Loss for Current Water Year
Cumulative Length-at-Date (LAD) Loss for Current Water Year

Predicted Weekly Loss

Predicted and Observed Weekly Loss — Tillotson Model
Table of Tillotson et al., (2022) model output of predicted weekly losses for Natural-origin Winter-run Chinook with model weekly average inputs including observed loss, Old and Middle Rivers (OMR), USGS tidally filtered flow (CFS), combined exports from CVP and SWP facilities (CFS), flow at Sacramento and San Joaquin (CFS), and water temperature at Mallard Island (°C).
WY weekDateMedian weekly predicted loss [lower CI, upper CI]Observed Data
Observed lossOMR USGS tidally filtered (CFS)Export, SWP & CVP (CFS)Avg flow at Sacramento (CFS)Avg flow at San Joaquin (CFS)Avg water temperature at Mallard Island (°C)
142025-12-3117.1 [0.0, 109.4]0.0-5344.35673.363590.42732.911.0
132025-12-2413.0 [0.0, 133.0]2.9-5665.76727.963788.23999.711.7
122025-12-170.0 [0.0, 125.5]0.0-5751.46841.422016.33421.310.4
112025-12-100.0 [0.0, 11.7]0.0-3388.62922.010079.51161.410.1
102025-12-030.0 [0.0, 7.9]0.0-3937.03456.710460.52037.811.7
92025-11-260.0 [0.0, 3.2]0.0-6551.47064.312044.91292.413.4
82025-11-190.0 [0.0, 8.7]0.0-8214.39724.416832.31911.515.4
72025-11-120.0 [0.0, 0.0]0.0-7208.66889.012650.71325.216.9
62025-11-050.0 [0.0, 0.0]0.0-5752.95641.610914.51147.717.6
52025-10-290.0 [0.0, 0.0]0.0-5190.04730.411089.91682.717.7
42025-10-220.0 [0.0, 0.0]0.0-4530.04474.411554.72092.118.1
32025-10-150.0 [0.0, 0.0]0.0-4995.74695.412199.62095.018.5
22025-10-080.0 [0.0, 0.0]0.0-5984.35233.015629.01260.719.8
12025-10-010.0 [0.0, 0.0]0.0-9802.99468.018779.41021.020.7

Adults in Ocean

CWT Smolt-to-Adult — annual data

PFMC Abundance, Harvest, Impact — annual data

Table II-2 Sacramento River winter Chinook abundance forecasts, allowable age-3 impact rates, and management performance (reproduced from PFMC 2024a)
Year a/ 3-Year Geometric Mean b/ Abundance Forecast c/ Postseason Abundance d/ Postseason Abundance Value Footnote Age-3 impact rate south of Point Arena, CA
Maximum Allowable (%) e/ Preseason Forecast (%) Postseason Estimate (%) Postseason Estimate Value Footnote
200021.4
2001850823.3
2002909221.8
2003597610.3
20041809024.8
20051890717.2
2006261915.1
2007295417.8
200841520.0
200914390.0
2010696e/
2011326328.3
20121797596013.713.712.6
20131521306712.912.918.8
20142380371815.415.415.8
2015365986719.017.5e/
2016398150819.912.810.7
20172521211715.812.217.6
20181594813914.48.513.9
20191924693515.714.810.0
202030771085420.016.212.6
20219063634620.014.718.8
20225971307120.015.226.2g/
20234540f/20.00.0NAh/
20241013f/12.1NANA
20254507f/20.0NANA
Table II-2 Footnotes
a/ Year indicates the management year in which age-3 SRWC are exposed to ocean fisheries.
b/ Allowable impact rates from 2012-2017 were determined by an abundance-based control rule, where abundance was defined as the most recent three-year geometric mean of escapement.
c/ Since 2018 the abundance forecast has been defined as the predicted age-3 escapement in the absence of fisheries. Forecasts were made using a life cycle model through 2023. Beginning in 2024, forecasts were made using a Gaussian Process model.
d/ Postseason estimates of the age-3 escapement in the absence of fisheries.
e/ Beginning in 2018, allowable impact rates were determined by a new control rule utilizing forecasts of the age-3 escapement in the absence of fisheries.
f/ Insufficient data for postseason estimate.
g/ Preliminary. Incomplete cohort data (age-4 escapement unavailable).
h/ Not estimated. Incomplete cohort data (age-3 and age-4 escapement unavailable).

Adults in River

Adult Escapement — annual data

plot CDFW Grandtab Escapement All Winter run Chinook Sacramento River System
plot CDFW Grandtab Escapement All In-River Winter run Chinook Sacramento River System
plot CDFW Grandtab Escapement All Hatchery Winter run Chinook Sacramento River System