Track-a-Cohort -- Steelhead

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.

Juveniles in River

Migration Timing — annual data

Today Percent

Average Percent by 01/28, 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
Steelhead, Unclipped (January-December) 1.1%
(0.0%,2.3%)
BY: 2015 - 2025		 25.9%
(9.6%,42.2%)
BY: 2015 - 2025		 31.7%
(13.6%,49.9%)
BY: 2015 - 2025		 5.8%
(-3.2%,14.8%)
BY: 2015 - 2025		 4.0%
(-0.6%,8.6%)
BY: 2015 - 2025		  
Steelhead, Unclipped (Water Year)           8.7%
(1.1%,16.4%)
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 Unclipped Steelhead
Historical salvage timing for Clipped Steelhead

Delta STARS Survival and Routing Probabilities

Winter-run Chinook presented as surrogate for Steelhead

Winter-run Chinook as surrogate for Steelhead
Winter-run Chinook as surrogate for Steelhead
Winter-run Chinook as surrogate for Steelhead

Total Loss — Clipped and Unclipped Steelhead

Size (Fork Length) Distribution of Steelhead Loss, Combined

Figure compares density plots that highlight historical (WY1994 to WY2023) size distribution and histogram of current year (WY2024) size distribution by rear type (yellow = unclipped; blue = clipped). Fork lengths below 750 mm were included in dataset.

WY Size (Fork Length) Distribution of Steelhead Loss

Cumulative Loss by BiOp Status and Hydrologic Classification Index

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.

Loss Single Year Thresholds

Included from Salmonids, Steelhead, and Current Conditions for the Delta Actions Team (DAT), Workgroups & Teams.

graph Natural Central Valley Steelhead with WY2009-2018 history
Natural Central Valley Steelhead Loss Cumulative to Date with Historical Loss and Single Year Loss Thresholds
line graph loss Hatchery Central Valley Steelhead
Hatchery Central Valley Steelhead Loss Cumulative to Date

Minimization of Loss

Annual loss of clipped juvenile steelhead at the salvage facilities and total hatchery juvenile steelhead release numbers. Coleman NFH releases from USFWS, CDFW hatchery releases available from calfish.org, salvage from Fish Salvage Monitoring, CDFW Bay Delta Region, and loss calculated by SacPAS. Loss and percent loss for WY2026 is incomplete.
Water Year (WY)Brood Year (BY)Total Hatchery Steelhead Releases (BY)Loss of clipped steelhead at the facilities (WY)% Loss of Total Hatchery Releases
202620251373848279.850.020
2025202417988592532.140.141
2024202315929982850.320.179
2023202216234833655.740.225
202220211696967639.790.038
202120201853751341.690.018
202020191084899659.440.061
2019201812649395777.700.457
201820178113792462.900.304
201720161019501164.290.016
20163566.87
20151841.19
2014327.83
20131901.95
20121141.16
20112823.07
20106548.28
20092439.11
20086558.86
20074173.84
20062758.54
20056661.86
200418643.98
200324077.48
20025957.45
200124779.83
200018795.42
1999555.64
1998496.44
19974.33
1996330.74
1995146.72
1994125.25
19931576.95

Daily Loss and Export with OMR

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 Steelhead 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)
172026-01-2120.0 [0.0, 261.0]2.7-5562.06372.332142.82339.510.4
162026-01-1417.3 [0.0, 134.4]0.0-4711.45506.947209.22576.410.4
152026-01-0740.1 [0.0, 306.5]38.5-5178.66781.070255.23328.310.8
142025-12-3117.3 [0.0, 220.0]2.7-5344.35673.363590.42732.911.0
132025-12-240.0 [0.0, 108.6]2.7-5665.76727.963788.23999.711.7
122025-12-170.0 [0.0, 65.7]0.0-5751.46841.422016.33421.310.4
112025-12-100.0 [0.0, 2.7]0.0-3388.62922.010079.51161.410.1
102025-12-030.0 [0.0, 17.3]0.0-3937.03456.710460.52037.811.7
92025-11-260.0 [0.0, 17.3]0.0-6551.47064.312044.91292.413.4
82025-11-190.0 [0.0, 100.5]0.0-8214.39724.416832.31911.515.4
72025-11-120.0 [0.0, 17.3]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, 5.6]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, 17.3]0.0-5984.35233.015629.01260.719.8
12025-10-010.0 [0.0, 17.3]0.0-9802.99468.018779.41021.020.7

Adults in Ocean

CWT Smolt-to-Adult — annual data

Adults in River

No data sets or products to offer at this time.