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Track-a-Cohort

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.

Steelhead

Juveniles in River

Migration Timing — annual data

Today Percent

Average Percent by 03/28, 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) 3.5%
(1.7%,5.3%)
BY: 2015 - 2024		 55.0%
(33.1%,76.9%)
BY: 2015 - 2024		 55.1%
(34.6%,75.5%)
BY: 2015 - 2024		 61.2%
(35.7%,86.7%)
BY: 2015 - 2024		 51.4%
(32.8%,70.0%)
BY: 2015 - 2024		  
Steelhead, Unclipped (Water Year)           52.8%
(42.3%,63.3%)
WY: 2015 - 2024
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 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

Minimization of Loss

Annual loss of clipped juvenile steelhead at the salvage facilities and total hatchery juvenile steelhead release numbers for brood years 2016 to 2023*. From 2016 to 2024, average annual % lost to the facilities was 0.153%. Note that release locations and dates, which vary by year, were not considered for this calculation. USBR acquired hatchery release numbers from: CDFW hatchery releases- Calfish.org and USFWS hatchery releases data provided by Kevin Offill, 3/13/2024. Water facility loss data acquired from: SacPAS and reflects Water Year 2017 - 3/12/2024. * BY23 includes all fish released prior to 3/14/2024 (data is preliminary).
BroodYearTotal Hatchery Steelhead Release Number (BY)Loss of clipped steelhead at the facilities (WY)% Total Hatchery Release Number Lost to the FacilitiesWaterYear
20161,019,501164.290.0162017
2017811,3792,462.900.3042018
20181,264,9395,777.700.4572019
20191,084,899659.440.0612020
20201,853,751341.690.0182021
20211,676,701639.790.0382022
20221,623,4833,650.300.2252023
20231,592,9982,576.290.1622024

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)
252025-03-1877.4 [1.7, 483.0]87.8-4553.36355.951043.04759.412.7
242025-03-11115.8 [0.0, 515.4]39.6-5785.76453.737456.52720.912.5
232025-03-0452.6 [0.0, 383.7]22.9-5840.06014.739237.31848.312.8
222025-02-2552.0 [0.0, 382.9]50.0-5990.06102.154856.11537.312.6
212025-02-1891.8 [3.4, 517.4]85.6-5437.16419.370208.31845.311.3
202025-02-1157.6 [0.0, 389.0]47.2-5700.06281.674267.42099.19.8
192025-02-0460.6 [0.0, 603.2]41.2-7130.06841.675838.91286.510.0
182025-01-2821.7 [0.0, 382.9]2.7-6428.66265.631222.21196.69.7
122024-12-170.0 [0.0, 157.5]17.3-3885.73505.941744.81266.310.0

Adults in Ocean

CWT Smolt-to-Adult — annual data

Adults in River

No data sets or products to offer at this time.