Spring-Run Juvenile Production Estimate Independent Peer Review

Background

The California Department of Water Resources (DWR) operates, maintains, and manages the State Water Project (SWP) facilities. This project is a water storage and delivery system, comprising reservoirs, aqueducts, power plants, and pumping plants. Its main purpose is to store water and release it for flood control, hydropower generation, water supply diversion, and environmental and fishery beneficial uses.

Central Valley spring-run Chinook salmon (Oncorhynchus tshawytscha; “spring-run”) are listed as threatened under both the California Endangered Species Act and the federal Endangered Species Act.

Orientation and Focus

The California Department of Fish and Wildlife (CDFW) issued an Incidental Take Permit (ITP) to DWR for the continued operation of the SWP in 2024. The 2024 ITP requires the development of a Juvenile Production Estimate (JPE) for spring-run Chinook Salmon (SRJPE) to support the development of future measures to minimize the impacts of water operations on spring-run and to improve or develop new spring-run life cycle models. A JPE is a forecast for the number of young salmon entering the Sacramento-San Joaquin Delta on their way to the ocean.

The goal of this independent scientific peer review is to review the scientific approach developed for calculating an annual SRJPE and provide recommendations to DWR and the multi-agent team tasked with its development. The SRJPE plan will incorporate feedback from this review prior to submittal to CDFW and the National Marine Fisheries Service (NMFS) for approval and prior to implementation. The planning team for this review includes representatives from DWR, CDFW, United States Bureau of Reclamation, National Oceanic and Atmospheric Administration, United States Fish and Wildlife Service, and the Delta Stewardship Council’s Delta Science Program.

Peer Review Report

The Delta Science Program coordinates reviews in accordance with its mission to provide the best possible unbiased scientific information to inform water and environmental decision-making. As requested by DWR, the review will include a Panel Review Report developed by the Reviewers, which will address the Review Questions in the Charge based on their expertise.

View DWR’s request letter to Delta Lead Scientist, Dr. Lisamarie Windham-Myers.

View Dr. Windham-Myers's response in PDF format.

Review Materials

Review documents

  1. Introduction and IPR Materials Package Overview
  2. Monitoring and Data Overview
  3. SRJPE Integrated Forecast Model
  4. BT-SPAS-X Tributary Outmigrant Abundance Model at Rotary Screw Traps*
  5. BT-SPAS-X Mainstem Outmigrant Abundance Model at Rotary Screw Traps*
  6. PLAD Run-assignment Model
  7. Stock-Recruit Model
  8. In season-Outmigrant Model
  9. Smolt Survival Model*

*Documents Available Upon Request

Supplemental Materials

  1. Chapter 4 Appendix A Capture Abundance Tributaries All Run*
  2. Chapter 4 Appendix B Capture Abundance Tributaries Spring Run
  3. Chapter 5 Appendix A Capture Abundance Mainstem All Run*
  4. Chapter 5 Appendix B Capture Abundances Mainstem Spring Run
  5. Chapter 6 Appendix A Probabilistic Length-at-Date Model Run Type Predictions for Sacramento River and Tributary Rotary Screw Trap Sites
  6. Chapter 7 Appendix A Pearson Correlations
  7. Chapter 7 Appendix B Posterior Distributions
  8. Chapter 8 Appendix A Weekly Outmigration Timing Uncertainty
  9. Chapter 8 Appendix B Annual Out-of-Sample Error

*Documents Available Upon Request

Charge to the Independent Review Panel

The Charge to the independent review panel provides the direction, context, and timeline for the review. The Charge includes orientation and focus for the review effort, support materials to be considered, and specific questions for the Reviewers to address during the review process.

View the Charge.

Final Review Report

Expected April 2026

Reviewers

Charlie Chamberlain - Lead Author

100 Dogs Fluvial

Charlie earned his BS in Agricultural Science from California State University, Fresno. His graduate work at Humboldt State University (now Cal Poly Humboldt) investigated the habitat needs of Tidewater Goby in the northern half of their California range. He started his family while at Humboldt and began a long career in fisheries monitoring and restoration in the Klamath and Trinity River basins, where he worked for the US Forest Service, the Yurok Tribal Fisheries Program, and the US Fish and Wildlife Service. He moved to the Redding area in 2015, where he finished out his 30+ year federal career in fish monitoring and restoration in the Sacramento River Basin. He currently serves on the Board of Directors for the Western Shasta Resource Conservation District and started a fish and restoration consulting service, 100 Dogs Fluvial.

Dr. Greg Ruggerone - Panel Chair

Salmon Science

Greg has investigated population dynamics, ecology, and management of Pacific salmon in Alaska and the Pacific Northwest since 1979. Most of his research involves factors that affect growth, age at maturation, and survival of salmon in freshwater and marine habitats, including predation studies involving seabirds, bears, char, and salmon in Alaska and the Columbia Basin. He has served on the NWPCC's Independent Scientific Advisory Board (ISAB), Independent Scientific Review Panel (ISRP), Hatchery Scientific Review Group (HSRG), and other salmon science panels in Alaska and California. For the past 25 years, he has used the unique biennial pattern and exceptional abundance of pink salmon to test for their effects on other Pacific salmon species and other marine species.

Dr. Kelly Vasbinder

University of California, Santa Cruz

Kelly Vasbinder is a postdoctoral researcher for Dr. Jerome Fiechter in the Ocean Sciences department at the University of California, Santa Cruz, and will be transitioning into an Assistant Project Scientist position there in January 2026. Her research interests lie in the early life stages of fish and how we can better represent the dynamics of larval and juvenile stages in models. Her current research focus is on the use of Individual Based Modeling (IBMs) of juvenile Chinook salmon to move towards a better understanding of their predator-prey dynamics, their place in local trophic structures, their potential to be impacted by management strategies, and their possible responses to future changes in the environment.

Dr. Julian Olden

Procrustes Environmental Consults

Julian Olden’s research program spans multiple levels of biological organization and modes of inquiry to advance the science and practice of conserving freshwater ecosystems. His principal interests include ecohydrology (dams, environmental flows), community ecology (freshwater fishes, amphibians, invertebrates), invasion biology (science and development of management tools), macroecology (testing and advancing the field of biogeography), climate change (impacts and adaptation strategies), and conservation biology (science and implementation at local and regional scales). Although his research program focuses on these major areas, his enthusiasm for research bridges both basic and applied ecology. A common thread throughout this research is a strong emphasis on the application of quantitative approaches to data analysis, including the development of innovative statistical techniques for exploring complex ecological data.

Dr. Carl Schwarz

StatMathComp Consulting by Schwarz Inc.

Carl Schwarz obtained his Ph.D. from the University of Manitoba’s Department of Statistics in 1988. He was a member of the Faculty at UM until 1993, when he moved to Simon Fraser University. He remained at SFU until the end of 2018, when he retired. He holds P.Stat. (Professional Statistician) designations from both the Statistical Society of Canada and the American Statistical Association. He received the Impact of Applied and Collaborative Research Award from the SSC and has been named a Fellow of the ASA. He has received university-wide teaching awards from the UM and SFU.

Carl’s research interests are in statistical ecology, particularly capture-recapture and related methods to estimate parameters of animal populations such as abundance, survival, movement, occupancy, etc. Projects have ranged from estimating dolphin numbers in the Gulf of Mexico, killer whale numbers in the Strait of Georgia, and salmon escapement in Canada and the United States, to more recent efforts in monitoring illegally killed elephants in Africa and Asia.

He is also the principal of StatMathComp Consulting, which offers short courses in statistical methods for ecology, R, and related subjects, as well as design and analysis support for ecological projects for government, non-profits, and industry.