Credit: Getty Images
The Delta Stewardship Council’s Delta Science Program and California Sea Grant have announced eight recipients of the 2025 Delta Research Awards, providing nearly $6 million to study critical challenges facing California's Sacramento-San Joaquin Delta (Delta). The Delta Research Awards support projects that combine innovative science with community engagement to address pressing environmental and social needs. The projects, selected following a competitive peer review process, address priorities identified in the 2022-2026 Science Action Agenda.
The research initiatives range from advancing our understanding of endangered sturgeon migration to interweaving Traditional Ecological Knowledge (TEK) with predominant science and management to improve environmental stewardship. The awards are funded by the Delta Stewardship Council and administered in partnership with California Sea Grant. These projects begin in mid-2025 and will run for up to three years. Furthermore, the State Water Contractors will provide funding for two additional, highly ranked projects identified through the Delta Research Awards solicitation.
"The Delta faces complex challenges from changing environmental conditions to protecting endangered species," says Dr. Shauna Oh, director of California Sea Grant. "These research projects bring fresh perspectives and innovative approaches to finding solutions. What's particularly exciting is how many of these studies directly involve Delta communities and combine different types of expertise — from Traditional Ecological Knowledge to cutting-edge technology."
Two-thirds of Californians receive at least some of their fresh water from the Delta, which is one of the largest estuaries in the Americas on the West Coast, supporting farms, wildlife and local communities. Yet this vital region faces mounting challenges. Environmental changes, habitat degradation and aging infrastructure threaten the ecosystems, cultures and economies of the Delta, and beyond. These pressures make the management of the Delta increasingly complex. Since its creation in 2009, the Delta Science Program has worked to provide scientific leadership and to promote research that informs Delta management and policy. The new infusion of research funding includes supporting scientists working directly with Delta communities to find practical solutions to those complex challenges.
"By investing in science that brings together researchers and community members, we're building a stronger foundation for evidence-based decisions about the Delta's future," says Dr. Lisamarie Windham-Myers, lead scientist for the Delta Science Program. "These projects will advance our understanding of the Delta ecosystem and help us develop more effective solutions for its future."
Brief descriptions and linked project pages for Delta Stewardship Council-funded projects can be found below.
The 2025 Delta Research Award recipients funded by the Delta Stewardship Council’s Delta Science Program include:
Project Leads: Karrigan Börk (University of California, Davis), Jonathan Walter (University of California, Davis)
Co-Investigators: Scott Colborne (Michigan State University)
Associated Personnel: Erin Tracy (University of California, Davis), Francisco Bellido-Leiva (University of California, Davis), Sarah Yarnell (University of California, Davis)
Summary: Green sturgeon, ancient fish that have lived in California's waters for thousands of years, are now threatened with extinction due to declining populations and impacts from human activities like dam operations and water management. The Sacramento River and its tributaries serve as critical habitat for these fish, creating a major challenge for water management in the Delta where the needs of large population centers and agriculture have to be balanced with those of threatened species like the green sturgeon. The project will model how changes in river flow patterns affect the migration of endangered green sturgeon in California's rivers. By combining extensive fish tracking data with environmental measurements, the project will create tools that will inform water management decisions, ultimately working to protect these ancient fish while maintaining water supplies for human needs.
UNDERSTANDING SOCIAL-ENVIRONMENTAL INTERACTIONS IN SUISUN-DELTA TIDAL MARSH RESTORATION
Project Leads: Julie Gonzalez (San Francisco State University), Stuart Siegel (San Francisco State University)
Co-Investigators: Cristina Grosso (San Francisco Estuary Institute), Melissa Haeffner (Portland State University)
Summary: The Delta and Suisun Marsh regions are critical parts of California's water system, providing vital habitat and water resources while facing significant environmental challenges. While there has been considerable research on the ecological aspects of tidal marsh restoration in these areas, less is known about how these projects affect and are perceived by different communities, particularly underserved groups. This project seeks to improve how we measure the success of tidal marsh restoration in the Delta and Suisun Marsh by looking at both environmental benefits and community impacts, with special attention to how these projects affect local people. The research team will analyze public support for restoration, document how different communities are affected by these projects and develop tools to help decision-makers better incorporate social factors into restoration planning and evaluation.
Project Lead: Jeff Lauder (Sierra Streams Institute)
Co-Investigators: Shelly Covert (California Heritage: Indigenous Research Project), Aaron Zettler-Mann (South Yuba River Citizens League), Kristen Hein Strohm (Wolf Creek Community Alliance)
Summary: The Delta receives much of its water from streams and rivers that begin in the Sierra Nevada mountains. As changes in temperature, runoff timing and precipitation patterns affect these headwater streams, scientists need better tools to understand and predict how these changes will impact both the streams themselves and the Delta system they feed into. This project will create such tools by combining environmental monitoring, ecological modeling and Traditional Ecological Knowledge, with the ultimate goal of reducing scientific uncertainty about the Delta’s water supply and water quality. The research team will analyze 25 years of water quality and biological data from multiple “sentinel” stream sites that serve as indicators of overall stream health, while working closely with the Nevada City Rancheria Nisenan to develop new models that can identify which waterways and tribal values are most vulnerable to changes in environmental conditions and help guide conservation efforts.
OPTIMIZING MONITORING TOOLS FOR CYANOBACTERIAL HARMFUL BLOOMS IN THE SACRAMENTO-SAN JOAQUIN DELTA
Project Lead: Holly Bowers (Coastal Conservation and Research, Inc)
Co-Investigators: Gry Mine Berg (Environmental Science Associates), Ellen Preece (California Department of Water Resources), Laura Nickelhoff (Environmental Science Associates), Spencer Fern (Restore the Delta)
Summary: Harmful algal blooms have become increasingly frequent and severe in the Delta, posing toxin risks to both the ecosystem and human health. This project aims to develop and validate tools to better monitor harmful cyanobacterial blooms in the Delta by creating an image classification model that can consistently evaluate bloom severity from photos. By improving and standardizing how these blooms are monitored, the project will help water managers and communities better track and respond to potentially harmful algal blooms that affect water quality and public health.
ECO-CULTURAL RENEWAL OF DELTA TULE LANDSCAPES
Project Lead: April Robinson (San Francisco Estuary Institute)
Co-Investigators: Malissa Tayaba (Shingle Springs Band of Miwok Indians), Pamela Cubbler (Koy’o Land Conservancy)
Summary: The Sacramento-San Joaquin Delta has been profoundly shaped by both natural processes and human management over thousands of years. While Indigenous peoples historically stewarded these wetlands through Traditional Ecological Knowledge (TEK), tribal science has been largely overlooked in modern management strategies. This disconnect has resulted in both ecological and cultural losses in the Delta region. This project is a collaboration between the San Francisco Estuary Institute, Shingle Springs Band of Miwok Indians and Colfax Todds Valley Consolidated Tribe to document and integrate TEK and Tribal science of tule wetlands into Delta management and restoration. Through interviews with Tribal elders, literature reviews, a Tribal workshop and interagency summit, the project aims to integrate TEK and western science, to the benefit of Tribes, agencies and others invested in wetland management in the Delta.
LEVERAGING CITIZEN SCIENCE TO STUDY STURGEON MORTALITY IN THE SAN FRANCISCO ESTUARY
Project Lead: Benjamin Burford (University of California, Santa Cruz)
Summary: The San Francisco Bay-Delta Estuary is home to both white sturgeon and federally threatened green sturgeon, but these ancient fish face growing challenges to their survival. While some recreational fishing impacts on white sturgeon survival are known, there is limited understanding of other sources of sturgeon deaths, particularly from ship strikes in the busy shipping channels of the Carquinez Strait. This project will use citizen science to study and quantify non-fishing deaths of sturgeon in the Bay-Delta, with a particular focus on ship strikes in the Carquinez Strait. Through a combination of public reporting, mark-recapture studies and analysis of sturgeon carcasses, the research aims to better understand the scope of sturgeon mortality beyond recreational fishing and inform protections for these threatened species.
Project Lead: Ted Grantham (University of California, Berkeley)
Co-Investigators: Melissa Rohde (Rohde Environmental Consulting, LLC), John Stella (SUNY College of Environment, Science and Forest), James Gilbert (University of California, Santa Cruz)
Summary: The Delta is a critical hub of California's water system, where the needs of cities and farms must be balanced with environmental protection and community values. Currently, decisions about water management in the Delta often rely on limited technical data and do not adequately consider the perspectives of local communities, particularly Native American tribes and other historically marginalized groups. This project aims to develop an integrated approach to understanding and managing the Delta watershed by combining community knowledge with scientific modeling. Through collaborative research with local communities, Native American tribes and other interested parties, the project will create a publicly accessible knowledge platform that links water management decisions to ecosystem health and community values, helping inform more sustainable stewardship of the Delta's waterways and floodplains.
IMPROVING SUBSIDENCE AND CARBON EMISSION MODELING
Project Lead: Steven Deverel (HydroFocus, Inc.)
Summary: The Delta, a crucial hub for California's water supply and agriculture, faces an ongoing challenge to its physical structure: Delta peat soils are gradually sinking and releasing significant greenhouse gases when drained for farming. This process, known as subsidence, threatens levee stability and agricultural sustainability while contributing approximately 1.2 million metric tons of carbon dioxide emissions annually. This project aims to improve and update a key mathematical model called SUBCALC that estimates how much land is sinking and how much greenhouse gas is being released from drained farmland in California's Delta. This essential information helps landowners and planners make decisions about converting farmland to wetlands to reduce these environmental impacts.
The 2025 Delta Research Award recipients, funded by the State Water Contractors, include:
FIT FOR THE WILD: CULTIVATING RELEASE-READY DELTA SMELT IN IMPOUNDMENTS
Project Leads: Florian Mauduit (University of California, Davis), Nann Fangue (University of California, Davis)
Summary: The Delta Smelt, a small fish found only in California's Bay-Delta, has become a symbol of the conflict between environmental conservation and human water demands. Once abundant, this critically endangered species is now nearing extinction despite significant conservation efforts. The University of California, Davis Fish Conservation and Culture Laboratory currently raises Delta Smelt in captivity, but these fish often struggle to survive when released into the wild due to domestication effects. This project aims to develop more effective and cost-efficient methods for rearing Delta Smelt by using natural impoundments: enclosed natural environments that provide more variable and realistic rearing conditions. The researchers will compare key fitness traits between fish raised in impoundments and those raised in traditional hatchery settings. The team will also explore natural spawning methods within these impoundments. The goal of this project is to produce Delta Smelt that are better adapted to wild conditions, potentially improving post-release survival rates and increasing overall production of this critically endangered species.
UNCOVERING GENETIC AND LIFE HISTORY RESILIENCE IN SPRING-RUN CHINOOK SALMON
Project Lead: Flora Cordoleani (University of California, Santa Cruz)
Co-Investigators: Mariah Meek (Michigan State University), Carson Jeffres (University of California, Davis), Malte Willmes (Norwegian Institute for Nature Research)
Summary: California's spring-run Chinook salmon have declined dramatically and now face high extinction risk despite their strong ecological and cultural significance. This project will develop an innovative toolbox combining genetic and isotopic markers to assess Central Valley spring-run Chinook salmon population variety. Researchers will examine adult spawners across the entire population range in 2024-2025 using genomic sequencing, otolith analysis and eye lens isotope methods to characterize migratory strategies, habitat use and age structure. By analyzing how populations with different genetic profiles and habitat utilization patterns respond to environmental challenges like droughts, the project will provide critical insights to guide recovery efforts and inform restoration actions.
About California Sea Grant
NOAA’s California Sea Grant College Program funds marine research, education and outreach throughout California. Headquartered at Scripps Institution of Oceanography at the University of California San Diego, California Sea Grant is one of 34 Sea Grant programs in the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce.