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  • Title

    Functional diversity and predator dynamics along the Sacramento and San Joaquin River Delta

    Lead University of California - Santa Cruz [UCSC]
    Description This project's objectives are to: 1) determine snake species diversity and relative abundance, 2) establish resources available and examine the functional role that snakes play along field sites within the Sacramento-San Joaquin River Delta, 3) document predator-prey interactions, and 4) assess the thermal physiology of snakes and the thermal profile of microhabitats along the Sacramento-San Joaquin Delta.
    Science topics Habitat, Invasive and non native species
    Updated February 27, 2025
  • Title

    Using high frequency flux measurements to constrain dissolved inorganic carbon in a tidal wetland carbon budget

    Lead California State University - East Bay
    Description The main purpose of this project is to determine how much carbon (C) is annually sequestered and exported laterally in a tidal wetland environment through the calculation of a net ecosystem C budget. C hydrologic export, mainly in the form of dissolved inorganic C (DIC), is poorly constrained and can pose a significant component of a wetland C budget that is often overlooked. This project intends to reduce that uncertainty by providing a better understanding of the biogeochemical drivers of C cycling and give further insight into wetland management decision-making.
    Science topics Carbon, Restoration, Tidal wetlands
    Updated February 27, 2025
  • Title

    Restoring tidal marsh foodwebs: assessing restoration effects on trophic interactions and energy flows in the San Francisco Bay-Delta

    Lead University of California - Berkeley [UC Berkeley]
    Description The objective of this research on tidal marsh food webs is to examine whether and how restoration (via breaching dikes) may translate into recovery of diverse energy pathways and trophic interactions between basal resources, primary consumers, and predators. By comparing food webs at several tidal marshes, I will answer the following questions: (1) How does food web structure vary between reference and restored tidal marshes over time (seasons and years) and across a salinity gradient? (2)What mechanisms explain variation in food web structure within and between reference and restored tidal marshes–are they related to energy flows (food quantity, quality, transfer efficiency), community composition, or both? (3) What role do non-native species play in potentially shifting food web structure–e.g., changing community membership, sequestering energy from natives? This project builds on a large breadth of research that has used stable isotopes to characterize tidal marsh food webs in the Bay-Delta and other regions.
    Science topics Food webs, Wetlands
    Updated February 27, 2025
  • Title

    Examining the relationship between Longfin Smelt and flow in the San Francisco Bay Delta

    Lead University of California - Berkeley [UC Berkeley]
    Description The number of longfin smelt in the San Francisco Estuary has been in decline for the past several decades. While decreased freshwater flow reaching the estuary has been identified as a contributing factor, the relationship between flow and smelt populations has proven complex and appears to be changing over time. This study examined how water flow affects longfin smelt populations across different habitats in the San Francisco Estuary, analyzing decades of monitoring data from state and federal agencies. The research explored both where smelt live in the estuary and how their populations change over time in response to varying water flows. The findings show that more freshwater flow generally helps smelt populations, especially young fish in shallow waters. However, this beneficial effect appears to be weakening over time in some areas, particularly in open waters away from the shore. This suggests that smelt may be adapting to changing conditions by moving to different parts of the estuary. To help protect this threatened species, conservation efforts may need to focus on both restoring natural water flows and improving habitat conditions throughout the estuary.
    Science topics Fish, Flows, Longfin Smelt, Zooplankton
    Updated February 27, 2025
  • Title

    Integrating social and ecological research to control invasive species: fostering collective action among private and public stakeholders

    Lead Suisun Resource Conservation District
    Description This project will establish an integrated pest management approach for Phragmites (Common reed), an aggressive invasive plant in Delta wetlands. Results will highlight social and cultural barriers to collective action for invasive species control, and include communication tools for developing a regional strategy for Common reed control.
    Science topics Invasive and non native species, Pesticides, Phragmites, Socio economic drivers
    Updated June 10, 2026
  • Title

    Perceptions of risk and management of the Delta levee system

    Lead University of California - Santa Cruz [UCSC]
    Description This study of the perceptions of flood risk and management of the levee system in a deltaic region of California illuminates the social, cultural, and psychological complexities of risk assessment. In order to better understand risk tolerance, we included stakeholders from the following groups: agriculture, engineering, boating and recreation industry, local reclamation districts, conservation organizations, water exporters, county government, and state agencies. Methods employed are qualitative and quantitative and include interviews and media analysis. For decades the Sacramento-San Joaquin Delta has been ripe with political controversies stemming from conflicting interests for its natural resources. The results of this study reveal distinct views on the sustainability of the Delta’s levees, the resilience of local communities, and who is accountable for present conditions. The findings of this study also elucidate nuances in the conversations on the viability of mitigation and adaptation as conditions in the Delta change. We conducted this study in two parts. First, we used the Q methodology and found five distinct views that shape stakeholders’ perceptions of risk of flooding from levee failure: fatalistic, skeptical, free market, bio-centric, and human ingenuity. Second, we collected over 500 newspaper articles from 1986 to 2017 to analyze the framing of issue of flooding in the Delta. As opposed to our study with diverse stakeholders, our media analysis show that the issue of flood risk has been framed in the media mostly along the binary lines of unpreventable catastrophe and control through emergency management.
    Science topics Levees
    Updated January 23, 2024
  • Title

    High-Frequency Monitoring of Delta Island Drainage Waters to inform carbon budgets and contaminant export

    Lead University of California - Santa Cruz [UCSC]
    Description This Proposition 1 funded study aims to use high-frequency measurements and paired grab samples to document water quality and carbon exports in relation to land use change on Delta Islands. The project involves monitoring one station on Twitchell Island and two on Staten Island.
    Science topics Landscape change
    Updated August 25, 2024
  • Title

    Coastal Wetland Restoration a Nature Based Decarbonization Multi-Benefit Climate Mitigation Solution: Policy and Governance

    Lead University of California - Davis [UC Davis]
    Description

    A team at UC Davis (Dr. Mark Lubell, Dr. Gwen Arnold, PhD Candidate Kyra Gmoser-Daskalakis) is conducting social science research on wetland restoration in the California Bay-Delta as part of a larger, interdisciplinary project on wetland restoration across multiple University of California campuses and national labs ("Coastal Wetland Restoration a Nature Based Decarbonization Multi-Benefit Climate Mitigation Solution"). First, the project is conducting social network and spatial analysis using the EcoAtlas project database to examine drivers of wetland restoration investment in the Bay-Delta from the 1980s to now. Second, case studies of individual restoration projects and interviews with 40+ restoration project partners examines barriers to the restoration implementation and perceptions and goals of multi-benefits among interested parties. Preliminary results have been shared at the State of the Estuary and Bay-Delta Science Conferences in 2024. See https://wetlands.ucsc.edu/index.html for more information.
    Science topics Carbon, Carbon storage, Nature-based solutions, Restoration, Restoration planning, Wetlands
    Updated January 29, 2026
  • Title

    How Delta food webs have changed: integrating detrital material into the Delta food web puzzle

    Lead University of California - Davis [UC Davis]
    Description

    Sacramento-San Joaquin Delta (Delta) ecosystems are suffering a collapse in pelagic ecosystems due in part to a decline in energy flow from detrital material (dead phytoplankton, aquatic and terrestrial vascular plants, and minerals), resulting in population declines in threatened and endangered native fish species. Declining primary productivity, decreasing sedimentary inputs to the Delta, impacts of climate change, and the shift in nutrients due to the EchoWater Resource Recovery Facility (EchoWater Facility) upgrade completed in 2023 together evoke a dire need to characterize rapidly changing algal and detrital particle sources and cycling within the Delta to inform management solutions that could improve the food web and better support native fish. To fill this knowledge gap, the researchers assessed the spatial distribution and availability of detrital particles to pelagic aquatic food webs within the Delta by modernizing and developing in-situ light sensors and integrating physical and chemical measurements. They also conducted lab experiments to characterize particle sources and quality by using biomarkers and genetic material to identify species present in the detritus.
    Science topics Detritus, Food webs
    Updated June 16, 2026