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Records

  • 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 / non native species
    Updated November 30, 2022
  • 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 November 30, 2022
  • 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 November 30, 2022
  • Title

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

    Lead University of California - Berkeley [UC Berkeley]
    Description The overarching goal of this study is to investigate the time-varying effects of flow variation and food availability on longfin smelt population dynamics, via advanced modeling of a diverse set of environmental and ecological monitoring time series. Specifically, this project will:(1) Assess how key environmental drivers (flow, salinity, temperature) and zooplankton abundance have changed over the past 5 decades (1967 to present) across the San Francisco Estuary (SFE); (2) Examine how longfin smelt population dynamics have changed over that time period, and whether/when breakpoints in abundance and trends exist (e.g., periods of 'decline' vs' stability'); (3) Quantify the effects of environmental vs. food-related drivers--and potential interactions between them--on driving observed fluctuations in longfin smelt dynamics; (4) Determine whether/how environment-smelt relationships have changed in magnitude or sign over time; and if they changed, whether such changes have been spatially consistent across the SFE. These goals will inform ongoing conservation efforts of longfin smelt by determining the combinations of flow, habitat, and prey availability conditions that lead to stable population dynamics for the species.
    Science topics Fish, Flows, Longfin Smelt, Zooplankton
    Updated November 30, 2022
  • 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 / non native species, Pesticides, Phragmites, Socio-economic drivers
    Updated October 13, 2023
  • 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