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  • Title

    Delta Landscapes Primary Production Project

    Lead San Francisco Estuary Institute [SFEI]
    Description This project compares first-order estimates of primary production among five major groups of primary producers, historically and today, to better identify the potential food production of different habitat types, and inform restoration actions that could increase food availability for wildlife.
    Science topics Primary production, Phytoplankton, Emergent macrophytes, Epiphytic algae, SAV/FAV
    Updated April 29, 2022
  • Title

    Soil type as a driver of agricultural climate change response in the Sacramento-San Joaquin Delta

    Lead University of California - Berkeley [UC Berkeley]
    Description This research project aims to increase understanding of how iron-rich peatland soils cycle carbon, nitrogen, and phosphorus in the delta and establish how carbon and nitrogen biogeochemistry and greenhouse gas emissions vary with management practices and crop type. It also explores how a drier future climate will influence biogeochemistry and greenhouse gas emissions in iron-rich soils and how to best adapt land management practices. The goal of this research is to identify agricultural practices that can generate a portfolio of climate change adaptation and greenhouse gas mitigation strategies for delta farmers. The greenhouse gas data collected as part of this research also helped to generate increasingly accurate emission offset credits for potential wetland restoration projects in California’s Cap-and-Trade program.
    Science topics Agriculture, Carbon, Nitrogen, Phosphorous, Soil
    Updated November 17, 2022
  • Title

    Simulating methylmercury production and transport at the sediment-water interface to improve the water quality in the Delta

    Lead University of California - Merced [UC Merced]
    Description The aim of this project was to improve basic knowledge of mercury cycling and aid management of net methylmercury production in the delta by developing a kinetic-thermodynamic reaction model that describes and quantifies mercury cycling in delta sediments. The model was used to assess uncertainties and estimate methylation and demethylation rates — the processes by which methylmercury is produced and breaks down. In addition, the project examined coupling of mercury cycling with cycling of iron, sulfur, and manganese.
    Science topics Bioaccumulation, Chemistry, Hg and methyl mercury
    Updated November 17, 2022
  • Title

    Quantifying Biogeochemical Processes through Transport Modeling: Pilot Application in the Cache Slough Complex

    Lead University of California - Davis [UC Davis]
    Description Funding for this project will focus on observations and hydrodynamic models of the Cache Slough Complex. To accomplish this, the project implementation will involve making extensive use of models developed in ongoing CDFW-funded projects. These projects have included the development and initial calibration of a two-dimensional hydrodynamic model of the Cache Slough Complex. The model utilizes the Deltares Flexible Mesh numerical model, an open-source hydrodynamic model applied in a growing number of studies in the Bay/Delta system. Work is continuing in that project to refine the model calibration within the Cache Slough Complex and extend the calibrated period. The model is also being applied to study how tidal forcing and channel configuration shape the hydrodynamic connections between parts of the system.
    Science topics None specified
    Updated November 18, 2022
  • Title

    Contaminant Effects on Two California Fish Species and the Food Web That Supports Them

    Lead University of California - Davis [UC Davis]
    Description Water temperatures are increasing due to global climate change, and are predicted to reach levels that exceed the thermal tolerance of sensitive Delta species such as the Delta Smelt by 2050. Little is directly known about the differences in sensitivity between Inland Silverside and Delta Smelt to such stressors, or how either species responds to multiple stressors. Funding will be use to study how these two species respond to drought-induced stressors (temperature, salinity, and reduced dilution of contaminants) which will provide key insights, given that one is near extinction and the other is thriving under drought conditions.
    Science topics None specified
    Updated November 19, 2022
  • Title

    Climate change impacts to San Francisco Bay-Delta wetlands: Links to pelagic food webs and predictive responses based on landscape modeling

    Lead San Francisco State University [SFSU]
    Description The purpose of this project is to 1) evaluate the potential impacts of climate change on SF Bay-Delta tidal wetlands, 2) improve our understanding of the linkage between these wetlands and the pelagic food web, especially fish populations, and 3) use this information to make predictions about potential effects of climate change on Bay-Delta fish populations.
    Science topics Pelagic fish, Wetlands
    Updated April 29, 2022
  • Title

    Comparison of Nutrient Sources and Phytoplankton Growth and Species Composition in Two Rivers: Their Roles in Determining Productivity and Food Web Conditions in Suisun Bay and the Delta

    Lead San Francisco State University [SFSU]
    Description
    Science topics Phytoplankton, Pelagic fish, Nitrogen / ammonia
    Updated April 29, 2022
  • Title

    A Non-Point Source of Contaminants to the Estuarine Food Web: Mobilized Particles from the Intertidal Zone

    Lead California State University [CSU]
    Description The purpose of this research project is to quantify the process of contaminant concentration and resuspension of shallow and intertidal cohesive sediments at sites along the salinity gradient from Prospect Island to San Pablo Bay. This research is important because it helps to understand the pathways by which contaminants are assimilated, which is essential to appropriately manage habitat areas.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Nutritional Quality of Zooplankton as Prey for Fish in the Sacramento-San Joaquin Dalta

    Lead University of California - Davis [UC Davis]
    Description Primary consumers (zooplankton) are a critical trophic link for energy transfer to upper trophic levels and a key food source for threatened and endangered fish species in the Delta. The zooplankton community was shaped by large spatial and temporal changes in both abundances and species composition that affected quantity of zooplankton carbon. It is also expected that taxonomic shifts affected quality of zooplankton carbon for fish due to altering biomass transfer at the base of the food web that can profoundly influence nutritional quality and population dynamics at higher trophic levels. Yet the biochemical composition of plankton remains largely unstudied in this system despite the fact that the importance of zooplankton nutritional quality for fish is one potential major component for the long-term decline and more recent collapse of pelagic fish species. The proposed research aims to measure essential nutritional status (stoichiometry, fatty acids, sterols) for zooplankton taxa and will calculate food-quality indices for fish. On the basis of nutritional plankton and biomass values, spatial patterns as well as long-term and recent changes in plankton quality associated with compositional shifts will be estimated. We propose that through integrating plankton food-quality into the management and restoration plan for the Delta, the dynamics of the ecosystem can be viewed from a new perspective that has key implications for understanding the decline in pelagic organisms.
    Science topics Zooplankton
    Updated April 29, 2022
  • Title

    An Open-Source, Three-Dimensional Unstructured-Grid Model of the Sacramento/San Joaquin Delta: Model Construction and Application to Delta Hydrodynamics and Temperature Variability

    Lead Stanford University
    Description Motivated by the need to predict transport in the Delta, this project will apply the open-source, unstructured-grid computer model, SUNTANS (Stanford Unstructured Nonhydrostatic Terrain following Adaptive Navier Stokes simulator) to the Sacramento/San Joaquin Delta. SUNTANS solves the governing equations of fluid flow on a grid that permits fine detail in areas of particular interest in the Delta, while allowing us to include the entirety of the Bay/Delta system so as to properly model oceanic and estuarine influences on the Delta We have two aims:(1) to carry out the model development needed to apply SUNTANS to the Delta;(2) to apply the model to look at aspects of the physical variability of the Delta that are critical to ecosystem function and to understanding how physical processes in the Delta affect ecosystem function, most notably entrainment of fish and other organisms by the export facilities. In particular, we propose to look at flow behavior at channel junctions, a key aspect of Delta hydrodynamics that influences dispersion in the Delta and thus the transport of biota, nutrients and contaminants. We also will examine the dynamics of spatial and temperature variability in the Delta in response to tides, atmospheric forcing, river flows, and diversions, variability that must be properly calculated to forecast how climate change and altered project operations may affect key species like Delta Smelt. We will carry out new fieldwork to support our modeling.
    Science topics Water temperature
    Updated April 29, 2022
  • Title

    Assessing Sediment Nutrient Storage and Release in the Delta: Linking Benthic Nutrient Cycling to Resotration, Aquatic Vegetation, Phytoplankton Productivity, and Harmful Algal Blooms

    Lead U.S. Geological Survey [USGS]
    Description Nutrients in sediment play a large role in influencing food webs, harmful algal blooms, aquatic vegetation, and drinking water quality. This study will investigate the amount, types, and dynamics of nutrients in Delta sediments. It will also examine sediment microbial communities that mediate these processes. Results of this study will help determine how the planned reduction in nutrient inputs to the Delta will effect sediment nutrients and microbial communities following the upgrade of the Sacramento Regional County Sanitation District’s wastewater treatment plant. Data will also inform how wetland restoration and invasive aquatic vegetation influence sediment nutrients and microbial communities. These data will contribute to improving computer models that inform large-scale nutrient management actions.
    Science topics Aquatic vegetation, Benthic, Cyanobacteria, Harmful algal blooms HAB, Nitrogen, Nitrogen / ammonia, Nutrients, Phytoplankton, Sediments
    Updated November 28, 2022
  • Title

    Environmental geochemistry and tidal wetland support of pelagic food webs

    Lead University of California - Davis [UC Davis]
    Description This project aims to characterize and quantify where detrital material (decaying plant matter) originates within wetlands, the composition of that material, and how export of detrital particles occurs. This project will combine powerful characterization tools and techniques that scale from molecules to ecosystems to assess spatial and temporal trends in particle sources, species and composition. Because restoration in the Sacramento-San Joaquin Delta will fundamentally alter particle distribution and food availability for aquatic organisms, this study will inform habitat restoration efforts and the revival of native fish populations. The tools developed and adapted for this project may inform management response during extreme conditions and climate events by helping to identify areas that may act as refugia for species.
    Science topics Wetlands
    Updated April 29, 2022
  • Title

    Nitrogen cycling and ecosystem metabolism before and after regulatory action

    Lead Stanford University
    Description This project focuses on nitrogen and carbon cycling within the Bay-Delta, both before and after planned 2021 upgrades to the Sacramento Regional Wastewater Treatment Plant (SRWTP). We will measure in situ benthic nitrate (NO3- ) and oxygen (O2) fluxes using a new non-invasive technique, which provides high frequency continuous data over a much larger sediment surface area than traditional methods. The SRTWP currently represents one of the largest point sources of nitrogen to the Bay-Delta, with the upgrades projected to cut nitrogen outputs from the plant by ~65%. This project will help assess the efficacy of this major management action and our results will add to biogeochemical models for the Bay-Delta.
    Science topics Nitrogen / ammonia
    Updated April 29, 2022
  • Title

    Understanding the Effects Of Nutrient Forms, Nutrient Ratios and Light Availability on the Lower Food Web of the Delta

    Lead University of Maryland - Center for Environmental Science
    Description This proposed study addresses how changes in nutrient form, ratio and loading (water quality) affect the lower pelagic food web that ultimately determines the quality and quantity of food for Delta fishes. Shifts in algal composition and food availability have been implicated in fish decline, but identifying the changes at the base of the food web that are linked to changes in nutrients has been difficult because of the complexity of factors contributing to stress on the food web. Nutrients may shape community composition in complex ways;they do not have to be limiting to be important drivers of plankton communities. Elevated nutrients, particularly chemically reduced forms of nitrogen (N), may be inhibitory rather than stimulatory. We hypothesize that when NO3- is proportionately abundant relative to NH4+ (and the N:P ratio is suitable), diatoms will dominate, but when NH4+ is proportionately abundant, cyanobacteria or flagellates will dominate. Reduced light availability will lead to communities with higher bacterial abundance, and/or higher proportions of flagellates able to alter their nutrition towards mixotrophy. This proposal will directly test these relationships by conducting experimental manipulations with different ambient communities from different sites and seasons. Data will be interpreted with respect to the long-term trends reported for the Bay Delta and supplied as an integrated product for management efforts concerned with water quality and fisheries.
    Science topics Nutrients, Food webs
    Updated April 29, 2022
  • Title

    Phytoplankton Communities in the San Francisco Estuary: Monitoring and Management using a Submersible Spectrofluorometer

    Lead California Department of Water Resource [DWR]
    Description The purpose of this project is to evaluate a new submersible spectrofluorometer, the bbe FluoroProbe, for phytoplankton monitoring and management in the SFE. Secondly, this project seeks to investigate high-frequency patterns in spatial phytoplankton group distributions among Delta habitats and along gradients from the western Delta and northern San Francisco Bay.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Biomass and Toxicity of a Newly Established Bloom of the Cyanobacteria Microcystis aeruginosa and its Potential Impact on Beneficial Use in the Sacramento-San Joaquin Delta

    Lead California Department of Water Resource [DWR]
    Description Monitoring and simple analysis of the extent of this cyanobacteria in the Delta, and preliminary exploration of the impacts of cystins on drinking water quality, and human and wildlife health.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Fish Diet and Condition

    Lead California Department of Fish and Wildlife [CDFW]
    Description Description The Diet and Condition study has provided information on the food habits of pelagic fishes in the estuary since 2005. We focus on the temporal and spatial differences in diet composition and feeding success of Delta Smelt, Striped Bass, Threadfin Shad, Longfin Smelt, Mississippi Silversides, and American Shad. Need Data from this project has been used to inform the Fall Low Salinity Habitat Program (FLaSH), Directed Outflow Project (DOP), and Management, Analysis and Synthesis Team reports, as well as life history models used for the conservation of fish and their habitats. Understanding what prey are utilized for food in the context of available prey, with the associated body-condition of fish, helps clarify the existence and timing of food limitation for young pelagic fish in the estuary. This work began as part of the Pelagic Organism Decline investigations and continued as a contributor to FLaSH investigations during which we in collaborated with the Fish Health Monitoring Project. Recently staff completed Longfin Smelt diet investigations as part element #296 (Longfin Smelt Investigations – in response to a litigation agreement) that will also contribute to the Longfin Smelt Conceptual Model and Synthesis effort (element #320). Finally, we will process Delta Smelt diets from investigations prompted by the Delta Smelt Resilience Strategy, and as part of the DOP. Objectives 1. What are the diets of pelagic fishes (especially Delta Smelt and Longfin Smelt) in the estuary and do they vary regionally or temporally? 2. Is there evidence of reduced feeding success spatially or temporally in the estuary? 3. Is feeding success associated with changes in relative weight or condition of fish? 4. Is there seasonal and regional overlap of diets between species (with a focus on age-0 Delta Smelt, Longfin Smelt, Striped Bass, Prickly Sculpin, Pacific Herring, and Threadfin Shad)?
    Science topics None specified
    Updated April 29, 2022
  • Title

    Food Temperature Optimization Model for CVP

    Lead U.S. Bureau of Reclamation [USBR]
    Description This study aims to improve understanding of how nutrient and zooplankton exports from CVP reservoirs impact downstream food web productivity.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Continuous Flow and Water Quality Monitoring Network in the Sacramento-San Joaquin Delta

    Lead U.S. Geological Survey [USGS]
    Description This project envisions the continuation, expansion, and further integration of high frequency monitoring for flow, water quality (including chlorophyll and nutrients), sediment, as well as biological responses at key locations in the Delta and Suisun Bay. The physical properties monitored by the fixed-station network are the primary drivers of the habitat conditions and biological responses that management actions hope to achieve. Nutrient dynamics are explicitly measured at select stations to improve our understanding of how physical dynamics, water quality and landscape features shape the base of Delta food webs. These data will provide information about drivers linked to food quantity and quality as well as potential toxins production by harmful algae. Suspended-sediment monitoring provides an understanding of the inputs and internal exchanges between regions, locations of sources and sinks, and provides insight into the underlying cause of turbidity variability in the study area. Suspended-sediment measurements gage the availability of suspended sediment for existing marshes and for proposed large-scale marsh restoration efforts in the Delta. There are a total of 5 sub-tasks in this project: • Task 1: Hydrodynamics Team – Fixed Station Network Operation and Maintenance • Task 2: BioGeoChemistry Team -- Fixed Station Network Operation and Maintenance • Task 3: Delta Sediment Team – Fixed Station Network Operation and Maintenance • Task 4: Bay Sediment Team – Fixed Station Network Operation and Maintenance • Task 5: Project Management
    Science topics Chlorophyll A / B, Conductivity, Dissolved oxygen, Flows, Nutrients, pH, Phytoplankton, Sediments, Stage, Surface water / flow, Tides, Turbidity, Velocity, Water operations / exports, Water temperature
    Updated January 19, 2024