Search

Science activities

Reset filters

11 records


















Records

  • Title

    The effects of early hypersaline acclimation due to climate change on the toxicity of pyrethroid, an insecticide, in salmonids.

    Lead University of California - Riverside [UC Riverside]
    Description Sea level rise and drought are expected to result in hypersaline waterways in the Delta. Endangered Chinook salmon and Steelhead trout go through smoltification to be able to live and mature in saline environments. However, with salinities and temperatures increasing in historically freshwater areas, these fish may be facing new stressors. Pesticide runoff into the Delta is common due to the urbanization and agriculture of many regions and can adversely affect fish. Additionally, previous research has shown that salinity exposure increases the toxicity of contaminants in anadromous fish, and it is had been demonstrated that bifenthrin, a common insecticide in the Bay, can have endocrine disrupting effects on juvenile salmonids. This project will examine the impacts of hypersaline conditions, various temperatures, and exposure to bifenthrin on the development and survival of juvenile Chinook salmon and Steelhead trout. Specifically, it will: Test the impacts of premature hypersaline acclimation and temperature on the survivial and smoltification process of a range of juvenile salmonids; Test the combined impacts of premature hypersaline acclimation, temperature, and bifenthrin exposure on smoltification, survival and behavior;and Predict the population level effects of drought and pesticide runoff on the health of endangered salmonids Additionally, this research will provide information to CA Department of Pesticide Regulation for potential pesticide management in the Delta, as well as to the CA Department of Fish and Wildlife for conservation practices of endangered juvenile salmonids in the Delta.
    Science topics Salinity
    Updated April 29, 2022
  • Title

    Impact of Climate Variability on Surface Water Quality: Cyanobacteria and Contaminants

    Lead University of California
    Description
    Science topics Harmful algal blooms HAB
    Updated April 29, 2022
  • Title

    Impacts of climate change on pesticide bioavailability and sublethal effects on juvenile Chinook salmon in the Delta: Potential benefits of floodplain rearing

    Lead University of California - Riverside [UC Riverside]
    Description The Project will include field studies to estimate loadings and bioavailability of pesticides, concentrations of pesticide residues in salmonid prey, and the trophic basis of juvenile Chinook salmon growth (benthic vs. pelagic food web pathways) and how each of these differ between floodplain and river channel habitats in the Delta. Data from the field studies will inform development of laboratory studies that will assess the potential effects of exposure to environmentally-relevant pesticide types and concentrations in prey on swimming performance, olfaction and neuroendocrinology of juvenile Chinook salmon. Laboratory studies will also evaluate how water temperature (including increased water temperatures predicted with climate change) influences these sub-lethal effects of pesticides on juvenile salmon.
    Science topics None specified
    Updated November 29, 2022
  • Title

    Physiological Mechanisms of Environmental tolerance in Delta Smelt [Hypomesus transpacificus]: From Molecules to Adverse Outcomes

    Lead University of California - Davis [UC Davis]
    Description The proposed project directly addresses priority research detailed by the Delta Science Program to protect native fishes that depend on the Bay-Delta system focusing on adaptations to local habitats and physiological tolerances to key environmental stressors;in delta smelt (Hypomesus transpacificus). Temperature and salinity changes associated with anthropogenic climate change are likely to further exacerbate delta smelt population declines. We hypothesize that delta smelt tolerance to forecasted temperature rises and salinity intrusions into the Bay-Delta system can be assessed at a mechanistic level, and that acclimation thresholds can be established by means of genomic responses. This proposal builds upon successful development of a cDNA microarray for delta smelt containing approximately 2000 individual gene fragments, and the subsequent application of biomarkers for assessing the effects of chemical stressors on larval development with links to swimming behavior. We propose to develop a Next Generation oligonucleotide microarray in delta smelt, with ca. 15K genes, in order to assess mechanistic tolerance to changes in gemperature and salinity. Genomic studies will be conducted integrating effects on energetic activity and swimming performance studies, in an interdisciplinary approach that will permit the establishment of links between tolerance mechanisms and adverse outcomes.
    Science topics Delta Smelt, Water temperature, Salinity, Turbidity
    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

    CASCaDE II: Computational Asessments of Scenarios of Change for the Delta Ecosystem

    Lead U.S. Geological Survey [USGS]
    Description This proposal builds upon an existing model-based effort to develop a holistic view of the Bay-Delta-River-Watershed system. CASCaDE I developed a set of linked models to assess Delta ecosystem response to climate change. In CASCaDE II, we propose to refine and extend those modeling capabilities to assess Delta ecosystem response to changes in climate and physical configuration. With a new state-of-the-art hydrodynamic and sediment model at its core, CASCaDE II will link models of climate, hydrology, hydrodynamics, sediment, geomorphology, phytoplankton, bivalves, contaminants, marsh accretion, and fish. Our goals are to apply these linked models to 1) better understand Delta ecosystem function, 2) assess possible futures of the Delta under scenarios of climate and structural change, and 3) provide science-based information to support the DSC in its co-equal goals of water supply and ecosystem protection. The tools developed will provide an objective basis for anticipating and diagnosing Delta ecosystem responses to planned and unplanned changes. Experiments using the linked models are designed to address questions such as: How will climate change, together with new conveyance structures or increased flooded island habitat, alter water flow and drinking water quality? With projected changes in residence time, turbidity, temperature, and salinity, how will primary productivity, invasive bivalves, marsh processes, contaminant dynamics, and fish populations respond?
    Science topics None specified
    Updated April 29, 2022
  • Title

    CASCaDE: Computational Asessments of Scenarios of Change for the Delta Ecosystem

    Lead U.S. Geological Survey [USGS]
    Description Agencies of the CALFED Bay-Delta Authority (CBDA) face tough decisions as they search for strategies to meet their programmatic goals of stabilizing water supplies in California, providing safe drinking water to a growing population, and sustaining diverse populations of native species and their supporting ecosystem functions. The challenge of finding balanced solutions to these goals is daunting because of the enormous complexity of the San Francisco Bay-Delta system and its tributary rivers and their watersheds. The challenge grows as we consider the additional layer of complexity imposed by the certainty that all the key forces that drive dynamics of this ecosystem (climate, hydrology, water management, land use, sea level) will change significantly in future decades. This proposal describes a model-based approach for developing a long view of the Bay-Delta-River-Watershed system. The long view will be developed through simulations with linked models to project changes under a range of plausible scenarios of global warming, hydrologic responses, land-use change, reconfigurations of within-Delta habitats, and sea level rise. Our goals are to develop and apply a model-based approach of ecological forecasting to project future states of the Delta ecosystem under prescribed scenarios of change, and to communicate the outcomes of those scenarios to resource managers facing the daunting challenge of meeting CBDP goals in a continually changing world.
    Science topics None specified
    Updated November 18, 2022
  • Title

    Estuarine fish community responses to climate, flow, and habitat

    Lead University of California - Berkeley [UC Berkeley]
    Description The goal of this research is to better understand how climate change will affect fishes with different life histories and habitat associations across the San Francisco Estuary. Existing datasets will be incorporated in synthetic analyses and cutting-edge statistical models to identify fish community responses to climate, flows, and habitats along the estuarine salinity gradient. This synthesis-science project will use rich long-term datasets that have been collected by Bay-Delta researchers for decades that will then be analyzed in a reproducible and open science framework. It will also support efforts by the Interagency Ecological Program’s Climate Change Project Work Team.
    Science topics Estuaries
    Updated April 29, 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

    Mapping the adaptation governance network of the Delta

    Lead University of California - Davis [UC Davis]
    Description Climate adaptation in the San Joaquin-Sacramento Delta involves multiple agencies, communities, venues, projects, and issues. Understanding how learning and cooperation occurs within this complex governance network is critical for carrying out effective and equitable adaptation. The main objective of this project is to understand how and why human communities (e.g., community organizations, local governments, and Tribal entities) are engaged in this governance system and the drivers of learning and cooperation for climate adaptation. To accomplish this, we will map the network of current adaptation actors, institutions, and actions, assess their engagement in the governance system, and conduct in-depth case studies on existing adaptation projects in the San Joaquin – Sacramento Delta.
    Science topics Climate change
    Updated May 8, 2024
  • Title

    In search of refuge: Investigating the thermal life history of Delta Smelt through in-situ oxygen isotope ratio analysis of otoliths.

    Lead University of California - Davis [UC Davis]
    Description The inner ear bones of fish, or otoliths, grow continuously and their chemistry reflects the water conditions that a fish has experienced throughout its life. In this project, researchers used in-situ chemical analysis to determine the oxygen isotopic composition of otoliths, which can reflect the water temperature that a fish has experienced. They applied this method to archived adult Delta Smelt otoliths from multiple different water years spanning the time from before and during the recent drought. Using these data, they investigated the relationship between delta smelt abundance and environmental parameters, such as water temperature. More specifically they investigated whether delta smelt are able to find temperature refuges, even in drought years.
    Science topics Climate change, Delta Smelt, Endangered species, Fish, Temperature
    Updated February 26, 2024