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  • Title

    Investigation of the resilience of the salt marsh harvest mouse and best management practices in response to climate change

    Lead University of California - Davis [UC Davis]
    Description This study aimed to investigate the response of the salt marsh harvest mouse to several threats of climate change, including extreme annual climate cycles and sea level rise. The study was based on ongoing population surveys in the Suisun Marsh, and a study of upland/elevated refuge throughout the species’ range, over the two-year study. It also involved the piloting of advance remote detection technology (camera traps, audio detectors, and digital mouse traps) and effective, affordable high tide refuge (islands and trellises). Finally, ongoing trapping efforts at established survey sites is providing data for ongoing analysis on the effects of weather patterns and space needs of populations.
    Science topics Climate change, Salt marsh harvest mouse, Saltwater / freshwater marshes
    Updated November 17, 2022
  • Title

    Effects of copper exposure on the olfactory response of Delta smelt [Hypomesus transpacificus]: Investigating linkages between morphological and behavioral anti-predator response

    Lead University of California - Davis [UC Davis]
    Description This study aimed to address the question of how water-borne copper can affect the ability of delta smelt to detect predator related odorants and conduct essential behaviors. To do this, the project included a thorough morphological and cytological study of the delta smelt olfactory organ, which had previously not been well-studied. The researchers also characterized the olfactory mediated antipredatory response to alarm cues and assessed the effects of copper exposure on the anti-predator behavior and morphology of the olfactory rosette of delta smelt.
    Science topics Copper, Delta Smelt, Toxicity
    Updated November 17, 2022
  • Title

    Defining habitat quality for young-of-year longfin smelt: Historical otolith-based reconstructions of growth and salinity history in relation to geography, climate, and outflow

    Lead University of California - Davis [UC Davis]
    Description This project aimed to use experiments to develop new otolith-based tools for longfin smelt and to then apply them to an extensive collection of archived wild Longfin Smelt specimens, to build a better understanding of longfin smelt life history, habitat use, and the interactions between stressors and abundance. In addition, the project aims to improve the understanding of how longfin smelt populations are affected by freshwater outflow. The project also aims to provide tools to support and evaluate habitat restoration, and facilitate development of a plan to recover this threatened species.
    Science topics Longfin Smelt, Outflow, Salinity
    Updated November 17, 2022
  • Title

    The Effect of Drought on Delta Smelt Vital Rates

    Lead University of California - Davis [UC Davis]
    Description This Project is necessary to obtain a better understanding of the effects of drought and management's response to drought on the Delta Smelt in order to avoid extinction. This study will test predication from other models to evaluate the impact of drought and management measures on Delta Smelt responses in terms of growth, phenotype diversity and survival during the spring and summer, when drought impacts are greatest.
    Science topics Delta Smelt, Drought
    Updated November 18, 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

    Reconstructing juvenile salmon growth, condition and Delta habitat use in the 2014-15 drought and beyond

    Lead University of California - Davis [UC Davis]
    Description This study uses otolith chemistry and microstructure to monitor how salmon use the Delta as rearing habitat and a migratory corridor, and the mechanisms cuing their outmigration from natal rivers. We will quantify the extent to which Delta-rearing contributes to salmon population resilency under different conditions (including drought and flood conditions) and provide baseline data to assess population responses to future habitat restoration and changing climate. Physical tags are limited to larger fish that are more sea-ready than fry, and are thus ineffective to estimate the full rearing potential of Delta habitats, while abundance surveys provide only a snapshot of information. Otolith reconstructions allow us to estimate “who” is using the Delta (which populations and life history types), for how long, and their growth rates relative to other rearing habitats. This project will generate empirical data that will inform management actions aimed at maximizing salmon abundance, life history diversity, and resilience to future stressors.
    Science topics Drought
    Updated April 29, 2022
  • Title

    Problems and Promise of Restoring Tidal Marsh to Benefit Native Fishes in the North Delta during Drought and Flood

    Lead University of California - Davis [UC Davis]
    Description The Project will improve scientific understanding of the North Delta ecosystem and to improve better basis for management and creation of restoration sites, as well as management of the region to benefit native fishes. The Project will improve scientific understanding of how fish populations are influenced by the interactions between wetlands and hydrology, geomorphology, water quality and food availability. Funding will be use to conduct water quality monitoring;hydrodynamic modeling;and fish and invertebrate surveys.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Application of cutting-edge tools to retrospectively evaluate habitat suitability and flow effects for Longfin Smelt

    Lead University of California - Davis [UC Davis]
    Description The Longfin Smelt (Spirinchus thaleichthys) is a native forage fish, characteristic of the natural biological community of the San Francisco Estuary (SFE). This study will examine variation and interactions among hatch dates, instantaneous and total growth rates, habitat use, and timing of transitions among habitats with different salinities, and variation among years with very different climate and freshwater outflow conditions. This information is crucial for managing freshwater flows and can be used to evaluate the effects of tidal wetland restoration in the San Francisco Estuary.
    Science topics None specified
    Updated November 19, 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

    Defining the fundamental niche of Longfin Smelt [Spirinchus thaleichthys]: Physiological mechanisms of environmental tolerance.

    Lead University of California - Davis [UC Davis]
    Description This Project will evaluate reproductive output, embryo to larval development, and growth and maturation of Longfin Smelt (Spirinchus thaleichthys). This Project is designed to comprehensively assess effects of extreme events and their interaction with contaminant effects, and aims to fill knowledge gaps relating to turbidity (e.g., stress levels associated with predation risk), age-specific fecundity, egg and early larval buoyancy, and other essential requirements for captive rearing conditions that will aid the successful culture.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Impact of Spatial and Temporal Dynamics of Water Flows on Migratory Behavior of Chinook Salmon Smolts in the South Delta

    Lead University of California - Davis [UC Davis]
    Description Funding for this study project will be use track the swimming movements of salmon smolts during migration using acoustic transmitters and detection arrays near the confluence of Old River and the San Joaquin River. Analyses will be carried out to determine swimming velocity relative to current velocity. Modeling will estimate fish distribution; fish transit times; entrainment of fish into channels of the south Delta; and alternative water export management scenarios that may result in reduced entrainment.
    Science topics None specified
    Updated November 19, 2022
  • Title

    Predicting the Effects of Invasive Hydrozoa [Jellyfish] on Pelagic Organisms Under Changing Salinity and Temperature Regimes

    Lead University of California - Davis [UC Davis]
    Description The purpose of this project seeks to investigate the potential effects of jellyfish, a devising invader of some ecosystems, on the SFE ecosystem, to determine the key factors allowing successful establishment and spread of these species, and to predict future effects and spread of the invasions.
    Science topics Water temperature, Salinity, Pelagic fish, Jellyfish
    Updated April 29, 2022
  • Title

    Quantitative Indicators and Life History Implications of Environmental Stress on Sturgeon

    Lead University of California - Davis [UC Davis]
    Description The purpose of this project is to analyze the effects of the pollutants on the overall fitness of different life stages of the green and white sturgeon. This research will significantly enhance our understanding of stressors on sturgeon and allow further development of life history models.
    Science topics Water temperature, Salinity, Pelagic fish, Methylmercury, Sturgeon
    Updated April 29, 2022
  • Title

    Are Apparent Sex Reversed Chinook Salmon a Symptom of Genotoxicity?

    Lead University of California - Davis [UC Davis]
    Description Goal was to test the relative importance of chemical stressors on population viability and genetic diversity for fall-run Chinook salmon (in association with environmental contaminant exposure in the Central Valley delta).
    Science topics Chinook Salmon
    Updated April 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

    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

    Integrating Ecosystems, Flood Control, Agriculture, and Water Supply Benefits: An Application to the Yolo Bypass

    Lead University of California - Davis [UC Davis]
    Description The Yolo Bypass presents an opportunity to develop mechanisms governing the management of flows across floodplains that balance ecosystem services with economic and recreational functions, and to study the untapped potential of such floodplains to play a role in conjunctive surface and groundwater management. Analysis to the necessary high degree of spatial resolution for such management decisions is generally lacking for the Yolo Bypass. This proposal seeks funding for an interdisciplinary study to better understand the economic, hydrologic, and ecological functioning of land and water across the bypass, and to develop tools that use this knowledge in identifying promising strategies for the timing and configuration of spring inundation. Agronomic, economic, and hydraulic models will be used with formal interviews to study the relationship between flooding and six Yolo Bypass functions: (1) Agricultural Economics, (2) Waterfowl management, (3) Native Fish habitat, (4) Flood Control, (5) Groundwater storage, and (6) Recreation. Data from these first efforts will be incorporated into an optimization model that identifies promising inundation alternatives for ecosystem services which minimize costs to landowners and waterfowl managers, and maximize potential conjunctive use benefits. This synthesis answers the Delta Science Program's request for coupled hydrologic and ecosystem models, and for water and ecosystem management decision support system development.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Low-Cost Satellite Remote Sensing of the Sacramento-San Joaquin Delta to Enhance Mapping for Invasive and Native Aquatic Vegetation

    Lead University of California - Davis [UC Davis]
    Description Invasive aquatic vegetation (IAV) acts as an ecosystem engineer by changing habitat conditions and water quality. This negatively affects the survival of native species. Over the past 15 years, IAV has more than doubled its footprint in the Sacramento-San Joaquin Delta waterways. The State of California spends millions of dollars each year to control IAV in the Delta-Suisun region and costs are likely to continue to rise. Gaining a better understanding of the spread, life history characteristics, and potential vulnerabilities of these species can lead to more effective control strategies. The recent launch of the Sentinel-2 satellite can fill temporal gaps left by annual airborne surveys. This study will create a data pipeline for sustained, low-cost satellite-based monitoring of aquatic and marsh vegetation year-round. To quantify one of the Delta Plan performance measures, the time and degree of floodplain inundation for the Yolo Bypass will be measured. This study will result in new metrics to measure progress toward habitat goals in several restoration sites.
    Science topics Aquatic vegetation, Invasive / non native species
    Updated October 3, 2024
  • Title

    Synchrony of Native Fish Movements: Synthesis Science Towards Adaptive Water Management in the Central Valley (FishSync)

    Lead University of California - Davis [UC Davis]
    Description Salmon and other native California fishes are in decline and increasingly targeted for enhanced conservation. Acoustic telemetry technologies have emerged, allowing researchers to track fish routes through the Central Valley. Yet while the use of acoustic telemetry has widened, little synthesis has occurred on the large, growing, and expensive datasets that already exist. The main goal of the project is to conduct a synthesis study of existing and high priority telemetry datasets for native and non-native fishes in the Central Valley. Using synchrony of movement rates, through space and time, we will develop a novel behavior-based statistical framework to gain understanding into the environmental conditions that promote movement/passage of diverse native fishes in the Central Valley. The project includes a Technical Advisory Group, composed of members of multiple conservation teams. The group will inform each step of study, strengthen syntheses, and enable rapid communication of results to decision makers. In total, the project will analyze 10 to 15 high-quality telemetry datasets encompassing a range of native fishes and life stages. This synthesis will yield major insights into water management practices that could help improve survival of native fish.
    Science topics Chinook Salmon, Fish, Salmon migration, Steelhead Trout, Sturgeon, White Sturgeon
    Updated December 4, 2022
  • Title

    Consequences of Phragmites invasion for community function in Suisun Marsh

    Lead University of California - Davis [UC Davis]
    Description This project aims to quantify the impacts of common reed (Phragmites) invasion on community structure and ecosystem function during early stages of tidal restoration in wetlands. The study will focus on the Tule Red Tidal Restoration site in Suisun Marsh. The research aims to produce a conceptual model that will describe habitat structure, invertebrate communities, and predator use of wetlands affected by Phragmites invasion. The conceptual model resulting from this study will guide future predictions of wetland response to invasion and to develop mitigation strategies. Data collected will also support food web models and the understanding of invasive plants as stressors, as well as foster translational science to the management community.
    Science topics Invasive / non native species
    Updated April 29, 2022
  • Title

    Risk of fish predation within and across tidal wetland complexes

    Lead University of California - Davis [UC Davis]
    Description This study focuses on understanding how restored tidal wetlands with different physical configurations function as refuge and rearing habitat for fishes, including native and imperiled species such as delta smelt and juvenile Chinook salmon. This research will assess the spatial distribution of predation risk as it varies within and across tidal wetlands. The proposed research will generate a statistical model that helps predict predation outcomes from various restored tidal wetland designs and channel configurations. This will be a powerful tool for managers to forecast how proposed habitat restoration or water management actions may impact native fish populations.
    Science topics Tidal wetlands
    Updated April 29, 2022
  • Title

    Phytoplankton and cyanobacteria growth and response to stressors

    Lead University of California - Davis [UC Davis]
    Description Pesticide and nutrient inputs from human activities are present in the Sacramenot-San Joaquin Bay-Delta, but the impact of these stressors together on algae is not well known. This research will examine the impacts of herbicides and nutrients on the growth and stress responses of phytoplankton and cyanobacteria present in the San Francisco Estuary. The algae in the delta are diverse with critical ecological effects, ranging from toxin-producing cyanobacteria that form hazardous algal blooms to benthic diatoms and green algae that make up the bulk of the aquatic food web. Contaminants and herbicides can cause changes in algae cellular health which may impact population growth. Understanding algal sub-lethal stress responses will improve our understanding of stressors on the bay-delta food web and bloom formation.
    Science topics Phytoplankton, Cyanobacteria
    Updated April 29, 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

    The effect of temperature on predation of juvenile salmonids

    Lead University of California - Davis [UC Davis]
    Description This study will investigate fish swim performance in response to temperature, using salmon and two of its known predators: largemouth bass and Sacramento pikeminnow. The researcher will assess swim performance metrics and predation risk inside and outside the ideal thermal range of each species to determine if a temperature advantage predicts salmon survival in predation scenarios. This project’s results will provide a mechanistic understanding of how temperature stress may influence mortality risk of juvenile Chinook salmon through predation, which will offer a more holistic perspective on the management of this species
    Science topics Temperature
    Updated April 29, 2022
  • Title

    Survivial and Migratory Pattern of Central Valley Juvenile Salmonids

    Lead University of California - Davis [UC Davis]
    Description The purpose of this project is to determine the survival and movement patterns of late-fall Chinook salmon smolts and steelhead smolts as they migrate downstream. This information is important to better understand how salmon move through the system.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Linking Trophic Ecology with Slough and Wetland Hydrodynamics, Food Web Production and Fish Abundance in Suisun Marsh

    Lead University of California - Davis [UC Davis]
    Description Suisun Marsh remains one of the most productive regions of the San Francisco Estuary (SFE), fueling interest in the Marsh as a model for restoring estuarine function to the region in the future. The UC Davis Suisun Marsh Fish Survey has 30 years of data on physical structure, water quality, benthic and pelagic invertebrates and fish. We will use these and other data to explore patterns of fish abundance in relation to zooplankton, slough geomorphology, and regional hydrodynamics. Our goal is to understand and predict the kinds of physical variability and structure that create attractive habitat for fish, in order to 1) serve as a template for wetland and subtidal habitat restoration in the Estuary and 2) anticipate the effects of sea level rise, levee failure and salinity increases that are expected to have a large impact on the Marsh in the near future. A comprehensive literature and data search will pull together known information for synthesis. Cluster analysis will identify slough complexes into types of functional habitat. Predictive maximum likelihood, hierarchical and multivariate autoregressive models will be used to predict how foodwebs and fish respond to environmental factors. Finally, coupled hydrodynamic-life history models for zooplankton will demonstrate how production is regulated by slough morphology. Results will be integrated as a white paper on the history, current functioning, and future of the Marsh.
    Science topics Levees, Climate change
    Updated April 29, 2022
  • Title

    Reconstructing Juvenile Salmon Growth, Condition, and Delta Habitat Use in 2014-15 Drought and Beyond [SAIL]

    Lead University of California - Davis [UC Davis]
    Description Description Life history diversity buffers salmon populations over space (e.g. the use of natal and non-natal rearing habitats and time (e.g. variable migration timing resulting in greater probability of meeting optimal ocean conditions). Historically the Sacramento-San Joaquin Delta provided critical salmon rearing habitat, but urban expansion, water diversions and species introductions have resulted in inhospitable conditions unlikely to meet rearing needs. This study fills critical data gaps regarding Delta rearing by juvenile Chinook salmon – primarily to determine the annual migrant portfolio (proportion of different populations and life stages) and the relative success of Delta vs. natal rearing (inferred by rearing duration, growth rate, diet and condition). We quantify the extent to which Delta rearing contributes to salmon population resiliency under different environmental conditions, including drought (2014-15) and flood conditions (2017, 2019), and provide baseline data to provide insights into population-level responses to future habitat restoration and climate change. The study uses annual collections of fall & late fall run salmon samples from sites upstream (Mossdale/Sherwood Harbor), within, and downstream (Chipps Island) of the Delta sampled by the IEP Delta Juvenile Fish Monitoring Program (DJFMP). Need Annual monitoring surveys routinely sample salmon entering and leaving the Delta, but the extent to which these juveniles rear there is virtually unknown, and has been highlighted as a critical data gap for parameterizing the NMFS Chinook salmon life cycle model (S. Lindley NOAA pers. comm.). There are limited tools available to monitor habitat use by native fishes, with most efforts providing a snapshot of fish presence/absence or abundance. Tagging studies provide key information about migratory pathways and survival through stretches of the Delta, but are typically limited to larger individuals and often use hatchery smolts with different rearing needs and seareadiness to the smaller individuals most likely to use Delta habitats. Otoliths represent a unique tool to reconstruct fish age, natal origin, growth history, movement patterns, and habitat use, even in fry <40mm fork length. Objectives We will use juvenile salmon collected by the IEP Delta Juvenile Fish Monitoring Program to assess: 1. Contributions of different rivers & hatcheries to sites upstream, within & downstream of the Delta. 2. Delta habitat use (frequency, duration) and success (growth rates, condition and diet). 3. Mechanisms governing juvenile salmon outmigration timing from the natal tributary.
    Science topics None specified
    Updated April 29, 2022
  • Title

    Suisun Marsh Fish Study

    Lead University of California - Davis [UC Davis]
    Description The University of California, Davis has been involved in fish and wildlife monitoring and research within Suisun Marsh for 35 years and has been instrumental in detecting important trends associated with naturally fluctuating environmental conditions as well as anthropogenic influences. Research has included a 35+ year time series on the fish and invertebrate communities of the slough networks, research on waterfowl nesting patterns and population biology, and research on the demography of salt marsh harvest mouse. The Suisun Marsh Fish Study anchors this effort as it is the longest established survey in Suisun marsh. It will continue the research of Professor Peter Moyle under the direction of John Durand, and will focus upon the detection of changes in the aquatic ecosystem in response to developing stressors in the San Francisco Estuary (SFE). This time series is designed to further our understanding of the ecology and function of the fish community residing within Suisun Marsh and the San Francisco Estuary (SFE), and acts as one of the key surveys with Interagency Ecological Program's monitoring effort.
    Science topics Stage, Tides, Salinity, Water temperature, Dissolved oxygen, Main channels, Sloughs, Chinook Salmon, Steelhead Trout, Green sturgeon, White Sturgeon, Delta Smelt, Longfin Smelt, Sacramento Splittail, Pelagic fish, Benthos, Salt marsh harvest mouse, Mollusks, Crustaceans, Striped bass, Corbicula/Potamocorbula, Conductivity, Environmental drivers, Other species, Fish, Invertebrates
    Updated April 29, 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

    Science for adaptive management of juvenile spring-run Chinook salmon in the San Joaquin River

    Lead University of California - Davis [UC Davis]
    Description Spring-run Chinook salmon rehabilitation efforts are intensifying on the San Joaquin River. Over the last three years, UC Davis has successfully tracked movement, behavior, reach-specific survival, and route selection for reintroduced juvenile spring-run Chinook salmon in this ecosystem. In 2019, information on salmon tracking was combined with state-of-art habitat (fast limnological automated measurements or “FLAMe”) and physiological (e.g. fish condition, survival and transcriptomic) approaches. Results from this work are ongoing but have yielded actionable information on key habitats and management strategies for promoting salmon life-cycles in the San Joaquin River and central Delta. Now UC Davis will further explore promising recent findings. First, the analysis of an additional year of juvenile salmon tracking will occur to glean more survival information across different water year conditions. This information would be married with expanded FLAMe surveys in space and time along with a second year of physiological assays using caged fish. UC Davis will also evaluate the ‘transport effect’ on salmon, in an attempt to explain consistently high losses of JSATS-tagged salmon through the restoration area. Numerous other synergies exist with new and ongoing telemetry work that will be benefitted by a continuation of this work. The goal is to provide actionable science, and open access data, with a high potential to facilitate adaptive management in the San Joaquin River and central Delta.
    Science topics Chinook Salmon, Endangered species, Estuaries, Fish, Habitat restoration
    Updated October 3, 2023
  • Title

    Non-Invasive Environmental DNA Monitoring to Support Tidal Wetland Restoration

    Lead University of California - Davis [UC Davis]
    Description In this project we use single-species and multi-species environmental DNA (eDNA) approaches to monitor tidal wetland restoration sites and paired reference sites (existing, unrestored tidal wetlands located near restoration sites) in the San Francisco Bay Delta (SFBD). We are working in coordination with the CDFW Fish Restoration Program (FRP) and other collaborators so our eDNA detections can be paired with physical detections of fishes from their trawling efforts. Ultra-sensitive DNA single species detection methods are being used to identify restoration site use by listed species (Delta Smelt, Longfin Smelt, winter- and spring-run Chinook Salmon) while the DNA metabarcoding approach will evaluate entire fish communities (groups of different fish species) at restored and reference sites. Aside from revealing restored habitat use by other fishes, metabarcoding will reveal potential ecological interactions between Endangered Species Act listed and non-listed species, through concurrent detection in time and space. Sampling throughout the year will allow us to identify seasonal trends in fish use of restored and reference sites. This project will demonstrate the utility of eDNA detection as a non-invasive (no take), cost-effective monitoring tool that can complement conventional surveys of restored tidal wetlands in the SFBD. Our results can be incorporated into an adaptive monitoring framework for tidal wetland restoration, to increase success of future restoration projects.
    Science topics Chinook Salmon, Delta Smelt, Endangered species, Estuaries, Fish, Green sturgeon, Habitat, Habitat restoration, Invasive / non native species, Invertebrates, Longfin Smelt, Mollusks, Pelagic fish, Restoration, Restoration planning, Sacramento Splittail, Salmon migration, Salmon rearing, Steelhead Trout, Striped bass, Sturgeon, Tidal wetlands, Wetlands, White Sturgeon
    Updated May 24, 2024
  • Title

    Evaluating contributions of hatchery-origin fish to conservation of endangered Sacramento River winter run Chinook salmon during a drought

    Lead University of California - Davis [UC Davis]
    Description Hatchery-reared fish have been used to supplement endangered winter-run Chinook salmon in the upper Sacramento River since 1989. Intense drought in the past five years has led fisheries managers to substantially modify their hatchery protocols, increasing the total number of fish released and using hatchery-origin adults for producing juveniles. However, the impact of these practices is not fully understood. This project evaluated multiple aspects of how hatchery–reared fish contribute to natural production of winter-run Chinook salmon in the upper Sacramento River. The researchers assessed whether hatchery-reared fish are spawning in the wild and producing natural-origin offspring using a novel panel of genetic markers developed during the study. The study also assessed if inadvertent domestication selection was occurring in the hatchery during the drought years and if more highly related hatchery broodstock pairings returned fewer offspring than less related pairs.
    Science topics Drought
    Updated February 1, 2024
  • Title

    Managing Agricultural Soils for Carbon and Water Benefits in the California Delta: Understanding Influences on Decision-Making and Practice Adoption of in-Delta Farmers.

    Lead University of California - Davis [UC Davis]
    Description This project investigated and analyzed the major factors contributing to decision-making and adoption of soil management practices by farmers in the delta. In this project, Rudnick applied a mixed-methods approach to better understand what drives farmers’ decisions. To collect these data, the fellow used semi-structured interviews with farmers and relevant agricultural stakeholders, and participant observations at a number of public meetings and grower outreach events, including water coalition meetings, farmer field demo days, UC Davis outreach days, industry group conferences.
    Science topics Agriculture, Urban development
    Updated February 26, 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
  • 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 Restoration, Restoration planning
    Updated September 25, 2024
  • Title

    Feasibility of Acoustic Telemetry in Delta Smelt

    Lead University of California - Davis [UC Davis]
    Description

    This project aims to test the feasibility of using novel acoustic transmitters to track Delta smelt in the San Francisco Bay-Delta. Successful utilization of acoustic telemetry to track Delta smelt can provide researchers and resource managers with information about the species’ habitat preferences, the effects of water-management practices on Delta smelt movement and distribution, and the success of ongoing supplemental release efforts. The assessment of feasibility will include a comprehensive analysis of both the lethal and sublethal effects of surgical tag implantation on Delta smelt, as well as the development of a species-specific tagging protocol.
    Science topics Delta Smelt
    Updated October 15, 2024