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Longfin Smelt

Development of a spatially explicit ecosystem model to explore physiochemical drivers of step changes in POD species abundance and distribution in the Sacramento-San Joaquin Delta and Suisun Bay

Prior to 2000, the four most abundant resident pelagic fishes in the study area included two native species, delta smelt (Hypomesus transpacificus) a federal listed endangered species, and longfin smelt (Spirinchus thaleicthys) a state listed endangered species, and two introduced species, threadfin shad (Dorosoma petenense) and age-0 striped bass (Morone saxatilis).
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California Water Science Center
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Development of a spatially explicit ecosystem model to explore physiochemical drivers of step changes in POD species abundance and distribution in the Sacramento-San Joaquin Delta and Suisun Bay

Prior to 2000, the four most abundant resident pelagic fishes in the study area included two native species, delta smelt (Hypomesus transpacificus) a federal listed endangered species, and longfin smelt (Spirinchus thaleicthys) a state listed endangered species, and two introduced species, threadfin shad (Dorosoma petenense) and age-0 striped bass (Morone saxatilis).
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USGS

Modeling in support of development of biocriteria for wadeable California streams and rivers

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop biological objectives for wadeable freshwater streams and rivers for the entire state.
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California Water Science Center
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Modeling in support of development of biocriteria for wadeable California streams and rivers

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop biological objectives for wadeable freshwater streams and rivers for the entire state.
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Closeup image of Corbicula fluminea clams.

The role of the alien clam Corbicula fluminea in the regulation of organic carbon in the San Joaquin River watershed

Sources and fate of various forms of organic carbon in the Sacramento-San Joaquin Delta (Delta) and San Joaquin River watershed are of concern because of the importance of identifying the sources of carbon contributing to the oxygen depletion zone on the San Joaquin River near the city of Stockton, the need to understand the causes of the low primary and secondary production in the Delta, and the...
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California Water Science Center
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The role of the alien clam Corbicula fluminea in the regulation of organic carbon in the San Joaquin River watershed

Sources and fate of various forms of organic carbon in the Sacramento-San Joaquin Delta (Delta) and San Joaquin River watershed are of concern because of the importance of identifying the sources of carbon contributing to the oxygen depletion zone on the San Joaquin River near the city of Stockton, the need to understand the causes of the low primary and secondary production in the Delta, and the...
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Location of sampling sites for a regional monitoring program in Southern California

Development of Numeric Flow Criteria to Support Freshwater Biological Objectives and Hydrologic Modification Management in California's Wadeable Streams

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop numerical biological objectives for wadeable freshwater streams and rivers for the entire state. Use of biological endpoints for regulatory or compliance purposes requires the ability to relate specific stressors to key biological metrics and to use this understanding to influence management actions...
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California Water Science Center
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Development of Numeric Flow Criteria to Support Freshwater Biological Objectives and Hydrologic Modification Management in California's Wadeable Streams

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop numerical biological objectives for wadeable freshwater streams and rivers for the entire state. Use of biological endpoints for regulatory or compliance purposes requires the ability to relate specific stressors to key biological metrics and to use this understanding to influence management actions...
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juvenile fish being held in palm of hand

Aquatic Ecology Group

The California Water Science Center's Aquatic Ecology Group is making great strides in research and reporting.
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California Water Science Center
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Aquatic Ecology Group

The California Water Science Center's Aquatic Ecology Group is making great strides in research and reporting.
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USGS

Whiskeytown Aquatic Inventory Assessment

The project focuses on the assessment of aquatic biology, habitat, and water quality conditions of the major WHIS watersheds
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California Water Science Center
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Whiskeytown Aquatic Inventory Assessment

The project focuses on the assessment of aquatic biology, habitat, and water quality conditions of the major WHIS watersheds
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The general study area

Estimating Natural Flows for Hydrologic Reference Streams

Scientists develop metrics of expected hydrological conditions at ungaged sites throughout Callifornia
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California Water Science Center
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Estimating Natural Flows for Hydrologic Reference Streams

Scientists develop metrics of expected hydrological conditions at ungaged sites throughout Callifornia
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Fish sampling sites in the San Joaquin River

Application of the SmeltCam to Describe Processes Influencing Delta Smelt Distribution and Movements

The California Water Science Center's "SmeltCam" helps describe processes influencing Delta Smelt distribution and movement.
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California Water Science Center
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Application of the SmeltCam to Describe Processes Influencing Delta Smelt Distribution and Movements

The California Water Science Center's "SmeltCam" helps describe processes influencing Delta Smelt distribution and movement.
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close-up Santa Ana Sucker

Native Fish Population and Habitat Study - Santa Ana River

California Water Science Center scientists further research on two native fish species.
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California Water Science Center
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Native Fish Population and Habitat Study - Santa Ana River

California Water Science Center scientists further research on two native fish species.
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Longfin Smelt

Exploring Drivers of Pelagic Fish Population Decline in Bay-Delta

USGS scientists develop spatially explicit ecosystem model to explore changes pelagic fish species population and distribution in the Sacramento-San Joaquin Delta and Suisun Bay.
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California Water Science Center
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Exploring Drivers of Pelagic Fish Population Decline in Bay-Delta

USGS scientists develop spatially explicit ecosystem model to explore changes pelagic fish species population and distribution in the Sacramento-San Joaquin Delta and Suisun Bay.
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Aerial overview of locations of tidal wetlands sampled

Ecology of Selected Tidal Wetlands of the San Francisco Estuary

Researachers study differences of tidal marsh restoration efforts throughout Bay-Delta ecosystem.
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California Water Science Center
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Ecology of Selected Tidal Wetlands of the San Francisco Estuary

Researachers study differences of tidal marsh restoration efforts throughout Bay-Delta ecosystem.
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Santa Ana River Native Fish Population and Habitat Data, Santa Ana River, California, 2020

This dataset includes 2020 reach fish data and reach habitat data collected to support development of the upper Santa Ana River Habitat Conservation Plan for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California.
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California Water Science Center

Data used in projected flow analysis in Yolo Bypass under 20 scenarios of climate change

Yolo Bypass is an ecological feature of the Bay-Delta ecosystem in California that provides floodplain habitat for spawning and rearing of Sacramento Splittail (Pogonichthys macrolepidotus) and rearing of juvenile Chinook Salmon (Oncorhynchus tshawytscha) when inundated. We used outputs from 10 climate change models for two Representative Concentration Pathways (RCPs) for greenhouse gas concentrat
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California Water Science Center

SAR 2018 Native Fish Population and Habitat Study, Santa Ana and San Gabriel Rivers, California

This dataset includes 2018 reach fish data and reach habitat data collected to support development of the upper Santa Ana River Habitat Conservation Plan for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana and San Gabriel Rivers, California.
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California Water Science Center

SAR 2019 Native Fish Population and Habitat Study, Santa Ana River, California

This dataset includes 2019 reach fish data and reach habitat data collected to support development of the upper Santa Ana River Habitat Conservation Plan for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California.
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California Water Science Center

SAR 2017 Native Fish Population and Habitat Study, Santa Ana River, California

This dataset includes: 1) microhabitat use data for fish 100 mm and larger; 2) reach fish data; and 3) reach habitat data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California. Habitat availability data was not collected in 2017.
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California Water Science Center

SAR 2016 Native Fish Population and Habitat Study, Santa Ana River, California

Data included in this dataset include: 1) population estimate data; 2) microhabitat use data; and 3) microhabitat availability data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California.
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California Water Science Center
Filter Total Items: 107

Synthesis of data and studies relating to Delta Smelt biology in the San Francisco Estuary, emphasizing water year 2017

In the San Francisco Estuary (SFE), the effects of freshwater flow on the aquatic ecosystem have been studied extensively over the years and remains a contentious management issue. It is especially contentious with regards to the Delta Smelt (Hypomesus transpacificus), a species endemic to the SFE that has been listed as threatened under the Federal Endangered Species Act and endangered by the Sta
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Water Resources, California Water Science Center

Disentangling stationary and dynamic estuarine fish habitat to inform conservation: Species-specific responses to physical habitat and water quality in San Francisco Estuary

Estuaries represent critical aquatic habitat that connects surface water distributed between Earth’s landmasses and oceans. They are dynamic transitional ecosystems, which provide important habitat for fishes and other aquatic organisms. Effective conservation of species inhabiting estuaries requires knowledge of the habitat features that drive their abundance and distribution. We sought to elucid
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Water Resources, California Water Science Center

Toward improved decision-support tools for Delta Smelt management actions

The Collaborative Science and Adaptive Management Program (CSAMP) has endorsed a goal of reversing the recent downward trajectory of the Delta Smelt population within 5-10 generations, with the long-term aim of establishing a self-sustaining population. An ambitious agenda of management actions is planned, and more management actions are being considered. This White Paper furthers one of the recom
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Water Resources, California Water Science Center

Resistance and resilience of pelagic and littoral fishes to drought in the San Francisco Estuary

Many estuarine ecosystems and the fish communities that inhabit them have undergone substantial changes in the past several decades, largely due to multiple interacting stressors that are often of anthropogenic origin. Few are more impactful than droughts, which are predicted to increase in both frequency and severity with climate change. In this study, we examined over five decades of fish monito
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Water Resources, California Water Science Center

Hydrodynamics drive pelagic communities and food web structure in a tidal environment

Hydrodynamic processes can lead to the accumulation and/or dispersal of water column constituents, including sediment, phytoplankton, and particulate detritus. Using a combination of field observations and stable isotope tracing tools, we identified how hydrodynamic processes influenced physical habitat, pelagic communities, and food web structure in a freshwater tidal system. The pelagic habitat
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Water Resources, California Water Science Center

Characterizing benthic macroinvertebrate and algal biological condition gradient models for California wadeable Streams, USA

The Biological Condition Gradient (BCG) is a conceptual model that describes changes in aquatic communities under increasing levels of anthropogenic stress. The BCG helps decision-makers connect narrative water quality goals (e.g., maintenance of natural structure and function) to quantitative measures of ecological condition by linking index thresholds based on statistical distributions (e.g., pe
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Water Resources

Food web conceptual model

This chapter describes a general model of food webs within tidal wetlands and represents how physical features of the wetland affect the structure and function of the food web. This conceptual model focuses on how the food web provides support for (or may reduce support for) threatened fish species. This model is part of a suite of conceptual models designed to guide monitoring of restoration site
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Water Resources, California Water Science Center

Conceptual model for invasive bivalve control on wetland productivity

Tidal wetlands were the historically dominant features of many coastal regions around the world, including the San Francisco Estuary (Callaway et al. 2011; Whipple et al. 2012). These mosaics of varied interconnected habitats (Mitsch and Gosselink 1993) provide a host of ecosystem services, including biodiversity maintenance, fish and wildlife habitat, water quality improvement, flood abatement, a
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Water Resources

Pelagic nekton abundance and distribution in the northern Sacramento–San Joaquin Delta, California

Knowledge of the habitats occupied by species is fundamental for the development of effective conservation and management actions. The collapse of pelagic fish species in the Sacramento–San Joaquin Delta, California, has triggered a need to better understand factors that drive their distribution and abundance. A study was conducted in summer–fall 2014 in an attempt to identify physical and biologi
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Water Resources, California Water Science Center

Climate change and the Delta

Anthropogenic climate change amounts to a rapidly approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic variability, complex water-management systems have been developed, even as the Delta’s natural ecosystems have been largely devastated. Climate change is projected to challenge these management and ecological systems in
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Water Resources, California Water Science Center

Food webs of the Delta, Suisun Bay and Suisun Marsh: an update on current understanding and possibilities for management

This paper reviews and highlights recent research findings on foodweb processes since an earlier review by Kimmerer et al. (2008). We conduct this review within a conceptual framework of the Delta-Suisun food web, which includes both temporal and spatial components. The temporal component is based on knowledge that the landscape has changed markedly from historical conditions. The spatial componen
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Water Resources, California Water Science Center

Delta smelt: Life history and decline of a once abundant species in the San Francisco Estuary

This paper reviews what has been learned about Delta Smelt and its status since the publication of The State of Bay-Delta Science, 2008 (Healey et al. 2008). The Delta Smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain the population. As a listed species living in the central node of Calif
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Water Resources, California Water Science Center

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