Frederick Feyrer
Frederick Feyrer - California Water Science Center
I'm a Research Fish Biologist with the U.S. Geological Survey's California Water Science Center in Sacramento, California. My research program is broadly focused on applied aquatic ecology with an emphasis on fishes. In general, my work aims to fill critical data gaps needed by fisheries and water resource managers to implement effective restoration and conservation measures for imperiled species and ecosystems. In particular, my work has focused on how aquatic ecosystems function at varying spatio-temporal scales and how this influences species-habitat relationships. Recent and active study topics span the range of life history studies of threatened and endangered species to the role of climate variability and climate change on species and communities.
To learn more about my work visit my USGS Program Website or my Google Scholar Profile.
Science and Products
Hydrologic and Aquatic Ecology Studies at Clear Lake, California
Studying Threatened Fish Species in Clear Lake, CA
Aquatic Ecology Group
Longfin Smelt Distribution in the Coastal Pacific Ocean
Role Nutrients Play in Fish Death Rates at Rodeo Lagoon
Application of the SmeltCam to Describe Processes Influencing Delta Smelt Distribution and Movements
Technical Support and Synthesis of Data Collected on the Health and Status of Delta Smelt
Rearing Habitats of Longfin Smelt in the Low Salinity Zone of the San Francisco Estuary
Physical and Biological Drivers of Longfin Smelt Vertical Distribution
Abiotic and Biotic Effects on Delta Smelt Abundance and Distribution
Abundance and Distribution of Fishes in Clear Lake, Lake County, California, 2017-2023
Water Quality Data from Ponds on Bouldin Island in the Sacramento-San Joaquin Delta, California
Water Quality and Biological Data from Ponds on Islands of the Sacramento-San Joaquin Delta
Distribution and stomach contents of fishes in the northern Sacramento-San Joaquin Delta, 2020-2022
Marine Observations of Longfin Smelt Spirinchus thaleichthys in the northeast Pacific Ocean
Detection range and efficiency of acoustic telemetry receivers in Clear Lake, Lake County, California
Mercury in fishes from Clear Lake, California, 2019 and 2020 (ver. 2.0, February 2022)
Vertical Distribution of Longfin Smelt in the San Francisco Estuary (ver. 2.1, August 2020)
Diets and Stable Isotopes of Fishes in Rodeo Lagoon, California, 2016-2017
Zooplankton Survey of the Northern Sacramento-San Joaquin Delta, California, 2016-2018
Underwater Videographic Observations of Cultured Delta Smelt in Field Enclosures: Video Clips and Summary Data
Little Holland Tract and Wildlands Flux Study; Zooplankton, Phytoplankton, and Larval Fish Taxonomic Data, 2017-2018
Wetland geomorphology and tidal hydrodynamics drive fine-scale fish community composition and abundance
Physics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary
Etiology of a fish kill, Including the endangered Tidewater Goby (Eucyclogobius newberryi), in a northeastern pacific coastal lagoon
Hydrodynamics and habitat interact to structure fish communities within terminal channels of a tidal freshwater delta
Habitat-specific foraging by striped bass (Morone saxatilis) in the San Francisco Estuary, California: Implications for tidal restoration
Gill-net selectivity for fifteen fish species of the upper San Francisco Estuary
Underwater videographic observations of domesticated Delta smelt in field enclosures
Climate change and fishes in estuaries
Ocean connectivity drives trophic support for consumers in an intermittently closed coastal lagoon
Disentangling stationary and dynamic estuarine fish habitat to inform conservation: Species-specific responses to physical habitat and water quality in San Francisco Estuary
Interagency Ecological Program long-term monitoring element review: Pilot approach and methods development (2020)
Eye lenses reveal ontogenetic trophic and habitat shifts in an imperiled fish, Clear Lake hitch (Lavinia exilicauda chi)
Science and Products
- Science
Hydrologic and Aquatic Ecology Studies at Clear Lake, California
The USGS California Water Science Center conducts a variety of research activities at Clear Lake, California, including surface-water monitoring and water quality and aquatic habitat studies.Studying Threatened Fish Species in Clear Lake, CA
The Clear Lake Hitch ( Lavinia exilicauda chi ) population, which once flourished in great abundance, has been decimated by loss of spawning habitat, nursery areas, and the encroachment of non-native species. In order to make an informed decision, the California Water Science Center has been asked by the U.S. Fish and Wildlife Service to conduct studies into the fish’s habitat, specifically...Aquatic Ecology Group
The California Water Science Center's Aquatic Ecology Group is making great strides in research and reporting.Longfin Smelt Distribution in the Coastal Pacific Ocean
Longfin Smelt ( Spirinchus thaleichthys ) is a pelagic fish species found in waters along the Pacific coast, from Alaska to central California. Its complex life cycle makes it vulnerable to threats in both freshwater and at sea. Longfin Smelt is listed as a threatened species by the state of California.Role Nutrients Play in Fish Death Rates at Rodeo Lagoon
Scientists investigate excessive nutients levels in Rodeo Lagoon that are believed to be cause of dying fishApplication 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.Technical Support and Synthesis of Data Collected on the Health and Status of Delta Smelt
USGS scientists work to provide data to UC Davis researchers on health and growth of smelt population in Bay-Delta.Rearing Habitats of Longfin Smelt in the Low Salinity Zone of the San Francisco Estuary
Scientists study habitats occupied by longfin smelt larvae to better understand their ecology and to inform water management operations, species management, and habitat restoration efforts.Physical and Biological Drivers of Longfin Smelt Vertical Distribution
Research scientists study conditions that affect abundance and distributions Longfin Smelt fish population.Abiotic and Biotic Effects on Delta Smelt Abundance and Distribution
Scientists research the importance of abiotic versus biotic (food supply) habitat features as drivers of delta smelt abundance and distribution. - Data
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Abundance and Distribution of Fishes in Clear Lake, Lake County, California, 2017-2023
Field data for fishes sampled using bottom and surface gill nets during daylight hours in Clear Lake, California, USA. This data release includes all measured environmental parameters and fish taxa included in the analysis. First posted - December 20, 2018 (available from author) Revision - November 26, 2019 (available from author) Revision - January 21, 2022 (available from author) Revision - OcWater Quality Data from Ponds on Bouldin Island in the Sacramento-San Joaquin Delta, California
This data release includes water quality data collected from ponds on Boudin Island in the Sacramento-San Joaquin Delta. Data were collected in the Bouldin East and Bouldin West ponds concurrently with a Delta Smelt Enclosure Study which involved three cages in each pond with approximately 60 Delta Smelt (Hypomesus transpacificus) in each cage. There were two fish deployments, the first deploymentWater Quality and Biological Data from Ponds on Islands of the Sacramento-San Joaquin Delta
This data includes information on water quality, zooplankton, and fish sampled in ponds on delta islands in San Joaquin County, California. The islands include Bacon (North and South ponds), Bouldin (East and West ponds), Holland Tract (Middle, North, and South ponds), and Webb Tract (East, Middle, and North ponds). Discrete water quality parameters were measured bimonthly and continuous temperatuDistribution and stomach contents of fishes in the northern Sacramento-San Joaquin Delta, 2020-2022
This data set includes count, location, and ancillary habitat data for fishes sampled in adjacent reaches of Georgiana Slough, Sacramento River, and Steamboat Slough in the northern Sacramento-San Joaquin Delta. It also includes data on the stomach contents of selected individual black basses (Micropterus). Fishes were sampled by boat electrofishing from approximately January-May, 2020-2022, plusMarine Observations of Longfin Smelt Spirinchus thaleichthys in the northeast Pacific Ocean
This dataset is a compilation of Longfin Smelt observations from multiple sources, including research institutions and museums, and local, state, and federal fisheries agencies.Detection range and efficiency of acoustic telemetry receivers in Clear Lake, Lake County, California
Data on the detection range and efficiency of VR2W-69 kHz acoustic receivers (Innovasea Marine Systems Canada Inc., Bedford, Nova Scotia, Canada; https://www.vemco.com/) were collected to guide the development of telemetry studies of the Clear Lake Hitch (Lavinia exilicauda chi), an imperiled fish species endemic to Clear Lake, Lake County, California. The study took place June 21, 2021 through JuMercury in fishes from Clear Lake, California, 2019 and 2020 (ver. 2.0, February 2022)
Comma-separated values (.csv) file containing data related to mercury in fishes collected from Clear Lake, California.Vertical Distribution of Longfin Smelt in the San Francisco Estuary (ver. 2.1, August 2020)
Field data for fishes sampled using mid-water trawls, otter trawls, and the SmeltCam during day and night in San Pablo Bay, CA. This data release includes all measured environmental parameters and fish taxa included in the analysis.Diets and Stable Isotopes of Fishes in Rodeo Lagoon, California, 2016-2017
This dataset includes lab data for fish, fish diets, and stable isotopes for fish tissue, vegetation, and invertebrates collected during daylight hours in the Rodeo Lagoon and Lake in Golden Gate National Recreation Area at the Pacific Coast, USA during 2016 and 2017. This data release includes all animal taxa, and isotope values included in the analysis.Zooplankton Survey of the Northern Sacramento-San Joaquin Delta, California, 2016-2018
This data set contains information on zooplankton and associated environmental parameters for sampling conducted in California's northern Sacramento-San Joaquin Delta between May 2016 and April 2018. Macrozooplankton were sampled with horizontal tows (water surface) of a 50 cm-diameter conical plankton net that was 150cm long with 102um mesh. Samples were preserved in the field in 10 percent formaUnderwater Videographic Observations of Cultured Delta Smelt in Field Enclosures: Video Clips and Summary Data
All data is part of a pilot study aimed to observe Delta Smelt behavior within enclosures deployed in the wild. The enclosures used were designed by The California Department of Water Resources and UC Davis as part of their ongoing Delta Smelt enclosure deployment studies. Study 1: This data includes 16 17:43 minute videos of observations of Delta Smelt behavior in a floating field enclosure and aLittle Holland Tract and Wildlands Flux Study; Zooplankton, Phytoplankton, and Larval Fish Taxonomic Data, 2017-2018
This data set includes taxonomic data for zooplankton, larval fish, and phytoplankton sampled in Little Holland Tract and Liberty Island Conservation Bank, in the northern Sacramento-San Joaquin River Delta, California. Zooplankton and larval fish were collected with target specific trawl nets and phytoplankton was collected from water grabs. This data release includes all measured environmental p - Publications
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Wetland geomorphology and tidal hydrodynamics drive fine-scale fish community composition and abundance
Effective restoration of tidal wetlands for fish communities requires clear goals and mechanistic understanding of the ecosystem drivers which affect fish distribution and abundance. We examined fish community responses to abiotic habitat features in two adjacent but dissimilar freshwater tidal wetlands in the Sacramento-San Joaquin Delta, CA, USA, each of which represents a potential restorationAuthorsJustin Kinsey Clause, Mary Jade Farruggia, Frederick V. Feyrer, Matthew J. YoungPhysics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary
Executive SummaryThe Bureau of Reclamation (Reclamation) operates the Central Valley Project (CVP), one of the nation’s largest water projects. Reclamation has an ongoing need to improve the scientific basis for adaptive management of the CVP and, by extension, joint operations with California’s State Water Project. The U.S. Geological Survey (USGS) works cooperatively with the Bureau of ReclamatiAuthorsLarry R. Brown, David E. Ayers, Brian A. Bergamaschi, Jon R. Burau, Evan T. Dailey, Bryan D. Downing, Maureen A. Downing-Kunz, Frederick V. Feyrer, Brock M. Huntsman, Tamara E. C. Kraus, Tara Morgan, Jessica R. Lacy, Francis Parchaso, Catherine A. Ruhl, Elizabeth B. Stumpner, Paul Stumpner, Janet Thompson, Matthew J. YoungEtiology of a fish kill, Including the endangered Tidewater Goby (Eucyclogobius newberryi), in a northeastern pacific coastal lagoon
Ecological disturbances such as fish kills can negatively impact ecosystem processes in coastal lagoons. To gain an understanding of factors causing fish kills, we examined conditions associated with a summertime fish kill in a northeastern Pacific coastal lagoon (Rodeo Lagoon, CA, USA). Examination of available data indicated the fish kill was likely caused by hypoxia involving the following etioAuthorsFrederick V. Feyrer, Matthew J. Young, Tamara E. C. Kraus, Elizabeth B. Stumpner, Darren Fong, Kurt D. CarpenterHydrodynamics and habitat interact to structure fish communities within terminal channels of a tidal freshwater delta
Terminal channels were historically a common feature of tidal delta ecosystems but have become increasingly rare as landscapes have been modified. Tidal hydrodynamics are a defining feature in tidal terminal channel ecosystems from which native aquatic communities have evolved. However, few studies have explored the relationship between fish community structure and hydrodynamics in these tidal terAuthorsBrock Huntsman, Matthew J. Young, Frederick V. Feyrer, Paul Stumpner, Larry R. Brown, Jon R. BurauHabitat-specific foraging by striped bass (Morone saxatilis) in the San Francisco Estuary, California: Implications for tidal restoration
Non-native predatory fish strongly impact aquatic communities, and their impacts can be exacerbated by anthropogenic habitat alterations. Loss of natural habitat and restoration actions reversing habitat loss can modify relationships between non-native predators and prey. Predicting how these relationships will change is often difficult because insufficient information exists on the habitat-specifAuthorsMatthew J. Young, Frederick V. Feyrer, Collin Smith, Dennis A. ValentineGill-net selectivity for fifteen fish species of the upper San Francisco Estuary
Gill-net size selectivity for 15 fish species occurring in the upper San Francisco Estuary was estimated from a data set compiled from multiple studies which together contained 7,096 individual fish observations from 882 gill net sets. The gill nets considered in this study closely resembled the American Fisheries Society’s recommended standardized experimental gill nets for sampling inland watersAuthorsMarissa L. Wulff, Frederick V. Feyrer, Matthew J. YoungUnderwater videographic observations of domesticated Delta smelt in field enclosures
The delta smelt (Hypomesus transpacificus) is a small, euryhaline fish species endemic to the Sacramento–San Joaquin Delta; it is protected under the U.S. and California Endangered Species Acts, and because of declines in population abundance, the delta smelt may be vulnerable to extinction. The California Department of Water Resources (DWR) is conducting studies to test the viability of using domAuthorsEthan Enos, Oliver Patton, Frederick V. FeyrerClimate change and fishes in estuaries
This chapter provides an overview of the main drivers of change in estuarine systems, their expected causes and impacts on estuarine fish and fisheries. An analysis of global, regional and local patterns of estuarine fish and how climate-induced change may impact estuarine systems and their fish communities is provided. We also examine the main environmental, climatic and biological stressors likeAuthorsBronwyn M Gillanders, Matthew N. McMillan, P. Reis-Santos, Lee J. Baumgartner, Larry R. Brown, John Conallin, Frederick V. Feyrer, Sofia Henriques, Nicola C. James, Andrés J Jaureguizar, André L. M. Pessanha, Rita P. Vasconcelos, An V. Vu, Benjamin Walther, Arif WibowoOcean connectivity drives trophic support for consumers in an intermittently closed coastal lagoon
Estuarine food webs are complex, as marine, freshwater, and terrestrial inputs combine and contribute variable amounts of organic material. Seasonal fluctuations in precipitation amplify the dynamism inherent to estuarine food webs, particularly in lagoonal estuaries, which can be seasonally closed and disconnected from the ocean in low-runoff periods (bar-built lagoons). Despite their abundance aAuthorsMatthew J. Young, Frederick V. Feyrer, Darren Fong, Rachel C. Johnson, Tamara E. C. Kraus, Veronica Larwood, Elizabeth B. Stumpner, Megan B. YoungDisentangling 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 elucidAuthorsFrederick V. Feyrer, Matthew J. Young, Brock Huntsman, Larry R. BrownInteragency Ecological Program long-term monitoring element review: Pilot approach and methods development (2020)
This report describes the first-year, pilot-phase of what is intended to be a larger, multiple-year review of all IEP core long-term monitoring elements (LTMEs). Here we hope to provide evidence that the review team arrangement and communication schedule was effective at developing a framework to objectively evaluate a suite of LTMEs. We focused on developing methods for an effective review, documAuthorsJereme W. Gaeta, Samuel M. Bashevkin, Frederick V. Feyrer, Brock Huntsman, Brian Mahardja, Steven D Culberson, Michael P Beakes, Stephanie Fong, Stephen LouieEye lenses reveal ontogenetic trophic and habitat shifts in an imperiled fish, Clear Lake hitch (Lavinia exilicauda chi)
Stable isotopes recorded in fish eye lenses are an emerging tool to track dietary shifts coincident with use of diverse habitats over the lifetime of individuals. Eye lenses are metabolically inert, sequentially deposited, archival tissues that can open avenues to chronicle contaminant exposures, diet histories, trophic dynamics and migratory histories of individual fishes. In this study, we demonAuthorsMatthew J. Young, Veronica Larwood, Justin Kinsey Clause, Miranda Bell-Tilcock, George Whitman, Rachel C. Johnson, Frederick V. Feyrer - News