Katy O'Donnell
Katy O'Donnell - California Water Science Center
Science and Products
In situ chlorophyll fluorometer validation and comparison study
The Sacramento-San Joaquin Delta (Delta) supplies drinking water to much of California. The Delta also provides irrigation water to the Central Valley and is an important habitat to many aquatic and terrestrial species. In the past decade, there has been an increase in harmful algal blooms (HABs) in the Delta. While some HABs are nontoxic, others contain cyanobacteria that can produce dangerous...
Biogeochemistry Group
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Causes and Relevance of Phytoplankton Blooms in the Northern Sacramento-San Joaquin Delta
Phytoplankton are an important part of aquatic food webs and ecosystems. These single-celled plants grow faster in the stronger light of spring or summer, resulting in population explosions called phytoplankton blooms. These blooms in turn feed zooplankton (free-floating aquatic microorganisms), providing food for many aquatic species, including fish, shrimp, crabs, and other invertebrates.
Filter Total Items: 21
Above-water hyperspectral field spectroscopy and associated water quality measurements in the Sacramento-San Joaquin Delta, California, collected in 2024 and 2025 Above-water hyperspectral field spectroscopy and associated water quality measurements in the Sacramento-San Joaquin Delta, California, collected in 2024 and 2025
Broad-area, high-resolution, boat-based water quality mapping surveys of the Sacramento-San Joaquin Delta (Delta) were conducted in June and September of 2024. Each survey was comprised of one day of high-resolution mapping. The regions covered included Discovery Bay and Old and Middle Rivers in the South Delta Tidal Transition Zone. On each day, the route of the mapping survey was...
Water quality and nutrient data from San Joaquin River and Stockton Waterfront, April and August 2024 Water quality and nutrient data from San Joaquin River and Stockton Waterfront, April and August 2024
This dataset records diel changes to water quality parameters, nutrients, and phytoplankton biomass in the south-eastern region of the Sacramento-San Joaquin Delta. Sampling occurred in August 2024 in the Stockton Waterfront (City of Stockton, San Joaquin County, California, USA) and San Joaquin River. Data was collected from approximately 6am to 9pm Pacific Standard Time on August 6, 13...
Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2023 High resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2023 High resolution mapping surveys
Broad-area, high-resolution, boat-based water quality mapping surveys of the Sacramento-San Joaquin Delta and Suisun Bay (Delta) of California, USA were conducted under different environmental/flow conditions in May, July, and October of 2023. The spatial and temporal variability of nutrients, phytoplankton, and related water quality parameters were assessed. This dataset includes...
Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2022 High-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2022 High-resolution mapping surveys
Broad-area, high-resolution, boat-based water quality mapping surveys of the Sacramento-San Joaquin Delta and Suisun Bay (Delta) of California, USA were conducted under different environmental/flow conditions in May, July, and October of 2022. The spatial and temporal variability of nutrients, phytoplankton, and related water quality parameters were assessed. This dataset includes...
Above-water hyperspectral field spectroscopy measurements at Franks Tract in the Sacramento-San Joaquin Delta, California Above-water hyperspectral field spectroscopy measurements at Franks Tract in the Sacramento-San Joaquin Delta, California
Hand-held hyperspectral spectroscopy data were collected in 2022 in Franks Tract, a flooded area located in the central Sacramento-San Joaquin Delta of California. The data were collected from a boat and co-located within pixels from the Ocean Land Color Imaging (OLCI) sensor on the Sentinel-3A and 3-B satellites. Data from 16 sites within 7 OLCI pixels were collected on three days: July...
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the San Francisco Bay, California: 2021-2022 High-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the San Francisco Bay, California: 2021-2022 High-resolution mapping surveys
The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the San Francisco Bay of California, USA in 2021 and 2022. The dataset includes nitrate, temperature, conductivity, dissolved oxygen, and chlorophyll as well as information about phytoplankton community composition. Data-collection cruises were...
Water quality, nutrient, and phytoplankton data from Franks Tract, Mildred Island, and neighboring channels in the California Sacramento-San Joaquin Delta: 2022 and 2023 High-resolution mapping surveys Water quality, nutrient, and phytoplankton data from Franks Tract, Mildred Island, and neighboring channels in the California Sacramento-San Joaquin Delta: 2022 and 2023 High-resolution mapping surveys
Surface water quality, water isotope, and phytoplankton enumeration data were collected to evaluate the impact of an Emergency Drought Barrier (EDB) in False River in the Sacramento-San Joaquin Delta. Data were collected on six days during 2022 and 2023 (June 7, June 21, July 27, August 9, October 12, November 30, 2022, and February 21, 2023). Sampling occurred in Franks Tract, Mildred...
KdPAR and surface water-quality data collected in the Sacramento-San Joaquin River Delta in 2013 and 2014 KdPAR and surface water-quality data collected in the Sacramento-San Joaquin River Delta in 2013 and 2014
Data release provides diffuse light attenuation coefficient of photosynthetically active radiation (KdPAR) derived from in-situ light measurements, along with surface water-quality and atmospheric data collected in the Sacramento-San Joaquin Rive Delta in California between January 2013 and May 2014. These associated surface level water-quality and atmospheric data, and categorical...
Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2020-2021 High-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2020-2021 High-resolution mapping surveys
The dataset documents the spatial and temporal variability of nutrients, phytoplankton, and related water quality parameters at high spatial resolution in the Sacramento-San Joaquin River Delta and Suisun Bay of California, USA. The dataset includes nitrate, ammonium, orthophosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, and chlorophyll as well as...
Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta during treated wastewater effluent holds: August and September 2019 high resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta during treated wastewater effluent holds: August and September 2019 high resolution mapping surveys
The study is comprised of daily survey data consisting of high resolution mapping and discrete sample collection of nutrients, phytoplankton, and related water quality constituents conducted in the Sacramento River, Georgiana Slough, and the North and South Forks of the Mokelumne River on August 28 and September 10-12, 2019, coincident with planned holds of treated wastewater effluent...
Phytoplankton Species Composition and Abundance in the Sacramento-San Joaquin River Delta: Microscopic Enumeration of USGS Samples, beginning in 2016 (ver. 1.1, December 2023) Phytoplankton Species Composition and Abundance in the Sacramento-San Joaquin River Delta: Microscopic Enumeration of USGS Samples, beginning in 2016 (ver. 1.1, December 2023)
This dataset contains taxonomy, density (cells/mL), and biovolume (μm3/mL) data for phytoplankton sampled across the Sacramento San Joaquin River Delta and San Francisco Bay (Bay-Delta) beginning in 2016. Whole water phytoplankton samples were collected intermittently during special projects and during routine visits to service continuous monitoring stations. Samples were preserved with...
Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta related to the 2015 installation of the False River Emergency Drought Barrier: 2015 and 2016 high-resolution m Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta related to the 2015 installation of the False River Emergency Drought Barrier: 2015 and 2016 high-resolution m
This data release documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the western and central portion of the Sacramento-San Joaquin River Delta of California, USA. The data set includes water residence time, nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen...
Filter Total Items: 16
Identifying conditions associated with outliers produced by three different chlorophyll fluorometers: A comparison of instrumentation and development of correction formulae Identifying conditions associated with outliers produced by three different chlorophyll fluorometers: A comparison of instrumentation and development of correction formulae
Measurements of chlorophyll concentration reported by fluorometers (fChl) are used in environmental research and monitoring, as inputs to models, and in the interpretation of remote sensing data. Researchers and managers benefit from understanding how to interpret and ensure the accuracy of fChl data collected by in situ fluorometers. Although fChl values produced by different...
Authors
Emily Richardson, Tamara Kraus, Crystal Sturgeon, Katy O’Donnell, Brian Bergamaschi
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—Comparison of four (2018, 2020, 2021, 2022) spring high-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—Comparison of four (2018, 2020, 2021, 2022) spring high-resolution mapping surveys
Executive Summary This report summarizes results from boat-based, high-resolution water-quality mapping surveys completed before, during, and after upgrades to the EchoWater Resource Recovery Facility (EchoWater Facility), the regional wastewater facility for the City of Sacramento and surrounding areas, near Elk Grove, California. Surveys were completed in the tidal aquatic environments...
Authors
Emily Richardson, Tamara Kraus, Katy O’Donnell, Jeniffer Soto-Perez, Crystal Sturgeon, Elizabeth Stumpner, Brian Bergamaschi
Amphibian and reptile conservation in the United States of America Amphibian and reptile conservation in the United States of America
Wildlife stewardship is of utmost importance in the United States, where management for sustainable natural resources is extended to native species including amphibians and reptiles. The U.S. wildlife conservation framework is a nested system of authorities regulating species and habitats, science-based management and policy decisions, and adaptive management as new knowledge is applied...
Authors
Deanna H. Olson, David S. Pilliod
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—2018 high resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—2018 high resolution mapping surveys
Executive Summary This study examined the abundance and distribution of nutrients and phytoplankton in the tidal aquatic environments of the Sacramento–San Joaquin Delta (Delta) and Suisun Bay, comprising three spatial surveys conducted in May, July, and October of 2018 that used continuous underway high frequency sampling and measurements onboard a high-speed boat to characterize...
Authors
Brian Bergamaschi, Tamara Kraus, Bryan Downing, Elizabeth Stumpner, Katy O’Donnell, Jeffrey Hansen, Jeniffer Soto Perez, Emily Richardson, Angela M. Hansen, Alan Gelber
A simple approach to modeling light attenuation in the Sacramento-San Joaquin Delta using commonly available data A simple approach to modeling light attenuation in the Sacramento-San Joaquin Delta using commonly available data
The diffuse attenuation coefficient of photosynthetically active radiation (KdPAR) is commonly used to predict light attenuation in aquatic productivity models, but obtaining measurements of PAR to compute KdPAR is difficult. In situ calculations of KdPAR require multiple measurements of PAR through the water column, and these measurements are infeasible for real-time recording. Instead
Authors
Emily Richardson, Keith Bouma-Gregson, Katy O’Donnell, Brian Bergamaschi
A novel boat-based field application of a high-frequency conductometric ammonium analyzer to characterize spatial variation in aquatic ecosystems A novel boat-based field application of a high-frequency conductometric ammonium analyzer to characterize spatial variation in aquatic ecosystems
Documenting dissolved inorganic nitrogen (DIN) concentration and form at appropriate temporal and spatial scales is key to understanding aquatic ecosystem health, particularly as DIN fuels primary productivity. In addition to point and non-point source nutrient inputs, factors such as hydrology, geomorphology, temperature, light, and biogeochemical transformations influence nutrient...
Authors
Emily Richardson, Angela Hansen, Tamara Kraus, Bryan Downing, Don Forsberg, John Stillian, Katy O’Donnell, Crystal Sturgeon, Brian Bergamaschi
Priority research needs to inform amphibian conservation in the Anthropocene Priority research needs to inform amphibian conservation in the Anthropocene
The problem of global amphibian declines has prompted extensive research over the last three decades. Initially, the focus was on identifying and characterizing the extent of the problem, but more recently efforts have shifted to evidence-based research designed to identify best solutions and to improve conservation outcomes. Despite extensive accumulation of knowledge on amphibian...
Authors
Evan Campbell Grant, Staci Amburgey, Brian Gratwicke, Victor Acosta Chaves, Anat Belasen, David Bickford, Carsten Bruhl, Natalie Calatayud, Nick Clemann, Simon Clulow, Jelka Crnobrnja-Isailovic, Jeff Dawson, David De Angelis, C. Dodd, Annette Evans, Gentile Francesco Ficetola, Mattia Falaschi, Sergio Gonzalez-Mollinedo, David Green, Roseanna Gamlen-Greene, Richard Griffiths, Brian J. Halstead, Craig Hassapakis, Geoffrey Heard, Catharina Karlsson, Tom Kirschey, Blake Klocke, Tiffany Kosch, Sophia Kusterko Novaes, Luke Linhoff, John Maerz, Brittany Mosher, Katherine M. O'Donnell, Leticia Ochoa-Ochoa, Deanna H. Olson, Kristiina Ovaska, J. Roberts, Aimee Silla, Tariq Stark, Jeanne Tarrant, R. Upton, Judit Voros, Erin L. Muths
Using structured decision making to evaluate potential management responses to detection of dreissenid mussel (Dreissena spp.) environmental DNA Using structured decision making to evaluate potential management responses to detection of dreissenid mussel (Dreissena spp.) environmental DNA
Environmental (e)DNA tools are sensitive and cost-effective for early detection of invasive species. However, the uncertainty associated with the interpretation of positive eDNA detections makes it challenging to determine appropriate natural resource management responses. Multiple sources of error can give rise to positive detections of eDNA in a sample when individuals of that species...
Authors
Adam Sepulveda, David Smith, Katherine M. O'Donnell, Nathan Owens, Brittany White, Cathy Richter, Christopher Merkes, Skylar Wolf, Mike Rau, Matthew Neilson, Wesley M. Daniel, Christine Dumoulin, Margaret Hunter
Maximizing species distribution model performance when using historical occurrences and variables of varying persistency Maximizing species distribution model performance when using historical occurrences and variables of varying persistency
Occurrence data used to build species distribution models often include historical records from locations in which the species no longer exists. When these records are paired with contemporary environmental values that no longer represent the conditions the species experienced, the model creates false associations that hurt predictive performance. The extent of mismatching increases with...
Authors
Jason Bracken, Amelie Y. Davis, Katherine M. O’Donnell, William Barichivich, Susan C. Walls, Tereza Jezkova
Moving from decision to action in conservation science Moving from decision to action in conservation science
Biodiversity loss is a major threat to the integrity of ecosystems and is projected to worsen, yet the path to successful conservation remains elusive. Decision support frameworks (DSFs) are increasingly applied by resource managers to navigate the complexity, uncertainty, and differing socio-ecological objectives inherent to conservation problems. Most published conservation research...
Authors
Alexander Wright, Riley Bernard, Brittany Mosher, Katherine O'Donnell, Taylor Braunagel, Graziella DiRenzo, Jillian Fleming, Charles Shafer, Adrianne Brand, Elise Zipkin, Evan Campbell Grant
Category count models for adaptive management of metapopulations: Case study of an imperiled salamander Category count models for adaptive management of metapopulations: Case study of an imperiled salamander
Managing spatially structured populations of imperiled species presents many challenges. Spatial structure can make it difficult to predict population responses to potential recovery activities, and learning through experimentation may not be advised if it could harm threatened populations. Adaptive management provides an appealing framework when experimentation is considered too risky...
Authors
Katherine M. O’Donnell, Paul Fackler, Fred Johnson, Mathieu Bonneau, Julien Martin, Susan Walls
Seeking shelter from the storm: Conservation and management of imperiled species in a changing climate Seeking shelter from the storm: Conservation and management of imperiled species in a changing climate
Climate change is anticipated to exacerbate the extinction risk of species whose persistence is already compromised by habitat loss, invasive species, disease, or other stressors. In coastal areas of the southeastern United States (USA), many imperiled vertebrates are vulnerable to hurricanes, which climate models predict to become more severe in the 21st century. Despite this escalating...
Authors
Susan Walls, William Barichivich, Jonathan Chandler, Ashley Meade, Marysa Milinichik, Katherine O'Donnell, Megan Owens, Terry Peacock, Joseph Reinman, Rebecca Watling, Olivia Wetsch
Bay- Delta Water Quality, Nutrient and Phytoplankton Mapping | US Geological Survey Bay- Delta Water Quality, Nutrient and Phytoplankton Mapping | US Geological Survey
Data visualization tool created for California's Bay-Delta Regional Monitoring Program. This web applicaton visualizes nutrients and phytoplankton spatially and temporally.
Science and Products
In situ chlorophyll fluorometer validation and comparison study
The Sacramento-San Joaquin Delta (Delta) supplies drinking water to much of California. The Delta also provides irrigation water to the Central Valley and is an important habitat to many aquatic and terrestrial species. In the past decade, there has been an increase in harmful algal blooms (HABs) in the Delta. While some HABs are nontoxic, others contain cyanobacteria that can produce dangerous...
Biogeochemistry Group
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Causes and Relevance of Phytoplankton Blooms in the Northern Sacramento-San Joaquin Delta
Phytoplankton are an important part of aquatic food webs and ecosystems. These single-celled plants grow faster in the stronger light of spring or summer, resulting in population explosions called phytoplankton blooms. These blooms in turn feed zooplankton (free-floating aquatic microorganisms), providing food for many aquatic species, including fish, shrimp, crabs, and other invertebrates.
Filter Total Items: 21
Above-water hyperspectral field spectroscopy and associated water quality measurements in the Sacramento-San Joaquin Delta, California, collected in 2024 and 2025 Above-water hyperspectral field spectroscopy and associated water quality measurements in the Sacramento-San Joaquin Delta, California, collected in 2024 and 2025
Broad-area, high-resolution, boat-based water quality mapping surveys of the Sacramento-San Joaquin Delta (Delta) were conducted in June and September of 2024. Each survey was comprised of one day of high-resolution mapping. The regions covered included Discovery Bay and Old and Middle Rivers in the South Delta Tidal Transition Zone. On each day, the route of the mapping survey was...
Water quality and nutrient data from San Joaquin River and Stockton Waterfront, April and August 2024 Water quality and nutrient data from San Joaquin River and Stockton Waterfront, April and August 2024
This dataset records diel changes to water quality parameters, nutrients, and phytoplankton biomass in the south-eastern region of the Sacramento-San Joaquin Delta. Sampling occurred in August 2024 in the Stockton Waterfront (City of Stockton, San Joaquin County, California, USA) and San Joaquin River. Data was collected from approximately 6am to 9pm Pacific Standard Time on August 6, 13...
Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2023 High resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2023 High resolution mapping surveys
Broad-area, high-resolution, boat-based water quality mapping surveys of the Sacramento-San Joaquin Delta and Suisun Bay (Delta) of California, USA were conducted under different environmental/flow conditions in May, July, and October of 2023. The spatial and temporal variability of nutrients, phytoplankton, and related water quality parameters were assessed. This dataset includes...
Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2022 High-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2022 High-resolution mapping surveys
Broad-area, high-resolution, boat-based water quality mapping surveys of the Sacramento-San Joaquin Delta and Suisun Bay (Delta) of California, USA were conducted under different environmental/flow conditions in May, July, and October of 2022. The spatial and temporal variability of nutrients, phytoplankton, and related water quality parameters were assessed. This dataset includes...
Above-water hyperspectral field spectroscopy measurements at Franks Tract in the Sacramento-San Joaquin Delta, California Above-water hyperspectral field spectroscopy measurements at Franks Tract in the Sacramento-San Joaquin Delta, California
Hand-held hyperspectral spectroscopy data were collected in 2022 in Franks Tract, a flooded area located in the central Sacramento-San Joaquin Delta of California. The data were collected from a boat and co-located within pixels from the Ocean Land Color Imaging (OLCI) sensor on the Sentinel-3A and 3-B satellites. Data from 16 sites within 7 OLCI pixels were collected on three days: July...
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the San Francisco Bay, California: 2021-2022 High-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the San Francisco Bay, California: 2021-2022 High-resolution mapping surveys
The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the San Francisco Bay of California, USA in 2021 and 2022. The dataset includes nitrate, temperature, conductivity, dissolved oxygen, and chlorophyll as well as information about phytoplankton community composition. Data-collection cruises were...
Water quality, nutrient, and phytoplankton data from Franks Tract, Mildred Island, and neighboring channels in the California Sacramento-San Joaquin Delta: 2022 and 2023 High-resolution mapping surveys Water quality, nutrient, and phytoplankton data from Franks Tract, Mildred Island, and neighboring channels in the California Sacramento-San Joaquin Delta: 2022 and 2023 High-resolution mapping surveys
Surface water quality, water isotope, and phytoplankton enumeration data were collected to evaluate the impact of an Emergency Drought Barrier (EDB) in False River in the Sacramento-San Joaquin Delta. Data were collected on six days during 2022 and 2023 (June 7, June 21, July 27, August 9, October 12, November 30, 2022, and February 21, 2023). Sampling occurred in Franks Tract, Mildred...
KdPAR and surface water-quality data collected in the Sacramento-San Joaquin River Delta in 2013 and 2014 KdPAR and surface water-quality data collected in the Sacramento-San Joaquin River Delta in 2013 and 2014
Data release provides diffuse light attenuation coefficient of photosynthetically active radiation (KdPAR) derived from in-situ light measurements, along with surface water-quality and atmospheric data collected in the Sacramento-San Joaquin Rive Delta in California between January 2013 and May 2014. These associated surface level water-quality and atmospheric data, and categorical...
Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2020-2021 High-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton and related water-quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2020-2021 High-resolution mapping surveys
The dataset documents the spatial and temporal variability of nutrients, phytoplankton, and related water quality parameters at high spatial resolution in the Sacramento-San Joaquin River Delta and Suisun Bay of California, USA. The dataset includes nitrate, ammonium, orthophosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, and chlorophyll as well as...
Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta during treated wastewater effluent holds: August and September 2019 high resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta during treated wastewater effluent holds: August and September 2019 high resolution mapping surveys
The study is comprised of daily survey data consisting of high resolution mapping and discrete sample collection of nutrients, phytoplankton, and related water quality constituents conducted in the Sacramento River, Georgiana Slough, and the North and South Forks of the Mokelumne River on August 28 and September 10-12, 2019, coincident with planned holds of treated wastewater effluent...
Phytoplankton Species Composition and Abundance in the Sacramento-San Joaquin River Delta: Microscopic Enumeration of USGS Samples, beginning in 2016 (ver. 1.1, December 2023) Phytoplankton Species Composition and Abundance in the Sacramento-San Joaquin River Delta: Microscopic Enumeration of USGS Samples, beginning in 2016 (ver. 1.1, December 2023)
This dataset contains taxonomy, density (cells/mL), and biovolume (μm3/mL) data for phytoplankton sampled across the Sacramento San Joaquin River Delta and San Francisco Bay (Bay-Delta) beginning in 2016. Whole water phytoplankton samples were collected intermittently during special projects and during routine visits to service continuous monitoring stations. Samples were preserved with...
Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta related to the 2015 installation of the False River Emergency Drought Barrier: 2015 and 2016 high-resolution m Assessing spatial variability of nutrients, phytoplankton, and related water quality constituents in the California Sacramento-San Joaquin Delta related to the 2015 installation of the False River Emergency Drought Barrier: 2015 and 2016 high-resolution m
This data release documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the western and central portion of the Sacramento-San Joaquin River Delta of California, USA. The data set includes water residence time, nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen...
Filter Total Items: 16
Identifying conditions associated with outliers produced by three different chlorophyll fluorometers: A comparison of instrumentation and development of correction formulae Identifying conditions associated with outliers produced by three different chlorophyll fluorometers: A comparison of instrumentation and development of correction formulae
Measurements of chlorophyll concentration reported by fluorometers (fChl) are used in environmental research and monitoring, as inputs to models, and in the interpretation of remote sensing data. Researchers and managers benefit from understanding how to interpret and ensure the accuracy of fChl data collected by in situ fluorometers. Although fChl values produced by different...
Authors
Emily Richardson, Tamara Kraus, Crystal Sturgeon, Katy O’Donnell, Brian Bergamaschi
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—Comparison of four (2018, 2020, 2021, 2022) spring high-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—Comparison of four (2018, 2020, 2021, 2022) spring high-resolution mapping surveys
Executive Summary This report summarizes results from boat-based, high-resolution water-quality mapping surveys completed before, during, and after upgrades to the EchoWater Resource Recovery Facility (EchoWater Facility), the regional wastewater facility for the City of Sacramento and surrounding areas, near Elk Grove, California. Surveys were completed in the tidal aquatic environments...
Authors
Emily Richardson, Tamara Kraus, Katy O’Donnell, Jeniffer Soto-Perez, Crystal Sturgeon, Elizabeth Stumpner, Brian Bergamaschi
Amphibian and reptile conservation in the United States of America Amphibian and reptile conservation in the United States of America
Wildlife stewardship is of utmost importance in the United States, where management for sustainable natural resources is extended to native species including amphibians and reptiles. The U.S. wildlife conservation framework is a nested system of authorities regulating species and habitats, science-based management and policy decisions, and adaptive management as new knowledge is applied...
Authors
Deanna H. Olson, David S. Pilliod
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—2018 high resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—2018 high resolution mapping surveys
Executive Summary This study examined the abundance and distribution of nutrients and phytoplankton in the tidal aquatic environments of the Sacramento–San Joaquin Delta (Delta) and Suisun Bay, comprising three spatial surveys conducted in May, July, and October of 2018 that used continuous underway high frequency sampling and measurements onboard a high-speed boat to characterize...
Authors
Brian Bergamaschi, Tamara Kraus, Bryan Downing, Elizabeth Stumpner, Katy O’Donnell, Jeffrey Hansen, Jeniffer Soto Perez, Emily Richardson, Angela M. Hansen, Alan Gelber
A simple approach to modeling light attenuation in the Sacramento-San Joaquin Delta using commonly available data A simple approach to modeling light attenuation in the Sacramento-San Joaquin Delta using commonly available data
The diffuse attenuation coefficient of photosynthetically active radiation (KdPAR) is commonly used to predict light attenuation in aquatic productivity models, but obtaining measurements of PAR to compute KdPAR is difficult. In situ calculations of KdPAR require multiple measurements of PAR through the water column, and these measurements are infeasible for real-time recording. Instead
Authors
Emily Richardson, Keith Bouma-Gregson, Katy O’Donnell, Brian Bergamaschi
A novel boat-based field application of a high-frequency conductometric ammonium analyzer to characterize spatial variation in aquatic ecosystems A novel boat-based field application of a high-frequency conductometric ammonium analyzer to characterize spatial variation in aquatic ecosystems
Documenting dissolved inorganic nitrogen (DIN) concentration and form at appropriate temporal and spatial scales is key to understanding aquatic ecosystem health, particularly as DIN fuels primary productivity. In addition to point and non-point source nutrient inputs, factors such as hydrology, geomorphology, temperature, light, and biogeochemical transformations influence nutrient...
Authors
Emily Richardson, Angela Hansen, Tamara Kraus, Bryan Downing, Don Forsberg, John Stillian, Katy O’Donnell, Crystal Sturgeon, Brian Bergamaschi
Priority research needs to inform amphibian conservation in the Anthropocene Priority research needs to inform amphibian conservation in the Anthropocene
The problem of global amphibian declines has prompted extensive research over the last three decades. Initially, the focus was on identifying and characterizing the extent of the problem, but more recently efforts have shifted to evidence-based research designed to identify best solutions and to improve conservation outcomes. Despite extensive accumulation of knowledge on amphibian...
Authors
Evan Campbell Grant, Staci Amburgey, Brian Gratwicke, Victor Acosta Chaves, Anat Belasen, David Bickford, Carsten Bruhl, Natalie Calatayud, Nick Clemann, Simon Clulow, Jelka Crnobrnja-Isailovic, Jeff Dawson, David De Angelis, C. Dodd, Annette Evans, Gentile Francesco Ficetola, Mattia Falaschi, Sergio Gonzalez-Mollinedo, David Green, Roseanna Gamlen-Greene, Richard Griffiths, Brian J. Halstead, Craig Hassapakis, Geoffrey Heard, Catharina Karlsson, Tom Kirschey, Blake Klocke, Tiffany Kosch, Sophia Kusterko Novaes, Luke Linhoff, John Maerz, Brittany Mosher, Katherine M. O'Donnell, Leticia Ochoa-Ochoa, Deanna H. Olson, Kristiina Ovaska, J. Roberts, Aimee Silla, Tariq Stark, Jeanne Tarrant, R. Upton, Judit Voros, Erin L. Muths
Using structured decision making to evaluate potential management responses to detection of dreissenid mussel (Dreissena spp.) environmental DNA Using structured decision making to evaluate potential management responses to detection of dreissenid mussel (Dreissena spp.) environmental DNA
Environmental (e)DNA tools are sensitive and cost-effective for early detection of invasive species. However, the uncertainty associated with the interpretation of positive eDNA detections makes it challenging to determine appropriate natural resource management responses. Multiple sources of error can give rise to positive detections of eDNA in a sample when individuals of that species...
Authors
Adam Sepulveda, David Smith, Katherine M. O'Donnell, Nathan Owens, Brittany White, Cathy Richter, Christopher Merkes, Skylar Wolf, Mike Rau, Matthew Neilson, Wesley M. Daniel, Christine Dumoulin, Margaret Hunter
Maximizing species distribution model performance when using historical occurrences and variables of varying persistency Maximizing species distribution model performance when using historical occurrences and variables of varying persistency
Occurrence data used to build species distribution models often include historical records from locations in which the species no longer exists. When these records are paired with contemporary environmental values that no longer represent the conditions the species experienced, the model creates false associations that hurt predictive performance. The extent of mismatching increases with...
Authors
Jason Bracken, Amelie Y. Davis, Katherine M. O’Donnell, William Barichivich, Susan C. Walls, Tereza Jezkova
Moving from decision to action in conservation science Moving from decision to action in conservation science
Biodiversity loss is a major threat to the integrity of ecosystems and is projected to worsen, yet the path to successful conservation remains elusive. Decision support frameworks (DSFs) are increasingly applied by resource managers to navigate the complexity, uncertainty, and differing socio-ecological objectives inherent to conservation problems. Most published conservation research...
Authors
Alexander Wright, Riley Bernard, Brittany Mosher, Katherine O'Donnell, Taylor Braunagel, Graziella DiRenzo, Jillian Fleming, Charles Shafer, Adrianne Brand, Elise Zipkin, Evan Campbell Grant
Category count models for adaptive management of metapopulations: Case study of an imperiled salamander Category count models for adaptive management of metapopulations: Case study of an imperiled salamander
Managing spatially structured populations of imperiled species presents many challenges. Spatial structure can make it difficult to predict population responses to potential recovery activities, and learning through experimentation may not be advised if it could harm threatened populations. Adaptive management provides an appealing framework when experimentation is considered too risky...
Authors
Katherine M. O’Donnell, Paul Fackler, Fred Johnson, Mathieu Bonneau, Julien Martin, Susan Walls
Seeking shelter from the storm: Conservation and management of imperiled species in a changing climate Seeking shelter from the storm: Conservation and management of imperiled species in a changing climate
Climate change is anticipated to exacerbate the extinction risk of species whose persistence is already compromised by habitat loss, invasive species, disease, or other stressors. In coastal areas of the southeastern United States (USA), many imperiled vertebrates are vulnerable to hurricanes, which climate models predict to become more severe in the 21st century. Despite this escalating...
Authors
Susan Walls, William Barichivich, Jonathan Chandler, Ashley Meade, Marysa Milinichik, Katherine O'Donnell, Megan Owens, Terry Peacock, Joseph Reinman, Rebecca Watling, Olivia Wetsch
Bay- Delta Water Quality, Nutrient and Phytoplankton Mapping | US Geological Survey Bay- Delta Water Quality, Nutrient and Phytoplankton Mapping | US Geological Survey
Data visualization tool created for California's Bay-Delta Regional Monitoring Program. This web applicaton visualizes nutrients and phytoplankton spatially and temporally.