Larry Brown (Former Employee)
Science and Products
Filter Total Items: 121
Effects of urban development on stream ecosystems in nine metropolitan study areas across the United States
Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a half of almost continuous development. Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the d
Authors
James F. Coles, Gerard McMahon, Amanda H. Bell, Larry R. Brown, Faith A. Fitzpatrick, Barbara C. Scudder Eikenberry, Michael D. Woodside, Thomas F. Cuffney, Wade L. Bryant, Karen Cappiella, Lisa Fraley-McNeal, William P. Stack
Upper Clear Creek watershed aquatic chemistry and biota surveys, 2004-5, Whiskeytown National Recreation Area, Shasta County, California
The U.S. Geological Survey, in cooperation with the National Park Service and Whiskeytown National Recreation Area, performed a comprehensive aquatic biota survey of the upper Clear Creek watershed, Shasta County, California, during 2004-5. Data collected in this study can provide resource managers with information regarding aquatic resources, watershed degradation, and regional biodiversity withi
Authors
Marissa L. Wulff, Jason T. May, Larry R. Brown
Predicting biological condition in southern California streams
As understanding of the complex relations among environmental stressors and biological responses improves, a logical next step is predictive modeling of biological condition at unsampled sites. We developed a boosted regression tree (BRT) model of biological condition, as measured by a benthic macroinvertebrate index of biotic integrity (BIBI), for streams in urbanized Southern Coastal California.
Authors
Larry R. Brown, Jason T. May, Andrew C. Rehn, Peter R. Ode, Ian R. Waite, Jonathan Kennen
Comparison of stream invertebrate response models for bioassessment metric
We aggregated invertebrate data from various sources to assemble data for modeling in two ecoregions in Oregon and one in California. Our goal was to compare the performance of models developed using multiple linear regression (MLR) techniques with models developed using three relatively new techniques: classification and regression trees (CART), random forest (RF), and boosted regression trees (B
Authors
Ian R. Waite, Jonathan Kennen, Jason T. May, Larry R. Brown, Thomas F. Cuffney, Kimberly A. Jones, James L. Orlando
Life histories, salinity zones, and sublethal contributions of contaminants to pelagic fish declines illustrated with a case study of San Francisco Estuary, California, USA
Human effects on estuaries are often associated with major decreases in abundance of aquatic species. However, remediation priorities are difficult to identify when declines result from multiple stressors with interacting sublethal effects. The San Francisco Estuary offers a useful case study of the potential role of contaminants in declines of organisms because the waters of its delta chronically
Authors
Marjorie L. Brooks, Erica Fleishman, Larry R. Brown, Peggy W. Lehman, Inge Werner, Nathaniel Scholz, Carys Michelmore, James R. Loworn, Michael L. Johnson, Daniel Schlenk
Concentrations of mercury and other metals in black bass (Micropterus spp.) from Whiskeytown Lake, Shasta County, California, 2005
This report presents the results of a reconnaissance study conducted by the U.S. Geological Survey (USGS) to determine mercury (Hg) and other selected metal concentrations in Black bass (Micropterus spp.) from Whiskeytown Lake, Shasta County, California. Total mercury concentrations were determined by cold-vapor atomic absorption spectroscopy (CVAAS) in fillets and whole bodies of each sampled fis
Authors
Jason T. May, Roger L. Hothem, Marissa L. Bauer, Larry R. Brown
Associations of benthic macroinvertebrate assemblages with environmental variables in the upper Clear Creek watershed, California
Benthic macroinvertebrates are integral components of stream ecosystems and are often used to assess the ecological integrity of streams. We sampled streams in the upper Clear Creek drainage in the Klamath—Siskiyou Ecoregion of northwestern California in fall 2004 (17 sites) and 2005 (original 17 plus 4 new sites) with the objectives of documenting the benthic macroinvertebrate assemblages support
Authors
Larry R. Brown, Jason T. May, Marissa Wulff
A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems
Pesticides applied on land are commonly transported by runoff or spray drift to aquatic ecosystems, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of ecosystem processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the cumulative eff
Authors
Nathaniel L. Scholz, Erica Fleishman, Larry Brown, Inge Werner, Michael L. Johnson, Marjorie L. Brooks, Carys L. Mitchelmore, Daniel Schlenk
Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change
Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing
Authors
James E. Cloern, Noah Knowles, Larry R. Brown, Daniel Cayan, Michael D. Dettinger, Tara L. Morgan, David H. Schoellhamer, Mark T. Stacey, Mick van der Wegen, R. Wayne Wagner, Alan D. Jassby
Statistical models of temperature in the Sacramento-San Joaquin Delta under climate-change scenarios and ecological implications
Changes in water temperatures caused by climate change in California's Sacramento–San Joaquin Delta will affect the ecosystem through physiological rates of fishes and invertebrates. This study presents statistical models that can be used to forecast water temperature within the Delta as a response to atmospheric conditions. The daily average model performed well (R2 values greater than 0.93 durin
Authors
R. Wayne Wagner, Mark T. Stacey, Larry R. Brown, Mike Dettinger
Statistical models of temperature in the Sacramento-San Joaquin delta under climate-change scenarios and ecological implications
Changes in water temperatures caused by climate change in California’s Sacramento–San Joaquin Delta will affect the ecosystem through physiological rates of fishes and invertebrates. This study presents statistical models that can be used to forecast water temperature within the Delta as a response to atmospheric conditions. The daily average model performed well (R 2values greater than 0.93 durin
Authors
R.W. Wagner, Mark T. Stacey, Larry R. Brown, Michael D. Dettinger
Projected evolution of California's San Francisco bay-delta-river system in a century of climate change
Background: Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing
Authors
James E. Cloern, Noah Knowles, Larry R. Brown, Daniel R. Cayan, Michael D. Dettinger, Tara L. Morgan, David H. Schoellhamer, Mark T. Stacey, Mick Van der Wegen, R.W. Wagner, Alan D. Jassby
Science and Products
Filter Total Items: 121
Effects of urban development on stream ecosystems in nine metropolitan study areas across the United States
Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a half of almost continuous development. Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the d
Authors
James F. Coles, Gerard McMahon, Amanda H. Bell, Larry R. Brown, Faith A. Fitzpatrick, Barbara C. Scudder Eikenberry, Michael D. Woodside, Thomas F. Cuffney, Wade L. Bryant, Karen Cappiella, Lisa Fraley-McNeal, William P. Stack
Upper Clear Creek watershed aquatic chemistry and biota surveys, 2004-5, Whiskeytown National Recreation Area, Shasta County, California
The U.S. Geological Survey, in cooperation with the National Park Service and Whiskeytown National Recreation Area, performed a comprehensive aquatic biota survey of the upper Clear Creek watershed, Shasta County, California, during 2004-5. Data collected in this study can provide resource managers with information regarding aquatic resources, watershed degradation, and regional biodiversity withi
Authors
Marissa L. Wulff, Jason T. May, Larry R. Brown
Predicting biological condition in southern California streams
As understanding of the complex relations among environmental stressors and biological responses improves, a logical next step is predictive modeling of biological condition at unsampled sites. We developed a boosted regression tree (BRT) model of biological condition, as measured by a benthic macroinvertebrate index of biotic integrity (BIBI), for streams in urbanized Southern Coastal California.
Authors
Larry R. Brown, Jason T. May, Andrew C. Rehn, Peter R. Ode, Ian R. Waite, Jonathan Kennen
Comparison of stream invertebrate response models for bioassessment metric
We aggregated invertebrate data from various sources to assemble data for modeling in two ecoregions in Oregon and one in California. Our goal was to compare the performance of models developed using multiple linear regression (MLR) techniques with models developed using three relatively new techniques: classification and regression trees (CART), random forest (RF), and boosted regression trees (B
Authors
Ian R. Waite, Jonathan Kennen, Jason T. May, Larry R. Brown, Thomas F. Cuffney, Kimberly A. Jones, James L. Orlando
Life histories, salinity zones, and sublethal contributions of contaminants to pelagic fish declines illustrated with a case study of San Francisco Estuary, California, USA
Human effects on estuaries are often associated with major decreases in abundance of aquatic species. However, remediation priorities are difficult to identify when declines result from multiple stressors with interacting sublethal effects. The San Francisco Estuary offers a useful case study of the potential role of contaminants in declines of organisms because the waters of its delta chronically
Authors
Marjorie L. Brooks, Erica Fleishman, Larry R. Brown, Peggy W. Lehman, Inge Werner, Nathaniel Scholz, Carys Michelmore, James R. Loworn, Michael L. Johnson, Daniel Schlenk
Concentrations of mercury and other metals in black bass (Micropterus spp.) from Whiskeytown Lake, Shasta County, California, 2005
This report presents the results of a reconnaissance study conducted by the U.S. Geological Survey (USGS) to determine mercury (Hg) and other selected metal concentrations in Black bass (Micropterus spp.) from Whiskeytown Lake, Shasta County, California. Total mercury concentrations were determined by cold-vapor atomic absorption spectroscopy (CVAAS) in fillets and whole bodies of each sampled fis
Authors
Jason T. May, Roger L. Hothem, Marissa L. Bauer, Larry R. Brown
Associations of benthic macroinvertebrate assemblages with environmental variables in the upper Clear Creek watershed, California
Benthic macroinvertebrates are integral components of stream ecosystems and are often used to assess the ecological integrity of streams. We sampled streams in the upper Clear Creek drainage in the Klamath—Siskiyou Ecoregion of northwestern California in fall 2004 (17 sites) and 2005 (original 17 plus 4 new sites) with the objectives of documenting the benthic macroinvertebrate assemblages support
Authors
Larry R. Brown, Jason T. May, Marissa Wulff
A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems
Pesticides applied on land are commonly transported by runoff or spray drift to aquatic ecosystems, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of ecosystem processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the cumulative eff
Authors
Nathaniel L. Scholz, Erica Fleishman, Larry Brown, Inge Werner, Michael L. Johnson, Marjorie L. Brooks, Carys L. Mitchelmore, Daniel Schlenk
Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change
Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing
Authors
James E. Cloern, Noah Knowles, Larry R. Brown, Daniel Cayan, Michael D. Dettinger, Tara L. Morgan, David H. Schoellhamer, Mark T. Stacey, Mick van der Wegen, R. Wayne Wagner, Alan D. Jassby
Statistical models of temperature in the Sacramento-San Joaquin Delta under climate-change scenarios and ecological implications
Changes in water temperatures caused by climate change in California's Sacramento–San Joaquin Delta will affect the ecosystem through physiological rates of fishes and invertebrates. This study presents statistical models that can be used to forecast water temperature within the Delta as a response to atmospheric conditions. The daily average model performed well (R2 values greater than 0.93 durin
Authors
R. Wayne Wagner, Mark T. Stacey, Larry R. Brown, Mike Dettinger
Statistical models of temperature in the Sacramento-San Joaquin delta under climate-change scenarios and ecological implications
Changes in water temperatures caused by climate change in California’s Sacramento–San Joaquin Delta will affect the ecosystem through physiological rates of fishes and invertebrates. This study presents statistical models that can be used to forecast water temperature within the Delta as a response to atmospheric conditions. The daily average model performed well (R 2values greater than 0.93 durin
Authors
R.W. Wagner, Mark T. Stacey, Larry R. Brown, Michael D. Dettinger
Projected evolution of California's San Francisco bay-delta-river system in a century of climate change
Background: Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing
Authors
James E. Cloern, Noah Knowles, Larry R. Brown, Daniel R. Cayan, Michael D. Dettinger, Tara L. Morgan, David H. Schoellhamer, Mark T. Stacey, Mick Van der Wegen, R.W. Wagner, Alan D. Jassby
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government