Larry Brown (Former Employee)
Science and Products
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).
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.
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...
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...
Aquatic Ecology Group
The California Water Science Center's Aquatic Ecology Group is making great strides in research and reporting.
Whiskeytown Aquatic Inventory Assessment
The project focuses on the assessment of aquatic biology, habitat, and water quality conditions of the major WHIS watersheds
Estimating Natural Flows for Hydrologic Reference Streams
Scientists develop metrics of expected hydrological conditions at ungaged sites throughout Callifornia
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.
Native Fish Population and Habitat Study - Santa Ana River
California Water Science Center scientists further research on two native fish species.
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.
Ecology of Selected Tidal Wetlands of the San Francisco Estuary
Researachers study differences of tidal marsh restoration efforts throughout Bay-Delta ecosystem.
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...
Reed, Denise; Acuna, Shawn; Ateljevich, Eli; Brown, Larry R.; Geske, Ben; Gross, Edward; Hobbs, Jim; Kimmerer, Wim J.; Lucas, Lisa; Nobriga, Matthew; Rose, Kenneth A 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...
Mahardja, Brian; Tobias, Vanessa; Khanna, Shruti; Mitchell, Lara; Lehman, Peggy W.; Sommer, Ted; Brown, Larry R.; Culberson, Steven; Conrad, Louise 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...
Young, Matthew; Feyrer, Frederick; Stumpner, Paul; Larwood, Veronica; Patton, Oliver; Brown, Larry R. 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...
Paul, Michael J.; Jessup, Ben; Brown, Larry R.; Carter, James; Cantonati, Marco; Charles, Donald F.; Gerritsen, Jeroen; Herbst, Dave; Stancheva, Rosalina; Howard, Jeannette K.; Isham, Bill; Lowe, Rex; Mazor, Raphael D; Mendez, Patina K.; Ode, Peter R; O'Dowd, Alison; Pan, Yangdong; Rehn, Andrew C.; Spaulding, Sarah A.; Sutula, Martha; Theroux, Susanna 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...
Hartman, Rosemary; Brown, Larry R.; Hobbs, Jim 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...
Hartman, Rosemary; Brown, Larry R.; Thompson, Janet K.; Parchaso, Francis Native fish population and habitat study, Santa Ana River, California
Collection of additional data on the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) has been identified as a needed task to support development of the upper Santa Ana River Habitat Conservation Plan (HCP; http://www.uppersarhcp.com/). The ability to monitor population abundance and understanding the habitats used by...
Wulff, Marissa L.; Brown, Larry R.; May, Jason 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...
Feyrer, Frederick; Slater, Steven B.; Portz, Donald E.; Odom, Darren; Morgan-King, Tara L.; Brown, Larry R. 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...
Dettinger, Michael D.; Anderson, Jamie; Anderson, Michael L.; Brown, Larry R.; Cayan, Daniel; Maurer, Edwin P. 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...
Brown, Larry R.; Kimmerer, Wim J.; Conrad, Louise; Lesmeister, Sarah; Mueller-Solger, Anke 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...
Moyle, Peter B.; Brown, Larry R.; Durand, John R; Hobbs, James A. Linking hydrodynamic complexity to delta smelt (Hypomesus transpacificus) distribution in the San Francisco Estuary, USA
Long-term fish sampling data from the San Francisco Estuary were combined with detailed three dimensional hydrodynamic modeling to investigate the relationship between historical fish catch and hydrodynamic complexity. Delta Smelt catch data at 45 stations from the Fall Midwater Trawl (FMWT) survey in the vicinity of Suisun Bay were used to...
Bever, Aaron J.; MacWilliams, Michael L.; Herbold, Bruce; Brown, Larry R.; Feyrer, Frederick V.