Marissa Wulff is a Biologist at the California Water Science Center.
Marissa Bauer Wulff is a biologist with the U.S. Geological Survey’s California Water Science Center, where she researches and assists in projects relating to aquatic biology and ecology. Marissa has been involved in ecosystem modeling for the Sacramento-San Joaquin Delta as well as flow-regime and aquatic mercury studies. Marissa is currently involved in research looking at the effects of climate change on selected fish species of the San Francisco Bay-Delta.
Science and Products
Aquatic Ecology Group
The California Water Science Center's Aquatic Ecology Group is making great strides in research and reporting.
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.
Data used in projected air and water temperatures for selected regions of the upper San Francisco Estuary and Yolo Bypass under 20 scenarios of climate change 2020-2099
Understanding the effects of climate change is a substantial challenge in estuarine systems because the mixing of freshwater and ocean water adds complexity to climate change projections. Such climate change projections have been conducted in the San Francisco Estuary as part of the U.S. Geological Survey's CASCaDE Project. In this project, we assessed downscaled air temperature data from 10 Globa
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
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.
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.
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.
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.
Assessment of interim flow water-quality data of the San Joaquin River restoration program and implications for fishes, California, 2009-11
After more than 50 years of extensive water diversion for urban and agriculture use, a major settlement was reached among the U.S. Departments of the Interior and Commerce, the Natural Resources Defense Council, and the Friant Water Users Authority in an effort to restore the San Joaquin River. The settlement received Federal court approval in October 2006 and established the San Joaquin River Res
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
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
Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations
Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologi
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
Cliff swallows Petrochelidon pyrrhonota as bioindicators of environmental mercury, Cache Creek Watershed, California
To evaluate mercury (Hg) and other element exposure in cliff swallows (Petrochelidon pyrrhonota), eggs were collected from 16 sites within the mining-impacted Cache Creek watershed, Colusa, Lake, and Yolo counties, California, USA, in 1997-1998. Nestlings were collected from seven sites in 1998. Geometric mean total Hg (THg) concentrations ranged from 0.013 to 0.208 ??g/g wet weight (ww) in cliff
Mercury and trace elements in crayfish from northern California
We collected two species of crayfish, Pacifastacus leniusculus and Procambarus clarkii, from Cache and Putah Creeks, California, and analyzed them for mercury and trace elements. Trace elements were higher in carcasses in 40 cases, higher in tails in 5 cases, and not different in 35 cases; no concentration exceeded levels considered harmful. Mercury concentrations were similar among sites, with no
Pre-USGS Publications
Pintor, L. M., Sih, A. and Bauer, M. L. (2008), Differences in aggression, activity and boldness between native and introduced populations of an invasive crayfish. Oikos, 117: 1629–1636. doi:10.1111/j.1600-0706.2008.16578.x
Science and Products
- Science
Aquatic Ecology Group
The California Water Science Center's Aquatic Ecology Group is making great strides in research and reporting. - Data
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.Data used in projected air and water temperatures for selected regions of the upper San Francisco Estuary and Yolo Bypass under 20 scenarios of climate change 2020-2099
Understanding the effects of climate change is a substantial challenge in estuarine systems because the mixing of freshwater and ocean water adds complexity to climate change projections. Such climate change projections have been conducted in the San Francisco Estuary as part of the U.S. Geological Survey's CASCaDE Project. In this project, we assessed downscaled air temperature data from 10 GlobaData 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 concentratSAR 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.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.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.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. - Publications
Assessment of interim flow water-quality data of the San Joaquin River restoration program and implications for fishes, California, 2009-11
After more than 50 years of extensive water diversion for urban and agriculture use, a major settlement was reached among the U.S. Departments of the Interior and Commerce, the Natural Resources Defense Council, and the Friant Water Users Authority in an effort to restore the San Joaquin River. The settlement received Federal court approval in October 2006 and established the San Joaquin River ResAssociations 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 supportUpper 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 withiEffects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations
Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologiConcentrations 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 fisCliff swallows Petrochelidon pyrrhonota as bioindicators of environmental mercury, Cache Creek Watershed, California
To evaluate mercury (Hg) and other element exposure in cliff swallows (Petrochelidon pyrrhonota), eggs were collected from 16 sites within the mining-impacted Cache Creek watershed, Colusa, Lake, and Yolo counties, California, USA, in 1997-1998. Nestlings were collected from seven sites in 1998. Geometric mean total Hg (THg) concentrations ranged from 0.013 to 0.208 ??g/g wet weight (ww) in cliffMercury and trace elements in crayfish from northern California
We collected two species of crayfish, Pacifastacus leniusculus and Procambarus clarkii, from Cache and Putah Creeks, California, and analyzed them for mercury and trace elements. Trace elements were higher in carcasses in 40 cases, higher in tails in 5 cases, and not different in 35 cases; no concentration exceeded levels considered harmful. Mercury concentrations were similar among sites, with noPre-USGS Publications
Pintor, L. M., Sih, A. and Bauer, M. L. (2008), Differences in aggression, activity and boldness between native and introduced populations of an invasive crayfish. Oikos, 117: 1629–1636. doi:10.1111/j.1600-0706.2008.16578.x