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Cathy Richter, PhD

Dr. Cathy Richter is a Research Molecular Biologist at the Columbia Environmental Research Center.

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CERC researchers collecting eDNA

Threatened, Endangered or Rare Species Detection

The non-invasive nature of eDNA methods for species detection is a great advantage for monitoring of rare, threatened, or endangered species.
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Columbia Environmental Research Center
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Threatened, Endangered or Rare Species Detection

The non-invasive nature of eDNA methods for species detection is a great advantage for monitoring of rare, threatened, or endangered species.
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Flat Creek in Missouri

Searching for Shiners in Missouri

Researchers from the University of Central Missouri (UCM), in collaboration with the Missouri Department of Conservation (MDC) and Columbia Environmental Research Center (CERC), implement environmental DNA (eDNA) methods to identify and manage Topeka Shiner populations in Missouri.
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Columbia Environmental Research Center
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Searching for Shiners in Missouri

Researchers from the University of Central Missouri (UCM), in collaboration with the Missouri Department of Conservation (MDC) and Columbia Environmental Research Center (CERC), implement environmental DNA (eDNA) methods to identify and manage Topeka Shiner populations in Missouri.
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CERC researchers collecting eDNA

Molecular Section: eDNA Research

Environmental DNA (eDNA) research at CERC focuses on the development and utility of eDNA tools as well as interpretation of eDNA data in real-world management applications. We work with academic, state, federal and international partners in developing standards and best practices for eDNA technology and exploring the factors that affect eDNA detection in the field. Our lab's eDNA research covers...
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Columbia Environmental Research Center
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Molecular Section: eDNA Research

Environmental DNA (eDNA) research at CERC focuses on the development and utility of eDNA tools as well as interpretation of eDNA data in real-world management applications. We work with academic, state, federal and international partners in developing standards and best practices for eDNA technology and exploring the factors that affect eDNA detection in the field. Our lab's eDNA research covers...
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Scientist holding a brook trout with gloved hands

Fishing and Hunting Integrated Science Team

The Fishing and Hunting integrated science team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing...
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Ecosystems, Environmental Health, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Environmental Health Program
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Fishing and Hunting Integrated Science Team

The Fishing and Hunting integrated science team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing...
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Physiological and molecular endpoints observed in juvenile largemouth bass in response to an estrogen (17α-ethinylestradiol) and subsequently a bacterial challenge (Edwardsiella piscicida) exposure under laboratory conditions.

Physiological and molecular endpoints observed in juvenile largemouth bass in response to an estrogen (17α-ethinylestradiol) and subsequently a bacterial challenge (Edwardsiella piscicida) exposure under laboratory conditions. Also included are water quality and chemical concentration data.
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Columbia Environmental Research Center

Polyacrylamide gel electrophoresis results with thiaminase activity stain of recombinant putative thiaminases expressed in E. coli

Data describe results of a set of laboratory experiments using polyacrylamide gel electrophoresis with a thiaminase activity stain to test the solubility and thiaminase activity of recombinant putative thiaminases expressed in E. coli. Parameters described include the presence and relative mobility of thiaminases, and the presence and relative mobility of recombinant proteins. Experiments were con
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Columbia Environmental Research Center

Longnose darter (Percina nasuta) eDNA survey results from the St. Francis River, Missouri 2018

Data describe a designed environmental DNA (eDNA) survey for the detection of longnose darter (Percina nasuta) in field collected water samples. Parameters described include the limit of detection and limit of quantification of the assay; a list of freshwater fish species tissue samples that were used to test specificity of the assay; and field collected water samples that were tested to detect th
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Columbia Environmental Research Center

Metabarcoding data from freshwater mussel eDNA collected in Clinch River, Virginia 2017

Data from metabarcoding assays to detect a suite of mussel species using mitochondrial DNA regions of the cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit (ND1) genes sequences.
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Mucket eDNA detection in Wallen's Bend, Clinch river, Tennessee, September 2019

The data describe the technical performance of a designed qPCR assay for the detection of mucket (Actinonaias ligamentina) eDNA from field collected water samples. Parameters described include the sequences of the primers and probes used; the limit of detection and limit of quantification for the assay; a list of freshwater mussels species that were used to test specificity of the assay; and in si
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17a-ethinylestradiol)

Largemouth base histological development and transcriptomic changes in gonad tissue after early life stage exposure to Atrazine (1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine) or the model estrogen 17a-ethinylestradiol.
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Ecosystems, Contaminant Biology, Columbia Environmental Research Center

Asian carp eDNA and egg morphology data collected from Truman Reservoir tributaries, Missouri, USA, 2014

Ichthyoplankton tows samples collected from Truman reservoir tributaries evaluated for eDNA. Data also includes hydrologic and water quality parameters and morphology of grass carp eggs.
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Columbia Environmental Research Center

eDNA sampling sites in the Grand Canyon region near breccia pipe uranium mines_2015_2016

Geospatial locations of eDNA sampling sites in the Grand Canyon region near breccia pipe uranium mines
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Columbia Environmental Research Center
Filter Total Items: 35

Exposure to 17α-ethinylestradiol results in differential susceptibility of largemouth bass (Micropterus salmoides) to bacterial infection

Disease outbreaks, skin lesions, mortality events, and reproductive abnormalities have been observed in wild populations of centrarchids. The presence of estrogenic endocrine disrupting compounds (EEDCs) has been implicated as a potential causal factor for these effects. The effects of prior EEDC exposure on immune response were examined in juvenile largemouth bass (Micropterus salmoides) exposed
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Ecosystems, Fisheries Program, Columbia Environmental Research Center, Eastern Ecological Science Center, Western Fisheries Research Center

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 are not pr
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Ecosystems, Columbia Environmental Research Center, Northern Rocky Mountain Science Center, Upper Midwest Environmental Sciences Center, Wetland and Aquatic Research Center

A comparison of eDNA and visual survey methods for detection of longnose darter Percina nasuta in Missouri

The longnose darter Percina nasuta is a rare and cryptic fish that recently disappeared from much of its historic range. We developed and used an environmental DNA (eDNA) assay for longnose darter paired with visual surveys to better determine the species’ range and compare detection probability between sampling approaches in an occupancy modeling framework. We detected longnose darter eDNA furthe
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Ecosystems, Columbia Environmental Research Center

Grass carp reproduction in small tributaries of Truman Reservoir, Missouri: Implications for establishment in novel habitats

Substantial work has been conducted to estimate the river length required for recruitment of invasive Grass Carp and bigheaded carp; however, the distance upstream and size of stream required for spawning remain unclear. Adult Grass Carp are regularly captured in Truman Reservoir, Missouri although there have been only unconfirmed sightings of Silver Carp. Fertile diploid Grass Carp are used legal
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Reproduction

Lake charr Salvelinus namaycush are typically fall spawners although one ecotype has populations that spawn during spring and fall (siscowets in Lake Superior). Lake charr are iteroparous (reproduce more than once in a lifetime) with group-synchronous ovarian development and typically spawn once per year. However, lake charr may not reproduce every year, a phenomenon known as skipped spawning. Fre
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Ecosystems, Columbia Environmental Research Center, Great Lakes Science Center

Metabarcoding assays for the detection of freshwater mussels (Unionida) with environmental DNA

Freshwater mussels of the order Unionida are a widely distributed taxon that are important in maintaining freshwater ecosystems and are also highly imperiled throughout the world. Monitoring of mussel populations with environmental DNA (eDNA) is an attractive alternative to traditional methods because it is noninvasive and requires less labor and taxonomic knowledge from field personnel. We develo
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Development and testing of species-specific quantitative PCR assays for environmental DNA applications

New, non-invasive methods for detecting and monitoring species presence are being developed to aid in fisheries and wildlife conservation management. The use of environmental DNA (eDNA) samples for detecting macrobiota is one such group of methods that is rapidly becoming popular and being implemented in national management programs. Here we focus on the development of species-specific targeted as
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17α-ethinylestradiol)

Endocrine disrupting contaminants are of continuing concern for potentially contributing to reproductive dysfunction in largemouth and smallmouth bass in the Chesapeake Bay watershed (CBW) and elsewhere. Exposures to atrazine (ATR) have been hypothesized to have estrogenic effects on vertebrate endocrine systems. The incidence of intersex in male smallmouth bass from some regions of CBW has been c
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Use of environmental DNA to detect grass carp spawning events

The timing and location of spawning events are important data for managers seeking to control invasive grass carp populations. Ichthyoplankton tows for grass carp eggs and larvae can be used to detect spawning events; however, these samples can be highly debris-laden, and are expensive and laborious to process. An alternative method, environmental DNA (eDNA) technology, has proven effective in det
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Ecosystems, Columbia Environmental Research Center

Reporting the limits of detection and quantification for environmental DNA assays

BackgroundEnvironmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully establis
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Ecosystems, Wetland and Aquatic Research Center , Upper Midwest Environmental Sciences Center, Columbia Environmental Research Center

Thiamine deficiency in fishes: Causes, consequences, and potential solutions

Thiamine deficiency complex (TDC) is a disorder resulting from the inability to acquire or retain thiamine (vitamin B1) and has been documented in organisms in aquatic ecosystems ranging from the Baltic Sea to the Laurentian Great Lakes. The biological mechanisms leading to TDC emergence may vary among systems, but in fishes, one common outcome is high mortality among early life stages. Here, we r
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Ecosystems, Columbia Environmental Research Center

Metabarcoding of environmental DNA samples to explore the use of uranium mine containment ponds as a water source for wildlife

Understanding how anthropogenic impacts on the landscape affect wildlife requires a knowledge of community assemblages. Species surveys are the first step in assessing community structure, and recent molecular applications such as metabarcoding and environmental DNA analyses have been proposed as an additional and complementary wildlife survey method. Here, we test eDNA metabarcoding as a survey t
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Columbia Environmental Research Center

Non-USGS Publications**

Taylor, J.A., Richter, C.A., Suzuki, A., Watanabe, H., Iguchi, T., Coser, K.R., Shioda, T., and vom Saal, F.S., 2012, Dose-related estrogen effects on gene expression in fetal mouse prostate mesenchymal cells: PLOS ONE, v. 7, no. 10, p. e48311
Taylor, J.A., Richter, C.A., Ruhlen, R.L., and vom Saal, F.S., 2011, Estrogenic environmental chemicals and drugs: Mechanisms for effects on the developing male urogenital system: The Journal of Steroid Biochemistry and Molecular Biology, v. 127, no. 1, p. 83-95
Richter, C.A., Taylor, J.A., Ruhlen, R.L., Welshons, W.V., and vom Saal, F.S., 2007, Estradiol and Bisphenol A stimulate androgen receptor and estrogen receptor gene expression in fetal mouse prostate mesenchyme cells: Environmental Health Perspectives, v. 115, no. 6, p. 902-908
vom Saal, F.S., Richter, C.A., Mao, J., and Welshons, W.V., 2005, Commercial animal feed: Variability in estrogenic activity and effects on body weight in mice: Birth Defects Research Part A: Clinical and Molecular Teratology, v. 73, no. 7, p. 474-475
Timms, B.G., Howdeshell, K.L., Barton, L., Bradley, S., Richter, C.A., and vom Saal, F.S., 2005, Estrogenic chemicals in plastic and oral contraceptives disrupt development of the fetal mouse prostate and urethra: Proceedings of the National Academy of Sciences of the United States of America, v. 102, no. 19, p. 7014-7019
Richter, C., Timms, B., and vom Saal, F., 2005, Prostate development: mechanisms for opposite effects of low and high doses of estrogenic chemicals, in Naz, R., ed., Endocrine Disruptors: Effects on Male and Female Reproductive Systems: New York, CRC Press, p. 379-410.
vom Saal, F.S., Richter, C.A., Ruhlen, R.R., Nagel, S.C., Timms, B.G., and Welshons, W.V., 2005, The importance of appropriate controls, animal feed, and animal models in interpreting results from low-dose studies of bisphenol A: Birth Defects Research Part A: Clinical and Molecular Teratology, v. 73, no. 3, p. 140-145
vom Saal, F.S., Richter, C.A., Ruhlen, R.R., Nagel, S.C., and Welshons, W.V., 2004, Disruption of laboratory experiments due to leaching of Bisphenol A from polycarbonate cages and bottles and uncontrolled variability in components of animal feed, in National Research Council, ed., The Development of Science-based Guidelines for Laboratory Animal Care: Proceedings of the November 2003 International Workshop: The National Academies Press, p. 65-69.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

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