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Concentrations of pesticides in sediment in 82 streams and in biofilms in 54 streams in California in 2017


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Mahler, B.J., Schmidt, T.S., Nowell, L.H., Van Metre, P.C., and Hladik, M.L., 2020, Concentrations of pesticides in sediment in 82 streams and in biofilms in 54 streams in California in 2017: U.S. Geological Survey data release,


Hydrophobic (sediment-associated) pesticides were measured in sediment samples collected from 82 wadeable streams and in biofilm in 54 of those streams in the Central California Foothills and Coastal Mountains ecoregion.115 current-use and 3 legacy pesticides were measured in stream sediment; 93 of the current-use pesticides and the same 3 legacy pesticides were measured in biofilm. On average 4 times as many current-use pesticides were detected in biofilm at a site (median of 2) as in sediment (median of 0.5). This data release provides data for the pesticide concentrations, information on the pesticide compounds, and input data and R scripts for statistical models used in the analysis presented in the journal article "Biofilms provide [...]


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BifBF.reg.diag.46s.R1a.DR.R 12.18 KB text/x-rsrc
BifBF.reg.diag.46s.R1b.DR.R 12.2 KB text/x-rsrc
BifBF.reg.diag.46s.R1c.DR.R 12.21 KB text/x-rsrc
Bifsed.reg.diag.46s.R1a.DR.R 12.06 KB text/x-rsrc
Bifsed.reg.diag.46s.R1b.DR.R 12.08 KB text/x-rsrc
Bifsed.reg.diag.46s.R1c.DR.R 12.07 KB text/x-rsrc 10.6 KB text/csv
GAM_script.RMD 78.98 KB text/plain
RMarkdown_GAM_script.docx 79.71 KB application/vnd.openxmlformats-officedocument.wordprocessingml.document
Table1_Site_information.txt 6.33 KB text/plain
Table2_Sediment_chemistry.txt 434.4 KB text/plain
Table3_Biofilm_chemistry.txt 231.46 KB text/plain
Table4_Compound_information.txt 8.48 KB text/plain
Table5_Bifenthrin_use.txt 1.61 KB text/plain
Tobit_regression_data.txt 9.75 KB text/plain


The National Water-Quality Assessment (NAWQA) Project was established to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has produced scientific data and knowledge that is used by national, regional, state, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs. A prominent feature of NAWQA is the development of long-term consistent and comparable information on streams, rivers, ground water, and aquatic systems. As part of the NAWQA project, the Regional Stream Quality Assessment (RSQA) addresses the question of how physical and chemical stressors affect the ecology of small streams. The goals of the RSQA are to characterize multiple water-quality factors that are stressors to aquatic life ‐ contaminants, nutrients, sediment, and streamflow alteration – and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region. As part of the RSQA Pesticide data for sediment and biofilm samples were collected from small streams in California to better assess their occurrence and potential risks to aquatic communities. The dataset provides concentrations of 118 pesticides in sediment and 96 pesticides in biofilm in samples collected in May 2017 at 82 and 54 wadeable California streams, respectively. The purpose of data collection was to characterize and compare occurrence of pesticides in sediment and biofilm and investigate their potential effects on benthic invertebrate community structure.



  • National Water-Quality Assessment Project
  • USGS Data Release Products



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DOI doi:10.5066/P9YYD8DI

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