Matthew De Parsia
Matthew De Parsia is a hydrologist at the California Water Science Center.
Science and Products
Pesticide Fate Research Group (PFRG)
Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2021
Zooplankton samples were collected at one site upstream of the Yolo Bypass in Northern California, three sites within the Bypass, and at a comparison site on the Sacramento River below the city of Sacramento and analyzed for a large suite of current-use pesticides and degradates. Samples were collected every two weeks from early August 2021 to mid-October 2021. Samples were collected by towing a 1
Results from U.S. Geological Survey Environmental Health Food Resources Lifecycle Integrated Science Team, Graton Pesticides (GRAPE) Study, in Graton, California, April–May 2021
In the spring of 2021, six households with private wells were selected throughout Graton, California, based on proximity to agriculture (within one mile of agriculture), well depth (i.e., less than 150 feet in depth), and well type (i.e., dug versus drilled). Silicone bands were deployed for 30 days at outdoor locations at each household to passively sample pesticides in ambient air. On May 3, 202
Naled and dichlorvos in water and aquatic organisms from a canal and rice fields near Sacramento, California
Ultra-low volumes of naled are applied by aircraft over rice fields and canals to reduce adult mosquito populations near Sacramento, California. Each summer, the pesticide is applied approximately 7-10 times between July and October. Naled and its major degradate (dichlorvos) were quantified in water, biofilm, and invertebrates following aerial applications. In 2020, samples were collected before
Current-use pesticides, nutrients, chloride, and metals in ponds and stormwater basins of the New Jersey Pinelands, 2018-20
The data presented in this data release include concentrations of current-use pesticides, nutrients, chloride, and metals in surface water collected from 60 wetlands including natural ponds, excavated ponds (Xponds), and stormwater basins in the New Jersey Pinelands, 2018-20. Site information, basic water-quality parameters, and method information also are included.
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2017-2020
Zooplankton samples were collected at a site in the Yolo Bypass in Northern California and at a comparison site on the Sacramento River below the city of Sacramento and analyzed for a large suite of current-use pesticides and degradates. Samples were collected biweekly in the summer/fall 2017 and 2018, and from May 2019-March 2020. Samples were collected by towing a 150-micron conical plankton net
Pesticide detections in streams throughout the foothills of the Sierra Nevada range using passive samplers from 2017 to 2019
This dataset was produced from analyzing Affinisep SDB-RPS, Affinisep HLB, and Restek Resprep C18 disks that were deployed with the use of Chemcatcher� passive sampling devices. Silicone bands were also deployed and used for exploring economical methods of sampling for pesticides in surface water. Sampling assemblies were deployed in streams throughout the foothills of the Sierra Nevada range and
Current-use pesticides and emerging amphibian pathogens in natural ponds, excavated ponds, and stormwater basins from 24 sites varying in land-use classifications throughout the New Jersey Pinelands, 2014-2016
Water, sediment, anuran food (leaf litter and detritus) and whole body larval amphibian composites were analyzed for over 100 current-use pesticides from 24 wetlands representing land-use gradients in the New Jersey Pinelands, USA during 2014-2016. Emerging amphibian pathogens, Ranavirus and Batrachochytrium dendrobatidis (Bd) were also assessed in individual larvae at the 24 wetlands. Tables in t
Methods of analysis—Determination of pesticides in filtered water and suspended sediment using liquid chromatography- and gas chromatography-tandem mass spectrometry
The widespread application of pesticides in agricultural and urban areas leads to their presence in surface waters. Presence of these biologically active chemicals in environmental waters potentially has adverse effects on nontarget organisms. To better understand the environmental fate of these contaminants, a robust method to capture chemicals with wide-ranging physicochemical properties has bee
Authors
Michael S. Gross, Corey J. Sanders, Matthew D. De Parsia, Michelle L. Hladik
Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19
Passive sampler devices were deployed in six northern California streams five times between November 2018 and December 2019 to measure the presence or absence of current-use pesticides in surface water. In the targeted areas, there are reported pesticide uses for agriculture, commercial forestry, and rights of way maintenance along with unreported pesticide use at private residences and cannabis g
Authors
Matthew D. De Parsia, James L. Orlando, Michelle L. Hladik
Pesticide concentrations associated with augmented flow pulses in the Yolo Bypass and Cache Slough Complex, California
Surface-water and suspended-sediment samples were collected and analyzed by the U.S. Geological Survey for multiple current-use pesticides and pesticide degradates approximately every 2 weeks at up to five sites in the Yolo Bypass and Cache Slough Complex before, during, and after augmented flow pulses in summer and fall 2016 and 2018 as well as during ambient flow conditions in summer and fall 20
Authors
James L. Orlando, Matt De Parsia, Corey J. Sanders, Michelle L. Hladik, Jared Frantzich
Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program
The Delta Regional Monitoring Program was developed by the Central Valley Regional Water Quality Control Board in response to the decline of pelagic fish species in the Sacramento–San Joaquin Delta that was observed in the early 2000s. The U.S. Geological Survey, in cooperation with the Delta Regional Monitoring Program, has been responsible for collecting and analyzing surface-water samples for a
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
An initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16
A study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission and Montclair State University, was designed to compare pesticide concentrations and the presence and prevalence of amphibian pathogens between natural ponds and two types of created wetlands, excavated ponds and stormwater basins, throughout the New Jersey Pinelands. The study described herein
Authors
Kelly L. Smalling, John F. Bunnell, Jonathan Cohl, Kristin M. Romanok, Lisa Hazard, Kirsten Monsen, Denise M. Akob, Angela M. Hansen, Michelle L. Hladik, Nicole Abdallah, Quratulain Ahmed, Araba Assan, Matthew D. De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna Williams
Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program
Emergent hypotheses about causes of the pelagic organism decline in the Sacramento–San Joaquin Delta (Delta) indicate that a more complete understanding of the quality of water entering the Delta is needed. Less than half of all pesticides used in the Delta watershed are measured in samples collected for routine monitoring, and with new pesticides continually being registered for use, the concentr
Authors
Matthew D. De Parsia, James L. Orlando, Megan M. McWayne, Michelle L. Hladik
Increasing neonicotinoid use and the declining butterfly fauna of lowland California
The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative association be
Authors
Matthew L. Forister, Bruce Cousens, Joshua G. Harrison, Kayce Anderson, James H. Thorne, Dave Waetjen, Chris C. Nice, Matt De Parsia, Michelle Hladik, Robert Meese, Heidi van Vliet, Arthur M. Shapiro
Science and Products
Pesticide Fate Research Group (PFRG)
Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2021
Zooplankton samples were collected at one site upstream of the Yolo Bypass in Northern California, three sites within the Bypass, and at a comparison site on the Sacramento River below the city of Sacramento and analyzed for a large suite of current-use pesticides and degradates. Samples were collected every two weeks from early August 2021 to mid-October 2021. Samples were collected by towing a 1
Results from U.S. Geological Survey Environmental Health Food Resources Lifecycle Integrated Science Team, Graton Pesticides (GRAPE) Study, in Graton, California, April–May 2021
In the spring of 2021, six households with private wells were selected throughout Graton, California, based on proximity to agriculture (within one mile of agriculture), well depth (i.e., less than 150 feet in depth), and well type (i.e., dug versus drilled). Silicone bands were deployed for 30 days at outdoor locations at each household to passively sample pesticides in ambient air. On May 3, 202
Naled and dichlorvos in water and aquatic organisms from a canal and rice fields near Sacramento, California
Ultra-low volumes of naled are applied by aircraft over rice fields and canals to reduce adult mosquito populations near Sacramento, California. Each summer, the pesticide is applied approximately 7-10 times between July and October. Naled and its major degradate (dichlorvos) were quantified in water, biofilm, and invertebrates following aerial applications. In 2020, samples were collected before
Current-use pesticides, nutrients, chloride, and metals in ponds and stormwater basins of the New Jersey Pinelands, 2018-20
The data presented in this data release include concentrations of current-use pesticides, nutrients, chloride, and metals in surface water collected from 60 wetlands including natural ponds, excavated ponds (Xponds), and stormwater basins in the New Jersey Pinelands, 2018-20. Site information, basic water-quality parameters, and method information also are included.
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2017-2020
Zooplankton samples were collected at a site in the Yolo Bypass in Northern California and at a comparison site on the Sacramento River below the city of Sacramento and analyzed for a large suite of current-use pesticides and degradates. Samples were collected biweekly in the summer/fall 2017 and 2018, and from May 2019-March 2020. Samples were collected by towing a 150-micron conical plankton net
Pesticide detections in streams throughout the foothills of the Sierra Nevada range using passive samplers from 2017 to 2019
This dataset was produced from analyzing Affinisep SDB-RPS, Affinisep HLB, and Restek Resprep C18 disks that were deployed with the use of Chemcatcher� passive sampling devices. Silicone bands were also deployed and used for exploring economical methods of sampling for pesticides in surface water. Sampling assemblies were deployed in streams throughout the foothills of the Sierra Nevada range and
Current-use pesticides and emerging amphibian pathogens in natural ponds, excavated ponds, and stormwater basins from 24 sites varying in land-use classifications throughout the New Jersey Pinelands, 2014-2016
Water, sediment, anuran food (leaf litter and detritus) and whole body larval amphibian composites were analyzed for over 100 current-use pesticides from 24 wetlands representing land-use gradients in the New Jersey Pinelands, USA during 2014-2016. Emerging amphibian pathogens, Ranavirus and Batrachochytrium dendrobatidis (Bd) were also assessed in individual larvae at the 24 wetlands. Tables in t
Methods of analysis—Determination of pesticides in filtered water and suspended sediment using liquid chromatography- and gas chromatography-tandem mass spectrometry
The widespread application of pesticides in agricultural and urban areas leads to their presence in surface waters. Presence of these biologically active chemicals in environmental waters potentially has adverse effects on nontarget organisms. To better understand the environmental fate of these contaminants, a robust method to capture chemicals with wide-ranging physicochemical properties has bee
Authors
Michael S. Gross, Corey J. Sanders, Matthew D. De Parsia, Michelle L. Hladik
Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19
Passive sampler devices were deployed in six northern California streams five times between November 2018 and December 2019 to measure the presence or absence of current-use pesticides in surface water. In the targeted areas, there are reported pesticide uses for agriculture, commercial forestry, and rights of way maintenance along with unreported pesticide use at private residences and cannabis g
Authors
Matthew D. De Parsia, James L. Orlando, Michelle L. Hladik
Pesticide concentrations associated with augmented flow pulses in the Yolo Bypass and Cache Slough Complex, California
Surface-water and suspended-sediment samples were collected and analyzed by the U.S. Geological Survey for multiple current-use pesticides and pesticide degradates approximately every 2 weeks at up to five sites in the Yolo Bypass and Cache Slough Complex before, during, and after augmented flow pulses in summer and fall 2016 and 2018 as well as during ambient flow conditions in summer and fall 20
Authors
James L. Orlando, Matt De Parsia, Corey J. Sanders, Michelle L. Hladik, Jared Frantzich
Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program
The Delta Regional Monitoring Program was developed by the Central Valley Regional Water Quality Control Board in response to the decline of pelagic fish species in the Sacramento–San Joaquin Delta that was observed in the early 2000s. The U.S. Geological Survey, in cooperation with the Delta Regional Monitoring Program, has been responsible for collecting and analyzing surface-water samples for a
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
An initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16
A study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission and Montclair State University, was designed to compare pesticide concentrations and the presence and prevalence of amphibian pathogens between natural ponds and two types of created wetlands, excavated ponds and stormwater basins, throughout the New Jersey Pinelands. The study described herein
Authors
Kelly L. Smalling, John F. Bunnell, Jonathan Cohl, Kristin M. Romanok, Lisa Hazard, Kirsten Monsen, Denise M. Akob, Angela M. Hansen, Michelle L. Hladik, Nicole Abdallah, Quratulain Ahmed, Araba Assan, Matthew D. De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna Williams
Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program
Emergent hypotheses about causes of the pelagic organism decline in the Sacramento–San Joaquin Delta (Delta) indicate that a more complete understanding of the quality of water entering the Delta is needed. Less than half of all pesticides used in the Delta watershed are measured in samples collected for routine monitoring, and with new pesticides continually being registered for use, the concentr
Authors
Matthew D. De Parsia, James L. Orlando, Megan M. McWayne, Michelle L. Hladik
Increasing neonicotinoid use and the declining butterfly fauna of lowland California
The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative association be
Authors
Matthew L. Forister, Bruce Cousens, Joshua G. Harrison, Kayce Anderson, James H. Thorne, Dave Waetjen, Chris C. Nice, Matt De Parsia, Michelle Hladik, Robert Meese, Heidi van Vliet, Arthur M. Shapiro