Research Microbiologist
Email:
mmarvin@usgs.gov
Office Phone:
650-329-4442
Fax:
650-329-4463
ORCID:
0000-0002-8186-9167
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Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale...
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Sediment cores were collected in the Cache Creek Settling Basin (CCSB), Yolo County, California, during October 2011 at 10 locations (borehole sites) and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Detailed subsampling (3-centimeter intervals) was done at total of seven locations: six along an east-west transect in the southern part of the Cache Creek Settling Basin and at one in the northern part of the basin for analyses of total mercury; organic content; and cesium-137, which was used for dating. This data release reports results of the analyses of each subsample of these...
Categories: Data;
Tags: Cache Creek Settling Basin,
Sacramento River Watershed,
Sacramento–San Joaquin River Delta,
USGS Science Data Catalog (SDC),
Woodland, CA, All tags...
Yolo Bypass,
Yolo County,
basin,
cesium,
chemical analysis,
drilling and coring,
environment,
field sampling,
geochemistry,
isotopic analysis,
mercury,
mercury contamination,
none,
sediment geochemistry,
wetlands, Fewer tags
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Note: This data release has been superseded by version 3.0, available here: https://doi.org/10.5066/P9Q2YP9K. The Hamilton Wetland Restoration Project (HWRP) is a joint venture between the US Army Corps of Engineers (USACE; San Francisco District) and the California State Coastal Conservancy. The site is located on the property of the former Hamilton Army Airfield in Novato, California, along the western edge of San Pablo Bay, which is part of northern San Francisco Bay. The initial stages of wetland restoration, which included dredged sediment reuse, took place during 2009–2011. From 2011 until April 2014, the site was maintained as partially flooded through a temporary one-way culvert that allowed bay water onto...
Categories: Data,
Data Release - Revised;
Tags: Geochemistry,
Novato,
San Francisco Bay,
San Pablo Bay,
USGS Science Data Catalog (SDC), All tags...
Water Quality,
biochemistry,
boundaries,
carbon isotope analysis,
iron,
mercury,
mercury contamination,
nutrient content (water),
oxygen content (water),
sediment geochemistry,
sulfur,
suspended material (water),
wetland ecosystems,
wetland restoration, Fewer tags
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The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration, and particulate and dissolved methyl mercury (MeHg), concentration, in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted flow-through sensors, and c) satellite-based remote sensing. The focus of this specific Child Page is to present all field and laboratory-based data associated with...
Categories: Data;
Tags: Lower Sacramento,
San Francisco Bay,
San Joaquin Delta,
chemical analysis,
datasets, All tags...
dissolved metals,
environment,
field monitoring stations,
field sampling,
laboratory methods,
mercury,
mercury analysis,
nutrient content (water),
oxygen content (water),
real-time monitoring and reporting,
surface water quality,
suspended material (water),
water chemistry,
water column reflectivity,
water pH,
water properties,
water quality,
water sampling,
water sampling,
water temperature, Fewer tags
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The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration and particulate and dissolved methyl mercury (MeHg) concentration in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted, flow-through, sensors and c) satellite-based remote sensing. The focus of this specific Child Page is to present all data collected during the underway boat mapping component...
Categories: Data;
Tags: California,
Lower Sacramento,
Sacramento,
San Francisco Bay,
San Joaquin Delta, All tags...
Solano,
Yolo,
chemical analysis,
dissolved organic compounds,
environment,
environmental proxies,
field inventory and monitoring,
field sampling,
nutrient content (water),
optical methods,
oxygen content (water),
real-time monitoring and reporting,
salinity,
surface water quality,
suspended material (water),
transect sampling,
water chemistry,
water column reflectivity,
water pH,
water properties,
water sampling,
water sampling,
water temperature, Fewer tags
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