A5059891812- Mercury impact and mitigation studies
- Toxic Organic Pollutants Impact
- Marine animal studies overview
- Heavy Metal Exposure and Toxicity
- Heavy metals in environment
- Environmental Toxicology and Ecotoxicology
- Isotope Analysis in Ecology
- Water Treatment and Disinfection
- Atmospheric and Environmental Gas Dynamics
- Mine drainage and remediation techniques
- Methane Hydrates and Related Phenomena
- Air Quality and Health Impacts
- Soil and Water Nutrient Dynamics
- Marine and environmental studies
- Marine and coastal ecosystems
- Geochemistry and Geologic Mapping
- Water Quality and Resources Studies
- Marine Bivalve and Aquaculture Studies
- Fish Ecology and Management Studies
- Geochemistry and Elemental Analysis
- Geological Studies and Exploration
- Chemical Analysis and Environmental Impact
- Iron oxide chemistry and applications
- Indigenous Studies and Ecology
- Water Quality and Pollution Assessment
Wright State University
2015-2025
University of Connecticut
2001-2010
Woods Hole Oceanographic Institution
2004-2007
Connecticut Sea Grant
2007
National Taiwan University
2004
Science Museum of Minnesota
2004
University of Wisconsin–La Crosse
2002
We examined temporal differences in sedimentary production of monomethylmercury (MMHg) at three sites Long Island Sound (LIS). Sediment-phase concentrations Hg species decreased from west to east LIS surface sediments, following the trend organic matter. However, methylation potentials, measured by incubation with an isotopic tracer (200Hg), increased east. 200Hg potentials were enhanced August relative March and June, attributable activity sulfate-reducing bacteria. Organic matter...
Abstract A major surface circulation feature of the Arctic Ocean is Transpolar Drift (TPD), a current that transports river‐influenced shelf water from Laptev and East Siberian Seas toward center basin Fram Strait. In 2015, international GEOTRACES program included high‐resolution pan‐Arctic survey carbon, nutrients, suite trace elements isotopes (TEIs). The cruises bisected TPD at two locations in central basin, which were defined by maxima meteoric dissolved organic carbon concentrations...
We reconstruct from lake-sediment archives atmospheric Hg deposition to Arctic Alaska over the last several centuries and constrain a contemporary lake/watershed mass-balance with real-time measurement of fluxes in rainfall, runoff, evasion. Results indicate that (a) anthropogenic impact is similar magnitude at temperate latitudes; (b) whole-lake sedimentation determined 55 210Pb-dated cores five small lakes demonstrates 3-fold increase since advent Industrial Revolution; (c) because high...
A connection between accumulation of methylmercury (MeHg) in wild fish populations and atmospheric mercury deposition has not been made. Large databases for both MeHg have assimilated from monitoring efforts spanning the contiguous United States. Here, we compare results these data sets show that state-wide average concentrations a cosmopolitan freshwater fish, largemouth bass Micropterus salmoides, are related positively to wet Hg fluxes among most 25 states analyzed, which span 5-fold...
We examined effects of dietary methylmercury (MeHg) on reproduction fathead minnows (Pimephales promelas). Juvenile fish were fed one four diets until sexual maturity (phase 1): a control diet (0.06 μg Hg g-1 dry weight) and three contaminated with MeHg at 0.88 (low), 4.11 (medium), 8.46 weight (high). At maturity, male female paired, again the diets, allowed to reproduce 2). To assess during gametogenesis, some phase 2 that differed from those 1. Spawning success pairs same phases 1 was 75%...
Threshold concentrations associated with adverse effects of dietary exposure to methylmercury (MeHg) were derived from published results laboratory studies on a variety fish species. Adverse related mortality uncommon, whereas growth occurred only at MeHg exceeding 2.5 µg g(-1) wet weight. behavior had wide range effective concentrations, but generally above 0.5 In contrast, reproduction and other subclinical endpoints that much lower (<0.2 wt). Field lack information exposure, yet available...
A new method for the determination of concentration and conditional stability constant dissolved organic matter that binds mercury (Hg) has been developed using an in vitro assay reducible Hg. The technique is a wet chemical analogue to electrochemical approaches now use ligand studies many other trace transition metals natural waters. Ligand characteristics are obtained from additions ionic Hg buffered lake, river water, seawater chemically fraction following equilibration spike. This...
The fate of atmospherically deposited and environmentally active Hg is uncertain in the Arctic, greatest toxicological concern transformation to monomethylmercury (MMHg). Lake/watershed mass balances were developed examine MMHg cycling four northern Alaska lakes near ecological research station at Toolik Lake (68° 38' N, 149° 36' W). Primary features cycle are watershed runoff, sedimentary production mobilization, burial, photodecomposition water column. principal source situ benthic with...
A connection between loadings of inorganic Hg, especially from the atmosphere, and accumulation methylmercury (MeHg) in aquatic biota has not been firmly established. Mosquitoes (Diptera: Culicidae) may be a useful indictor Hg contamination or MeHg ecosystems because they have life stages, their ubiquitous distribution permits sampling across wide ranges climate, biological productivity, atmospheric deposition. We examined adult mosquitoes subtropical (Florida), maritime (California),...
Sunlight-induced decomposition is the principal sink for methylmercury (CH3Hg+) in arctic Alaskan lakes and reduces its availability accumulation aquatic food webs. However, mechanistic chemistry of this process natural waters unknown. We examined experimentally mechanism photochemical CH3Hg+ filter-sterilized epilimnetic Toolik Lake Alaska (68° 38′N, 149° 36′W), a region illuminated by sunlight almost continuously during summer. Results from situ incubation tests indicate that not...
ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTImportance of Integration and Implementation Emerging Future Mercury Research into the Minamata ConventionMae Sexauer Gustin*†, David C. Evers‡, Michael S. Bank§, Chad R. Hammerschmidt⊥, Ashley Pierce#, Niladri Basu∇, Joel Blum○, Paco Bustamante∧, Celia Chen◆, Charlie T. Driscoll¶, Milena Horvat@, Dan Jaffe$, Jozef Pacyna%, Nicola Pirrone&, Noelle Selin●View Author Information† Department Natural Resources Environmental Science, University...
We conducted a laboratory intercomparison of total mercury (Hg) determination in seawater collected during U.S. GEOTRACES Intercalibration cruises 2008 and 2009 to the NW Atlantic NE Pacific Oceans. Results indicated substantial disagreement between participating laboratories, which appeared be affected most strongly by bottle cleanliness preservation procedures. In addition, we examined effectiveness various collection sample preparation procedures that may used on future cruises. The type...