Download or read book Distribution and Transport of Total Mercury and Methylmercury in Mercury contaminated Sediments in Reservoirs and Wetlands of the Sudbury River East central Massachusetts written by and published by . This book was released on 1999 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Distribution and Transport of Total Mercury and Methylmercury in Mercury contaminated Sediments in Reservoirs and Wetlands of the Sudbury River East central Massachusetts written by and published by . This book was released on 1999 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Water resources Investigations Report written by and published by . This book was released on 1999 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2000 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mercury Distribution in Sediments and Uptake Into an Aquatic Food Web at Cottage Grove Reservoir Oregon written by Donna L. Morgans and published by . This book was released on 2003 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cottage Grove Reservoir has been impacted by a point source (Black Butte Mine), where mercury mining and processing has occurred within its watershed from the 1890's to the late 1960's. Total mercury concentrations in surface sediments transect samples, core samples, tributary samples, and representative food web species were measured in 2002. Mercury stratigraphy in reservoir sediment cores and tributary surficial sediments from 2002 and 1995 (unpublished data) were compared and contrasted, core dating was performed to estimate sediment deposition rates and long-term trends for mercury accumulation, and mercury contamination in low trophic levels was assessed. Mercury concentrations in tributary stream sediments strongly correlate with its upstream or downstream proximity to the mine. Current results strongly suggest that the mine area is a continuing source of mercury to downstream tributaries with a strong concentration gradient from the area of the mine to the headwaters of the Coast Fork of the Willamette River. Mercury concentrations in surface sediment transects gradually increase from locations near the inlet to the dam, suggesting an increased mercury deposition rate as suspended solids approach the dam. Sediment cores from both time periods were collected from the deepest most stable region of the reservoir which is likely to have the highest sediment accumulation rates. Mercury concentrations from both cores increase from the surface to the bottom of the core. Core dating results indicate that approximately 40 years lapsed before mercury input to the reservoir stabilized and mercury input has remained relatively stable over the last 20 years. In an aquatic foodweb, methylmercury is the most important form of mercury because it is highly bioavailable for uptake into aquatic organisms. Bioaccumulation of mercury into aquatic organisms can occur through multiple pathways including uptake from sediment arid water, through the skin or cuticle, ventilation of gills, or consumption of contaminated sediment or prey. Biomagnification of methylmercury occurs at successively higher trophic levels of a foodweb. Total mercury concentrations were measured in organisms representative three trophic levels including benthic invertebrates, omnivorous/herbivorous amphibians and fish, and piscivorous fish. Mercury concentrations measured in benthic invertebrates (concentrations ranged from 0.035 mg/kg to 0.075 mg/kg wet-weight) and omnivorous/herbivorous amphibians and fish (concentrations ranged from less than 0.02 mg/kg to 0.043 mg/kg wet-weight) suggest little biomagnification has occurred at these trophic levels. Mercury concentrations in epaxial muscle of largemouth bass (concentrations ranged from 0.86 mg/kg to 1.6 mg/kg wet-weight) are at levels of concern for human health, and fish consumption advisories are posted at the Reservoir. Food web results indicate that significant biomagnification is occurring at higher trophic levels within the foodweb. Current studies suggest that elevated mercury concentrations in largemouth bass are strongly linked to the life history characteristics of the fish.

Download or read book Control of Mercury Contamination in Freshwater Sediments written by George Feick and published by . This book was released on 1972 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography of Agriculture with Subject Index written by and published by . This book was released on 2000 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Factors Affecting the Mobilization Transport and Bioavailability of Mercury in Reservoirs in the Upper Missouri River Basin written by Glenn R. Phillips and published by . This book was released on 1987 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings and Summary Report written by and published by . This book was released on 2002 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Factors Affecting the Mobilization Transport and Bioavailability of Mercury in Reservoirs of the Upper Missouri River Basin written by U.S. Fish and Wildlife Service and published by . This book was released on 1987 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Factors controlling the mobilization, transport, and bioavailability of mercury in relation to coal mining and other mercury sources were studied in reservoirs of the Upper Missouri River Basin. We assessed mercury and selenium contamination of fishes and sediments in 10 reservoirs, estimated mercury fluxes in Tongue River Reservoir, determined dietary accumulation of methylmercury by fish, and related limnological conditions in three reservoirs to rates of mercury accumulation by fish. Detailed limnological studies were conducted in Nelson, Cookson, and Tongue River reservoirs. Mercury concentrations were higher in walleyes (Stizostedion vitreum vitreum) from headwater reservoirs with unregulated inflows than in fish of the same size from downstream reservoirs. Erosion and leaching during flooding apparently facilitated mercury accumulation by fish in reservoirs.

Download or read book Distribution and Transport of Mercury Within the Nooksack River Drainage Whatcom County Washington written by Richard Thomas Falley and published by . This book was released on 1974 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Mercury Transport and Transformation in the Aquatic Environment written by Andrew E. Bale and published by . This book was released on 1995 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many heavy metals are recognized as toxic to aquatic life in minute concentrations. Small amounts of these metals may be bioaccumulated up the food chain, throughout which they can cause disorder and death. Mercury is such a potentially harmful heavy metal and methyl mercury (MeHg), an organic species of mercury, has been found in relatively high levels in fish and invertebrates throughout the world. To effectively evaluate both the potential for harmful bioaccumulation and proposed measures to mitigate that harm, the spatial and temporal distribution of heavy metals within an aquatic system must be characterized. This dissertation provides background on mercury in the environment, reviews numerical models of mercury transport and speciation, and describes the construction and application of a numerical model, RMA4Hg, representing mercury transport and transformation in the aquatic environment.

Download or read book An In situ Assessment of Mercury Contamination in the Sudbury River Massachusetts Using Bioaccumulation and Growth in Transplanted Freshwater Mussels written by S. M. Salazar and published by . This book was released on 1996 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partitioning and Transport of Total and Methyl Mercury in the Lower Fox River Wisconsin written by James P. Hurley and published by . This book was released on 1998 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Remediation Options for Mercury contaminated Sediments Within the Yuba River Watershed written by Tara Fitzgerald and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Historical hydraulic mining activities in the Yuba River watershed have impacted the watershed and the San Francisco Bay. The research evaluates pathways for mercury entry into the watershed and potential remediation technologies to reduce the risk of future mercury contamination from hydraulic mining debris. Remediation technologies for the Yuba Goldfields and Englebright Reservoir are discussed and compared separately. The major pathway for mercury entry into surface water along Yuba Goldfields is within suspended sediment mobilized during flooding conditions. While multiple remediation options are available for the Yuba Goldfields, phytostabilization is the least costly and has the fewest environmental impacts. A non-profit organization is currently working on a restoration project attempting to increase vegetation cover in areas with hydraulic mining debris, creating the potential for synergy in remediation and restoration goals and effort. A phytostabilization pilot study is recommended along the Yuba Goldfields as well as additional characterization of mining debris deposited within the Yuba Goldfields. The major pathway for mercury entry into surface water along Englebright Reservoir is from methylation of mercury in shallow sediments and subsequent movement of methyl mercury into the surface water. Within the Englebright Reservoir, aqueous capping is currently the most promising technology that allows mercury contaminated sediments to remain in place while removing ability for mercury to methylate. An aqueous capping pilot study within Englebright Reservoir and additional characterization of sediments within the reservoir are recommended.

Download or read book Mobilization of Mercury contaminated Sediment in a Regulated River Androscoggin River Northern New Hampshire written by Jenica J. Andersen and published by . This book was released on 2013 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sediment-sorbed mercury contamination from past chlor-alkali production waste disposal occupies, and is mobilized through, hydropower reservoir sediments on the Androscoggin River in northern New Hampshire. The amount of transport and accumulation of mercury within each reservoir is unknown. Investigation of modern sedimentation patterns along with the application of 2D velocity modeling in a reservoir in the Androscoggin River allows for the identification of regions where velocities are sufficiently low to permit mercury-rich fine particles to be deposited. Conversely, identifying the frequency of discharges sufficient to mobilize mercury-rich fine particles allows for an estimate of the time required for mercury to be transported out of the reservoir. Modeled mercury-rich fine particle residence times agree well with residence times indicated by naturally occurring 7Be and 210Pb radionuclides in sediment-water interface samples throughout the Gorham Dam reservoir. Under mean annual flow conditions approximately 24% of the modeled reservoir area is capable of accumulating mercury-heavy sediment. Potential accumulation area decreases to 11% under flow with a five-year recurrence interval. Understanding modern sedimentation and contaminant inventory within this reservoir will serve the ultimate goal of identifying the fate of particle-bound contaminants in regulated rivers.

Download or read book Benthic Flux of Mercury Between Sediments and the Overlying Water in the St Lawrence River Near Cornwall Ontario written by Mahsa Fathi and published by . This book was released on 2009 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: