BACKGROUND: Public laws regulating dredged material disposal (Section 404 of the Clean Water Act and Section 103 of the Ocean Dumping Act) require ecological evaluation prior to the permitting of operations. Assessment of the potential for bioaccumulation of chemical contaminants in sediment, including heavy metals, is required as part of the evaluation process. Metals can represent significant...

Mogpog River is located in the island of Marinduque, Philippines. It used to be a relatively healthy river where local communities dotting its banks from Barangay Taluntunan down to Barangay Janagdong obtained fishes, crustaceans and other aquatic organisms. Harvesting these resources were either for local consumption or for cash. The river also served as a place for bathing, swimming, washing ...

Master Student, Department of Applied Environmental Science, Halmstad university, Halmstad, Sweden ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract Heavy metal pollutants are a worldwide concern. It causes negative effects on aquatic organisms and human health. Heavy metals concentration and tran...

Uses Background Concentrations Environmental Chemistry General Chemical Properties Mode of Action Fate in Soils and Water Lethal and Sublethal Effects General Terrestrial Plants and Invertebrates Aquatic Organisms Birds Mammals Recommendations Acknowledgments References Tables Number 1 Paraquat concentrations in field collections of selected organisms and nonbiological materials 2 Chemical and ...

Pulp and paper mill, controversially, is one of the largest and major contributors of pollution in aquatic environment, affecting aquatic organisms in general and fishes in particular. Several field and laboratory studies were conducted worldwide on effects of both treated and untreated paper mill effluents on fish. The studies showed wide ranges of toxicity at organismal as well as at populati...

Hydrologic alterations resulting from dam construction and other human activities have negatively impacted the biodiversity and ecological integrity of rivers worldwide (Dudgeon 2000, Pringle et al. 2000). These alterations have included habitat fragmentation, conversion of lotic to lentic habitat, variable flow and thermal regimes, degraded water quality, altered sediment transport processes, ...

In this talk (Slide 1), I will summarize the studies of methylmercury uptake by freshwater phytoplankton that Carl Watras and I have been conducting over the past few years. These investigations have helped motivate the development both of new analytical methods by Dr. Watras and his mercury biogeochemistry group located at Trout Lake Station in northern Wisconsin and new modeling approaches by...

The textile dyeing units of Pallipalayam area of Namakkal District play a vital role in polluting the river Cauvery directly and spoiling the underground water levels indirectly by letting off their dyeing effluents. This leads to serious environmental hazards of aquatic organisms. In the present study, the textile dyeing effluents of six major textile dyeing units (ST1, ST2, ST3, ST4, ST5 and ...

Ecosystems can be linked by the movement of matter and nutrients across habitat boundaries via aquatic insect emergence. Aquatic organisms tend to have higher concentrations of certain toxic contaminants such as methylmercury (MeHg) compared to their terrestrial counterparts. If aquatic organisms come to land, terrestrial organisms that consume them are expected to have elevated MeHg concentrat...

Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of m...