A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic compo...

Background & Aims of the Study: Aquatic macrophytes, given their rapid growth and high bio mass production, great potential to accumulate heavy metals in their organs. Phragmites australis as a hyper-cumulative plant plays an important role in the bioremediation. The Badavar River of Noorabad, Lorestan province, is exposed to urban wastewater and agricultural runoffs. In order to heavy metals (...

In this study, some metals (aluminium, chromium, copper, iron, manganese, lead, zinc and vanadium) and metalloid (silicon) were determined in water, sediment and some tissues of fish Cyprinus carpio from Mogan Lake. Fish samples were caught in March 2007. As a result of the examination of metals in the water aluminium has the lowest and silicon has the highest concentration. In sediment samples...

Background: The pollution of the aquatic environment with heavy metals has become a worldwide problem during recent years, due to their potential toxic effects and ability to bio-accumulate in aquatic ecosystems. Heavy metals are sensitive indicators for monitoring changes in the aquatic environment. Methods: In this study, total concentrations of Cr, Pb, Cu, Zn, and Fe were measured in water...

Dating lake sediments by accelerator mass spectrometry (AMS) C analysis of terrestrial plant macrofossils overcomes one of the main problems associated with dating bulk sediment samples, i.e., the presence of old organic matter. Even so, many AMS dates from arctic and boreal sites appear to misrepresent the age of the sediment. To understand the nature of these apparent dating anomalies better,...

Records from lake sediment cores are critical for assessing the relative stability of climate and ecosystems over the Holocene. Duck Lake in south-central Lower Michigan, USA, was the focus of a study that identified how changes in the geochemical variables in lake sediments relate to variations in regional climate and local land use during the Holocene. More than 8.5 m of lacustrine sediment w...

The objectives of this study were to evaluate the infaunal, facultative deposit-feeding clam Amiantis umbonella as a bioindicator of trace-metal contamination and the relative importance of clam burrow sediment and porewater to total accumulation in an urban/industrial coastal environment. Concentrations of eight trace metals (cadmium [Cd], chromium, copper, mercury [Hg], nickel, lead [Pb], van...

In this study, some metals (aluminium, chromium, copper, iron, manganese, lead, zinc and vanadium) and metalloid (silicon) were determined in water, sediment and some tissues of fish Cyprinus carpio from Mogan Lake. Fish samples were caught in March 2007. As a result of the examination of metals in the water aluminium has the lowest and silicon has the highest concentration. In sediment samples...

Fish from Silver Stream reservoir in Newburgh, New York (USA) were examined in 1985 and 1986 following reports by fishermen who had found a high prevalence of skin lesions in brown bullheads Ictalurus nebulosus caught in the reservoir Oral and skin papillomas were found in 43.2 % and 60.0 O/o of the brown bullheads from these respective samplings, whereas no papillomas were found in yellow bull...