Lake-level variations at Marcella Lake, a small, hydrologically closed lake in the southwestern Yukon Territory, document changes in effective moisture since the early Holocene. Former water levels, driven by regional palaeohydrology, were reconstructed by multiproxy analyses of sediment cores from four sites spanning shallow to deep water. Marcella Lake today is thermally stratified, being pro...

In order to improve the trophic state of Lake Sempach, a eutrophied lake in central Switzerland, its external phosphorus (P) load has been decreased and its hypolimnion has been artificially oxygenated to lower the lake-internal P recycling. Based on more than 15 yr of experience, we conclude that the reduction of the external P load resulted in a corresponding decrease of the lake’s P concentr...

Sediment oxygen demand (SOD) is believed to be an important process affecting dissolved oxygen (DO) concentrations and has become an integral part of modeling dissolved oxygen (DO) in surface water bodies. Because no SOD data are measured at specific study sites, it is common for researchers to take SOD values from the literature for use in DO modeling. This paper focuses on an approach for mea...

Deposition rates were measured by means of sediment traps at five stations in hypertrophic Takahamairi Bay of Lake Kasumigaura for the selected periods of 1981-1986. Separation of deposited fluxes into autochthonous and sediment resuspension components was attempted on the basis of chlorophyll a concentration for the tracer. Even at the central station of the bay, the average daily flux of auto...

Anthropogenic activities have increased the amount of mercury (Hg) transported atmospherically to the Arctic. At the same time, recent climate warming is altering the limnology of arctic lakes and ponds, including increases in aquatic primary production. It has been hypothesized that climate-driven increases in aquatic production have enhanced Hg scavenging from the water column, and that this ...

Microcosm studies were performed to evaluate the survival of Escherichia coli, Salmonella paratyphi and Vibrio parahaemolyticus in water and sediment collected from the freshwater region of Vembanad Lake (9'35 °N 76'25 °E) along the south west coast of India. All three test microorganisms showed significantly (p < 0.01) higher survival in sediment compared to overlying water. The survival in di...

Variation of the chemical composition of bottom sediments collected from three lakes with different water mixis, morphometric parameters, catchment areas and anthropogenic pressures was analyzed. Sediment samples were characterized by water content and concentrations of organic matter, nitrogen, phosphorus, calcium, iron and aluminium. Statistically significant correlations between the content ...

Anthropogenic radionuclide signatures associated with nuclear testing are increasingly utilized in environmental science to explore recent sedimentation. In this study, we assess the suitability of Pu radioisotope analysis in floodplain lake environments in the Amazon Basin to form geochronologies during the 20 century. The 240Pu + 239Pu (240+239Pu) signatures in six sediment cores indicate sed...

In response to nuisance growths of algae and vascular plants, such as dioecious hydrilla ( Hydrilla verticillata L.f. Royle), copper formulations have been applied in lakes and reservoirs for a number of years. Concerns have arisen regarding the long-term consequences of copper applications and those concerns have appropriately focused on sediment residues. In this study, we evaluated the toxic...

Profiles of dissolved O(2) and methane with increasing depth were generated for Lake Washington sediment, which suggested the zone of methane oxidation is limited to the top 0.8 cm of the sediment. Methane oxidation potentials were measured for 0.5-cm layers down to 1.5 cm and found to be relatively constant at 270 to 350 micromol/liter of sediment/h. Approximately 65% of the methane was oxidiz...