-The distribution of toxic heavy metals was studied throughout the process of treatment of domestic wastewater by stabilization ponds. The concentrations and distribution of free and bound zinc, cadmium, lead and copper through the various stages of a treatment plant were analyzed by Anodic Stripping Voltammetry (ASV). Only a slight decrease in the total metals concentration was observed during...

Frog breeding phenology in temperate zones is usually compared to progress of spring temperatures at a regional scale. However, local populations may differ substantially in phenology. To understand this, local climate and other aspects must be studied. In this study, breeding phenology of the common frog, Rana temporaria, in a set of ponds in southern Sweden is analyzed. There was within year ...

the seasonal diversity and distribution of microphytes and macrophytes in 40 artificial irrigationponds constructed in a semi-arid region, and the most suitable conditions to maintain these enclaves asbiodiversity spots were studied for the first time. a total of 104 species were detected. bacillariophyta,cyanobacteria and chlorophyta dominated both pelagic and benthic microphytic communities, ...

The Copper River Delta in the southeast Alaskan Chugash National Forest offers unique opportunities for investigations of pond and stream ecosystem structure and function and the implications of climate change on plant and animal communities of these aquatic habitats. The economic, recreational, and social impact of these investigations is large and carries very significant management implicati...

Caribbean salt ponds are unique wetlands that have received little scientific attention. They are common features of dry Caribbean coastlines, but they are threatened by rapid coastal development. We compared hydrology and salinity of 17 salt ponds in the British Virgin Islands. Ponds were mostly hypersaline (>50 ppt), and they exhibited dramatic salinity fluctuations in response to rainfall an...

Three techniques for treating fish ponds with agricultural limestone were evaluated in ponds with clayey soils in Brazil and in ponds with sandy soils in South Africa. Amounts of agricultural limestone equal to the lime requirement of bottom soils were applied by the following methods to each of three ponds: (1) direct application over the pond surface; (2) spread uniformly over the bottom of t...

The regional dynamics of pond-breeding amphibians are often discussed in the context of metapopulations, under the assumption that individual ponds support distinct subpopulations. We used a combination of indirect and direct methods to assess the spatial population structure of California tiger salamanders (Ambystoma californiense) relative to two basic requirements of metapopulation models: (...

Mercury is an environmental contaminant that negatively affects the health of vertebrate consumers such as fish, birds, and mammals. Although aquatic macroinvertebrates are a key link in the trophic transfer of Hg to vertebrate consumers, Hg contamination in macroinvertebrate communities has not been well studied. The purpose of the present study was to examine how Hg in macroinvertebrate commu...

The influences of coal-mine hollow fills and associated settling ponds in three headwater streams were assessed in southern West Virginia, USA. Fill drainage waters had elevated conductivities and metal concentrations, compared to a regional reference. Benthic macroinvertebrate richness was not affected consistently by the hollow fill drainages, relative to a regional reference, although a more...

this research summarizes the data on benthic macro invertebrates collected from 25 points in the urmia lake wetlands during november 2008 to february 2009. the purpose of the study was to assess the effects of elevated salinity and nutrient (nitrogen and phosphorus) levels on macro invertebrate abundance and composition. a total of 32 taxa were collected, and the common taxa, including chirono...