Because of their unique physical, optical, and mechanical properties, nanomaterials hold great promise in improving on a wide variety of current technologies. Consequently, their use in research and consumer products is increasing rapidly, and contamination of the environment with various nanomaterials seems inevitable. Because surface waters receive pollutants and contaminants from many source...

Understanding river food webs requires distinguishing energy derived from primary production in the river itself (autochthonous) from that produced externally (allochthonous), yet there are no universally applicable and reliable techniques for doing so. We compared the natural abundance stable isotope ratios of hydrogen (deltaD) of allochthonous and autochthonous energy sources in four differen...

Invasive species are a growing threat in the United States, causing losses in biodiversity, changes in ecosystems, and impacts on economic enterprises such as agriculture, fisheries, and international trade. The costs of preventing and controlling invasive species are not well understood or documented, but estimates indicate that the costs are quite high. The costs of aquatic invasive species a...

The hippopotamus grazes nocturnally on land and resides in water during the day. Much of the ingested material must therefore be defecated directly into the aquatic system and can thus be considered an allochthonous resource available to aquatic consumers. The utility of stable isotope analyses of carbon and nitrogen to distinguish hippo faecal matter from other potential basal resources was te...

Releases of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) from industrial or thermal processes to the aquatic environment are considered small compared emissions air today. However, have occasionally released PCDD/PCDFs into local environments. . PCDD/PCDF formation releases were re-examined based on investigations conducted before introduction water quality regulations in Ja...

Sediment screening criteria for many munition constituents (MC) are not available in sources typically used in regulatory-driven ecological risk assessments for contaminated sediment sites. Preliminary sediment quality benchmarks (SQBs) for MC were developed for screening potential risks to marine benthic invertebrates at a munitions contaminated sediment site in Puget Sound, WA, USA. SQBs were...

Hydrogen stable isotopes (δ2H) have recently been used to complement δ13C and δ15N in food web studies due to their potentially greater power to separate sources of organic matter in aquatic food webs. However, uncertainties remain regarding the use of δ2H, since little is known about the potential variation in the amount of exchangeable hydrogen (Hex) among common sample materials or the patte...

karizes (qanat) prepare a part of fresh water sources in main desert of iran. the arid regions in deserts have isolated suitable aquatic habitats as strong barriers, thus only a few places with surface waters have remained accessible for water- related insects. this paper represents the results of only study on dragonfly species of karizes. we identified 10 species of typical desert dragonflies...