Mercury (Hg) bioaccumulation in salamanders has received little attention despite widespread Hg contamination of aquatic ecosystems and worldwide amphibian declines. Here we report concentrations of methyl Hg (MeHg) and total Hg in larval northern two-lined salamanders (Eurycea bislineata bislineata) collected from streams in Acadia National Park (ANP), Maine, and Bear Brook Watershed, Maine (B...

A model aquatic ecosystem is devised for studying relatively volatile organic compounds and simulating direct discharge of chemical wastes into aquatic ecosystems. Six simple benzene derivatives (aniline, anisole, benzoic acid, chlorobenzene, nitrobenzene, and phthalic anhydride) and other important specialty chemicals: hexachlorobenzene, pentachlorophenol, 2,6-diethylaniline, and 3,5,6-trichlo...

Background: Anthropogenic activities release high concentrations of heavy metals into the aquatic ecosystems, which can be absorbed by the aquatic organisms. In this study, the accu-mulation of cadmium (Cd) and arsenic (As) was compared in liver, gill and muscle tissues of toothed carp (Aphanius sophiae) in fresh and salt water. Methods: A total of 175 fish samples were collected from the Sh...

Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the f...

In October 2012, in a survey in order to study the flora of paddy fields and aquatic ecosystems of Gilan province (N Iran), we encountered an unknown species in “Aynak lagoon” in southeast of Rasht, covered surface of about 12 ha pond densely. Comparing the flora of pond with previous years or adjacent ponds showed that, the new weed was dominant in interference with natural flora of aquatic ec...

This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds u...

Recent studies have shown that silver is no longer restricted to just being found in soil and natural waters. The metal and its various forms are used in medicine as nanoparticles for various applications. After assimilating and reviewing a considerable volume of literature, it can be safely stated that silver displays different extents of bioaccumulation depending on the ecosystem involved. Aq...

This paper describes a method for deriving site-specific water quality criteria for selenium using a two-step process: (1) gather information on selenium residues and biological effects at the site and in down-gradient systems and (2) examine criteria based on the degree of bioaccumulation, the relationship between measured residues and threshold concentrations for reproductive effects in fish ...