نتایج جستجو برای: biomagnification
تعداد نتایج: 374 فیلتر نتایج به سال:
Abstract This study investigates the trophic interactions and As Cd transfer along seven marine ecosystems in Peru. Five of these are driven by aquaculture Peruvian scallop Argopecten purpuratus . A southward increased gradient δ 15 N was observed among three examined regions coast. The stable isotope analysis R (SIAR)‐stable mixing models helped to clarify feeding ecology A. its important pred...
Organochlorine and mercury (Hg) pollution has been one possible reason for a decline in the size of the population of the Saimaa ringed seal (Phoca hispida saimensis) in Lake Haukivesi, Finland. In this study, we analyzed changes in the concentrations of organochlorine compounds (OCls) and extractable organic halogen (EOX) in the blubber of Saimaa ringed seals that died from 1981 to 2000. In ad...
Insects are integral to most freshwater and terrestrial food webs, but due to their accumulation of environmental pollutants they are also contaminant vectors that threaten reproduction, development, and survival of consumers. Metamorphosis from larvae to adult can cause large chemical changes in insects, altering contaminant concentrations and fractionation of chemical tracers used to establis...
PCBs are mixtures of chlorinated biphenyls with different degrees of chlorination, are hydrophobic chemicals, very persistent and bioaccumulative in aquatic organisms, especially in fishes that are at the end of the food chain and are the final receptors of toxicants. PCBs can be classified as narcotics: they produce no change in the biophase and elicit anesthetic reversible effects. Bioaccumul...
As root symbionts of cycad trees, cyanobacteria of the genus Nostoc produce beta-methylamino-l-alanine (BMAA), a neurotoxic nonprotein amino acid. The biomagnification of BMAA through the Guam ecosystem fits a classic triangle of increasing concentrations of toxic compounds up the food chain. However, because BMAA is polar and nonlipophilic, a mechanism for its biomagnification through increasi...
Concentrations of several persistent organic pollutants (POPs: PCBs, PBDEs, OCPs) in aquatic species from the Scheldt estuary were related with factors (body size, lipids, trophic position) possibly influencing their bioaccumulation. Stable nitrogen isotope ratios (δ(15)N) were used as a measure for trophic position. A decreasing trend in POP levels toward the sea was observed. For POP concentr...
Concentrations of polychlorinated biphenyls (PCBs), DDT and its metabolites (DDTs), HCH isomers (HCHs), chlordane compounds (CHLs) and hexachlorobenzene (HCB) were determined in sediment, soil, whole body homogenates of resident and migratory birds and their prey items (including fish, green mussel, snail, earthworm, crabs, prawn, lizard and frogs), bird eggs and bats collected from southern In...
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