biomagnification


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Related to biomagnification: bioaccumulation

biomagnification

(bī′ō-măg′nə-fĭ-kā′shən)
n.
The increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successively higher levels in a food chain.

biomagnification

The result of bioaccumulation and biotransfer by which tissue concentrations of chemicals in organisms at one trophic level exceed tissue concentrations in organisms at the next lower trophic level in a food chain.

biomagnification

(bī″ō-mag″nĭ-fĭ-kā′shŏn) [ bio- + magnification]
The increase in the concentration of biologically active substances in organisms as they rise up the food chain. Pesticides are one example of a substance that biomagnifies. Trace concentrations of agricultural pesticides may be ingested by aquatic organisms, such as plankton. Plankton may be consumed by filter-feeding clams or small fish, which will store larger concentrations of toxins in fat or muscle. These animals may be eaten by predators such as trout or salmon, which may subsequently be consumed by carnivores such as bear, eagles, osprey, or humans. In each successive level of the food chain, higher and higher concentrations of pesticides will be found. Ultimately enough pesticide may be present in individual organisms to cause disease.
References in periodicals archive ?
High plankton densities reduce mercury biomagnification.
However, in most settings there are contributions of metals from a variety of natural and anthropogenic sources, and the processes of bioaccumulation and biomagnification can obscure the origins of the metals, making source apportionment very complex.
Sunstein also fails to reveal that humans are not resistant to higher levels of food-borne chemical residues; that the most used chemical, Roundup, has been implicated in many cancers, including non-Hodgkins lymphoma; that GES have extinguished many developing world crop species and caused human deaths, diseases, fatal allergic reactions, outbreaks of herbicide-resistant weeds, biomagnification of toxins, and plant and animal poisonings.
As a result of biomagnification, the concentration of mercury in a human body will be greater than that in a fish the human eats.
It is important, therefore, to determine the concentrations of PCBs in aquatic biotic media because biomagnification of PCBs through estuarine and marine food chains can pose a significant health hazard to humans who consume contaminated seafood products.
For instance, consider the bioaccumulation and biomagnification of PCBs, starting from a lake containing some PCB molecules deposited by airborne drift.
15] values indicates that the birds feed on virtually the same trophic level and, thus, Hg biomagnification was not apparent.
Captive muskox showed little biomagnification with a concentration ratio close to 1, whereas caribou had a concentration ratio of 12.
Prior to bioconcentration and biomagnification in higher trophic levels, atmospherically deposited inorganic divalent mercury (HgII) must be transformed, via anaerobically mediated microbial processes, to (C[H.
These observations fit well with the limited knowledge available in the literature on organic contaminants and indicate that the biomagnification of comparable PACs could take place in finfish under the appropriate environmental conditions.
Biomagnification, long persistence in the environment, carcinogenicity--all these allegations have been refuted.
The three main aspects of study are biomagnification, or the transfer and accumulation of metals up to the food chain; developing more useful, relevant, and statistically acceptable criteria for selection of metal toxicity thresholds in soil; and empirical study of the effects of other metal toxicity that may modify the thresholds for individual metals.