Ecological magnification

Tomizawa L. 1980. Biological accumulation of pesticides in an ecosystem-evaluation of biodegradability and ecological magnification of rice pesticides by a model ecosystem. Japanese Agricultural Research Quarterly 14 143-149. 

Aquatic Ecosystem and Fish. Metcalf et al. (2) studied the fate of diflubenzuron (radiolabeled separately in three different positions) in their model ecosystem. Diflubenzuron was dubbed "moderately persistent" in algae, snails, salt marsh caterpillars, and mosquito larvae as evidenced by limited biodegradability (Table IV). However, diflubenzuron and its nonpolar metabolites were not prone to ecological magnification in Gambusia fish. The lack of bioaccumulation of diflubenzuron residues in fish was substantiated by Booth and Ferrell (14) who used the channel catfish, Ictalurus, in a simulated lake ecosystem. They treated separate soil samples at 0.007 and 0.55 ppm, respectively. 

Metcalf, R.L., Sangha, G.K., and Kapoor, I.P. Model ecosystemfor the evaluation of pesticide biodegradability and ecological magnification. Environ. Sci. Technol, 5(8) 709-713, 1971. 

The definition of bioconcentration has to be distinguished from the terms of indirect contamination such as biomagnification, bioaccumulation, and ecological magnification [12,19]. 

Bioconcentration factor (BCF) is a parameter to measure the tendency of a chemical to concentrate in aquatic organisms, notably fish 83), BCF is defined as the ratio of the concentration in an organism or the tissue of an organism to that in water. A similar term used in the terrestrial-aquatic ecosystem is ecological magnification (EM) (74). 

Using a model ecosystem, Metcalf (1972) studied pesticide biodegradability and ecological magnification by means of autoradiography and thin-layer chrom-... 

Laboratory studies have shown a similar relationship for ecological magnification (Lu and Metcalf, 1975) (equation 7). 

Bioaccumulation is generally referred to as a process in which the chemical concentration in an organism achieves a level that exceeds that in the respiratory medium (e.g., water for a fish or air for a mammal), the diet, or both. The extent to which chemicals bioaccumulate is expressed by several quantities, including the bioconcentration factor (BCF), bioaccumulation factor (BAF), biomagnification factor (BMF), and trophic or food web magnification factor (TMF) [6]. The ecological, biological and chemical parameters involved in the transfer and accumulation of contaminants in food webs are complex. 

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