Bioaccumulation aquatic model ecosystem

Ohkawa, H., R. Kikuchi, and J.S. Miyamoto. 1980. Bioaccumulation and biodegradation of the (S)-acid isomer of fenvalerate (Sumicidin ) in an aquatic model ecosystem. Jour. Pestic. Sci. 5 11-22. 

Table IV. Bioaccumulation of DDT and its metabolites in aquatic model ecosystem...

Table VIII. Bioaccumulation ratio of total C and fenitrothion in aquatic model ecosystem.

The modified terrestrial-aquatic model ecosystem described here has been found to be a useful tool in studying the environmental fate of drugs and related residues present in animal excreta used as manure. The operation of the ecosystem is relatively simple and yet it allows one to study the complex metabolic transformations of a drug or related residues in its various components. Especially interesting is the study of the degradation of a compound in the soil in the presence of microorganisms found in the animal excreta. This information is important since it eventually determines whether a compound and/ or its metabolites will bioaccumulate in the various elements of the environment. 

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. 

There are two types of laboratory tests toxicity determinations on wildlife and aquatic organisms and the use of model ecosystems to measure bioaccumulation and transport of toxicants and their degradation products. 

Amot JA and Gobas FAPC, A food web bioaccumulation model for organic chemicals in aquatic ecosystems, Environ. Toxicol. Chem., 23, 2343, 2004. 

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