Research Article: Biosorption of some heavy metals (chromium and copper) by microalgae, amphipoda, and beluga in the Caspian Sea

The absorption or accumulation of metals by the organisms of an ecosystem will have a different effect on their food chain. This research compares the heavy metal absorption of copper and chromium in algae, amphipods, and sturgeon species. In Materials and Methods respectively, included the preparation stage including algae cultivation, catching and propagating gammarus and fish and the digestion stage including initial digestion by nitric acid and the final digestion by Header Digest. In this research, algae had a better efficiency in chromium absorption at the initial time. A significant difference was observed in the absorption of algae between copper and chromium (p<۰.۰۱). On the contrary, gammarus had a better efficiency in copper absorption, and the absorption process increased during the time. A significant difference was observed in the biosorption of gammarus between heavy metals copper and chromium (p<۰.۰۱). The accumulation of heavy metals in the liver was more than in muscle. There was a significant difference between fish tissues in the accumulation of heavy metals (p<۰.۰۱). In body tissue, copper accumulates more than chromium. A significant difference was observed, the comparison between the accumulation of copper and chromium metals in fish tissues (p<۰.۰۱). The highest absorption and accumulation of metal was observed by algae and gammarus respectively, in fish body tissues. Algae are strong metal absorbers from the environment and remove metal from the fish body. Gammarus absorbs the metals from the environment and transports them to the fish body. The absence of Spirulina algae in the coastal ecosystem of the Caspian Sea causes the direct transfer of heavy metals to small organisms such as gammarus, and the consumption of these organisms by fish will have harmful effects on their health and ultimately on humans.

کلیدواژه ها:

Biosorption ، Heavy metals ، Food webs ، Arthrospira platensis ، Pontogammarus maeoticus ، Huso huso