department of environment, faculty of natrual resources, university of tehran, karaj, iran
Abstract
In recent years, the monitoring of aquatic ecosystems has resulted in quantitatively measuring the number of contaminants in water, sediment and fish tissues to qualitative measurements of the effects of pollutants on aquatic organisms, and assessing the health status of aquatic organisms and ultimately the health status of the ecosystem. Biomarkers or biological markers are genetic, biochemical, cellular, tissue, hematological, enzymatic and population indicators that track the secondary effects of pollutants on aquatic organisms and examine the aquatic physiological status for assessing aquatic health and eventually aquatic ecosystems. The advantages of biomarkers include on time detection of the effects of pollutants before ecological damage, ease of implementation, non-complexity of procedures, low cost and implementation in various laboratory and environmental conditions. Specific proteins used as markers include enzymes involved in detoxification and enzymes controlling the metabolism and excretion of foreign chemicals. These proteins include metallothioneins and cytochrome p450 enzymes, stress proteins. Another batch of proteins used as biomarkers are proteins involved in fish or early embryonic development. This category contains vitellogenin, egg proteins, and various cell receptors such as estrogen receptors. Contamination biomarkers in aquatic animals, depending on the type of contaminant, include protein induction, hormonal changes, sexual changes, etc., which are further detailed in terms of the type of contaminant and aquatic species.
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