Bimonitoring of Gamasiab River using Biomarkers of acetylcholinesterase enzyme and metallothionein in two species of salmon and common carp.

Metallothionein protein and acetylcholinesterase enzyme are among the most important biomarkers in evaluating the health of aquatic ecosystems and have been introduced as one of the defense mechanisms of aquatic organisms in the face of various pollutants. Therefore, the aim of this study was to evaluate and biologically monitor the organic and mineral pollution of Gamasyab River using the biomarkers of acetylcholinesterase enzyme and metallothionein protein in two species of rainbow (Onchorhynchus mykiss) and common carp (Cyprinus carpio). Sampling was done from five rainbow trout farms and eight common carp farms along the Gamasiab River, and the samples were quickly frozen in liquid nitrogen and transported to the laboratory. The amount of metallothionein (MT) was measured based on spectrophotometric method and the analysis of cholinesterase enzyme (AchE) in fish brain was performed based on Elman's method. The findings showed that there was a statistically significant difference between different sampling locations in terms of the average values and effects of AchE and MT in two fish species (P<0.05). In addition, the average values of total AchE and MT in carp fish are equal to 3.42 µm/min/g and 707.75 µg/g, respectively, and in rainbow trout it is equal to 1.33 µm/min/g and µg, respectively. /g were 3105.7 and the comparison of the average amount of AchE and MT between two species of carp and rainbow trout showed that the amount of MT in rainbow salmon is higher than that of carp, And the amount of AchE activity in carp was higher than that of rainbow trout. The differences in the level of MT and AchE biomarkers can be caused by exposure of fish species exposed to different levels of pollutants due to differences in their feeding habits and behavior as well as differences in sampling points with environmental conditions and the entry of polluting sources are different. In this study, the application of 2 specific biomarkers to investigate the presence and effects of two groups of organic and inorganic pollutants in the Gamasiab River were determined without conducting any type of chemical analysis. directly exposed to the simultaneous entry of organic and mineral pollutants due to the extent and dispersion of different human uses on its margins, which can be detected by tracking specific biomarkers in indicator species (including rainbow trout and carp) to be a basis for monitoring the pollution of ecosystems.