Fish Diseases Analysis Used as Bioindicators for Water Quality and its Importance for Environmental Monitoring

Abstract

Species of fish are important vehicles for the transfer of contaminants to human populations, and may show the potential exposure to pollutants. They have been used as representative taxocenosis of aquatic ecosystem biotic community and as a environmental quality assessment tool. Its use in environmental monitoring has several advantages because they are directly associated with agent stressors. The objective of this study was to relate the histopathological changes observed and to verify the significance of histological analysis as a method of histopathological evaluation in studies carried out in the area. The study also includes the importance of such type of analysis in environmental change and to efficiently measure the degree of exposure in aquatic organisms to chemical contaminant. For histological analysis the animals were fixed in 10% formaldehyde and then decalcified, dehydrated with ethyl alcohol for impregnation and paraffin embedding and cut at 5-7 µm. The sections were stained with Hematoxylin and Eosin. Several types of alterations were observed in the specimens, some of them macroscopically visible. The occurrence of this type of alteration is evidence of the presence of pollutants and/or degraded habitats of the environments and the analysis of the spatial and temporal variation of their frequency of occurrence in these environments represents an important source of evaluation and monitoring of water quality in these environments.

Physical and chemical water quality characteristics in six wetlands of Lake Tana, Ethiopia

“…Physicochemical variables measured in this study were temperature, dissolved oxygen, conductivity, pH, secchi disk depth a.m., and p.m., total dissolved substance, salinity, nitrite (NO 2 ), nitrate (NO 3 ), soluble reactive phosphorous, total ammonia (NH 4 + NH 3 ), total phosphorus (TP), total nitrogen (TN), and chlorophyll a (Chl-a). These variables were monitored because they de ne the status and quality of the water and phosphorous can be directly harmful to sh in concentrations beyond the normal ranges (Zhang et al, 2022;Dar et al, 2021;Lopes, 2021;Holmes & Taylor, 2015). Temperature affects the speed of chemical reactions, the rate of photosynthesis, the metabolic rate of aquatic organisms, as well as how pollutants, parasites, and other pathogens interact with aquatic residents.…”