Role of effective microorganisms on hematological and biochemical indices of cultured Oreochromis niloticus exposed to lead, copper, and cadmium under temperature variations

The freshwater environment suffers from a combination of stressors; pollution and global warming. Multiple effects of copper sulfate, cadmium chloride, and lead nitrate Pb were studied on Nile tilapia under three temperatures ranges, compared to bioremediation using effective microorganisms (EMs). The fish were divided into eight groups, with each group exposed to three temperatures (24, 28, and 32°C). Water physicochemical parameters were measured, and fish hematological, physiological, and biochemical changes were considered. Water quality parameters revealed a significant increase in both electrical conductivity and total dissolved solids in the EM/Cu fish group in the Cu fish group at 32°C. The chemical oxygen demand levels indicated a remarkable fluctuation with a slight decrease in the control group (at 28°C) while reduced in the control and EM. The results were highly significant incomplete blood cells, total red blood cell count, hemoglobin concentration (Hb), hematocrit, mean corpuscular Hb, mean corpuscular Hb concentration, and total protein (g/dl) in the EM group and control group. It can be concluded that using EM in fish farms (1:1000) could help fish adapt to different temperatures and reduce the effects of toxic pollutants.