Evaluation of copper and zinc contamination in Otolithes ruber and sediments of the Pozm Bay (north of Oman Sea): Histopathology and chemical analysis

The aim of this study was to investigate the heavy metals accumulation (copper and zinc) in the sediment and liver tissue of Otolithes ruber of the Pozm Bay and assessment of liver histopathological changes. Fish were collected from five stations by gillnet. Also, sediment samples were taken by using a Van Veen Grab. The concentration of heavy metals was measured using Flame Atomic Absorption Spectrophotometer after digestion. Liver tissue was prepared for histological study using routine histology methods. The highest and lowest concentration of copper was in sediments of C station (252.5 ± 3.31) and B station (107.3 ± 40.85), μg/g dry weight, respectively. Also, the highest and lowest concentration of zinc were in sediments of B station (328.3 ± 20.38) and in C station (106.5 ± 9.9), μg/g dry weight, respectively. Accumulation of copper and zinc in the liver tissue of Otolithes ruber was recorded more than muscle tissue at all stations. The most frequent lesions in the liver were: leukocytes infiltration, vacuolation, hemorrhage, melanomacrophage centers aggregation, necrosis and nucleus hypertrophy. It was concluded histological lesions in the liver tissue of Otolithes ruber in Pozm Bay could indicate a longer time of exposed fish to contaminants.