Impacts of Heavy Metal and Bacterial Pollution on the Common Seabream (Pagrus pagrus) in Benghazi Seaport, Libya

Abstract

Background: Pollution of seawater could imply deleterious effects on marine ecosystem and pose a serious threat to fish and, then, public health. Aim: This study assessed the impact of water pollution on common seabream (Pagrus pagrus) fish in Benghazi seaport, Libya, with focus on heavy metal contamination and bacterial load. Methods: Common seabream fish were obtained from seaport area and dissected for tissue analysis of heavy metal content and bacteriological examination. Likewise, seaport water samples collected from three different depth points were analyzed for investigating their pollution status. Fish blood samples were used for hematological analysis. Results: Fish tissue samples (gills, kidneys and muscles) showed elevated levels of toxic metals such as lead and cadmium and essential metals such as iron and zinc, with gills exhibiting the highest Metal Pollution Index (5.23 µg/g). Seaport water samples contained excessive concentrations of iron (6.091 mg/l) and zinc (0.427 mg/l), exceeding recommended limits. Bacterial counts, including Enterobacter cloacae and Escherichia coli, reached 100CFU/100ml near the seaport pier (ship berth). Hematological analysis of fish revealed stress responses, such as elevated white blood cell counts (64.25×10³/µl) and decreased blood thrombocytes (functionally equivalent to mammalian platelets (levels. Conclusion: These findings highlight a significant pollution from contaminated water and industrial discharges, posing risks to marine ecosystems and public health.