Assessment of Heavy Metals Concentration in Different Organs of Labeo rohita and Cyprinus carpio

Abstract

The current study was conducted to assess the concentration of heavy metals in rohu (Labeo rohita) and common carp (Cyprinus carpio). A total of three sites namely Rawal Lake Islamabad, Head Balloki, and a private fish farm in Muridke were selected. Fish were dissected and tissues from the liver, kidneys, gills, and muscles were separated. Chemical digestion of samples was carried out with aqua regia. Three metals namely chromium (Cr), cadmium (Cd), and mercury (Hg) were detected by using atomic absorption spectroscopy in the labs of Pakistan Council of Scientific and Industrial Research (PSCIR), Lahore, Pakistan. All metals were found at a higher level in different tissues of both the fish species. The overall trend of metals in the two fish species namely rohu and carp was recorded as Hg > Cd > Cr. It was observed that the level of Hg remained very high as compared to other metals. Statistical analysis was performed using one-way ANOVA and significant differences at p < 0.001 were noticed for the metals in different organs. While, independent sample t test showed non-significant differences at p > 0.483 between the two fish species. The liver was found to have the highest metal load, followed by the kidneys and gills. The metal load was above the permissible limit set by World Health Organization (WHO). However, the heavy metals concentration in muscles was below the permissible limit. It was noticed that heavy metal contamination was higher in Rawal Lake as compared to the private fish farm. It was concluded that contaminated water bodies are affecting the exposed organisms. So, there is a need to save them from pollutants for the best survival of aquatic life.