Environmental impacts of anthropogenic activities on the mineral uptake in Oreochromis mossambicus from Indus River in Pakistan.

We examined the extent of mineral uptake in different tissues of Oreochromis mossambicus from Indus River which is claimed to be polluted by human activities. Samples of water and fish tissues were analysed from two sites (SK = upstream and CH = downstream) of Indus River. Whilst the water quality appeared to be suitable for aquatic life, significant differences between fish tissues and sampling sites were observed for different mineral concentrations. Fins generally had the highest metal load followed by muscles, gills, scales and skin. Na, Mg, Mn and Zn concentrations in different fish tissues were greater for CH than SK, whereas K, Ca, Pb, Cu, Fe, Hg and Cr were higher at SK than CH (P < 0.001). This variation in metal profiles of different locations of the Indus River was a reflection of relevant mineral pollutions at these sites. It appeared that the pattern of metal uptake in fish tissues can be utilised as an indicator of environmental contamination of river water systems. These studies may help us plan strategies to alleviate the ecotoxicological impacts of heavy metals in freshwaters on fish and human populations.