Freshwater fish otolith as biomonitoring tool for heavy metal evaluation in Gobindsagar reservoir Himachal Pradesh and Ropar Wetland Punjab

Abstract

The present study explored the role of freshwater fish otoliths as long-term biomonitoring tool to study the seasonal changes of the heavy metal pollution of the freshwater bodies, Gobindsagar reservoir (H.P.) and Ropar wetland (Punjab) in the Sutlej River for the period of two years w.e.f. October 2020 to May 2022. The result of physico-chemical analysis showed that the water quality index (WQI) of the Gobindsagar reservoir is good in comparison to the Ropar wetland which depicted a poor quality of water. The metals in river Sutlej were within the permissible limits at both the study area but MI depicted that the surface water exceeded the CCME guidelines for aquatic life. The variation of concentration in otoliths and water depicted that the elemental uptake in otoliths varied with seasons. The indices approach showed that trace metal signatures of Hg, Se and As in B. dero otolith, Hg in the C. carpio and Hg, Zn, Cu, Se, and Cd in S. seenghala which indicated significant anthropogenic influence into the otoliths. It was concluded that the trace metals in the otoliths have a potential to be used as long-term tracer of metal pollution during varied seasons and gave a better scenario of heavy metals in the Sutlej River. Thus, evaluation of the heavy metal s deposition in the fish otolith from its ambient environment could provide good information about the history of the water bodies and their deteriorating status. newline