Evaluation of sediment and water quality status of Parakkai Lake, part of the Suchindram Theroor Wetland complex (a Ramsar Site), using various pollution indices

The study evaluates sediment and water quality in Parakkai Lake, part of the Suchindram Theroor wetland complex, an Important Bird Area (IBA). It aims to identify pollution sources and their effects on the lake ecosystem. Fifteen samples generally met WHO and BIS standards, with a Water Quality Index indicating good to excellent quality. Water is characterized as NaCl, Na + K, and Cl based on the Piper diagram. Trace element levels were mostly within WHO limits, though some samples showed higher concentrations, particularly in the lake’s northern part due to human activities. Water quality for irrigation showed issues at site 6 due to nearby fertilizer use. The Parakkai Ramsar site is at low risk based on the study. Sediment metal concentrations ranked as Zr > Ba > Ga > Cu > Zn > La > Sr > Fe > Cr > Al > Rb > Ni > Mn > V, with Zn being the most abundant. Ecological risk indices suggest marginal heavy metal pollution in sediments. The key factor affecting the determination of water quality is the growth in urbanisation and agricultural practises around these lakes. Urbanization and agriculture were identified as main factors affecting water quality. Regular monitoring is crucial for lake protection.