Indicators of the ecological stress and environmental susceptibility of Keenjhar Lake,Sindh, Pakistan

Keenjhar Lake, mega storage of drinking water for the residents of Karachi metropolis, agriculture cultivation and a well‐known recreational place, has been steadily contaminated. This study was aimed to understand the level of pollution and the reasons for a decrease in fish production over the past decade based on the available datasets. Focusing on some heavy metals such as Fe, Zn, Ni, Mn, Cu, Cr, Cd and Pb, beyond limit can cause of human health risk, here we provide a critical review of the previous studies conducted to findout reasonable solutions to cope with rapid environmental changes. A multivariate approach of principal component analysis (PCA) was applied to test the relationships among physicochemical parameters in relation to the heavy metals. The first component PCI revealed 88.09%, variability in the loaded dataset and PCII II 6.05% of the total variations. A cluster analysis was established to delineate heavy metal intensity in the corresponding years. Results indicated that since 2012, there has been a steady increase in heavy metal concentration, which can subsequently pose a significant threat to human health. Therefore, it is emphasized that carcinogenic health effects of such contamination on human health need to be investigated. However, over a decade datasets can solely fill knowledge gaps associated with framework conservation and management strategies.