Status of cyanotoxin contamination and water quality in major irrigational and recreational reservoirs in Sri Lanka

The rapid depletion of water quality in reservoirs is considered as a global ecological and health consequences. Hence, the regular monitoring of water quality status in such reservoirs is mandatory to ensure a safe water supply for the general public. The present study was conducted to evaluate the water quality, contamination status of cyanotoxins, species composition and abundance of phytoplankton in 43 selected major reservoirs in Sri Lanka. The water temperature, pH, Dissolved oxygen (DO), and Electrical Conductivity (EC) were measured at the site and the other water quality parameters, Total Nitrogen (TN), Total Phosphates (TP), Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Fluoride, Total Hardness (TH), Chlorophyll- a (Chl- a ), Cyanotoxins; Microcystin-LR (MC-LR), Cylindrospermopsin (CYN), Saxitoxin (SAX), Nodularin (NOD), Anatoxin-a (ANA-a) concentrations and Faecal Coliform were measured following the standard methods. The water temperature, pH, DO, EC, TN, TP, COD, BOD, Fluoride, TH, and Chl- a were ranged from 20.5 to 29.7 ℃, 6.5 to 8.8, 2.1 to 7.9 mg/L, 25.6 to 1752 µS/cm,