eng Science and Education Publishing Journal of Geosciences and Geomatics 2373-6704 2022-03-15 10 1 18 30 10.12691/jgg-10-1-2 JGG20221012 article Jay Bergi jay.bergi@gmail.com 1 Ratna Trivedi 2 Department of Biotechnology, Shree Ramkrishna Institution of Computer Education and Applied Sciences, M.T.B. College Campus, Athwalines, Surat, Gujarat-395001 Department of Environmental Science, Shree Ramkrishna Institution of Computer Education and Applied Sciences, M.T.B. College Campus, Athwalines, Surat, Gujarat-395001 Water reservoirs as one of the sources for the supply of domestic water to Surat city are having extensive algal blooms that may contain species of toxic cyanobacteria. Current water treatment procedures do not detect or try to remove toxins possibly produced by these toxic cyanobacteria. These toxins are potent health hazard if present in drinking water. The aim of the present study was to study the presence of any such toxic cyanobacteria along with its diversity and their toxins in surface water of river Tapi. Detail analysis of nutrient pollution in surface water along with seasonal variation in cyanobacterial population was studied. Detecting genes responsible for toxin production in cyanobacteria that identify the possible health hazard of cyanobacterial toxins in drinking water reservoirs of Surat city. http://pubs.sciepub.com/jgg/10/1/2/jgg-10-1-2.pdf cyanobacteria seasonal variation health hazards water reserviour toxin