Cyanobacteria and Cyanotoxins in Lake Patzcuaro, Michoacan, Mexico

Abstract

One of the most common features in eutrophic water bodies is the presence of cyanobacteria which can produce cianotoxins. In several states of Mexico, many events of cyanobacteria blooms have been reported, as well as in different urban water bodies in Mexico City. From 2009 to 2011, cyanobacteria blooms have also been observed in Pátzcuaro Lake, and in six stations, data of Mycrocistin-LR toxin, chlorophyll and the quantification of cyanobacteria were obtained. This information helped to determine the lake’s health risk, according to the World Health Organization (WHO) Guide. In 2009 and according to the WHO Guide, Embarcadero, Espíritu and Quiroga stations and secondly Pacanda station, presented a very high probability of health risk; and in 2010, Quiroga, Espíritu and Pacanda, also showed a high health risk; lastly, in 2011, all stations showed an increased health risk in the month September, except in Napízaro station. It is highly recommended to have a comprehensive and effective plan to treat domestic sewage discharges and reduce diffuse pollution sources in the affected water bodies. In the case of drinking water supply and for the removal of toxins and source cyanobacteria control, the treatment process needs an appropriate and strategic design. Finally, it is vital to inform the surface water users of the implications and health risks of using water with a clear and / or persistent presence of toxic cyanobacteria.

Key Words: Cyanobacteria, Cyanotoxin, Eutrophication, Blooms, Health Risk.