Limnological and ecotoxicological aspects of water samples from the reservoir Itupararanga (Ibiuna-SP): emphasis on cyanotoxins potential

• Grant number: 13/18564-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2013
• End date: October 31, 2014
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Renata Fracácio Francisco
• Grantee: Rachel Garofalo de Oliveira Pedroso
• Host Institution: Universidade Estadual Paulista (UNESP). Campus Experimental de Sorocaba. Sorocaba , SP, Brazil

Abstract

The reservoir Itupararanga is inserted into an area of around multiple uses, especially human activities related to agricultural cultivation, urban expansion areas and areas of environmental protection. Among the waste generated by the occupations described above, we highlight the possible pesticides used to combat pests of crops, fertilizers and sewage dumps. Through the sources of point and diffuse pollution, the waste reaches water bodies and can interact with the biota, undergo changes in the water or sediment, and again come in contact with biological systems. In these processes, the contact of pollutants with the biota may trigger injuries, characterizing system toxicity. In this sense, there is the problem of eutrophication, which occurs by excess nutrients in water bodies independent sources of contribution, resulting in algal blooms. Among them, the group of cyanobacteria can produce toxins with active ingredients that according to literature are associated with serious poisoning in aquatic environments highlighting the mortality of fish and other organisms. Considering that the reservoir Itupararanga falls as water body class 2, according to CONAMA Resolution 357/05, which, among other uses provides for the protection of aquatic biota and highlighting the fact that the literature indicate the presence of blooms of cyanobacteria and signs of toxicity in water samples, the aim of this work is to perform ecotoxicological tests with raw water samples and maintain cultures of cyanobacteria collected in the environment and work with the toxicity of lyophilized samples, to determine whether the toxicity of the system is correlated with the potentially toxic cyanobacteria. The test organisms are the microcrustacean Ceriodaphnia dubia (microcrustacean) and seaweed Pseudokirshneriella subcapitata.