Effects of the chlorothalonil and Dichlofluanid biocides on microalgae Tetraselmis SP

• Grant number: 15/14140-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2016
• End date: November 30, 2017
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Denis Moledo de Souza Abessa
• Grantee: Giam Luca Altafim
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

In order to preserve the integrity of human structures installed in marine and coastal areas, as well as ship hulls, many substances have historically been used to prevent the biofouling process; these initially included, wax and tar, that were substituted by antifouling paints. Organotin coumpouonds (OC), began to be used as antifouling paints and achieved great efficacy, however the environmental costs and impacts of their use made them to be ultimately banned. New compounds substituted the OCs constituting the third generation of biocides, which require further studies on their fate and effect. Marine microalgae are among the organisms targeted of these biocides, representing thus an important object of study, since they are in the base of marine food web, and are responsible for the initial phases of the biofouling process. The objective of this work is to observe the effects of two new generation biocides on the microalgae Tetraselmis sp. To achieve that, chronic toxicity tests with clototalonil and dichlofluanid will be carried out using Tetraselmis sp, following protocols adopted worldwide. The density of microalgae the testing replicas will be daily monitored by direct cell counting (in Neubauer chambers), and the biomass will be estimated after measuring the contents of chlorophyll-a by the use of a fluorimeter. The results be statistically analyzed by analysis of variance (ANOVA) followed by the Dunnet's teste, in order to observe the significantly toxic concentrations.