Evaluation of protease activity in oysters exposed to Chlorothalonil

• Grant number: 17/07603-3
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): December 01, 2017
• Effective date (End): November 30, 2018
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Rodrigo Brasil Choueri
• Grantee: Giovanna Sayuri Azarias Utsumi
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

After banning the use of organotin compounds as an active principle in antifouling paints, Chlorothalonil, a widely used fungicide in the agricultural sector, started to be commercialized worldwide as part of antifouling systems in ship hulls. Due to its high partition coefficient octanol-water, in marine and estuarine aquatic environments, this biocide tends to associate with the sediment. Therefore, sediments can act as reservoirs of these chemical compounds functioning as secondary source of contamination for the infauna and/or benthic epifauna. Oysters are sessile and filter feeding organisms that can be found in direct contact with the sedimet and therefore have been widely used as bioindicators to monitor the environmental health of aquatic ecosystems. Environmental biomonitoring programs have used biological effects of these organisms as biomarkers. However, studies usually use the established biomarkers for the environmental risk assessment of Chlorothalonil, rather than developing specific biomarkers based on the mode of action of this biocide. The present study aims to verify the use of the activity of cysteine proteases (caspases and cathepsins) as a tool to assess the ecological risk of Chlorothalonil by exposing Crassostrea gigas oysters to fortified sediments in the laboratory. The results of this study will help to better understand the effects of Chlorothalonil on non-target marine organisms and may contribute to the ecological risk assessment of Chlorothalonil. (AU)