Bivalve molluscs as contemporary and historical sentinels of microplastic contamination

• Grant number: 22/08669-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date until: December 01, 2022
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Ítalo Braga de Castro
• Grantee: Victor Vasques Ribeiro
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated scholarship(s): 24/07277-2 - Accumulation and dynamics of Microplastics in bivalves: a bi-national assessment, BE.EP.DR

Abstract

Microplastics (MPs <5 mm) are ubiquitous in natural environments, being bioavailable to a core set of aquatic organisms, mainly filter-feeding bivalve molluscs. In addition to being appreciated in cooking, widely distributed and important in the assessment of environmental quality, these organisms have been used as sentinels of MPs contamination. Studies carried out by our research group showed that the highest concentrations of MPs reported for oysters and mussels around the world were found in the Santos Estuarine System. Despite this, the Brazilian coast is scarcely studied regarding the spatial distribution and the historical trends of this type of contamination. Furthermore, little is known about the accumulation and depuration rates of MPs in bivalve species inhabiting our coast. Considering these knowledge gaps, the present proposal aims to evaluate the dynamics of MPs accumulation in oysters (Crassostrea brasiliana) and mussels (Perna perna) using an experimental approach of transplanting organisms between sites under different levels of anthropogenic pressure. This approach will be used to validate and compare the use of such species as sentinels of contamination, allowing their simultaneous application in a monitoring of densely urbanized estuaries along the Brazilian coast. Additionally, historical trends and the temporal relationship with potential sources of MPs contamination will be evaluated based on the comparison of past organisms (deposited in zoological collections) with samples obtained contemporaneously. By carrying out this proposal, it is expected to verify whether the species studied reflect the environmental conditions of exposure as a function of concentrations and exposure time, enabling their use also as active assessment tools. Furthermore, the project will provide a diagnosis of contamination levels in six estuarine systems under the high anthropogenic pressures in Brazil, identifying hotspots and sources of contamination. Finally, the project will perform a temporal analysis of MPs contamination in bivalves, demonstrating how these impacts have evolved over the years on the Brazilian shores, potentially indicating the main contributing sources. Therefore, the information generated will enable the elaboration of measures seeking to contain and mitigate contamination by MPs on the Brazilian coast, improving national plans for the management of this type of waste. The execution of the proposal will also contribute to the training of personnel with a high level of qualification.