Microplastic evaluation in the gill plates of the bentfin devilray, Mobula thurstoni (Lloyd, 1908), from western South Atlantic (Chondrichthyes, Mobulidae)

• Grant number: 24/14648-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Biological Sciences - Zoology - Applied Zoology
• Principal Investigator: Otto Bismarck Fazzano Gadig
• Grantee: Lia Ferreira Moura
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Microplastics (MPs; <5 mm) are currently recognized as emerging pollutants of great global concern. They are considered ubiquitous in different environmental matrices, presenting a major impact and risk to the health of aquatic biota, including filter-feeding megafauna, whose eating habits lead to the retention of plastic particles. The present work will seek to identify and classify MPs in gill plates (GPs) of the manta ray, Mobula thurstoni (Lloyd, 1908), from the west coast of the Atlantic Ocean. To achieve this purpose, the MPs present in GPs will be classified according to their shape, color, size and chemical structure, as well as estimating the average number of plastic per individual and comparing the abundance between the different gill plates. For this, 5 specimens accidentally captured by the artisanal fishing fleet in the coastal area of the central coast of São Paulo will be used. All GPs on the left side will be extracted, subjected to chemical digestion, using Hydrogen Peroxide (H2O2) reagent at 45°C, for 24 to 72 hours, the remaining content will be filtered through a 100 µm filter and the retained particles will be highlighted for analysis. following. Subsequently, the particles will be analyzed using Raman spectroscopy to verify the polymeric composition and the resulting spectra will be compared to specific literature. To compare the abundance of these particles along the GPs, a Generalized Linear Mixed Model (GLMM) will be used. In order to test whether this particle composition varies significantly between PBs, a Multivariate Permutational Analysis of Variance (PERMANOVA) will be adopted, followed by a Multivariate Dispersion Analysis (PERMDISP). To visualize the similarity of particle composition between the plates, Non-Metric Multidimensional Scalings (nMDS) will be performed.