Assessment of Quantity and Quality of Microplastics in the Sediments, Waters, Oysters, and Selected Fish Species in Key Sites Along the Bombong Estuary and the Coastal Waters of Ticalan in San Juan, Batangas

• Main Authors: Espiritu, Emilyn Q, Dayrit, Sophia Angeli SN, Coronel, Annabel Soledad O, Paz, Natasha Sophia C, Ronquillo, Pilar Isabel L, Castillo, Virgil Christian G, Enriquez, Erwin P
• Format: text
• Published: Archīum Ateneo 2019
• Subjects: fishes; FTIR; microplastics; oysters; sediments; water; Biochemistry; Chemistry; Terrestrial and Aquatic Ecology
• Online Access: https://archium.ateneo.edu/chemistry-faculty-pubs/1; https://archium.ateneo.edu/cgi/viewcontent.cgi?article=1000&context=chemistry-faculty-pubs
• Institution: Ateneo De Manila University

Microplastics (or MPs; < 5 mm in size) pollution is largely unstudied in the Philippines. From an environmental sustainability standpoint, it is important to understand the characteristics, abundance, and environmental fate of plastic debris of various sizes, and these include microplastics that are not more easily and readily detected. In this study, we assessed the extent of microplastics contamination in the sediments, waters, oysters, and selected fishes found in the rivers and coastal areas of Ticalan, Batangas, which were identified from water quality parameters as Class C and CS, respectively. The microplastics were extracted from these samples by chemical digestion of the matrix, series of filtration, and separation by flotation through a density gradient to finally isolate the microplastics which were not dissolved by chemical digestion. The isolated samples were imaged by optical microscopy and characterized based on their descriptive attributes. The results showed the presence of microplastics in all the samples tested, which were found mostly in the form of filaments, fragments, films, and pellets – with most showing weathered, degraded, or angular and irregular surfaces. Identification was done through spectral matching of the Fourier transform infrared spectra of isolated fragments with that of known plastics, although identification in some cases is made uncertain by possibility of degradation of the plastics in the environment. The majority of the isolates showed signature absorption bands of the C-H stretching vibrations of polyethylene-based plastics.