Microplastic contamination and growth pattern of oyster; Crassostrea gigas in a coastline

Oysters (Crassostrea gigas) are one food source commonly consumed by the community and an important commodity with high economic value. Environmental issues, such as microplastics, have become a worldwide concern for its implications for aquatic organisms, especially oysters. This study aims to identify the microplastics and growth patterns of oysters in Aceh Province, Indonesia's north and east coasts. This study aims to determine which oysters are suitable for consumption and food health based on research locations along the east-north coast of Aceh Province. The locations in this study include nine regencies/cities, which are directly facing the Malacca Straits. Microplastic isolation from oysters using 10 percent potassium hydroxide and incubation process were done to dissolve the organic materials. The growth pattern was analyzed to determine the growth rate of oysters at each study location. The results of this study showed that oysters in all sampling locations were contaminated with microplastics, with a high prevalence of 48 percent found in Langsa, followed by Aceh Timur and Pidie each (40 percent), Banda Aceh (38 percent), Aceh Utara (32 percent), Aceh Besar and Bireun (30 percent), Lhokseumawe (12 percent), and Aceh Tamiang (8 percent). The analysis of the growth patterns revealed that the growth of oysters at each location was not optimal (b <3 or negative allometric). In 500 oyster samples collected, 139 were contaminated with microplastics. The most dominant type of microplastic contaminating oysters is fiber up to 170 particles, followed by films 28 particles, and fragments 19 particles. Negative allometric growth pattern might correlate with microplastics that contaminate the waters and enter the oyster's digestive organs. The results of this study reveal that oysters consumed by people have been contaminated with microplastics, so stakeholders must carry out socialization for early prevention to be realized.