Unraveling Macroplastic Pollution in Rural and Urban Beaches in Sarangani Bay Protected Seascape, Mindanao, Philippines

Abstract

Plastic pollution in the ocean is an emerging environmental concern in the Philippines. This study was conducted to investigate the prevalence of macroplastics, composition of plastic litter, and the clean-coast index (CCI) of urban and rural beaches in Sarangani Bay. Plastic litter was collected by delineating a 100-m transecting line with three 4 m × 4 m quadrats. The density of macroplastic litter in urban areas (0.66 items m−2) was significantly higher than in rural areas (0.29 items m−2). The plastics sampled were predominantly food packaging, such as polyethylene bags, which are locally known as sando bags. The accumulation rate of macroplastic litter ranged from 0.07 items d−1 m−2 to 0.40 items d−1 m−2, in which urban beaches (0.25 items d−1 m−2) have a significantly higher accumulation rate than rural beaches (0.11 items d−1 m−2). Overall, the calculated CCI of the beaches of Sarangani Bay was categorized as clean to moderately clean for rural beaches and moderately clean to extremely dirty for urban beaches.