Microplastic pollution on seagrass blades in two coastal bays in Northern Mindanao, Philippines

Seagrass, a key component of marine environments, can also act as a conduit for microplastics (< 5mm) into the food web. In this pioneering study, we investigated the occurrence of microplastics on seagrass blades in the Philippines for the first time. Our research focused on Thalassia hemprichii and Cymodocea rotundata in Buru-un, Iligan City; and Enhalus acoroides and Halodule uninervis in Tubajon, Laguindingan. Using Fourier transform infrared spectroscopy (FTIR) analysis, we identified 53 particles as microplastics. Microplastic density ranged from 0.054 ±0.061n/cm2 to 0.255 ±0.306n/cm2, with C. rotundata exhibiting the highest density. Poly(methyl methacrylate) particles were the most prevalent in all four seagrass species. This study presents the first scientific literature on microplastics found on seagrass blades in the Philippines. It underscores the necessity for immediate and ongoing microplastic monitoring in biota and other seagrass components to trace microplastic pathways in the marine food web, highlighting the urgent need to address this issue.