Patterns of plastic occurrence during the pre- and post-Super Typhoon Rai (Odette) event in Olango Island Wildlife...

Plastic waste is a growing global concern, with extreme weather events such as typhoons potentially exacerbating its transport to marine environments. The Philippines, experiencing an average of 20 typhoons annually, provides a critical case study. Olango Island Wildlife Sanctuary (OIWS), a Ramsar site in Cebu, Philippines, was impacted by Super Typhoon Rai in 2021. Field sampling across five mangrove transects and satellite imagery (DeMPS) for four different periods showed an increase in macroplastics after the typhoon. Mean plastic loads over four sampling periods were 0.43 ± 0.88, 0.69 ± 1.51, 0.87 ± 1.80, and 0.36 ± 0.32 items/m² (9.39 ± 21.37, 8.6 ± 21.31, 8.23 ± 20.36, 7.98 ± 5.48 g/m²), while mean plastic sizes ranged 38.93 ± 139.88 to 477.88 ± 1234.22 cm²/m². The spatial distribution shifted from landward dominance pre-typhoon to seaward dominance post-typhoon, reverting in pattern after two years. Results reveal that extreme weather events can increase plastic transport from land to sea; however, mangroves can trap these plastics, delaying their release into the ocean. Thus, while plastics are trapped in mangroves after a typhoon, they can be recovered, preventing irreversible input into the marine ecosystem.