Plastic Predominance in Coastal Waste Streams: A Baseline Audit of a Secondary Urban Shoreline in the Philippines

Abstract

Marine litter, particularly plastics, has been recognized as a global threat to ecosystems, economies, and human well-being, with Sustainable Development Goal (SDG) 14 calling for urgent action to reduce marine pollution by 2025. The Philippines, as an archipelagic nation, is especially vulnerable to plastic leakage due to its high coastal population density and limited solid waste infrastructure. This study conducted a coastal waste audit along a one-kilometer secondary urban shoreline using the International Coastal Cleanup (ICC) protocol, the Ocean Trash Data Form, and the Clean Swell application. A total of 2,314 debris items were collected, with plastics accounting for over 80% of the total. The most common items were plastic bags, beverage bottles, food wrappers, and sachets, complemented by fishing gear, diapers, construction debris, and electronics. Waste density was calculated at 2,314 pieces per kilometer, placing the site among highly impacted Philippine coastlines. The presence of entangled wildlife further emphasized ecological risks. These findings are congruent with national and international literature, which similarly document the predominance of plastics in marine litter. They also highlight gaps in the enforcement of Republic Act 9003 and the Extended Producer Responsibility Act of 2022 and point to the need for local monitoring systems as emphasized in the National Climate Change Action Plan (2011–2028) and the Harmonized National Research and Development Agenda (2022–2028). The study concludes that plastic predominance in secondary urban coastlines demands integrated responses involving policy enforcement, infrastructure development, and community-based monitoring. Recommendations include institutionalizing regular coastal audits, enhancing local compliance with waste laws, and expanding school- and community-led monitoring programs. By establishing a baseline dataset, this study contributes to advancing national research priorities and accelerating progress toward the targets of SDG 14: Life Below Water.