Plastic ingestion by marine biota in five Southeast Asian Nations: Complex challenges and long-term implications

Plastic pollution has drastically increased in the world's oceans, with significant contributions from Southeast Asian countries like Indonesia, Malaysia, Thailand, the Philippines, and Vietnam, which collectively account for a substantial portion of global plastic debris due to inadequate waste management. Despite the severe ecological and health impacts of plastic ingestion on marine species, there is a lack of comprehensive studies addressing both the affected species and the methodologies used to assess plastic ingestion. The study aims to comprehensively review existing literature on plastic ingestion by marine biota in Southeast Asia, identifying gaps in knowledge about affected species and assessing the various techniques and tools used to investigate this issue. Reviewing 35 articles, this study identifies that research on plastic ingestion by marine species in Southeast Asia predominantly focuses on Teleostei (40%) while overlooking significant gaps in studies on seabirds, sea snakes, and commercially important fish species. Necropsy is the most effective technique for evaluating plastic ingestion in larger marine species, providing detailed post-mortem insights, while laboratory inspection is ideal for studying smaller organisms like bivalves and copepods. FTIR and μ-Raman spectroscopy are the best tools for confirming plastic ingestion, with FTIR excelling in bulk analysis and polymer identification, and μ-Raman offering high spatial resolution for particle-level molecular identification.