A Decade of Microplastic Ingestion in Coral Fish: A Systematic Review of Trends in Asia

Microplastic (MP) pollution poses an escalating threat to marine ecosystems, yet its ingestion by coral reef-associated fish in Asia remains insufficiently studied. This systematic review synthesizes findings from 26 peer-reviewed studies published between 2015 and 2025, examining spatial trends, contamination patterns, and biological impacts of MPs in marine fish, with a specific focus on reef species. Results show a surge in publications since 2018, with research predominantly concentrated in Malaysia, Indonesia, and Thailand, while key biodiversity hotspots such as the Philippines and Pacific Islands remain underrepresented. Fibers emerged as the dominant MP type ingested, largely linked to fishing activities, textiles, and wastewater discharges. Although advanced polymer identification methods like FTIR and Raman spectroscopy are increasingly adopted, inconsistent methodologies hinder data comparability across studies. MP ingestion is associated with oxidative stress, tissue damage, altered behavior, and reduced growth in fish. However, data on reproductive or ecosystem-level effects remain scarce. Crucially, MPs may disrupt key mutualistic interactions between reef fish and corals, threatening reef resilience and local livelihoods. By highlighting critical gaps and regional disparities, this review provides a focused synthesis to guide future research and inform integrated management strategies to mitigate microplastic pollution in Asia’s coral reef ecosystems.