Overview of monitoring methods and environmental distribution: Microplastics in the Indian Ocean

Microplastics are ubiquitous globally, posing a significant threat to human health. Notably, the Indian Ocean ranks second in microplastic contamination, emerging as a major source of pollution. In response to this risk, neighboring countries are actively addressing severe plastic pollution and deficiencies in waste management. Research on microplastics in Indian Ocean seawater commenced in 2016. This paper reviews the research status and trends, detailing sampling, extraction, and identification methods. We categorize 43 studies by trawl sampling and other techniques, summarizing microplastic abundance, size, shape, color, and polymer types. Microplastic distribution varies widely in the Indian Ocean, peaking in the East, West, and along the Indian coast. Fiber and debris microplastics are the most, the main colors are black, blue, white and transparent, and the polymer types are mainly PE, PP and PS. Oceanic convergence intensity affects microplastic distribution globally, intensifying accumulation. This study highlights the need for standardized microplastic sampling and analysis in Indian Ocean countries. Collaborative surveys and investigations are crucial to addressing pollution.