Overview

• Microplastics have been confirmed at all ocean depths, including the Mariana Trench, with concentrations reaching 13,500 particles per cubic meter in some areas.
• A decade-long study analyzed data from 1,885 sampling stations worldwide, creating the first global map of microplastic distribution by size and type across the water column.
• Smaller microplastics (1–100 µm) sink deeper and distribute evenly, while larger particles (100–5,000 µm) remain concentrated near the surface, especially in gyres.
• Microplastics contribute to oceanic carbon flux, making up 0.1% of carbon particles at 30 meters depth and increasing to 5% at 2,000 meters, altering natural carbon processes.
• Researchers identified over 56 plastic polymer types, highlighting uneven monitoring methods and calling for international collaboration to address the environmental and health impacts of persistent microplastic pollution.