Microplastic pollution in zooplankton communities from an active shallow water hydrothermal vent, West Pacific, Taiwan

Abstract

Microplastics (MPs) are pervasive pollutants in marine ecosystems; however, their bioaccumulation and potential ecological impacts on meso- and mero-zooplankton in hydrothermal vent systems remain poorly understood. This study investigates MP ingestion across multiple zooplankton taxa collected from a shallow-water hydrothermal vent near Kueishantao, Taiwan. Results indicate a significant level of MP contamination in the vent water (2.96 f 0.22 MPs/L) and widespread ingestion among resident mero-zooplankton, including fish larvae (0.92 f 0.17 items/individual), brachyuran larvae (0.44 f 0.15), shrimp larvae (0.56 f 0.21), salps (0.64 f 0.06), and chaetognaths (0.68 f 0.07). Mesozooplankton species such as Paracalanus sp. (0.60 f 0.25), Acrocalanus sp. (0.64 f 0.31), and Canthocalanus sp. (0.44 f 0.07) also exhibited notable MP ingestion. The dominant MP types were fibers, beads, fragments, and foams, primarily composed of polyethylene (PE), polystyrene (PS), polypropylene (PP), polyvinyl chloride (PVC), and carbon-based materials. Particle sizes ranged from 3.8 f 1.42 mu m to 205 f 58.03 mu m and were predominantly red, black, transparent, and white. Correlation and regression analyses revealed significant associations between MP ingestion and particle size, depth, and polymer type. These findings highlight the ecological vulnerability of vent-associated zooplankton to MP contamination and the potential for trophic transfer within shallow-water hydrothermal food webs, underscoring the urgent need for targeted mitigation strategies.