Accumulation and re-distribution of microplastics via aquatic plants and macroalgae - A review of field studies

The aquatic plants and macroalgae are primary producers with major roles regarding the maintenance of ecosystems but their interaction with microplastics (MPs) has received less attention than animals. We summarize the methodologies used, the MPs abundances and their characteristics across the literature on MPs pollution in aquatic plants and macroalgae. The sampling and quantification of MPs still lacks consistency between studies, which increased the uncertainty in cross-comparisons. The abundance of MPs varied by orders of magnitude between species and were mostly fibers and polymers with large degrees of production and applications. Filamentous species contained more MPs than others. The average ratio of MPs between vegetated and unvegetated sites reached 3:1. The average ratio of MPs between the biotic and abiotic fractions reached 2193:1, suggesting a high level of retention in fields. Our findings supported that aquatic plants and macroalgae are critical in the plastic flux within the marine environments.

Automated summary

The interaction between aquatic plants and macroalgae with microplastics has been given less attention compared to animals, despite their major roles as primary producers in ecosystems. We reviewed the literature on microplastics pollution in aquatic plants and macroalgae, summarizing the methodologies used and the abundances and characteristics of microplastics. The sampling and quantification of microplastics varied greatly between studies, leading to uncertainty in cross-comparisons. Our findings showed that different species had varying abundances of microplastics, with filamentous species containing more microplastics. The presence of vegetation increased the ratio of microplastics compared to unvegetated sites, and there was a high level of retention in the biotic fraction compared to the abiotic fraction.