Occurrence of microplastics carried on Ulva prolifera from the Yellow Sea, China

Abstract As a new type of pollutant, microplastics have attracted widespread attention in recent years. Studies have shown that microplastics can affect the growth of microalgae, but little study has been done on macroalgae. In this paper, the enrichment and the characteristics of microplastics on Ulva prolifera, a green tide species, from the Yellow Sea of China were studied. Our results showed that U. prolifera enriched microplastic with an average abundance of 4603.3 ± 1167.2 items kg-1 d.w., which was more than 10,000 times of the microplastics in the ambient water (448.9 ± 145.68 items m-3). U. prolifera showed different enrichment capacity for microplastics with different shapes, with foam and film being the dominant shapes. The microplastic trapped by U. prolifera were usually in the size range of 2-5 mm and the main polymer types were polystyrenepe (PS) and polyethylene terephthalate (PET). The adsorption mechanism of microplastics on U. prolifera showed that its binding to microplastics was mainly through physical interaction. By salvaging U. prolifera at an amount of roughly 239,000 tons/year, a large amount of microplastics (approximately 35.6 tons/year.) can be removed from the Yellow Sea, which obviously plays a role in reducing the pollution of microplastics in the marine environment.