Extraction efficiency of different microplastic polymers from deep-sea sediments and their quantitative relevance

Abstract

An increasing number of methods for extracting microplastic particles from marine sediments have been published but without evaluating the extraction efficiency. Furthermore, while most of the procedures developed have been applied to sandy sediments from shallow water habitats, specific and standardized procedures for deep-water sediments (> 200 meters deep) are limited. In this study, we describe a specific protocol for extracting microplastics (2- 1000 µm) from deep-sea sediments and for quantifying and identifying them. We also assessed its extraction efficiency, which resulted in a high recovery (on average ca. 60%, and up to 80%) particularly, for polyethylene, polypropylene, and polystyrene. This method can be applied to all fine-grained/muddy sediments and allows the extraction of even the smallest fraction of microplastics (<20 µm), which are expected to have the most severe effects on marine biodiversity and ecosystem functioning and ultimately also have implications for human health.

Deep Sea Microplastic Pollution Extends Out to Sediments in the Northeast Atlantic Ocean Margins

“…The low abundance of MPs recorded at the majority of sites would indicate that none of these are accumulation areas and may reflect recent deposition, may be indicative of underwater activity in the area, and their distance to terrestrial sources. Canensi et al 46 and Villanova-Solano et al 51 similarly found no relationship between water depth and the density of MPs.…”

“…45 Caution needs to be taken when making inferences where MP results have low abundances and/or no replicates. Furthermore, Canensi et al 46 found that partitioning sediments of 250−50 g aliquots favors the extraction in the size range of 2−1000 μm with extraction efficiency changing depending on polymer type.…”