Underway water system of research vessels: Optimization of a method for microplastic sampling in oceanic waters.

Abstract

Broad scale monitoring efforts and microplastic sampling in open ocean waters are required to understand distribution, abundance and fate of these particles in the environment. For surface seawaters, towing a neuston net is the most common sampling method; however, the deployment of this infrastructure is not always an opportunity when at sea, and the underway water system of research vessels (RVs) has been tried for this purpose in several studies to date. Method validation and recovery checks have not been thoroughly applied, which may be resulting in wrong estimations. In this study, we investigated abundance, distribution and type of small microplastics (0,05-1 mm) sampled from subsurface waters using the underway system of RV Ángeles Alvariño and RV Sarmiento de Gamboa in NE Atlantic. Method validation was performed in order to compare the effectiveness for microplastic research comparing the samples taken through the intake system and samples filtered from the Rosetta. Sampling methods standardization and validation are essential to ensure the intercomparability of the data reported in the different sampling efforts worldwide concerning distribution and abundance of microplastics in marine open waters environments.