State of the Art Offshore In Situ Monitoring of Microplastic

Microplastics make up a significant amount of the overall quantity of plastic debris that is present in seawater. However, their detection and monitoring at sea is cost-inefficient and challenging; typically, it consists of water sampling with special manta nets, followed by long (i.e., weeks) laboratory analysis to obtain valid results. The analysis of the state-of-the-art technologies capable of monitoring/detecting microplastics in the sea (typically in coastal areas) presented in this paper shows that there are currently no specific tools to obtain quick measurements. The classic multiparametric probes are useless and the contribution of their relative chemical–physical parameters to determine the presence of microplastics in water is insignificant. The evolution in the last decade of hardware and software tools for capturing hologram images and related post-processing seems to be one of the most effective methods available currently for the rapid detection of microplastics in seawater. In particular, some results of monitoring campaigns carried out in the Adriatic Sea using this type of technology are reported. The acquired data are analyzed and discussed, highlighting their strengths and weaknesses, with indications of the possible methodologies that could be used to improve these systems.