Spatial and Temporal Distribution of Chemically Characterized Microplastics within the Protected Area of Pelagos Sanctuary (NW Mediterranean Sea): Focus on Natural and Urban Beaches

Silvia Merlino,Marina Locritani,Gabriele Bernardi,Marinella Abbate,Stefano Legnaioli,Carlotta Como,Vincenzo Palleschi

doi:10.3390/w12123389

Abstract

Data on the abundance and distribution of Anthropogenic Marine Debris (AMD) on the coastal areas of the northern Tyrrhenian coast are still scarce. The objective of this study is to characterize, in terms of size, color, morphology and polymeric nature, the Large Microplastics (LMPs), i.e., plastic objects within 1 and 5 mm, sampled on three beaches located within the coastal macro-area of the Pelagos Sanctuary, an international protected zone in the north-western Mediterranean. The beaches have similar morphological characteristics but different degrees of urbanization. LMPs were sampled seasonally for one year. The polymeric nature of a representative subsample of the collected LMPs was investigated using a portable Raman instrument, to assess the feasibility of in situ characterization. In this study, 26,486 items were sorted by typology (Expanded Polystyrene-EPS, fragments, and resin pellets), size, and for fragments and resin pellets, also by color and chemical nature. Statistical data on the quantity, density, type, spatial distribution, and seasonality of the sampled LMPs are presented. Differences in LMP abundance and composition were detected among sites. A seasonality trend emerges from our statistical analysis, depending on both LMP typology and urbanization degrees of the beaches. Our data do not show the existence of a relationship between the size of the investigated MPs and their color, while they suggest that the type of polymer influences the degree of fragmentation. This underlines the need to further investigate the mechanisms leading to the production and dispersion of MPs in coastal areas, taking into account both the urbanization of the beach, and therefore the possible sources of input, and the different types of MPs. Finally, a Raman portable instrument proved to be a valuable aid in performing in situ polymeric characterization of LMPs.

Highlights

Among the emerging problems affecting coastal areas, the accumulation of Anthropogenic Marine Debris (AMDs), called Marine Litter (ML), has received increasing attention in recent decades [1]
Polystyrene (PS)and andother other polymers, as Ethylene-vinyl acetate averaging the data of the two seasons, we found that EPS was the most abundant morphological and
One of the aims of this work was to overcome the lack of data concerning MPs on beaches in this part of the North-West Mediterranean Area, evaluating abundances, spatial and temporal distribution and characterization of Large Microplastics (LMPs) sampled in three sites of North Tyrrhenian coast, located inside in the very sensitive area of the Pelagos Sanctuary

Summary

Introduction

Among the emerging problems affecting coastal areas (erosion, loss of biodiversity, etc.), the accumulation of Anthropogenic Marine Debris (AMDs), called Marine Litter (ML), has received increasing attention in recent decades [1]. Studies have focused in particular on ML accumulation in the open sea [2,3,4], and in coastal areas [5,6], and in deep water sediment [7,8,9], in polar areas [10,11], and in freshwater systems [12,13,14,15]. Most of these works confirm that the percentage of “plastics”. Particles larger than 5 mm but smaller than 2.5 cm are defined

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Discussion

Conclusion