Presence, Spatial Distribution, and Characteristics of Microplastics in Beach Sediments Along the Northwestern Moroccan Mediterranean Coast

Abstract

Microplastics (MPs) (<5 mm) are recognized as an emerging global problem in all oceans and coastlines around the world. This paper provided the quantification and characteristics of microplastics found on fourteen beaches along the northwestern Moroccan Mediterranean coast. A total of 42 samples were gathered at a depth of 5 cm along the shoreline using a quadrant of 1 m × 1 m. Microplastics were detected in all sediment samples. The average abundance was 59.33 ± 34.38 MPs kg−1 of dry weight (median: 48.33 MPs kg−1 ), ranging from 22 ± 7.21 to 135.33 ± 38.80 MPs kg−1 . Statistical analyses revealed significant differences between sampling sites. All observed microplastics were classified according to their shape, color, and size. The microplastic shapes comprised fibrous MPs (77.61%), fragments (15.65%), films (4.49%), foams (1.85%), and pellets (0.40%). Microplastic particles in the sediment samples ranged from 0.063 to 5 mm in length and were composed of small (54.3%, <1 mm) and large sizes (45.7%, 1–5 mm). The size fractions with the greatest percentage of MPs were 1–2 mm (24.9%). The dominant color of the microplastics was transparent (43.2%), followed by black (15.8%) and blue (13.3%), with shapes that were mainly angular and irregular. The present results indicate a moderate level of microplastic contamination on the beaches throughout the northern Moroccan Mediterranean coast, and tourism, fishing activities, and wastewater discharges as the most relevant sources.