Identification and quantification of microplastics in surface water of a southwestern Mediterranean Bay (Al Hoceima, Morocco)

Abstract

In this study, we evaluated the pollution in Al Hoceima Bay (Southwestern Mediterranean, Morocco) by microplastics. Nine stations were investigated in 2019, 2020, and 2021, using the Manta net and the microplastics were identified and quantified with Raman Spectroscopy. The obtained results showed that fibers, fragments, pellets, and films were the predominant types of microplastics. The dominant size of microplastics ranged from 0.15 to5 mm while 0.3–0.5 mm was the most prevalent with 46.97 %. Seven colours counting white and blue as dominant items were recorded. The abundance of microplastics was 1–15 items/m3, with an average of 4.70 ± 4.50 items/m3. Four polymers dominated by Polyethylene (67.4 %), Polypropylene (23.2 %), Polystyrene (7.1 %), and Polyethylene Terephthalates (2.3 %) were identified. The spatial distribution of microplastics was variable. The abundance of microplastics was not related to the distance separating potential sources from the sampled stations. Our study provided the initial data on microplastics and their distribution along the Mediterranean coasts of Morocco, recommended for future investigations of marine pollution in the Mediterranean basin.

Keywords

• Microplastic pollution
• Water column
• Al Hoceima bay
• Mediterranean assessment
• Abundance