Quantity and spatial distribution of seafloor marine debris in the Moroccan Mediterranean Sea.

Abstract This paper qualifies, quantifies and localizes seafloor marine debris (SMD) in the Moroccan portion of the Mediterranean Sea. Six scientific trawl surveys were conducted by the Moroccan Institute of Fisheries Research from 2012 to 2015 between Cape Spartel (5°W) and Saidia (2°W), during which a total of 497 kg of SMD has been collected. Statistical analysis show that the mean abundance differed between surveys, generally ranging from 26 ± 68 to 80 ± 133 kg/km². A typology of SMD indicates that plastic represented 73% of the debris collected, followed by rubber (12%), textile (8%), metal (3%), glass (0.32%), and some unidentified materials (2.70%). Analysis of results shows that the abundance and the distribution of SMD were strongly influenced by the local anthropogenic activities and by rivers inputs. The movements and accumulations in the open sea were also shown to be influenced by the geomorphology and the hydrodynamics of the basin. Highlights • Six trawl surveys of seafloor marine debris (SMD) in the Moroccan Mediterranean Sea of Morocco from 2012 to 2015 • A total of 497 kg of SMD was collected, the majority of them are made of plastic. • The mean abundance ofăSMD during these surveys was ranging from 26 ± 68 to 80 ± 133 kg/km². • The hydrographic network plays a major role in the transportation of debris from land to the open sea. • The geomorphology and the hydrodynamics properties of the basin influence the distribution of SMD in the Moroccan Mediterranean Sea. [ABSTRACT FROM AUTHOR]