Spatiotemporal distribution of seabed litter in the SE Levantine Basin during 2012-2021

Abstract

This study explores the first record of spatiotemporal distributions of macro and micro-litter on the seafloor in the Southeastern (SE) Levantine Basin (LB) during 2012-2021. Macro-litter was surveyed by bottom trawls in water depths of 20-1600 m and micro-litter by sediment box corer/grab at a depths range of 4-1950 m. Maximal macro-litter concentrations were recorded at the upper continental slope (200 m), averaging 4700 ± 3000 items/km². Plastic bags and packages were the most abundant items (77 ± 9 %) with a maximum of 89 % at 200 m depth, and their size decreased with increasing water depth. Micro-litter debris were found mainly in shelf sediments (≤30 m water depth) with an average concentration of 40 ± 50 items/kg, while shit particles transferred to the deep sea. These findings suggest an extensive distribution of plastic bags and packages in the SE LB, predominantly accumulating in the upper continental slope and deeper, based on their size.

Keywords: Marine litter; Plastic; Seabed; Sediment; The Levantine basin; The Mediterranean Sea; micro-litter.