Floating Marine Litter in Eastern Mediterranean From Macro to Microplastics: The Lebanese Coastal Area as a Case Study

Abstract

Despite emerging and increasing concerns related to marine micro and macroplastics, no systematic surveys have been undertaken yet in the Lebanese marine area. To understand the spatio-temporal variation of plastic litter (macro and microplastics) in the Lebanese marine environment and to determine the sources of pollution, this study investigated the characteristics of plastic pollution in sea surface waters during wet and dry seasons in 22 sites of Beirut and Tyre regions. A total of 23,023 items were identified and assessed according to the shape, color, and concentration; moreover, the risk of microplastics (MPs) contamination was explored based on a risk assessment model. The obtained results demonstrated that the average macroplastics concentration was 0.45 ± 0.6 items/m3. The average microplastics concentration was found to be 20.1 ± 21.8 and 3.78 ± 5.2 items/m3 in spring and fall respectively. During fall, MPs fragments were dominant in Beirut (97%) and Tyre (91%), and no pellets were observed. During spring, filaments were most encountered in Beirut (76.5%). The most dominant marine litter color was blue followed by black and white. The Pollution Load Index (PLI) values showed a moderate contamination of the Lebanese coast with MPs (PLI: 5.79 ± 3.93) except for several sites in Beirut that showed high values of PLI, highlighting the local influence of cities and rivers on MPs concentration. This study serves as an important baseline for understanding the characteristics of the seasonal variation of MPs along the Lebanese marine environment; it will help stakeholders and countries to take proactive and reactive actions to face plastic litter pollution in the Lebanese coastal area.

Occurrence and risks of microplastics in the ecosystems of the Middle East and North Africa (MENA)

“…Kazour et al ( 2019 ) reported an average concentration of 4.3 ± 2.2 MPs/m 3 across the Lebanese coast. In a more recent study, the concentration nearly tripled to 12.13 MPs/m 3 (Jemaa et al 2021 ). The results of these studies are comparable to a study done in Iskenderun Bay, Turkey, where the recorded concentration was 7.26 MPs/m 3 (Gündoğdu 2017 ).…”

“…Moreover, the results are influenced by the meteorological, hydrodynamic, and climatological conditions dominating during sampling. For instance, Jemaa et al ( 2021 ) noticed a drop in MP concentration from 20.1 ± 21.8 MPs/m 3 in the spring season to 3.78 ± 5.2 MPs/m 3 in the fall season. This can be explained by the elevated surface runoff amounts due to rainfall events in the winter which increase the plastic load transported from land to the oceans (Jemaa et al 2021 ; Setiti et al 2021 ).…”

“…For instance, Jemaa et al ( 2021 ) noticed a drop in MP concentration from 20.1 ± 21.8 MPs/m 3 in the spring season to 3.78 ± 5.2 MPs/m 3 in the fall season. This can be explained by the elevated surface runoff amounts due to rainfall events in the winter which increase the plastic load transported from land to the oceans (Jemaa et al 2021 ; Setiti et al 2021 ). However, this scenario was not observed in the Israeli coastal waters where the MP concentration was higher during the dry season (van der Hal et al 2017 ).…”

“…While the authors did not provide an explanation, one reason could be that the samples were taken from hotspots where the lower water levels during the dry season concentrate MPs that would otherwise be more dispersed in the water column (Malli et al 2022 ). Also, the water currents in the Eastern Mediterranean basin act as attractors that accumulate MPs in the Lebanese and Israeli coastal waters (Jemaa et al 2021 ; Kazour et al 2019 ; van der Hal et al 2017 ). Finally, it is worth mentioning that the concentration reported by Kazour et al ( 2019 ) is high due to the usage of a 52-μm Manta trawl net.…”

“…Such studies would assist and push for legislating environmental policies regulating the emissions of plastics and MPs to the environment. Several metrics are currently used to assess the risk of MPs such as the pollution load index (PLI) based on the abundance of MPs in a defined zone and the hazard index (HI) based on the chemical composition of MPs (Ding et al 2022 ; Jemaa et al 2021 ; Picó et al 2021 ). However, these indices suffer from some pitfalls.…”