The Mediterranean Sea is the largest semi-enclosed sea and one of the worst affected regional seas with sub-basin scale heterogeneity in plastics concentration. Few studies on microplastics (MPs) ...pollution have been conducted in the Eastern part of the Mediterranean basin. This study aims to evaluate, for the first time, the MPs pollution of the Lebanese coast (Levantine Basin) as well as the most common polymers found, and to assess the potential role of coastal landfills in this pollution. Two important seafood species that are wholly consumed by the Lebanese community: the European anchovy, Engraulis encrasicolus, and the spiny oysters, Spondylus spinosus, were sampled in three different sites englobing the littoral (Tripoli, Beirut and Sidon). Sea water and sediment samples were also collected from the same sites. Results showed different patterns of MPs concentration in the analyzed matrices: Sidon water sample was highly contaminated in MPs (6.7 MPs/m3) while Tripoli had the highest MPs in sediments (4.68 MPs/g). The occurrence of MPs in the biota was high (83.4% and 86.3% in anchovies and spiny oysters, respectively). Both anchovies and oysters from Beirut region had the highest ingested MPs/individual (2.9 ± 1.9 and 8.3 ± 4.4 MPs/individual, respectively). This study is the first that investigated microplastics ingestion by Spondylus spinosus while indicating the most common polymers found in the three matrices (water, sediments and biota) in the Eastern Mediterranean. These results highlighted the high MPs pollution found in the Levantine Basin in comparison to other Western Mediterranean regions. In addition, the obtained results indicate a potential contribution of coastal landfills to this pollution.
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•First microplastics evaluation of the Lebanese coast in three different matrices•First evaluation of microplastics ingestion by Spondylus spinosus in the world•Lebanese waters, sediments and biota are highly contaminated in microplastics.•First polymer analysis in the Levantine Basin: dominance of PS, PP and PE•Coastal landfills may contribute in an important microplastics entry into the sea.
Levels of 20 trace elements (Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Sb, Ba, Hg, Pb, and U) were assessed in livers and muscles of two demersal fish species (
Siganus rivulatus
and
...Lithognathus mormyrus
) and one pelagic species (
Etrumeus teres)
from the Lebanese coast located in the Eastern Mediterranean. The samples were collected from three sites along the Lebanese coast during the wet and dry seasons in 2017. The trace elements were more concentrated in livers than in muscles and interspecific differences were also found. The herbivorous species
S. rivulatus
showed the highest levels for most trace elements, while the carnivorous species
L. mormyrus
showed the least contamination. Elemental seasonal differences were species dependent and were observed for Ti, Cr, Mn, Fe, Ni, As, and Hg, with higher values during the wet season. Multivariate analysis showed spatial differences mainly during the wet season, while being closely related to species that reflected different accumulation patterns in each site. Levels of most trace metals in livers were higher than those reported in other Mediterranean regions (up to 2 to 3 folds). Nevertheless, the levels of Cd, Pb, and Hg in fish muscle were below the maximum levels set by the European Commission indicating that the consumption of these fish species is not likely to have adverse effect on human health. However, exposure depends on dietary habits of the population and a continuous exposure to these elements may result in adverse effects.
The European sardine, Sardina pilchardus, exhibits a complex population structure, which has produced conflicting results in previous genetic studies. Despite its importance in the fisheries ...industry, stock delineation for management and conservation purposes is still a matter of debate throughout the distribution range of the species. This study examines whether otolith shapes are more efficient than genetic markers to detect population structure in pelagic species with large population sizes. Sardines were analyzed from 15 sampling localities in the Northeast Atlantic and Mediterranean Sea covering almost the whole distribution range of the species. A combination of otolith shape indices and elliptic Fourier descriptors was investigated by multivariate statistical procedures. Within the studied area, three distinct groups were identified with an overall correct classification of 77%. Group A: northern Mediterranean Sea and Gulf of Gabès; group B: Atlantic Morocco–south Alboran–Algero-provençal coasts; and group C: European Atlantic coast. The Almeria–Oran front and the Gibraltar strait are not an efficient barrier for sardine population separation as there seems to be exchanges between populations of the south-western Mediterranean Sea and those of the Moroccan Atlantic Ocean coast or Gulf of Cadiz. The results are discussed in relation to environmental conditions, oceanographic features, and physical barriers to dispersal in the study area, and compared with those obtained by previous genetic, morphometric, and meristic data. For pelagic species with high gene flow, present results highlighted the need to take into account the identification of phenotypic stocks to ensure sustainable fishery benefits and efficient conservation as they may have unique demographic properties and responses to exploitation.
•We analyzed the population structure of European sardine across its distribution range.•Otolith shape showed significant variation among locations.•Three distinct groups were discerned.•Oceanographic features are not an efficient barrier for sardine population separation.
Estuaries serve as nursery grounds for many marine fish species. However, increasing human activities within estuaries and surrounding areas lead to significant habitat quality degradation for the ...juveniles. In recent years, plastic pollution has become a global environmental issue as plastic debris are found in all aquatic environments with potential adverse impacts on marine biota. Given the important ecological role of estuaries and implications of microplastics (MP) in ecosystems, here we assess the occurrence, number, size, and polymer types of MP ingested by wild and caged juvenile European flounder (
Platichthys flesus
). We deployed caged fish for 1 month at five sites in three estuaries in the eastern English Channel. The Seine estuary, heavily impacted by manmade modifications and one of the most contaminated estuaries in Europe, was compared to two smaller estuaries (Canche and Liane) less impacted by industrial activities. We found that juvenile flounders (7–9 cm) were vulnerable to plastic ingestion. Seventy-five percent of caged fish and 58% of wild caught fish had the presence of MP items in their digestive tract. Fibers (69%) dominated in the fish’s digestive tract at all sites. An average of 2.04 ± 1.93 MP items were ingested by feral juvenile flounder and 1.67 ± 1.43 by caged juvenile flounder. For the caged fish, the three sites impacted by wastewater treatment plant (Liane, Le Havre harbor, and Rouen) were those with the highest percentage of individuals that has ingested MP items. Most of the isolated items were fibers and blue in color. Polymers identified by micro Raman spectroscopy were polycaprolactam, polyethylene terephthalate, and polyurethane. Although other environmental factors may have affected caged fish condition and mortality, we found no significant correlation with the number of ingested MP. However, the high occurrence of MP ingested by juvenile fish on nursery grounds raises concerns on their potential negative effects for fish recruitment success and population renewal. Finally, this study describes, for the first time, the feasibility of using caged juvenile fish as an assessing tool of MP contamination in estuarine nursery grounds.
This paper aims to identify the concentrations of PAHs in the sediments of four coastal zones in Lebanon and determine their possible sources and effects. For each region (Tripoli, Jounieh, Dora, and ...Tyre), sampling, lyophilization, Soxhlet extraction, rotary evaporation, and gas chromatography were performed on 11, 10, 7, and 11 samples, respectively. The total PAHs concentrations ranged from 1.22 to 731.93μg/kg dry weight. The lowest concentrations were found in Tyre and the highest in Dora and Jounieh. The level of PAHs was classified as low to moderate and their source was mainly pyrogenic.
•The total PAHs' concentrations ranged between 1.22 and 731.93μg/kg dry weight.•The highest PAHs' concentrations were found in marine sediments of Dora and Jounieh.•The lowest PAHs' concentrations were obtained for Tyre.•The source of PAHs was mainly pyrogenic.•PAHs' concentrations were low to moderate.
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/m
3
. The average microplastics concentration was found to be 20.1 ± 21.8 and 3.78 ± 5.2 items/m
3
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.
In this study, levels of 20 trace elements (Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Sb, Ba, Hg, Pb and U) and the respective biota–sediment accumulation factors (BSAF) were ...assessed for three marine species from the Eastern Mediterranean (Lebanese coast) belonging to different trophic levels in the food chain (algae, bivalves and shrimps). Multivariate analyses showed significant differences in trace element accumulation between seasons, sites and species thus highlighting the importance of a multi-species and seasonal approach to monitor trace metals in coastal areas. Biota–sediment accumulation factors (BSAF) showed limited transfer from sediments to marine organisms suggesting that the bioaccumulation of trace elements by marine organisms should be assessed by considering multiple sources of contaminants. Lead (Pb) levels (0.07–4.44 mg.kg−1) measured in algae and Cd (0.54–7.74 mg.kg−1) and Zn (42.88–972 mg.kg−1) levels found in the oyster, were similar and sometimes higher than those found in other polluted areas indicating that the Lebanese coast is subject to environmental pollution.
Pagellus erythrinus is a commercial fish in Lebanese marine waters. This species has been exploited by artisanal fisheries using gill or trammel nets, longlines and beach seines. Therefore, monthly ...biological P. erythrinus data have been collected since 2015 by the National Center for Marine Sciences – National Council for Scientific Research. Data from 2015, 2016, and 2017 were used to assess the growth and biology of this species along the Lebanese coast. A total of 1315 females and 446 males were collected and the sex ratio showed significant bias from 1:1. The weight-length relationship showed a negative allometry (b = 2.912 and R2 = 0.97), and the length ± SD at which 50% of the individuals were sexually mature was 16.38 ± 0.16 cm for both sexes. The average gonado-somatic index and condition factor demonstrated that the spawning period of the common pandora population is spring and revealed the well-being of the population.
Mercury (Hg) contamination in coastal sediments has been widely studied in clay deposits; however, equivalent results on carbonated sediments are scarce. This article aims to study Hg distribution in ...Lebanese carbonate coastal marine sediments (Eastern Mediterranean) in order to characterize their contamination level and to explore the postdepositional mobility of methylmercury (MeHg) in the deposits. Vertical distribution profiles of total (HgT) and MeHg have been established for the solid phase of sediment cores collected in various near-shore environments chosen for their hypothetical various degrees of anthropization. In addition, dissolved MeHg was determined in sediment pore waters to test its mobility and potential availability for biota. Three sites on the Lebanese coasts—Akkar, Dora, and Selaata—were selected. Akkar is far from any direct contamination source, whereas Dora, located near the Beirut harbor, is a heavily urbanized and industrialized zone including a huge dump site, and Selaata is near a chemical plant that produces phosphate fertilizers. Particulate HgT concentrations in the sediments varied between <0.04 and 0.65 μg/g, with a proportion of MeHg lower than 1%. Based on a sediment quality guideline (MacDonald et al.
2000
), we concluded that Dora bay sediments are heavily contaminated by Hg, with concentrations exceeding the “consensus-based threshold effect” level (0.17 μg/g) and almost reaching the “effects range-medium” level (0.71 μg/g). In spite of the low HgT concentration in Akkar and Selaata sediment (similar to natural carbonated sediment: 0.04 μg/g according to Turekian and Wedephol (
1961
), a closer analysis of the sediment core vertical profile allows one to observe an anthropogenic impact. This impact might be toxicologically insignificant; however, it allows tracing the time increase of Hg diffuse deposition. On the other hand, dissolved MeHg concentrations ranged from 0.04 to 0.09 and from 0.04 to 8.76 ng/l in the Selaata and the Dora sediments, respectively; MeHg vertical profiles in interstitial water enabled us to calculate diffusive fluxes of MeHg from the sediment varying from 0.3 to 1.0 ng/m
2
/day. Thus, the deposited sediments constitute a measurable source of bioavailable Hg for epibenthic organisms.
This study investigated the role of a municipal wastewater treatment plant (WWTP) effluent and an abandoned coastal landfill as pathways for microplastics (MPs) input into the marine environment. MPs ...were first analyzed in raw sewage influent, sludge and effluent samples, and their fate was studied along a distance gradient from the WWTP in three matrices: surface water, sediments and wild mussels. All suspected MPs were characterized according to their polymer nature using micro-Raman spectroscopy. The investigated WWTP had an estimated daily discharge of 227 million MPs. MPs were found in all matrices with a decreasing abundance from the effluent. Strong MPs abundances (higher than those found near the WWTP effluent) were observed in the vicinity of the coastal landfill suggesting its importance as a MPs entry route into the marine coastal environment. Our study supports the idea that blue mussels are a promising sentinel species for MPs (<200 μm).
•Fate of microplastics discharged by Wastewater treatment plant (WWTP) is evaluated.•96% of microplastics decrease with increasing distance from the WWTP effluent.•Coastal landfills should be regarded as an important microplastics entry source.•Mussels are a promising sentinel species for microplastics (<200 μm).
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