An Overview of the Commercial Catch from Beach Seine Fishing Method in the Southern Mediterranean Sea off Port Said, Egypt

Assessment of Noncommercial Catch Caught by the Beach Seine Operating in the Southern Mediterranean Sea off Port Said, Egypt

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The authors report in the present paper the capture of an abnormal specimen of the blackmouth catshark Galeus melastomus Rafinesque, 1810 from the central coast of Algeria (southern Mediterranean Sea). The specimen was a sub–mature female having 478 mm in total length (TL) and weighing 265 g in total body weight (TBW). The specimen displayed a severe atrophy of the right clasper and a poor development of the right pelvic fin. These abnomalities are compared with other similar patterns reported in elasmobranch. The origin of the abnormalities remains questionnable, due to unfavourable environmental conditions (action of pollutants) or to endogenous origin or genetic during embryonic development.

Microplastics in surface waters of the Gulf of Gabes, southern Mediterranean Sea: Distribution, composition and influence of hydrodynamics

Marine plastic pollution represents a major problem owing to its increasing presence in the environment, persistence and ability to spread in every compartment in the form of small plastic particles, namely microplastics (MPs). Studies concerning MPs abundance in the Mediterranean Sea are growing, but their occurrence in the Southern regions remains largely unexplored. In this study, distribution, abundance, size, and polymer type of microplastics were investigated in surface water samples collected with a Manta net (200 μm mesh size) and in 118 marine specimens of commercial interests, including fishes, crustaceans, and mollusks, during Spring and Autumn 2019 EU H2020 Claim Project sampling Campaigns in the Gulf of Gabes (Southern Mediterranean Sea). Laboratory characterization showed significant plastic pollution concentrations, with an average abundance of 312,887 and 77,110 items/km2 in surface water samples collected in Spring and Autumn, respectively. A 3D hydrodynamic and Tracking Model was used to identify dispersal and transport pathways of the floating plastics, reporting a seasonal variability observed in MPs distribution between I (Spring) and II Campaign (Autumn). Despite the high values of MPs abundance found in surface water samples, an overall low frequency of ingestion among studied species was observed, with a maximum value of 20% of individuals (in Scomber scombrus) found with ingested MPs. The present study contributes to expand our state of knowledge regarding MPs pollution level in water and biota samples collected in the Gulf of Gabes, an area of particular interest for its biological resources, but still little investigated.

Metapenaeus st ebbin gi was first described by Nobili (1904: 229). The speci mens were captured in the Red Sea and near Suez. Later, in 1906, the same author gave a more detailed account of the species and figured the petasma and the thelycum. While the figure of the petasma is fairly adequate that of the thelycum seems to be more diagrammatic. However, it shows all the essential parts of the thelycum. In 1921 Tattersall (: 365, as Penaeopsis stebbingi) recorded the same species from the Sudanese Red Sea and, judging from the figures, one can see that the males belong to the present species but that the females are certainly not M. stebbingi^). Barnard (1950: 599) in his catalogue of the South African Decapoda recorded the same species from Delagoa Bay. It may be mentioned here that he has erroneously placed the females of this species in a closely related species, M. monoceros. From the above records it is evident that the distribution of M. stebbingi is limited. It is found in the Red Sea and by migration through the Suez Canal reached Port Said. Besides this, two specimens are reported from S. Africa. The specimens at my disposal were collected in the Arabian Sea off Karachi and are the first to be recorded from here. They number fourteen of which only two are males; the largest specimen is a female measuring 22 mm in carapace length. The smallest female and both the males measure 15 mm in carapace length. It is of interest to note that the largest specimen recorded so far measured 90 mm in total length (Nobili, 1904), while the largest specimen from Karachi measures 97 mm from the tip of the rostrum to the telson. The specimens agree in general with the description of the species given by previous authors except in the details of thelycum and petasma. The petasma, on a careful examination, is found to be much more complicated than described by

Sources and spatial distribution of dissolved aliphatic and polycyclic aromatic hydrocarbons in surface coastal waters of the Gulf of Gabès (Tunisia, Southern Mediterranean Sea)

Significance of 2-methylhopane and 22,29,30Trisnorhop17(21)-ene biomarkers in holocene sediments from the Gulf of Tunis - Southern Mediterranean Sea

Abstract. Aerosol products by AERONET sun-sky radiometer measurements combined with air-mass backtrajectories were analyzed to identify source regions and pathways of air masses carrying aerosols to south-east Italy, and to determine the dependence of aerosol mean optical properties on advection patterns. Aerosol optical depth (AOD), fine mode fraction (η ), single scattering albedo (SSA), asymmetry factor (g), and lidar ratio (Lr) at 440 nm were used to characterize aerosol properties. The analysis of 5-day-backtrajectories ending in Lecce on south-east Italy and referring to 240 measurement days of the 2003–2004 years revealed that 32% of the measurement days were characterized by air masses coming from all continental European sources with the exception of Spain. 3% of the measurement days were characterized by air masses coming from both the Southern Mediterranean Sea and the Africa continent, and the Western Mediterranean, the Iberian Peninsula, and the Atlantic Ocean. 62% of the measurement days were characterized by mixed advection patterns. We found that AOD, SSA and g average values were not significantly dependent on air mass source regions. In contrast, η and Lr average values were quite affected by the air mass source region. AOD, &eta, SSA, g, and Lr average values, which were equal to 0.29±0.15, 0.93±0.03, 0.93±0.03, 0.67±0.03, and 72±20 sr, respectively indicated that the aerosol advected from all continental European sources with the exception of Spain, could be considered representative of "continental average aerosol", mostly made of water soluble and a small amount of soot and insoluble components. Polluted-desert dust particles characterized by AOD=0.29±0.05, η=0.72±0.05, SSA=0.94±0.03, g=0.69±0.02, Lr=56±13 sr, were advected over south-east Italy from the Southern Mediterranean Sea and the Africa continent. The Western Mediterranean, the Iberian Peninsula, and the Atlantic Ocean were instead responsible of the advection of maritime-polluted particles, which were characterized by AOD=0.27±0.17, η=0.8±0.1, SSA=0.94±0.03, g=0.67±0.03, Lr=58±24 sr. Hence, we found that the aerosol load over south-east Italy was dominated by moderately-absorbing, fine-mode particles even if it was also affected by the minor contribution of desert and maritime type aerosol. The application of an aerosol mask to the data points retrieved on measurement days characterized by mixed advection patterns, supported last comment

Coastal areas are sites of discharge of anthropogenic compounds, such as trace metals. In seawater, trace metals have a strong affinity for particulate organic matter or clay mineral and tend to accumulate in sediments. However, natural events and human activities can cause disturbances in surface sediments involving modification of chemical balances and contamination of surrounding waters. Here, we investigated the dynamics of trace metals in the Sfax coastal area (Gulf of Gabes, southern Mediterranean Sea), a shallow coastal ecosystem impacted by tides and submitted to urban/industrial effluents. We presented the spatial distribution of trace metals concentrations, their potential mobility in sediments and evaluated the potential sources of target elements in surface waters. The highest concentration levels in surficial sediments (3.51 µg/g) and surface waters (0.25 µg/L) were found for Cd. The latter showed a great affinity (50%) for the exchangeable phase while other elements (Cu, Cr and Ni) were found in most residual phases, reducing the environmental risk. Pb and Zn, associated Fe/Mn oxyhydroxides revealed potential inputs from urban and industrial effluents. Multivariate statistical analysis suggested that dissolved trace metals in surface waters were probably derived from effluents/wadis but also from sediment resuspension processes, induced by natural (tides, hydrodynamics) or anthropogenic (dredging) events. Overall, this study highlights the importance of the interactions between sediment and water column for the trace metal dynamics in very shallow coastal environments with an exacerbated pattern for Cd.

Origin and distribution of hydrocarbons and organic matter in the surficial sediments of the Sfax-Kerkennah channel (Tunisia, Southern Mediterranean Sea)

Grapsoid crabs (Crustacea: Decapoda: Brachyura) new to the Sirte Basin, southern Mediterranean Sea—the roles of vessel traffic and climate change

The objective of this work was to establish main morphological traits of the Atlantic lizardfish Synodus saurus in the Southern Mediterranean Sea (Benghazi, eastern Libya). Seventy fish random sample obtained from the artisanal catch of Benghazi was used to establish 5 morphogenic (descriptive), 15 morphometric, and 6 meristic traits. The fish was elongated, somewhat cylindrical, with hazy transverse rows in some. The snout was pointed, and the jaws had rows of fine teeth. The mean total length of the fish (TL) was 20.14 cm corresponding to a mean total weight (TW) of 66.93 gm. The ratio of head length to TL was 0.223. All the binary correlations between the morphometric parameters were positive and highly significant. The regressions of these parameters with TL were positive (i.e. all the parameters increase simultaneously during growth), highly significant, and mostly with high R2. The length-weight relationship, TW = 0.0053*TL**3.1109, n = 70, R2 = .965, P = .000, indicated isometric growth (conf. limits of b = ± 0.1411). The Fulton condition factor (CF) was 0.7443. The regression of CF vs TL indicated gradual improvement of the condition of the fish during growth (i.e. gradual increase of CF with increase of TL as indicator of growth), the slope (b) of the power regression was + 0.1110. The meristic traits were conservative, i.e. either did not correlate with TL, or had low "r" (in case of number of lateral line scales). The meristic formula derived from them was: D, 11-12(12); A, 9-12(11); P, 11–13(12); V, 7-8(8); LLS, 53-73(62); ALS, 5-10(7); BLS, 7-14(10); the values between parenthesis are the modes.

Occurrence, origin and potential ecological risk of dissolved polycyclic aromatic hydrocarbons and organochlorines in surface waters of the Gulf of Gabès (Tunisia, Southern Mediterranean Sea)

Particulate-bound aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs) were investigated in the surface waters of the Gulf of Gabès (Tunisia, southern Mediterranean Sea). Samples were collected off the Sfax and Gabès-Ghannouch coasts. Concentrations in total resolved n-alkanes ranged from 0.03 to 3.2μgL-1, and concentrations in total parents + alkylated PAHs ranged from bdl to 108.6ngL-1. The highest concentrations were recorded in the southern Sfax. AHs were mainly of biogenic origin with odd n-alkane predominance, although an anthropogenic contribution was also detected. The PAH molecular patterns revealed a mixed origin with the presence of low molecular weight and alkylated compounds, characteristic of uncombusted oil-derived products, and the presence of high molecular weight compounds, typical of combustion residues. Rainfall events induced an increase in PAH concentrations by a factor 1.5-23.5. The particle-water partition coefficients (Koc) suggest that the partitioning of PAHs between the particulate and dissolved phases is driven by hydrophobicity and organic matter composition.