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Sample records for eastern mediterranean sea

  1. box modeling of the eastern mediterranean sea

    Science.gov (United States)

    Ashkenazy, Y.; Stone, P. H.

    2003-04-01

    Recently (~1990) a new source of deep water formation in the Eastern Mediterranean was found in the southern part of the Aegean sea. Till then, the only source of deep water formation in the Eastern Mediterranean was in the Adriatic sea; the rate of the deep water formation of the new Aegean source is 1Sv=10^6m^3/s, three times larger then the Adriatic source. We develop a simple 3 box-model to study the stability of the thermohaline circulation of the Eastern Mediterranean sea. The 3 boxes represent the Adriatic sea, Aegean sea, and the Ionian sea. The boxes exchange heat and salinity and may be described by a set of nonlinear differential equations. We analytically analyze these equations and find that the system may have one, two, or four stable flux states. We consider two cases for which the temperatures of the boxes are (i) fixed or (ii) variable. After setting the parameters to correspond to the Eastern Mediterranean we find that the system has two stable states, one with (i) two thermally dominant sources of deep water formation in the Adriatic and Aegean and the other with (ii) a salinity dominant source of deep water formation in the Adriatic and a thermally dominant source in the Aegean. While the Adriatic thermally dominant source is comparable to the observed flux of 0.3Sv the Aegean source has much smaller flux than the observed value. This situation is analogous to the state of the thermohaline circulation pre 1990 where the only source of deep water formation was in the Adriatic. If we decrease the atmospheric temperature of the Aegean box by 2C in accordance with recent observations, we find that the deep water formation of the Aegean increases significantly to a value comparable to the recently observed flux.

  2. Palaeoceanography of the interglacial eastern Mediterranean Sea

    NARCIS (Netherlands)

    Marino, G.

    2008-01-01

    The sensitivity of the present interglacial climate to the ongoing anthropogenic-driven increase of atmospheric greenhouse gas poses a fundamental concern to modern society. The Mediterranean region is responding with a distinct change towards drier and warmer conditions, which affects also the hydr

  3. Palaeoceanography of the interglacial eastern Mediterranean Sea

    NARCIS (Netherlands)

    Marino, G.

    2008-01-01

    The sensitivity of the present interglacial climate to the ongoing anthropogenic-driven increase of atmospheric greenhouse gas poses a fundamental concern to modern society. The Mediterranean region is responding with a distinct change towards drier and warmer conditions, which affects also the hydr

  4. Silica cycling in the ultra-oligotrophic Eastern Mediterranean Sea

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    M. D. Krom

    2014-03-01

    Full Text Available Although silica is a key plant nutrient there have been few studies aimed at understanding the Si cycle in the Eastern Mediterranean Sea (EMS. Here we use a combination of new measurements and literature values to explain the silicic acid distribution across the basin and to calculate a silica budget to identify the key controlling processes. The surface water concentration of ~ 1 μM, which is unchanging seasonally across the basin was due to the inflow of Western Mediterranean Sea (WMS water at the Straits of Sicily. It does not change seasonally because there is only a sparse population of diatoms due to the low nutrient (N and P supply to the photic zone in the EMS. The concentration of silicic acid in the deep water of the western Ionian Sea (6.3 μM close to the S. Adriatic area of formation was due to the preformed silicic acid (3 μM plus biogenic silica (BSi from the dissolution of diatoms from the winter phytoplankton bloom (3.2 μM. The increase of 4.4 μM across the deep water of the EMS was due to silicic acid formed from in-situ diagenetic weathering of alumina-silicate minerals fluxing out of the sediment. The major inputs to the EMS are silicic acid and BSi inflowing from the western Mediterranean (121 × 109 mol Si year−1 silicic acid and 16 × 109 mol Si year−1 BSi, silicic acid fluxing from the sediment (54 × 109 mol Si year−1, riverine (27 × 109 mol Si year−1 and subterranean ground water (9.7 × 109 mol Si year−1 inputs, with only a minor direct input from dissolution of dust in the water column (1 × 109 mol Si year−1. This budget shows the importance of rapidly dissolving BSi and in-situ weathering of alumino-silicate minerals as sources of silica to balance the net export of silicic acid at the Straits of Sicily. Future measurements to improve the accuracy of this preliminary budget have been identified.

  5. Assessing Evaporation Duct Variability In The Eastern Mediterranean Sea In Support Of Radar And Radio Communications

    Science.gov (United States)

    2016-12-01

    EVAPORATION DUCT VARIABILITY IN THE EASTERN MEDITERRANEAN SEA IN SUPPORT OF RADAR AND RADIO COMMUNICATIONS by Süleyman C. Gürbüz December 2016...MEDITERRANEAN SEA IN SUPPORT OF RADAR AND RADIO COMMUNICATIONS 5. FUNDING NUMBERS 6. AUTHOR(S) Süleyman C. Gürbüz 7. PERFORMING ORGANIZATION NAME(S...IN THE EASTERN MEDITERRANEAN SEA IN SUPPORT OF RADAR AND RADIO COMMUNICATIONS Süleyman C. Gürbüz Lieutenant Junior Grade, Turkish Navy B.S

  6. A Sea Change : Exotics In the eastern Mediterranean.

    OpenAIRE

    Galil, B.S.; Zenetos, A

    2002-01-01

    The eastern Mediterranean is susceptible to biological invasions because of its placement between the Atlantic, Pontic and Erythrean regions, busy maritime traffic, and lagoons and bays that are crowded with fish and shellfish farms. However, the greatest influx of invaders resulted from the opening of the Suez Canal in 1869, which allowed entry of Indo-Pacific and Erythrean biota. Exotic macro phytes, invertebrates and fish are found in most coastal habitats in the eastern Med...

  7. Comparison of deep-sea sediment microbial communities in the Eastern Mediterranean

    NARCIS (Netherlands)

    Heijs, Sander K.; Laverman, Anniet M.; Forney, Larry J.; Hardoim, Pablo R.; van Elsas, Jan Dirk

    Bacterial and archaeal communities in sediments obtained from three geographically-distant mud volcanoes, a control site and a microbial mat in the Eastern Mediterranean deep-sea were characterized using direct 16S rRNA gene analyses. The data were thus in relation to the chemical characteristics of

  8. Diverse methane concentrations in anoxic brines and underlying sediments, eastern Mediterranean Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.

    Elevated methane (CH sub(4)) concentrations (128-2692x10 sup(3) nM) occur in the hypersaline anoxic brine pools of Bannock and Urania Basins, eastern Mediterranean Sea, compared to low concentrations (17-80x10 sup(3) nM) in the sediments below...

  9. Composition and sources of sedimentary organic matter in the deep Eastern Mediterranean Sea

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    R. Pedrosa-Pàmies

    2015-07-01

    Full Text Available Surface sediments collected from deep slopes and basins (1018–4087 m depth of the oligotrophic Eastern Mediterranean Sea have been analysed for bulk elemental and isotopic composition of organic carbon, total nitrogen and selected lipid biomarkers, jointly with grain size distribution and other geochemical proxies. The distribution and sources of sedimentary organic matter (OM have been subsequently assessed and general environmental variables, such as water depth and currents, have been examined as causative factors of deep-sea sediment characteristics. Lithogenic and biogenic carbonates are the dominant sedimentary fractions, while both bulk and molecular organic tracers reflect a mixed contribution from autochthonous and allochthonous sources for the sedimentary OM, as indicated by relatively degraded marine OM, terrestrial plant waxes and anthropogenic OM including degraded petroleum by-products, respectively. Wide regional variations have been observed amongst the studied proxies, which reflect the multiple factors controlling sedimentation in the deep Eastern Mediterranean Sea. Our findings highlight the role of deep Eastern Mediterranean basins as depocentres of organic-rich fine-grained sediments (mean 5.4 ± 2.4 μm, with OM accumulation and burial due to aggregation mechanisms and hydrodynamic sorting. A multi-proxy approach is hired to investigate the biogeochemical composition of sediment samples, which sheds new light on the sources and transport mechanisms along with the impact of preservation vs. diagenetic processes on the composition of sedimentary OM in the deep basins of the oligotrophic Eastern Mediterranean Sea.

  10. Vertical diffusion processes in the Eastern Mediterranean - Black Sea System

    Science.gov (United States)

    Kioroglou, Sotiris; Tragou, Elina; Zervakis, Vassilis; Georgopoulos, Dimitris; Herut, Barak; Gertman, Isaak; Kovacevic, Vedrana; Özsoy, Emin; Tutsak, Ersin

    2014-07-01

    The identification and examination of ‘complete' potential density overturns in CTD profiles, within the framework of SESAME project, are employed to assess vertical eddy diffusivities, mostly in the top 100 m of the water column, for a broad area covering the East Mediterranean, the Turkish Straits and the Black Sea. The implementation of this method shows that, mixing induced by mechanical turbulence is enhanced in frontal areas, in the proximity of straits and inside anticyclones; furthermore, that mechanical turbulence is insignificant, down to the scale of CTD resolution, within areas of double diffusive staircases, encountered in deep layers of the water column. Consequently, only laminar theories about double diffusion are applied for assessing diffusivities therein. Susceptibility to different types of double diffusion seems to be related to the interaction of different types of water masses.

  11. Abyssal and deep circulation in the Eastern Mediterranean Sea (Ionian Sea)

    Science.gov (United States)

    Artale, Vincenzo; Bensi, Manuel; Falcini, Federico; Marullo, Salvatore; Rubino, Angelo

    2016-04-01

    In the mid-1990s, experimental evidences on the Eastern Mediterranean Transient (EMT) were presented and it was shown that the Mediterranean abyssal circulation is not in a steady state but can be subjected to episodic sudden changes (Roether et al., 1996). In the last 10 years the Ionian Sea, the central and deepest part of the Mediterranean Sea, was subjected to relevant scientific interests from a theoretical and experimental point of view. Among these, there is the discovery of the BiOS (Bimodal Oscillating System), one new mechanism that drives a periodic (almost decadal) redistribution of surface and subsurface waters in the Eastern Mediterranean, with considerable feedbacks in the variability of the deep-water formation both in the southern Adriatic and in the Levantine and Aegean sub-basins (Gačić et al., 2010). In the Ionian Sea, numerous recent observational campaigns have been conducted to investigate the behaviour of deep and abyssal waters, at depths between 2000-4000m that are comparable to the mean global ocean depth (Rubino and Hainbucher, 2007; Bensi et al., 2013). There, advection, diffusion and vertical stability of the water masses can assume an important role on the internal quasi-periodical variability, creating the preconditions for catastrophic events such as the EMT or reversals of the Ionian circulation (Pisacane et al., 2006). Since there are no significant deep heat sources in the world ocean, waters that fill the deep ocean can only return to the sea surface as a result of downward mixing of heat from the sea surface to the bottom and vice versa and this occurs through eddy diffusion. Along our presentation, mainly through the analysis of the deepest CTD casts taken from 2009 to 2011 in the eastern basins and in particular in the Ionian Sea, we will show a significant change in the deep thermohaline structure (including its biogeochemical and hydrological characteristics), giving an indication on the time scale of the renewal of deep

  12. Investigation of sea level trends and the effect of the north atlantic oscillation (NAO) on the black sea and the eastern mediterranean sea

    Science.gov (United States)

    Ozgenc Aksoy, Aysegul

    2017-07-01

    The North Atlantic Oscillation (NAO) has significant effects on sea levels, weather, and climate. In this study, the sea level trends and the effects of the North Atlantic Oscillation Indices (NAOI) on annual mean sea level data were assessed for the Black Sea and the Eastern Mediterranean Sea. The trends of sea level and NAOI were determined using Mann-Kendall dimensionless z statistics. Generally, upward sea level trends were detected for the Black Sea and the Eastern Mediterranean Sea. In the Black Sea, significant and continuous upward trends were detected after the year 1950. Weaker trends were detected for the Eastern part of the Mediterranean Sea. Sea level trends were correlated with trends in NAO indices; negative correlations were detected for the Black Sea, whereas positive correlations were found for the Eastern Mediterranean Sea. Paired t tests were performed to determine the turning points for all sea level data sets. The value of t was positive for all data sets, which means that the mean value of the data set before the turning point was smaller than the mean value of the data set after the turning point.

  13. An oceanic box model of the Miocene Mediterranean Sea with emphasis on the effects of closure of the eastern gateway

    NARCIS (Netherlands)

    Karami, M.P.; Meijer, P.Th.; Dijkstra, H.A.; Wortel, M.J.R.

    2009-01-01

    The early Miocene Mediterranean Sea had two gateways toward the open ocean: the Indian Ocean in the east and the Atlantic Ocean in the west. Closure of the eastern connection during the middle Miocene had important effects on the water properties and circulation of the Mediterranean Sea. To gain ins

  14. The wind and thermally driven circulation of the eastern Mediterranean Sea. Part II: the Baroclinic case

    Science.gov (United States)

    Malanotte-Rizzoli, Paola; Bergamasco, Andrea

    1991-04-01

    anticyclonic ones in summer, according to the vorticity input by the wind. When surface thermal forcing is included, the winter-to-summer differences become very small and the yearly pattern is dominant. The second important result is that the intercomparisons of the various numerical experiments in which each driving mechanism is studied in isolation from the others allows us to classify unambiguously the three forcing mechanisms in order of relative importance in driving the circulation in the different sub-basins of the eastern Mediterranean. Specifically, for the Ionian Sea and Sea of Crete the dominant forcing is the inflow at the Straits of Sicily while for the Levantine Sea thermohaline fluxes are the main driving function. The wind-stress forcing induces a seasonal fluctuation only in the meandering path of the Atlantic jet entering the Ionian Sea through the Sicily Straits. We finally carry out a 'central experiment', the most realistic one in which all forcing functions drive the circulation that we compare quantitatively with other model results and qualitatively with observations. Major features can be recognized and are shown to be persistent all year long. These features are also found in the dynamic heights of the general hydrographic surveys of the Physical Oceanography of the Eastern Mediterranean (POEM) programme. The only POEM feature not reproduced by the model, an intense anticyclonic region in the south eastern Levantine, may be attributed to errors and specifically underestimates, of the available thermal fluxes whose effect is partially overcome by the wind-stress forcing. This anticyclonic cell is in fact obtained when the model is driven by the thermal fluxes alone. Overall, the model results compare well with the observational evidence provided by the POEM surveys and the thermohaline vertical circulation cell reproduced by the model is consistent with the preliminary results of the transient-tracer survey POEM-V-87. Finally, many of the persistent

  15. Food-web traits of the North Aegean Sea ecosystem (Eastern Mediterranean) and comparison with other Mediterranean ecosystems

    Science.gov (United States)

    Tsagarakis, K.; Coll, M.; Giannoulaki, M.; Somarakis, S.; Papaconstantinou, C.; Machias, A.

    2010-06-01

    A mass-balance trophic model was built to describe the food-web traits of the North Aegean Sea (Strymonikos Gulf and Thracian Sea, Greece, Eastern Mediterranean) during the mid-2000s and to explore the impacts of fishing. This is the first food-web model representing the Aegean Sea, and results were presented and discussed in comparison to other previous ecosystems modelled from the western and the central areas of the basin (South Catalan and North-Central Adriatic Seas). Forty functional groups were defined, covering the entire trophic spectrum from lower to higher trophic levels. Emphasis was placed on commercial invertebrates and fish. The potential ecological role of the invasive ctenophore, Mnemiopsis leidyi, and several vulnerable groups (e.g., dolphins) was also explored. Results confirmed the spatial productivity patterns known for the Mediterranean Sea showing, for example, that the total biomass is highest in N.C. Adriatic and lowest in N. Aegean Sea. Accordingly, food-web flows and several ecosystem indicators like the mean transfer efficiency were influenced by these patterns. Nevertheless, all three systems shared some common features evidencing similarities of Mediterranean Sea ecosystems such as dominance of the pelagic fraction in terms of flows and strong benthic-pelagic coupling of zooplankton and benthic invertebrates through detritus. The importance of detritus highlighted the role of the microbial food-web, which was indirectly considered through detritus dynamics. Ciliates, mesozooplankton and several benthic invertebrate groups were shown as important elements of the ecosystem linking primary producers and detritus with higher trophic levels in the N. Aegean Sea. Adult anchovy was shown as the most important fish group in terms of production, consumption and overall effect on the rest of the ecological groups in the model, in line with results from the Western Mediterranean Sea. The five fishing fleets considered (both artisanal and

  16. Data from investigation on seismic Sea waves events in the Eastern Mediterranean from 1800 to 1900 A.D.

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    J. ANTONOPOULOS

    1980-06-01

    Full Text Available Tsunamis from 1800-1900 A.D. in the Eastern Mediterranean
    Sea between 31-44 N and 18-36 E excluding the Black Sea and
    the Italian coasts of the Adriatic Sea is the object of the present
    paper.

  17. Data from investigation on seismic Sea waves events in the Eastern Mediterranean from 1900 to 1980 A.D.

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    J. ANTONOPOULOS

    1980-06-01

    Full Text Available Tsunamis from 1900 to 1980 A.D. in the Eastern Mediterranean
    Sea between 31-44 N and 18-36 E excluding the Black Sea
    and the Italian coasts of the Adriatic Sea is the object of the
    present paper.

  18. Data from investigation on seismic Sea waves events in the Eastern Mediterranean from 1000 to 1500 A.D.

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    J. ANTONOPOULOS

    1980-06-01

    Full Text Available Tsunamis from 1000 to 1500 A.D. in the Eastern Mediterranean
    Sea between 31-44 N and 18-36 E excluding the Black Sea
    and the Italian coasts of the Adriatic Sea is the object of the
    present paper.

  19. Data from investigation on seismic Sea waves events in the Eastern Mediterranean from 1500 to 1800 A.D.

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    J. ANTONOPOULOS

    1980-06-01

    Full Text Available Tsunamis from 1500-1800 A.D., in the Eastern Mediterranean
    Sea between 31-44 N and 18-36 E excluding the Black Sea and the
    Italian coasts of the Adriatic Sea is the object of the present
    paper.

  20. Zooplankton of the Black Sea and the Eastern Mediterranean: Similarities and dissimilarities

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    A.V. KOVALEV

    2012-12-01

    Full Text Available A synthesis of data on abundance and biomass of zooplankton in the Eastern Mediterranean (EMED and the Black Sea shows major differences in the composition and structure of pelagic communities in the two basins. Few Mediterranean planktonic animals have invaded and acclimatised in the Black Sea. The great bulk of Black Sea species is represented by coastal inhabitants that spread throughout the whole basin. This process has been called “neritization” of the Black Sea fauna. Peculiarities in zooplankton assemblages of the Black Sea have been further strengthened over the last few decades due to increasing eutrophication and the massive invasion of the ctenophore Mnemiopsis leidyi. The relative contribution of copepods, cladocerans, chaetognaths, and appendicularians to total zooplankton biomass has notably decreased , whereas gelatinous groups (mainly represented by Mnemiopsis and Aurelia aurita contributed up to 99% of total wet weight in 1995 in the Black Sea.The basic features of planktonic fauna in the Black Sea are mainly due do the geo-morphological characters of the basin and the limited exchanges with the EMED, that are confined to the surface-subsurface layers in the Dardanelles and Bosphorus Straits. However, the dramatic changes that recently occurred in the structure of zooplankton assemblages seem to have been caused by heavy anthropogenic impact on the pelagic system.

  1. Zooplankton of the Black Sea and the Eastern Mediterranean: Similarities and dissimilarities

    Directory of Open Access Journals (Sweden)

    A.V. KOVALEV

    2001-06-01

    Full Text Available A synthesis of data on abundance and biomass of zooplankton in the Eastern Mediterranean (EMED and the Black Sea shows major differences in the composition and structure of pelagic communities in the two basins. Few Mediterranean planktonic animals have invaded and acclimatised in the Black Sea. The great bulk of Black Sea species is represented by coastal inhabitants that spread throughout the whole basin. This process has been called “neritization” of the Black Sea fauna. Peculiarities in zooplankton assemblages of the Black Sea have been further strengthened over the last few decades due to increasing eutrophication and the massive invasion of the ctenophore Mnemiopsis leidyi. The relative contribution of copepods, cladocerans, chaetognaths, and appendicularians to total zooplankton biomass has notably decreased , whereas gelatinous groups (mainly represented by Mnemiopsis and Aurelia aurita contributed up to 99% of total wet weight in 1995 in the Black Sea. The basic features of planktonic fauna in the Black Sea are mainly due do the geo-morphological characters of the basin and the limited exchanges with the EMED, that are confined to the surface-subsurface layers in the Dardanelles and Bosphorus Straits. However, the dramatic changes that recently occurred in the structure of zooplankton assemblages seem to have been caused by heavy anthropogenic impact on the pelagic system.

  2. Trace element concentrations in the Mediterranean monk seal (Monachus monachus) in the eastern Mediterranean Sea.

    Science.gov (United States)

    Formigaro, Costanza; Karamanlidis, Alexandros A; Dendrinos, Panagiotis; Marsili, Letizia; Silvi, Marina; Zaccaroni, Annalisa

    2017-01-15

    The Mediterranean monk seal (Monachus monachus) is one of the most endangered marine mammals in the world. The biggest sub-population of the species survives in Greece, where understanding the effects of pollution on the survival of the species has been identified as a national research and conservation priority. From 1990 to 2013 we collected tissue samples from 59 deceased monk seals in order to: (i) Define the concentration of trace elements (As, Pb, Cd, Hg, Se, Cr, Ni) in three different matrices (i.e., blubber, liver and kidney), (ii) Determine whether differences in trace element concentrations are age- or gender-related, (iii) Evaluate the potential effects of these pollutants. The study recorded differences in trace element concentrations among matrices, but in general, trace element exposure in Mediterranean monk seals in Greece was low and within the non-acutely toxic levels for Pinnipeds. Only arsenic concentrations were at the upper limit of the normal range observed in other marine mammals (0.69±0.55mg/kg w.w. in blubber, 0.79±0.62mg/kg w.w. in liver and 0.79±0.59mg/kg w.w. in kidney). We recorded also exceptionally high Hg concentrations in a single adult female (24.88mg/kg w.w.). Age- and gender-related differences were also recorded and were due to various biological, ecological and chemical factors. Based on the results of the study, potentially adverse effects on the immune and endocrine system of the Mediterranean monk seal from some pollutants (e.g., As, Cd, Se, Ni, Cr) cannot be ruled out, which may expose the Mediterranean seal population in Greece to epizootics and stochastic phenomena of mass mortality. It is therefore of utmost importance that pollutant monitoring becomes an integral component of the standard monitoring protocol of the endangered Mediterranean monk seal in the eastern Mediterranean. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. A new morpho-bathymetric map of the Eastern Mediterranean Sea

    Science.gov (United States)

    Mascle, Jean; Brosolo, Laetitia

    2016-04-01

    A new morpho-bathymetric synthesis of the Eastern Mediterranean Sea has been compiled using a digital terrain model (DTM) based on a 100-meter grid. This DTM has been constructed using data provided by several peri-mediterranean Institutes, and collected using various swath bathymetry systems operated by different research vessels. One may estimate that 90% of the seabed extending by water depths higher than 2000m have been mapped using swath systems. The aim of this synthesis is chiefly to illustrate, in detail, the morphological features resulting from the various (sedimentary, tectonic, geochemical, magmatic, etc.) active geological processes operating on the four main physiographic domains, which characterize the Eastern Mediterranean Sea: the Calabria outer arc (Ionian Sea), the Mediterranean Ridge (most of the central basin), the Nile sedimentary cone (off Egypt) and the Eratosthenes seamount (south of Cyprus). For areas not yet covered by swath bathymetric systems the map has been completed by digital data extracted either from GEBCO or from EMODNET DTM files (http://www.gebco.net/data_and_products/gebco_digital_atlas/) (http://www.emodnet-hydrography.eu/). Several artifacts introduced by the use of these files, for example theoccurrences of their grids, can be detected along most of the steep continental slopes not yet mapped in detail, as well as in the southern domain of the Adriatic Sea. Similarly it has not been possible to systematically correct a few, but non-linear, discrepancies in Z values between various DTM files. Such discrepancies result either from the use of data collected by swath systems operating at different frequencies and/or from minor differences in seawater sound velocity corrections.

  4. Mesozooplankton biomass and abundance in Cyprus coastal waters and comparison with the Aegean Sea (eastern Mediterranean

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    C. C.S. HANNIDES

    2015-07-01

    Full Text Available Here we conduct the first comprehensive assessment of mesozooplankton abundance, biomass, and taxa composition in Cyprus coastal waters (Levantine Sea.  Mesozooplankton abundance and biomass sampled at several locations around the island ranged from 153 – 498 individuals m-3 and 0.7 – 5.2 mg dry weight m-3, respectively, with significantly larger biomass observed in winter-early spring (March than in summer (September.  The community was dominated by calanoid and cyclopoid copepods throughout the year (80% of total numbers, with higher abundances of predatory taxa (chaetognaths and medusae in winter and cladocerans in summer.  Overall, we find that coastal mesozooplankton communities around Cyprus appear to be more similar to communities in offshore waters or those around the island of Rhodes than to communities along the mainland Levantine coast.  We further highlight regional differences in the eastern Mediterranean by comparing our data with mesozooplankton in the western Aegean (Saronikos Gulf and northeastern Aegean Sea (NEA.  Distinct spatial differences were observed, for example anthropogenic influences in the Saronikos Gulf and the outflow of Modified Black Sea Water in the NEA drove generally greater biomass and abundance in these regions.  Overall, our comparison supports the concept of a latitudinal gradient in oligotrophy in the eastern Mediterranean, with ultra-oligotrophic conditions found in the Levantine Sea.

  5. The ecology of the Ostracoda (Crustacea) species obtained from the coasts of Iskenderun Bay (Eastern Mediterranean Sea)

    OpenAIRE

    Paçal, Ferda Perçin

    2011-01-01

    Abstract The aim of this study was to understand the ecology of the ostracoda species obtained from Iskenderun Bay, the Eastern Mediterranean Sea. Ecological parameters like temperature and salinity, affecting the distribution of the live ostracoda species are considerably higher in Iskenderun Bay than the middle and western parts of the Mediterranean Sea. This study was carried out along the coasts of Iskenderun Bay between 22-26 September 2002. Total of 27 genera and 56 ostracoda species we...

  6. Indications of low macrobenthic activity in the deep sediments of the eastern Mediterranean Sea

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    Daniela Basso

    2004-12-01

    Full Text Available The fluxes and budget of organic matter from the oligotrophic surface waters of the eastern Mediterranean to the deep waters are poorly known, and little information is available on past and present macrobenthic activity on the sea floor. Evidence of macrobenthic activity can be direct, through recovery of living organisms or their autochthonous skeletal remains, or indirect, through bioturbation and trace fossils. The evidence of biological activity in deep eastern Mediterranean sediments has been evaluated and compared through 210Pb profiles from box-cores and study of dredge samples from sites on Medina Rise (1374 m water depth, the Messina Abyssal Plain (4135 m and several sites along the Mediterranean Ridge, SW and S of Crete (1783 to 3655 m. All these sites are remote from the continental shelves, so the biological benthic activity is expected to depend primarily on primary production from surface waters. The results show that present-day macrobenthos and trace fossils are generally scarce, especially at depths > 2500 m. This observation is supported by surface sediment 210Pb excess distributions that show a surface mixed layer (SML 2500 m. The historical layer of some box-cores and the Pleistocene hardgrounds collected in the Cleft area (Mediterranean Ridge do, however, record a macrobenthic activity that is apparently more intense than at present, which may be related to higher primary production of the Pleistocene glacial intervals. In contrast with most areas of the present-day deep eastern Mediterranean which depend on surface primary production based on photosynthesis, a relatively dense and diversified macrobenthic community based on chemosynthesis has been recognised at depths > 1100 m on the Napoli Dome mud volcano in the Olimpi area, and on the Kazan and other mud volcanoes in the Anaximander Mountains.

  7. Tracers confirm downward mixing of Tyrrhenian Sea upper waters associated with the Eastern Mediterranean Transient

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    W. Roether

    2011-01-01

    Full Text Available Observations of tritium and 3He in the Tyrrhenian Sea, 1987–2009, confirm the enhanced vertical mixing of intermediate waters into the deep waters that has been noted and associated with the Eastern Mediterranean Transient in previous studies. Our evidence for the mixing rests on increasing tracer concentrations in the Tyrrhenian deep waters, accompanied by decreases in the upper waters, which are supplied from the Eastern Mediterranean. The downward transfer is particularly evident between 1987 and 1997. Later on, information partly rests on increasing tritium-3He ages; here we correct the observed 3He for contributions released from the ocean floor. The Tyrrhenian tracer distributions are fully compatible with data upstream of the Sicily Strait and in the Western Mediterranean. The tracer data show that mixing reached to the bottom and confirm a cyclonic nature of the deep water circulation in the Tyrrhenian. They furthermore indicate that horizontal homogenization of the deep waters occurs on a time scale of roughly 5 years. Various features point to a reduced impact of Western Mediterranean Deep Water (WMDW in the Tyrrhenian during the enhanced-mixing period. This is an important finding because it implies less upward mixing of WMDW, which has been named a major process to enable the WMDW to leave the Mediterranean via the Gibraltar Strait. On the other hand, the TDW outflow for several years represented a major influx of enhanced salinity and density waters into the deep-water range of the Western Mediterranean.

  8. Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the eastern Mediterranean Sea

    Science.gov (United States)

    Parinos, C.; Gogou, A.; Bouloubassi, I.; Pedrosa-Pàmies, R.; Hatzianestis, I.; Sanchez-Vidal, A.; Rousakis, G.; Velaoras, D.; Krokos, G.; Lykousis, V.

    2013-09-01

    Surface sediments collected from deep basins (1018-4087 m depth) of the eastern Mediterranean Sea (Ionian Sea, southern Aegean Sea and northwestern Levantine Sea) were analyzed for aliphatic and polycyclic aromatic hydrocarbons as tracers of natural and anthropogenic inputs. Concentrations of total aliphatic hydrocarbons, n-alkanes and the unresolved complex mixture (UCM) of aliphatic hydrocarbons varied significantly, ranging from 1.34 to 49.2 μg g-1, 145 to 4810 ng g-1 and 0.73 to 36.7 μg g-1, respectively, while concentrations of total polycyclic aromatic hydrocarbons (PAHs) ranged between 11.6 and 223 ng g-1. Molecular profiles of determined hydrocarbons reflect a mixed contribution from both natural and anthropogenic sources in deep-sea sediments of the eastern Mediterranean Sea, i.e., terrestrial plant waxes, degraded petroleum products, unburned fossil fuels and combustion of grass, wood and coal. Hydrocarbon mixtures display significant variability amongst sub-regions, reflecting differences in the relative importance of inputs from various sources and phase associations/transport pathways of individual hydrocarbons that impact on their overall distribution and fate. Hydrocarbon concentrations correlated significantly with the organic carbon content of sediments, indicating that the latter exerts an important control on their transport and ultimate accumulation in deep basins. Additionally, water masses' circulation characteristics also seem to influence the regional features and distribution patterns of hydrocarbons. Our findings highlight the role of deep basins/canyons as repositories of both natural and anthropogenic chemical species.

  9. Multidisciplinary oil spill modeling to protect coastal communities and the environment of the Eastern Mediterranean Sea

    Science.gov (United States)

    Alves, Tiago M.; Kokinou, Eleni; Zodiatis, George; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2016-11-01

    We present new mathematical and geological models to assist civil protection authorities in the mitigation of potential oil spill accidents in the Eastern Mediterranean Sea. Oil spill simulations for 19 existing offshore wells were carried out based on novel and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The simulations show a trend for east and northeast movement of oil spills into the Levantine Basin, affecting the coastal areas of Israel, Lebanon and Syria. Oil slicks will reach the coast in 1 to 20 days, driven by the action of the winds, currents and waves. By applying a qualitative analysis, seabed morphology is for the first time related to the direction of the oil slick expansion, as it is able to alter the movement of sea currents. Specifically, the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. This work suggests that oil spills in the Eastern Mediterranean Sea should be mitigated in the very few hours after their onset, and before wind and currents disperse them. We explain that protocols should be prioritized between neighboring countries to mitigate any oil spills.

  10. Multidisciplinary oil spill modeling to protect coastal communities and the environment of the Eastern Mediterranean Sea.

    Science.gov (United States)

    Alves, Tiago M; Kokinou, Eleni; Zodiatis, George; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2016-11-10

    We present new mathematical and geological models to assist civil protection authorities in the mitigation of potential oil spill accidents in the Eastern Mediterranean Sea. Oil spill simulations for 19 existing offshore wells were carried out based on novel and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The simulations show a trend for east and northeast movement of oil spills into the Levantine Basin, affecting the coastal areas of Israel, Lebanon and Syria. Oil slicks will reach the coast in 1 to 20 days, driven by the action of the winds, currents and waves. By applying a qualitative analysis, seabed morphology is for the first time related to the direction of the oil slick expansion, as it is able to alter the movement of sea currents. Specifically, the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. This work suggests that oil spills in the Eastern Mediterranean Sea should be mitigated in the very few hours after their onset, and before wind and currents disperse them. We explain that protocols should be prioritized between neighboring countries to mitigate any oil spills.

  11. Mitochondrial Control Region Variability in Mytilus galloprovincialis Populations from the Central-Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Ioannis A. Giantsis

    2014-06-01

    Full Text Available The variable domain 1 (VD1 domain of the control region and a small segment of the rrnaL gene of the F mtDNA type were sequenced and analyzed in 174 specimens of Mytilus galloprovincialis. Samples were collected from eight locations in four Central-Eastern (CE Mediterranean countries (Italy, Croatia, Greece and Turkey. A new primer, specific for the F mtDNA type, was designed for the sequencing procedure. In total 40 different haplotypes were recorded, 24 of which were unique. Aside from the two populations situated in Thermaikos gulf (Northern Aegean, Greece, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and Eastern Mediterranean populations. Eight out of the 40 haplotypes were shared by at least three populations while two of them were found in all populations. ΦST and cluster analysis revealed lack of structuring among CE Mediterranean populations with the exception of those located at the Sea of Marmara and Croatian coast which were highly differentiated. Apart from the species’ inherit dispersal ability, anthropogenic activities, such as the repeated translocations of mussel spat, seem to have played an important role in shaping the current genetic population structure of CE M. galloprovincialis mussels.

  12. Deep-sea tsunami deposits triggered by the explosion of Santorini (3500 y BP), eastern Mediterranean

    Science.gov (United States)

    Cita, M. B.; Aloisi, G.

    2000-09-01

    The collapse of the Santorini caldera after the catastrophic eruption of the Bronze Age, 3500 y BP, caused a tsunami wave that had catastrophic effects in the Ionian basin, including its deepest parts. Pelagic turbidites of local origin were deposited on the bottom of small perched basins of the Southern Calabrian, Western and Central Mediterranean Ridges (type A homogenite) whereas a megaturbidite of distal origin, presumably triggered by the tsunami wave hitting the shoreline of the Sirte Gulf, was deposited on the Ionian and Sirte Abyssal Plains, extending eastwards as far as the Western Herodotous Trough depositing a thick, acoustically transparent layer (type B homogenite). Three core transects crossing the deformation front of the Mediterranean Ridge are presented and discussed. A fourth transect of giant piston cores was collected on the abyssal plains located to the south of the Mediterranean Ridge. All those to the west of the collision zone contain the Holocene homogenite with a thickness in excess of 20 m, whereas the cores taken from the Herodotous Abyssal Plain east of the collision zone are devoid of the homogenite. Sedimentological analyses were performed on the only giant core that penetrated the sandy base of the homogenite and the underlying pelagic sediments of late Pleistocene (last glacial) age. The African provenance of this typical type B homogenite is corroborated by shallow-water fauna derived from the North African shelf. No sedimentological characteristics peculiar to tsunamiites are observed in the deep-sea homogenite of the eastern Mediterranean.

  13. Sedimentology and geochemistry of mud volcanoes in the Anaximander Mountain Region from the Eastern Mediterranean Sea.

    Science.gov (United States)

    Talas, Ezgi; Duman, Muhammet; Küçüksezgin, Filiz; Brennan, Michael L; Raineault, Nicole A

    2015-06-15

    Investigations carried out on surface sediments collected from the Anaximander mud volcanoes in the Eastern Mediterranean Sea to determine sedimentary and geochemical properties. The sediment grain size distribution and geochemical contents were determined by grain size analysis, organic carbon, carbonate contents and element analysis. The results of element contents were compared to background levels of Earth's crust. The factors that affect element distribution in sediments were calculated by the nine push core samples taken from the surface of mud volcanoes by the E/V Nautilus. The grain size of the samples varies from sand to sandy silt. Enrichment and Contamination factor analysis showed that these analyses can also be used to evaluate of deep sea environmental and source parameters. It is concluded that the biological and cold seep effects are the main drivers of surface sediment characteristics from the Anaximander mud volcanoes.

  14. Annual Acoustic Presence of Fin Whale (Balaenoptera physalus) Offshore Eastern Sicily, Central Mediterranean Sea

    Science.gov (United States)

    Sciacca, Virginia; Caruso, Francesco; Beranzoli, Laura; Chierici, Francesco; De Domenico, Emilio; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Simeone, Francesco; Viola, Salvatore; Riccobene, Giorgio

    2015-01-01

    In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus) in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea), throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, “NEMO-SN1”, deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO) Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz–1 kHz, sampling rate: 2 kHz) which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9–22.5 Hz) was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise. PMID:26581104

  15. LATE PLIOCENE-HOLOCENE DEBRIS FLOW DEPOSITS IN THE IONIAN SEA (EASTERN MEDITERRANEAN

    Directory of Open Access Journals (Sweden)

    GIOVANNI ALOISI DE LARDEREL

    1997-11-01

    Full Text Available Widespread coring of the Eastern Mediterranean Basin has outlined the existence of a systematic relation between lithology of debris flow deposits and physiographic setting. Whilst the topographic highs are characterized by pelagic sedimentation, the basin floors are alternatively subject to pelagic sedimentation and re-sedimentation pro cesses. Amongst the latters, turbidity flows and debris flows are the most common transport mechanisms.In this paper we present the study of the debris flow pro cess in the Ionian Sea using visual description of cores, grain size, carbonate content and smear slide analysis carried out on gravity and piston cores recovered over the past 20 years. A distinction has been made between debris flow deposits originating from the continental margins (North Africa and Malta Escarpment and those emplaced in the small basins amidst the Calabrian and Mediterranean ridges "Cobblestone Topography". As a result of the difference in setting, the former debris flow deposits include a great variety of lithologies and ages whilst the latter involve the pelagic sediments forming the typical Eastern Mediterranean Plio-Quaternary succession. A detailed study of clast and matrix structures makes it possible to describe the flows in terms of existing classifications of sediment gravity flows and to assume a clast support mechanism. Finally, biostratigraphy coupled with the presence of widespread marker beds enabled us to estimate the age of emplacement of the deposits and to hypothesize a triggering mechanism for flow initiation. Three flows are strictly related to the pelagic turbidite named homogenite, triggered by the explosive eruption of the Santorini volcano (Minoan eruption and therefore have an estimated age of 3,500 BP. The other deposits have ages ranging from 9,000 BP to about 70,000 BP and were originated by debris flows triggered by events such as earthquakes and glacial low sea level stands.    

  16. Spatial and seasonal variability of particulate matter optical and size properties in the Eastern Mediterranean Sea

    Science.gov (United States)

    Karageorgis, A. P.; Georgopoulos, D.; Kanellopoulos, T. D.; Mikkelsen, O. A.; Pagou, K.; Kontoyiannis, H.; Pavlidou, A.; Anagnostou, Ch.

    2012-12-01

    Particulate matter plays a paramount role in the biogeochemical processes taking place in the marine environment. We report seasonal (spring and summer 2008) distribution of particulate matter in the Eastern Mediterranean, along a transect extending from the open Ionian Sea to the North Aegean Sea, including measurements in the Levantine Sea. A suite of optical instruments measuring beam attenuation (beam cp), fluorescence and particle size, the latter obtained with the innovative in-situ laser particle sizer LISST-Deep are used in concert with traditional measurements of particulate matter concentration (PMC), and total chlorophyll α from bottle samples. PMCs were generally low during both seasons (range: 0.02-0.85 mg L- 1), with values substantially higher in the euphotic zone during spring. The deep waters (> 200 m) in the Eastern Mediterranean exhibit extremely low PMCs, well-below 0.1 mg L- 1. Total chlorophyll α concentrations ranged from 0.003 to 0.28 μg L- 1 in spring and from 0.08 to 0.19 μg L- 1 in summer, verifying the ultra-oligotrophic character of the area. A significant correlation of beam cp and fluorescence in spring suggests that sources of particles are primarily biogenic in the surface waters. Deep water formation triggered the development of a ~ 900-m thick benthic nepheloid layer in the N. Aegean Sea. LISST-Deep revealed valuable information on the particle volume concentrations and the median particle size. It is striking that large particles (range: 31-230 μm; median ~ 85 μm) predominate in the entire region, from the surface up to the deep waters. In addition, accumulation of particles in the pycnocline is observed during summer; however, it is possible that schlieren (increase in beam attenuation due to scattering off of density gradients) could be responsible for the high particle volume concentrations and large median particle diameters recorded. These measurements, conducted for the first time in the Eastern Mediterranean

  17. Influence of chemosynthetic ecosystems on nematode community structure and biomass in the deep eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    N. Lampadariou

    2013-08-01

    Full Text Available Mud volcanoes are a~special type of cold seeps where life is based on chemoautotrophic processes. They are considered to be extreme environments and are characterized by unique megafaunal and macrofaunal communities. However, very few studies on mud volcanoes taking into account the smaller meiobenthic communities have been carried out. Two mud volcanoes were explored during the MEDECO (MEditerranean Deep-sea ECOsystems cruise (2007 with the remotely operated vehicle (ROV Victor-6000: Amsterdam, located south of Turkey between 1700 and 2000 m depth (Anaximander mud field; and Napoli, south of Crete, located along the Mediterranean Ridge at about 2000 m depth (Olimpi mud field. The major aim of this study was to describe distributional patterns of meiofaunal communities and nematode assemblages from different seep microhabitats. Meiofaunal taxa and nematode assemblages at both mud volcanoes differed significantly from other Mediterranean sites in terms of standing stocks, dominance and species diversity. Density and biomass values were significantly higher at the seep sites, particularly at Amsterdam. Patterns of nematode diversity, the dominant meiofaunal taxon, varied, displaying both very high or very low species richness and dominance, depending on the microhabitat studied. The periphery of the Lamellibrachia and bivalve shell microhabitats of Napoli exhibited the highest species richness, while the reduced sediments of Amsterdam yielded a species-poor nematode community dominated by two successful species, one belonging to the genus Aponema and the other to the genus Sabatieria. Analysis of β-diversity showed that microhabitat heterogeneity of mud volcanoes contributed substantially to the total nematode species richness in the eastern Mediterranean Sea. These observations indicate a strong influence of mud volcanoes and cold-seep ecosystems on the meiofaunal communities and nematode assemblages.

  18. Integrated survey of elemental stoichiometry (C, N, P from the Western to Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    M. Pujo-Pay

    2010-10-01

    Full Text Available This paper provides an extensive vertical and longitudinal description of the biogeochemistry in the whole Mediterranean Sea during the summer 2008. During this strong stratified period, the distribution of nutrients, particulate and dissolved organic carbon (DOC, nitrogen (DON and phosphorus (DOP were investigated along a 3000 km transect (BOUM cruise crossing the Western and Eastern Mediterranean basins. The partitioning of chemical C, N and P species among all these mineral and organic pools has been analysed to produce a detailed spatial and vertical extended examination of the elemental stoichiometry. Surface Mediterranean waters were depleted in nutrients and the thickness of this depleted layer increased towards the East from about 10 m in the Gulf of Lion to more than 100 m in the Levantine basin, concomitantly to the gradual deepening of the thermocline and nutriclines. We used threshold in oxygen concentration to discriminate the water column in three layers; surface (Biogenic Layer BL, intermediate (Mineralization Layer ML, and deep layer (DL and to propose a schematic representation of biogeochemical fluxes between the different compartments and to compare the functioning of the two basins. The stoichiometry revealed a clear longitudinal and vertical gradient in the mineral fraction with a P-depletion evidenced on both dimension. As a consequence of the severe deficiency in phosphorus, the C:N:P ratios in all pools within the BL largely exceed the Redfield ratios. Despite these gradients, the deep estimated fluxes in the mineral compartment tend towards the canonical Redfield values in both basins. A change in particulate matter composition has been evidenced by a C increase relative to N and P along the whole water column in the western basin and between BL and ML in the eastern one. More surprisingly, a decrease in N relative to P with depth was encountered in the whole Mediterranean Sea. We suggest that there was a more rapid

  19. Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    C. Parinos

    2013-09-01

    Full Text Available Surface sediments collected from deep basins (1018–4087 m depth of the eastern Mediterranean Sea (Ionian Sea, southern Aegean Sea and northwestern Levantine Sea were analyzed for aliphatic and polycyclic aromatic hydrocarbons as tracers of natural and anthropogenic inputs. Concentrations of total aliphatic hydrocarbons, n-alkanes and the unresolved complex mixture (UCM of aliphatic hydrocarbons varied significantly, ranging from 1.34 to 49.2 μg g−1, 145 to 4810 ng g−1 and 0.73 to 36.7 μg g−1, respectively, while concentrations of total polycyclic aromatic hydrocarbons (PAHs ranged between 11.6 and 223 ng g−1. Molecular profiles of determined hydrocarbons reflect a mixed contribution from both natural and anthropogenic sources in deep-sea sediments of the eastern Mediterranean Sea, i.e., terrestrial plant waxes, degraded petroleum products, unburned fossil fuels and combustion of grass, wood and coal. Hydrocarbon mixtures display significant variability amongst sub-regions, reflecting differences in the relative importance of inputs from various sources and phase associations/transport pathways of individual hydrocarbons that impact on their overall distribution and fate. Hydrocarbon concentrations correlated significantly with the organic carbon content of sediments, indicating that the latter exerts an important control on their transport and ultimate accumulation in deep basins. Additionally, water masses' circulation characteristics also seem to influence the regional features and distribution patterns of hydrocarbons. Our findings highlight the role of deep basins/canyons as repositories of both natural and anthropogenic chemical species.

  20. Progress of KOERI Tsunami Warning System for the Eastern Mediterranean, Aegean and Black Seas

    Science.gov (United States)

    Necmioglu, Ocal; Meral Ozel, Nurcan; Ozer Sozdinler, Ceren; Yilmazer, Mehmet; Cokacar, Tulay; Comoglu, Mustafa; Pinar, Ali; Kekovali, Kivanc

    2016-04-01

    This presentation provides a progress report on the activities of the Bogazici University / Kandilli Observatory and Earthquake Research Institute - Regional Earthquake and Tsunami Monitoring Center (KOERI-RETMC) which provides services as a Candidate Tsunami Service Provider (CTSP) of ICG/NEAMTWS in the Eastern Mediterranean, Aegean and Black Seas since 1 July 2012. KOERI continues to operate 178 BB and 97 strong motion and 6 short period sensors and the regional coverage includes 77 stations from GFZ and additional 16 stations through bilateral agreements. One radar-type tide-gauge has been installed in Fethiye within the framework of "Inexpensive Device for Sea-Level Measurement" (IDSL) initiative offered as donation by the EC/JRC and planning is in progress for the possible installation of three more IDSLs in selected locations in the Aegean Sea coast of Turkey. The capabilities and the limitations of HF Radar technology for the purpose of tsunami detection in the Eastern Mediterranean has been identified and the maturity and the applicability of these systems for the possible use under the Tsunami Warning System has been determined. The development of the TsuComp as a user-friendly interface to be used in the assessment of tsunamigenic potential and as a single-point entry for message dissemination has been finalized. The work towards the creation of Tsunami Inundation Maps at the Tsunami Forecast Points in Turkey is near finalization. This work is partially funded by project ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839. The authors would like to thank EC/JRC and Mr. Alessandro Annunziato for their continuous support in the operational activities of RETMC and IDSL initiative.

  1. Life at cold seeps: a synthesis of biogeochemical and ecological data from Kazan mud volcano, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Werne, J.P.; Zitter, T.; Haese, R.R.; Aloisi, G.; Bouloubassi, I.; Heijs, S.; Fiala-Medioni, A.; Pancost, R.D.; Lange, G.J. de; Gottschal, J.; Foucher, J.-P.; Mascle, J.; Woodside, J.

    2004-01-01

    Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the MEDINAUT

  2. Life at cold seeps : a synthesis of biogeochemical and ecological data from Kazan mud volcano, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Werne, JP; Haese, RR; Zitter, T; Aloisi, G; Bouloubassi, L; Heijs, S; Fiala-Medioni, A; Pancost, RD; Damste, JSS; de Lange, G; Forney, LJ; Gottschal, JC; Foucher, JP; Mascle, J; Woodside, J

    2004-01-01

    Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the MEDINAUT

  3. Life at cold seeps: a synthesis of biogeochemical and ecological data from Kazan mud volcano, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Werne, J.P.; Zitter, T.; Haese, R.R.; Aloisi, G.; Bouloubassi, I.; Heijs, S.; Fiala-Medioni, A.; Pancost, R.D.; Lange, G.J. de; Gottschal, J.; Foucher, J.-P.; Mascle, J.; Woodside, J.

    2004-01-01

    Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the

  4. Life at cold seeps : a synthesis of biogeochemical and ecological data from Kazan mud volcano, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Werne, JP; Haese, RR; Zitter, T; Aloisi, G; Bouloubassi, L; Heijs, S; Fiala-Medioni, A; Pancost, RD; Damste, JSS; de Lange, G; Forney, LJ; Gottschal, JC; Foucher, JP; Mascle, J; Woodside, J

    2004-01-01

    Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the

  5. Life at cold seeps : a synthesis of biogeochemical and ecological data from Kazan mud volcano, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Werne, JP; Haese, RR; Zitter, T; Aloisi, G; Bouloubassi, L; Heijs, S; Fiala-Medioni, A; Pancost, RD; Damste, JSS; de Lange, G; Forney, LJ; Gottschal, JC; Foucher, JP; Mascle, J; Woodside, J

    2004-01-01

    Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the MEDINAUT

  6. Life at cold seeps: a synthesis of biogeochemical and ecological data from Kazan mud volcano, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Werne, J.P.; Zitter, T.; Haese, R.R.; Aloisi, G.; Bouloubassi, I.; Heijs, S.; Fiala-Medioni, A.; Pancost, R.D.; Lange, G.J. de; Gottschal, J.; Foucher, J.-P.; Mascle, J.; Woodside, J.

    2004-01-01

    Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the MEDINAUT

  7. Spatial scales of bacterial community diversity at cold seeps (Eastern Mediterranean Sea).

    Science.gov (United States)

    Pop Ristova, Petra; Wenzhöfer, Frank; Ramette, Alban; Felden, Janine; Boetius, Antje

    2015-06-01

    Cold seeps are highly productive, fragmented marine ecosystems that form at the seafloor around hydrocarbon emission pathways. The products of microbial utilization of methane and other hydrocarbons fuel rich chemosynthetic communities at these sites, with much higher respiration rates compared with the surrounding deep-sea floor. Yet little is known as to the richness, composition and spatial scaling of bacterial communities of cold seeps compared with non-seep communities. Here we assessed the bacterial diversity across nine different cold seeps in the Eastern Mediterranean deep-sea and surrounding seafloor areas. Community similarity analyses were carried out based on automated ribosomal intergenic spacer analysis (ARISA) fingerprinting and high-throughput 454 tag sequencing and were combined with in situ and ex situ geochemical analyses across spatial scales of a few tens of meters to hundreds of kilometers. Seep communities were dominated by Deltaproteobacteria, Epsilonproteobacteria and Gammaproteobacteria and shared, on average, 36% of bacterial types (ARISA OTUs (operational taxonomic units)) with communities from nearby non-seep deep-sea sediments. Bacterial communities of seeps were significantly different from those of non-seep sediments. Within cold seep regions on spatial scales of only tens to hundreds of meters, the bacterial communities differed considerably, sharing cold seep ecosystems contribute substantially to the microbial diversity of the deep-sea.

  8. Nutrient Limitation in Surface Waters of the Oligotrophic Eastern Mediterranean Sea: an Enrichment Microcosm Experiment

    KAUST Repository

    Tsiola, A.

    2015-12-01

    The growth rates of planktonic microbes in the pelagic zone of the Eastern Mediterranean Sea are nutrient limited, but the type of limitation is still uncertain. During this study, we investigated the occurrence of N and P limitation among different groups of the prokaryotic and eukaryotic (pico-, nano-, and micro-) plankton using a microcosm experiment during stratified water column conditions in the Cretan Sea (Eastern Mediterranean). Microcosms were enriched with N and P (either solely or simultaneously), and the PO4 turnover time, prokaryotic heterotrophic activity, primary production, and the abundance of the different microbial components were measured. Flow cytometric and molecular fingerprint analyses showed that different heterotrophic prokaryotic groups were limited by different nutrients; total heterotrophic prokaryotic growth was limited by P, but only when both N and P were added, changes in community structure and cell size were detected. Phytoplankton were N and P co-limited, with autotrophic pico-eukaryotes being the exception as they increased even when only P was added after a 2-day time lag. The populations of Synechococcus and Prochlorococcus were highly competitive with each other; Prochlorococcus abundance increased during the first 2 days of P addition but kept increasing only when both N and P were added, whereas Synechococcus exhibited higher pigment content and increased in abundance 3 days after simultaneous N and P additions. Dinoflagellates also showed opportunistic behavior at simultaneous N and P additions, in contrast to diatoms and coccolithophores, which diminished in all incubations. High DNA content viruses, selective grazing, and the exhaustion of N sources probably controlled the populations of diatoms and coccolithophores.

  9. Assimilation of ocean colour data into a Biochemical Flux Model of the Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. Triantafyllou

    2006-09-01

    Full Text Available Within the framework of the European MFSTEP project, an advanced multivariate sequential data assimilation system has been implemented to assimilate real chlorophyll data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS into a three-dimensional biochemical model of the Eastern Mediterranean. The physical ocean is described through the Princeton Ocean Model (POM while the biochemistry of the ecosystem is tackled with the Biochemical Flux Model (BFM. The assimilation scheme is based on the Singular Evolutive Extended Kalman (SEEK filter, in which the error statistics were parameterized by means of a suitable set of Empirical Orthogonal Functions (EOFs. A radius of influence was further selected around every data point to limit the range of the EOFs spatial correlations. The assimilation experiment was performed for one year over 1999 and forced with ECMWF 6 hour atmospheric fields. The accuracy of the ecological state identification by the assimilation system is assessed by the relevance of the system in fitting the data, and through the impact of the assimilation on non-observed biochemical processes. Assimilation of SeaWiFS data significantly improves the forecasting capability of the BFM model. Results, however, indicate the necessity of subsurface data to enhance the controllability of the ecosystem model in the deep layers.

  10. Paleodepth variations on the Eratosthenes Seamount (Eastern Mediterranean: sea-level changes or subsidence?

    Directory of Open Access Journals (Sweden)

    S. Spezzaferri

    2007-09-01

    Full Text Available The Eratosthenes Seamount (Eastern Mediterranean is interpreted as a crustal block in process of break up in response to subduction and incipient collision of the African and Eurasian Plates. Subsidence is considered to be the mechanism triggering the Messinian to Pleistocene water deepening above this unique structure. However, the application of a recently developed transfer equation of depth range distribution of benthic foraminifera indicates that sea-level changes may also have played a role, although it was generally minor. In particular, we suggest that across the Miocene/Pliocene boundary and during the Pliocene-Pleistocene, the eustatic signal is frequently coupled with uplifts and subsidence. The uplift of Cyprus across the Pliocene-Pleistocene transition is clearly recorded in the paleodepth curve. Micropaleontological studies and the use of this transfer equation based on the distribution of benthic foraminifera proves to be useful when studying the paleodepth history of complex sites, where tectonic and eustatic signals combine. We also show that marginal seas record global sea-level changes that can be identified even in tectonically active settings.

  11. Outer shelf seafloor geomorphology along a carbonate escarpment: The eastern Malta Plateau, Mediterranean Sea

    Science.gov (United States)

    Micallef, Aaron; Georgiopoulou, Aggeliki; Mountjoy, Joshu; Huvenne, Veerle A. I.; Iacono, Claudio Lo; Le Bas, Timothy; Del Carlo, Paola; Otero, Daniel Cunarro

    2016-12-01

    Submarine carbonate escarpments, documented in numerous sites around the world, consist of thick exposures of Mesozoic shallow water carbonate sequences - primarily limestones and dolomites - with reliefs of >1 km and slope gradients of >70°. Whilst most research efforts have focused on the processes that shaped carbonate escarpments into complex and extreme terrains, little attention has been paid to the geomorphology of shelves upslope of carbonate escarpments. In this study we investigate high resolution geophysical, sedimentological and visual data acquired from the eastern Malta Plateau, central Mediterranean Sea, to demonstrate that the outer shelf of a carbonate escarpment is directly influenced by escarpment-forming processes. We document forty eight erosional scars, six long channels and numerous smaller-scale channels, three elongate mounds, and an elongate ridge across the eastern Malta Plateau. By analysing their morphology, seismic character, and sedimentological properties, we infer that the seafloor of the eastern Malta Plateau has been modified by three key processes: (i) Mass movements - in the form of translational slides, spreading and debris flows - that mobilised stratified Plio-Pleistocene hemipelagic mud along the shelf break and that were likely triggered by seismicity and loss of support due to canyon erosion across the upper Malta Escarpment; (ii) NNW-SSE trending sinistral strike-slip deformation in Cenozoic carbonates - resulting from the development of a mega-hinge fault system along the Malta Escarpment since the Late Mesozoic, and SE-NW directed horizontal shortening since the Late Miocene - which gave rise to NW-SE oriented extensional grabens and a NNW-SSE horst; (iii) Flow of bottom currents perpendicular and parallel to the Malta Escarpment, associated with either Modified Atlantic Water flows during sea level lowstands and/or Levantine Intermediate Water flows at present, which was responsible for sediment erosion and deposition

  12. The surface circulation in the eastern basin of the Mediterranean Sea

    Science.gov (United States)

    Hamad, N.; Millot, C.; Taupier-Letage, I.

    2003-04-01

    The POEM-schema of the Atlantic Water (AW, http://ciesm.org/events/RT5-WaterMassAcronyms.pdf) circulation in the eastern basin of the Mediterranean Sea widely referred to nowadays (Robinson et al., 1991, completed by Robinson and Golnaraghi, 1993, and by Malanotte-Rizzoli et al., 1997) represents, in particular, a jet meandering offshore across the whole basin. No information is given on the southern part of the basin and no mention is made of a possible overall alongslope anticlockwise flow there, as suggested by a contemporaneous analysis of infrared satellite images (Le Vourch et al., 1992; Millot, 1992). A roughly similar controversy was elucidated in the western basin where such imagery was proven reliable. This has motivated the detailed analysis of daily and weekly composite images (about 1000) during the period 1996-2000, and of monthly composites available since 1985. Our analysis shows that AW circulates alongslope and anticlockwise around the whole basin, as indicated by Nielsen (1912) who considered the Coriolis effect as dominant. This circulation, which is permanent from Tunisia to Turkey, exists more or less temporarily in the Aegean, in the Ionian around Greece and in the Adriatic, due to the Etesians. However, a branch having spread for years (up to early 1998) from the channel of Sicily towards the northern Ionian before vanishing represents marked interannual (not seasonal) variability. Being unstable during most of its circuit, the AW flow generates mesoscale eddies which had not been correctly described before and which represent a relatively large amount of AW. Other eddies are known to be generated by orographic effects on the wind field, especially the Etesians. Both kinds of eddies play a fundamental role in spreading AW from alongslope towards the open basin. Although these eddies have characteristics almost specific to each subbasin and/or generation mechanism, the largest ones are anticyclonic, both kinds reach diameters of a few 100s km

  13. New data on the occurrence of two alien fishes, Pisodonophis semicinctus and Pomadasys stridens, from the Eastern Mediterranean Sea

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    M. BILECENOGLU

    2010-12-01

    Full Text Available The tropical Atlantic originated saddled snake eel, Pisodonophis semicinctus (Richardson, 1848 and the Indian Ocean originated striped piggy, Pomadasys stridens (Forsskål, 1775, are being recorded for the first time from Turkish coasts. First species is also a new addition to the eastern Mediterranean ichthyofauna, while the latter species has expanded its range to the northeastern Levant Sea.

  14. Anomalous distribution of fluoride and phosphorus forms in surface sediments along eastern Egyptian Mediterranean Sea coast.

    Science.gov (United States)

    El-Said, Ghada F; Khalil, Mona Kh; Draz, Suzanne E O

    2016-07-01

    The study focused on the distribution of fluoride, total phosphorus, and four phosphorus fractions in some sites along the Egyptian Mediterranean Sea coast. The geochemical parameters and textures of 30 surficial sediment samples from six sectors were determined. The sediment's geochemical parameters (total carbonates (TCO3) and total organic carbon (TOC), exchangeable and carbonate-associated phosphorus (Pex), iron- and aluminum-associated phosphorus (POH), calcium-associated phosphate/apatite (PHCl), residual phosphorus (PR), total phosphorus (TP), calcium (Cas), magnesium (Mgs), and fluoride (Fs)) showed variable values. The rank of phosphorus fractions in the sediments PHCl > PR > POH > Pex reflected that the eastern Egyptian coast was still uncontaminated. Generally, Pex levels gave a gradual increase in the offshore direction, while POH values varied along the stations of each sector. Also, the presented data indicated that the apatite-P fraction was the main storage of the phosphate in the sediments with a contribution to TP ranging from 58 to 87 %. The highest and lowest average fluoride contents (0.49 ± 0.10 and 0.25 ± 0.31 mg/g) were determined in the Port Said and Damietta sectors, respectively. Interestingly, the variability of both phosphorus and fluoride levels in the investigated area seemed to be accompanied with the sediment's character beside the proximity to potential effluent sources.

  15. Geological evidence of tsunamis and earthquakes at the Eastern Hellenic Arc: correlation with historical seismicity in the eastern Mediterranean Sea

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    Gerassimos Papadopoulos

    2012-12-01

    Full Text Available Sedimentary stratigraphy determined by trenching in Dalaman, south-western Turkey, revealed three sand layers at a distance of approximately 240 m from the shoreline and at elevations of +0.30, +0.55 and +0.90 cm. Storm surge action does not explain the features of these deposits that show instead typical characteristics of tsunami deposition. The sand layers correlate with historical tsunamis generated by large earthquakes which ruptured the eastern Hellenic Arc and Trench in 1303, 1481 and 1741. Accelerator mass spectrometry 14C dating of a wood sample from layer II indicated deposition in AD 1473±46, which fits the 1481 event. From an estimated average alluvium deposition rate of approximately 0.13 cm/year, layers I and III were dated at 1322 and 1724, which may represent the large 1303 and 1741 tsunamis. The geological record of the 1303 key event is very poor; therefore, sand layer I perhaps represents an important geological signature of the 1303 tsunami. However, the strong tsunami reported to have been generated by the 1609 earthquake is missing from Dalaman stratigraphy: this underlines the sensitivity of tsunami geological signatures to various local factors. The 1303 earthquake ruptured the trench between the islands of Crete and Rhodes. For the earthquakes of 1481, 1609 and 1741 we suggested that they were very likely generated in the Rhodes Abyssal Plain where sea depths of up to approximately 4200 m, together with the thrust component of seismotectonics, favor tsunami generation. Sand dykes directed upwards from layer I to layer II indicated that the 1481 earthquake triggered liquefaction of sand layer I. The results substantially widen our knowledge about the historical earthquake and tsunami activity in the eastern Mediterranean basin.

  16. Evaluating the impact of atmospheric depositions on springtime dinitrogen fixation in the Cretan Sea (Eastern Mediterranean - A mesocosm approach

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    Eyal Rahav

    2016-09-01

    Full Text Available Large amounts of dust and atmospheric aerosols, originating from surrounding desert areas (e.g., Sahara and Middle East are deposited annually on the surface of the Eastern Mediterranean Sea. These depositions can provide high amounts of micro (such as Fe, Zn, Co and macro nutrients (such as P and N to supplement nutrient-poor surface waters- that typically limit primary productivity and also dinitrogen (N2 fixation in many marine environments. Here, we studied the impact of the atmospheric deposition of dust and aerosols on N2 fixation in the Cretan Sea (Eastern Mediterranean Sea. Mixed polluted aerosols (hereafter A and Saharan dust (hereafter SD were added to nine mesocosms (3-m3 each containing surface mixed layer seawater (~10 m, and N2 fixation was evaluated for 6 days during May 2012 (springtime. The addition of SD triggered a rapid (30 h and robust (2-4 fold increase in N2 fixation rates that remained high for 6 days and contributed 3-8% of the primary productivity. The A addition also resulted in higher N2 fixation rates compared to the unamended control mesocosms, although the responses were less profound (1.5-2 fold and accounted for only 2-4% of the primary productivity. The microbial community responded differently to the two additions. Heterotrophic bacterial N2 fixers dominated the diazotroph community in A and the control mesocosms, while the non-filamentous cyanobacterial group Trichodesmium prevailed in the SD treatment (68% of all the operational taxonomic units, verified by qPCR analyses. Our results indicate that the aerosol source, its route prior to deposition, and its specific chemical composition, can alter the diazotrophic diversity and activity in the Eastern Mediterranean Sea and may thus impact both the N and C dynamics in this impoverished environment.

  17. Spatial distribution and abundance of the megabenthic fauna community in Gabes gulf (Tunisia, eastern Mediterranean Sea

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    H. EL LAKHRACH

    2012-12-01

    Full Text Available The aim of this paper is to bring to light the knowledge of marine diversity of invertebrates in Gabes gulf. The spatial distribution of the megabenthic fauna community in Gabes gulf (Tunisia, Eastern Mediterranean Sea, together with the bottom type and vegetation cover, were studied. The abundance of the megabenthic fauna was represented by eight groups: Echinodermata (38%, Crustacea (21%, Tunicata (19%, Mollusca (13%, Porifera (4%, Cnidaria (3%, Bryozoa, and Annelida (2%. It was spatially more concentrated in the coast area of the gulf than in the offshore waters. This area, especially, in Southern Kerkennah, North-est of Gabes and North-east of Djerba appeared to be in a good ecological condition  hosting a variety of species like the paguridsPaguristes eremita and Pagurus cuanensis, the brachyura Medorippe lanata, Inachus doresttensis, the Gastropoda Hexaplex trunculus, Bolinus brandaris, Aporrhais pespelecani, andErosaria turdus, the Bivalvia Fulvia fragilis, the Echinoidea Psammechinus microtuberculatus, Holothuria polii,Ophiothrix fragilis and Antedon mediterranea, and the AscidiaceaAplidium cf. conicum, Didemnum spp, and Microcosmus exasperatus.The species’ compositions of the megabentic fauna community showed clearly that the spatial analysis represented the differences between the community of these two regions (inshore waters and offshore waters. These differences were closely related to peculiar characters of the fauna and biotopes (depth, bottom type and vegetation cover community. The results of the present study should be considered as a necessary starting point for a further analysis of priceless benthic fauna contribution to the marine environment and its organisms.

  18. Sea level changes according to data of tide gauge station and its relationship with elements of climate in eastern Mediterranean: 1972-2009

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    Muhammed Zeynel Öztürk

    2011-08-01

    Full Text Available Mediterranean Sea is one of the areas that indicated the greatest increase in sea level rise during the 20th century. The eastern Mediterranean had also greatest increase in sea level with in the Mediterranean Sea. In this study, sea level data observed at 11 tide gauge stations located in the Levantine Sea, Cretan Sea and south of the Aegean Sea and gridded climatological data were used in the eastern Mediterranean Sea. In this frame, monthly and annual variations and trends in average, average maximum and average minimum sea levels data and mean air temperature, mean sea level pressure and total precipitation series were investigated. According to the results of analysis, there are statistically significant increase trends in temperature and all sea level series. These trend rates are of +1.57 mm/year in average sea level, +1.89 mm/year in average maximum, +1.36 mm/year in average minimum and 0.026 ºC/year in temperature. According to the long-term averages, annually amplitude is 14.9 cm, while, the highest and the lowest levels of amplitude are reached in August and March, respectively. According to the interannual average maximum and minimum sea level values, amplitude of 36.5 cm is seen.

  19. New techniques on oil spill modelling applied in the Eastern Mediterranean sea

    Science.gov (United States)

    Zodiatis, George; Kokinou, Eleni; Alves, Tiago; Lardner, Robin

    2016-04-01

    Small or large oil spills resulting from accidents on oil and gas platforms or due to the maritime traffic comprise a major environmental threat for all marine and coastal systems, and they are responsible for huge economic losses concerning the human infrastructures and the tourism. This work aims at presenting the integration of oil-spill model, bathymetric, meteorological, oceanographic, geomorphological and geological data to assess the impact of oil spills in maritime regions such as bays, as well as in the open sea, carried out in the Eastern Mediterranean Sea within the frame of NEREIDs, MEDESS-4MS and RAOP-Med EU projects. The MEDSLIK oil spill predictions are successfully combined with bathymetric analyses, the shoreline susceptibility and hazard mapping to predict the oil slick trajectories and the extend of the coastal areas affected. Based on MEDSLIK results, oil spill spreading and dispersion scenarios are produced both for non-mitigated and mitigated oil spills. MEDSLIK model considers three response combating methods of floating oil spills: a) mechanical recovery using skimmers or similar mechanisms; b) destruction by fire, c) use of dispersants or other bio-chemical means and deployment of booms. Shoreline susceptibility map can be compiled for the study areas based on the Environmental Susceptibility Index. The ESI classification considers a range of values between 1 and 9, with level 1 (ESI 1) representing areas of low susceptibility, impermeable to oil spilt during accidents, such as linear shorelines with rocky cliffs. In contrast, ESI 9 shores are highly vulnerable, and often coincide with natural reserves and special protected areas. Additionally, hazard maps of the maritime and coastal areas, possibly exposed to the danger on an oil spill, evaluate and categorize the hazard in levels from low to very high. This is important because a) Prior to an oil spill accident, hazard and shoreline susceptibility maps are made available to design

  20. Lithospheric Response of the Anatolian Plateau in the Realm of the Black Sea and the Eastern Mediterranean

    Science.gov (United States)

    Ergun, Mustafa

    2016-04-01

    The Eastern Mediterranean and the Middle East make up the southern boundary of the Tethys Ocean for the last 200 Ma by the disintegration of the Pangaea and closure of the Tethys Ocean. It covers the structures: Hellenic and Cyprus arcs; Eastern Anatolian Fault Zone; Bitlis Suture Zone and Zagros Mountains. The northern boundary of the Tethys Ocean is made up the Black Sea and the Caspian Sea, and it extends up to Po valley towards the west (Pontides, Caucasus). Between these two zones the Alp-Himalayan orogenic belt is situated where the Balkan, Anatolia and the Iran plateaus are placed as the remnants of the lost Ocean of the Tethys. The active tectonics of the eastern Mediterranean is the consequences of the convergence between the Africa, Arabian plates in the south and the Eurasian plate in the north. These plates act as converging jaws of vise forming a crustal mosaic in between. The active crustal deformation pattern reveals two N-S trending maximum compression or crustal shortening syntaxes': (i) the eastern Black Sea and the Arabian plate, (ii) the western Black Sea and the Isparta Angle. The transition in young mountain belts, from ocean crust through the agglomeration of arc systems with long histories of oceanic closures, to a continental hinterland is well exemplified by the plate margin in the eastern Mediterranean. The boundary between the African plate and the Aegean/Anatolian microplate is in the process of transition from subduction to collision along the Cyprus Arc. Since the Black Sea has oceanic lithosphere, it is actually a separate plate. However it can be considered as a block, because the Black Sea is a trapped oceanic basin that cannot move freely within the Eurasian Plate. Lying towards the northern margin of orogenic belts related to the closure of the Tethys Ocean, it is generally considered to be a result of back-arc extension associated with the northward subduction of the Tethyan plate to the south. Interface oceanic lithosphere at

  1. A new alien bryozoan Celleporaria brunnea (Hincks, 1884 in the Aegean Sea (eastern Mediterranean

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    Ferah Koçak

    2007-03-01

    Full Text Available The ascophoran Bryozoa Celleporaria brunnea, a new record for the Mediterranean Sea, was found on Mytilus galloprovincialis collected in the inner part of Izmir Bay (Aegean Sea, Turkey in September 2004. The species was previously reported from the Pacific coast of the United States. Its occurrence in the polluted inner part of Izmir Bay, near Alsancak Harbour, suggests that it has been newly introduced to the area, possibly via ship hulls. The morphological, ecological and zoogeographical characteristics of the species are given and discussed.

  2. A biomarker study of high resolution sedimentary records in the eastern Mediterranean Sea since the last glacial maximum

    Science.gov (United States)

    Katsouras, G.; Gogou, A.; Bouloubassi, I.; Emeis, K.-C.; Triantaphyllou, M. V.; Lykousis, V.

    2009-04-01

    Information stored in sedimentary records provides evidence on climate and environmental variability at decadal to centennial time scales. The eastern Mediterranean Sea and the related Aegean Sea exhibit high sedimentation rates in certain areas and are considered as sensitive regions to record paleo-environmental and -climatic changes. The aim of our study is to reconstruct high-frequency paleoclimatic variations and identify associated changes in the physical, chemical and biological environment in selected basins of the eastern Mediterranean Sea, using molecular biogeochemical proxies. Here we present a high-resolution multi-proxy study along two Aegean Sea cores (north (152SL) and southeast (NS-14)) and a Libyan Sea core (HCM2/22). An important time marker and indicator of remarkable climatic and environmental changes is sapropel S1, a sediment layer rich in organic carbon. Depending on the water column depth, the sediment accumulation rates and the proximity to freshwater and water formation sources, S1 deposited between ~9.8 to 6.4 kyr BP, with an apparent interruption in the S1 deposition that occurred from ~8.6 to 7.6 kyr BP. SSTs based on alkenone unsaturation index Uḱ 37, ^15tot, ^13Corg and various marine and terrestrial biomarkers are used to investigate the region's climatic variability, and the modifications in the biogeochemical functioning of the eastern Mediterranean Sea. Uḱ 37 SST distribution in our records reveals significant fluctuations in temperature over the last 20.000 yrs. Organic carbon stable isotopes values span a narrow range over the whole sequence, with values varying to typical marine origin. The distributions of land-plant biomarkers are indicative of variable terrigenous organic matter supply and the concomitant transport of nutrients to surface waters. Furthermore, the distribution patterns and characteristic ratios of marine biomarkers exhibit differences in the paleoproductivity trends and ventilation changes over the last

  3. Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea)

    Science.gov (United States)

    Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria

    2017-04-01

    Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to

  4. Aerosol sources and their contribution to the chemical composition of aerosols in the Eastern Mediterranean Sea during summertime

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    J. Sciare

    2003-01-01

    Full Text Available A detailed study on the temporal variability of compounds important in controlling aerosol chemical composition was performed during a one-month experiment conducted during summer 2000 at a background site on Crete, in the Eastern Mediterranean Sea. Contribution of different aerosol sources in the Eastern Mediterranean Basin could be investigated at this location since the site is influenced by a wide range of air masses originating mainly in Europe and Africa. Chemical apportionment was performed for various air mass origins and showed a strong impact of anthropogenic emissions in the Turkey and Central Europe sectors, with black carbon (BC and non-sea-salt sulfate (nss-SO4 concentrations higher than observed in the Eastern and Western Europe sectors. High levels of non-sea-salt calcium (nss-Ca were associated with air masses from Africa but also from Central Turkey. Evidence was found that BC calculation based on light absorbance during dust events was biased. This quality-controlled high temporal resolution dataset allowed to investigate in detail the source-receptor relationships responsible for the levels of BC, nss-SO4 and sulfur dioxide (SO2, observed in Crete. Among the results obtained from this model, the major contribution of Turkey and Central Europe was confirmed in terms of anthropogenic emissions. Comparisons with remote optical properties obtained from Satellite observations (SEAWIFS north of Crete indicates that our ground based aerosol characterization was suitable for describing aerosol properties in the atmospheric column for most of the time during the campaign.

  5. Biochemical biomarker responses to pollution in selected sentinel organisms across the Eastern Mediterranean and the Black Sea

    KAUST Repository

    Tsangaris, Catherine

    2015-09-23

    Pollution effects were assessed by means of biochemical biomarkers (catalase, glutathione S-transferase and acetylcholinesterase activities, and metallothioneins content) in five species at selected coastal sites across the Eastern Mediterranean and the Black Sea. The mussel Mytilus galloprovincialis, a well-established sentinel species, was investigated in the Adriatic Sea, Aegean Sea, and Black Sea. The mussel Brachidontes pharaonis and the striped red mullet Mullus surmuletus were used in the Levantine Sea where M. galloprovincialis is not present. The white seabream Diplodus sargus sargus and the gastropod Rapana venosa were additionally sampled in the Adriatic and the Black Sea, respectively. Mussels showed catalase, glutathione S-transferase, and acetylcholinesterase responses to pollution in most geographical areas while the response of metallothioneins was restricted to a few sites. R. venosa showed marked responses of catalase and metallothioneins whereas both fish species did not generally exhibit variations in biomarker values among sites. The approach based on the reference deviation concept using the “Integrated Biological Responses version 2” index was useful for the interpretation of overall biomarker responses.

  6. Biochemical biomarker responses to pollution in selected sentinel organisms across the Eastern Mediterranean and the Black Sea.

    Science.gov (United States)

    Catherine, Tsangaris; Vanessa, Moschino; Evangelia, Strogyloudi; Valentina, Coatu; Andreja, Ramšak; Rana, Abu Alhaija; Susana, Carvalho; Serena, Felline; Alisa, Kosyan; Yiota, Lazarou; Ioannis, Hatzianestis; Andra, Oros; Daniela, Tiganus

    2016-01-01

    Pollution effects were assessed by means of biochemical biomarkers (catalase, glutathione S-transferase and acetylcholinesterase activities, and metallothioneins content) in five species at selected coastal sites across the Eastern Mediterranean and the Black Sea. The mussel Mytilus galloprovincialis, a well-established sentinel species, was investigated in the Adriatic Sea, Aegean Sea, and Black Sea. The mussel Brachidontes pharaonis and the striped red mullet Mullus surmuletus were used in the Levantine Sea where M. galloprovincialis is not present. The white seabream Diplodus sargus sargus and the gastropod Rapana venosa were additionally sampled in the Adriatic and the Black Sea, respectively. Mussels showed catalase, glutathione S-transferase, and acetylcholinesterase responses to pollution in most geographical areas while the response of metallothioneins was restricted to a few sites. R. venosa showed marked responses of catalase and metallothioneins whereas both fish species did not generally exhibit variations in biomarker values among sites. The approach based on the reference deviation concept using the "Integrated Biological Responses version 2" index was useful for the interpretation of overall biomarker responses.

  7. Morphological recognition of Globigerinoides ruber morphotypes and their susceptibility to diagenetic alteration in the eastern Mediterranean Sea

    Science.gov (United States)

    Kontakiotis, G.; Antonarakou, A.; Mortyn, P. G.; Drinia, H.; Anastasakis, G.; Zarkogiannis, S.; Möbius, J.

    2017-10-01

    Planktonic foraminiferal geochemistry presents a valuable archive for paleoceanographic reconstructions. However in high salinity and carbonate super-saturated settings, precipitation of inorganic calcite onto foraminiferal tests can potentially alter the primary geochemical signal, biasing Mg/Ca ratios and ensuing paleoceanographic reconstructions. Here we utilize test biometrics (specifically related to the compression and elongation of the last chambers) to identify four distinct morphotypes (labelled A-D) of the paleoceanographically important planktonic foraminifer species Globigerinoides ruber, and further evaluate their susceptibility to diagenetic alteration from a suite of surface sediments in the eastern Mediterranean Sea. The three distinguished morphotypes (A-C) correspond to previously recognized morphotypes (;Normal;, ;Platys;, ;Elongate; respectively) in the Mediterranean Sea, while the remaining (D or ;Twin;) was designated for the first time. We also compare Scanning Electron Microscopy (SEM) observations performed on four distinguished morphotypes, indicative of potential diagenetic alteration influence. We identified 3 different overgrowth stages (OGA1-OGA3), as a function of geography in the study area. The early diagenesis degrees (involving all the morphotypes) are only geographically distinct along the eastern Mediterranean (increasing to the south), since the morphology does not play a role in the likelihood of diagenetic alteration. Particularly, in the north Aegean Sea, SEM analyses reveal the absence or limited presence of an overgrowth imprint in all recognized morphotypes, while in the central-south Aegean and Levantine Seas they show higher amplitudes of diagenetic overprint supporting the general trend to advanced diagenetic alteration. The semi-enclosed oligotrophic nature and high salinity of this setting, in combination with the different degree of carbonate precipitation and calcite super-saturation between the sub-basins, could

  8. High oxygen consumption rates in the deep layers of the North Aegean Sea (eastern Mediterranean

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    E. SOUVERMEZOGLOU

    2002-06-01

    Full Text Available Severe winter meteorological conditions promote dense water formation over the shelves of the North Aegean Sea. The newly formed dense water fills the deep basins of the North Aegean Sea, contributing to their ventilation and the downward transport of organic and inorganic material. The great bathymetric variability imposes limitations on the deep circulation and the communication between the various basins and makes the North Aegean Sea an appropriate area for the monitoring of oxygen consumption in the deep layers. Historical hydrographic data suggest that there was extensive production of dense water in the North Aegean Sea on two occasions during the last decade, the winters of 1987 and 1992-1993. Our data series from August 1986 to September 1989 and from March 1997 to February 1999, permitted us to follow, step by step, the oxygen consumption and the nutrient regeneration in the deep basins of the northern Aegean Sea during these periods of isolation. The organic matter reaching the bottom layer just after the deep water formation event is rich in labile and easily oxidizable material and its decomposition leads to a significant oxygen uptake during the first year of stagnation. The further decomposition of the remaining semi-labile and refractory material turns over on greater time scales, by consuming lesser amounts of oxygen. A more significant oxygen decrease is recorded in the eastern basin (Lemnos Basin of the North Aegean Trough, than in the central (Athos Basin and the western (North Sporades Basin ones and is attributed to the irregular contribution of the Black Sea Water (BSW to the water masses formed on the different shelves of the North Aegean Sea. Our results and the existing data on the Turkish straits showed that dissolved organic matter is the major constituent responsible for this high oxygen consumption. The slightly different particulate organic carbon fluxes to these depressions play a secondary role.

  9. High oxygen consumption rates in the deep layers of the North Aegean Sea (eastern Mediterranean

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    E. SOUVERMEZOGLOU

    2012-12-01

    Full Text Available Severe winter meteorological conditions promote dense water formation over the shelves of the North Aegean Sea. The newly formed dense water fills the deep basins of the North Aegean Sea, contributing to their ventilation and the downward transport of organic and inorganic material. The great bathymetric variability imposes limitations on the deep circulation and the communication between the various basins and makes the North Aegean Sea an appropriate area for the monitoring of oxygen consumption in the deep layers. Historical hydrographic data suggest that there was extensive production of dense water in the North Aegean Sea on two occasions during the last decade, the winters of 1987 and 1992-1993. Our data series from August 1986 to September 1989 and from March 1997 to February 1999, permitted us to follow, step by step, the oxygen consumption and the nutrient regeneration in the deep basins of the northern Aegean Sea during these periods of isolation. The organic matter reaching the bottom layer just after the deep water formation event is rich in labile and easily oxidizable material and its decomposition leads to a significant oxygen uptake during the first year of stagnation. The further decomposition of the remaining semi-labile and refractory material turns over on greater time scales, by consuming lesser amounts of oxygen. A more significant oxygen decrease is recorded in the eastern basin (Lemnos Basin of the North Aegean Trough, than in the central (Athos Basin and the western (North Sporades Basin ones and is attributed to the irregular contribution of the Black Sea Water (BSW to the water masses formed on the different shelves of the North Aegean Sea. Our results and the existing data on the Turkish straits showed that dissolved organic matter is the major constituent responsible for this high oxygen consumption. The slightly different particulate organic carbon fluxes to these depressions play a secondary role.

  10. First record of Aequorea macrodactyla (Cnidaria, Hydrozoa from the Israeli coast of the eastern Mediterranean Sea, an alien species indicating invasive pathways

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    Gur Mizrahi

    2015-07-01

    Full Text Available The species of Aequorea attract much scientific interest as they contain the unique Green Fluorescent Protein (GFP. In this work we describe for the first time the discovery of a hydrozoan jellyfish belonging to the genus Aequorea from the Israeli eastern Mediterranean that contains and exhibits fluorescent protein. Finding Aequorea macrodactyla (Brandt, 1835 in the eastern Mediterranean indicates that changes are occurring in the gelatinous fauna of this area. This hydromedusa is known in the seas adjoining the Mediterranean though most of its records are more than four decades old. We examined and identified the newly discovered Israeli Aequorea species by combining two phylogenetic systems, traditional morphological phylogeny and molecular phylogenetics. The molecular identification determined that the species is A. macrodactyla but with minor genetic differences in the mtDNA 16S gene marker. A 1% difference between the Israeli and the Japanese A. macrodactyla was demonstrated, which suggests that the genetic difference between the Israeli and the Japanese population is small but existent. Invasive pathways for this jellyfish were examined by phylogenetic and taxonomic relationships with similar Cnidaria. The results indicate introduction from the Indo-Pacific as invasive pathway, probably by human transportation, and the discovery of A. macrodactyla in the eastern Mediterranean Sea could be interpreted as part of the changes in marine biota as a result of cumulative effects of anthropogenic and global changes that affect the eastern Mediterranean basin.

  11. Gouge marks on deep-sea mud volcanoes in the eastern Mediterranean: Caused by Cuvier's beaked whales?

    Science.gov (United States)

    Woodside, J. M.; David, L.; Frantzis, A.; Hooker, S. K.

    2006-11-01

    Enigmatic seafloor gouge marks at depths of 1700-2100 m have been observed from submersible during geological survey work studying mud volcanoes in the eastern Mediterranean Sea. The marks consist of a central groove (about 10 cm deep and 1-2 m long), superimposed on a broader bowl-shaped depression (1-2 m long by about 50 cm wide) with raised rims (up to 10 cm high) to either side of the central groove. We discuss the potential biological causes of these marks, and conclude that they are probably created by Cuvier's beaked whales ( Ziphius cavirostris) during foraging dives to these depths. The mud volcanoes have a comparatively rich and diverse benthic ecology associated with methane-rich fluid seeps and thus could be the base of food chains that reach top predators like the deep-diving whales. The characteristic high acoustic backscatter of the mud volcanoes would facilitate their detection by the echolocation system of these whales.

  12. The Temporal Dynamics of Coastal Phytoplankton and Bacterioplankton in the Eastern Mediterranean Sea.

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    Ofrat Raveh

    Full Text Available This study considers variability in phytoplankton and heterotrophic bacterial abundances and production rates, in one of the most oligotrophic marine regions in the world-the Levantine Basin. The temporal dynamics of these planktonic groups were studied in the coastal waters of the southeastern Mediterranean Sea approximately every two weeks for a total of two years. Heterotrophic bacteria were abundant mostly during late summer and midwinter, and were positively correlated with bacterial production and with N2 fixation. Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates. Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients. Furthermore, a comparison of our results with results from the open Levantine Basin demonstrates that autotrophic and heterotrophic production, as well as N2 fixation rates, are considerably higher in the coastal habitat than in the open sea, while nutrient levels or cell abundance are not different. These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

  13. Surface heat fluxes and ecosystem function in the Cretan Sea (eastern Mediterranean: a modelling study

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    J. R. Siddorn

    Full Text Available As a component of the Mediterranean Forecast System Pilot Project, a data buoy was deployed in the Cretan Sea. A 1-D ecosystem model of the site has been used to investigate the role of surface heat fluxes in determining modelled ecosystem behaviour. The method of calculation of these fluxes, the quality of the data used, and the temporal resolution of the data all had an impact upon the modelled ecosystem function. The effects of the changes in heat flux formulation were substantial, with both annually averaged properties of the system and the seasonal evolution of the biology being affected. It was also found that the ecosystem model was extremely sensitive to the accuracy of the meteorological forcing data used, with substantial changes in biology found when offsets in the forcing data were imposed. The frequency of forcing data was relatively unimportant in determining the biological function, although lower frequency forcing damped high frequency variability in the biology. During periods of mixing the biology showed an amplified response to changes in physical dynamics, but during periods of stratification the variations in the physics were found to be less important. Zooplankton showed more sensitivity to physical variability than either phytoplankton or bacteria. The consequences for ecosystem modelling are discussed.

    Key words. Oceanography: physical (air-sea interactions; turbulence, diffusion, and mixing processes – Oceanography: biological and chemical (plankton

  14. Spatial and temporal variability of tropospheric ozone (O3) in the boundary layer above the Aegean Sea (eastern Mediterranean)

    Science.gov (United States)

    Kouvarakis, G.; Vrekoussis, M.; Mihalopoulos, N.; Kourtidis, K.; Rappenglueck, B.; Gerasopoulos, E.; Zerefos, C.

    2002-09-01

    To study the spatial and temporal variability of tropospheric ozone in the marine boundary layer over the Aegean Sea (eastern Mediterranean), an O3 analyzer has been installed onboard of a passenger vessel traveling on a regular basis in the Aegean Sea (from Heraklion/Crete 35°30'N, 25°13'E to Thessaloniki 40°64'N, 22°97'E) during a period of 14 months (August 1999 to November 2000). In addition, O3 data have been obtained on a daily basis at the regional background station of Finokalia (Crete; 35°30'N, 25°70'E) since September 1997, short-term measurements of O3 were performed over Crete during the PAUR II campaign (May 1999), and the first O3 data from a rural area (40°32'N, 23°50'E) close to Thessaloniki at the north of Greece have been collected from March 2000 to January 2001. This survey extensive points out the existence of a well-defined seasonal cycle in boundary layer O3 with maximum in summer both above the Aegean Sea and at Finokalia. However, the seasonal signal (defined as the summer/winter ratio) is not constant and varies as a function of air mass origin from 1.33 to 1.15 for the N-NE and SW-S sectors, respectively, in line with the geographical location of the O3 precursor sources. Our data show the absence of any significant longitudinal gradient over Crete at least during spring and autumn and the absence of significant latitudinal gradient between the north and south Aegean Sea during all seasons for air masses having similar origin. The above results indicate that long-range transport is the main factor accounting for the elevated O3 levels above the eastern Mediterranean Sea. Thus (1) O3 data from Finokalia, where the longest time series are available for the area, have regional significance and (2) over the entire Aegean basin, ozone values are above the 32 ppbv European Union (EU) phytotoxicity limit throughout the year and above the 53 ppbv EU health protection limit most of the time during the dry season of the year. The very

  15. Functional diversity patterns of abyssal nematodes in the Eastern Mediterranean: A comparison between cold seeps and typical deep sea sediments

    Science.gov (United States)

    Kalogeropoulou, V.; Keklikoglou, K.; Lampadariou, N.

    2015-04-01

    Spatial patterns in deep sea nematode biological trait composition and functional diversity were investigated between chemosynthetic and typical deep sea ecosystems as well as between different microhabitats within the chemosynthetic ecosystems, in the Eastern Mediterranean. The chemosynthetic ecosystems chosen were two mud volcanoes, Napoli at 1950 m depth and Amsterdam at 2040 m depth which are cold seeps characterized by high chemosynthetic activity and spatial heterogeneity. Typical deep sea ecosystems consisted of fine-grained silt-clay sediments which were collected from three areas located in the south Ionian Sea at 2765 to 2840 m depth, the southern Cretan margin at 1089 to 1998 m depth and the Levantine Sea at 3055 to 3870 m depth. A range of biological traits (9 traits; 31 categories) related to buccal morphology, tail shape, body size, body shape, life history strategy, sediment position, cuticle morphology, amphid shape and presence of somatic setae were combined to identify patterns in the functional composition of nematode assemblages between the two habitats, the two mud volcanoes (macroscale) and between the microhabitats within the mud volcanoes (microscale). Data on trait correspondence was provided by biological information on species and genera. A total of 170 nematode species were allocated in 67 different trait combinations, i.e. functional groups, based on taxonomic, morphological and behavioral characteristics. The Biological Trait Analysis (BTA) revealed significant differences between the mud volcanoes and the typical deep sea sediments indicating the presence of different biological functions in ecologically very different environments. Moreover, chemosynthetic activity and habitat heterogeneity within mud volcanoes enhance the presence of different biological and ecological functions in nematode assemblages of different microhabitats. Functional diversity and species richness patterns varied significantly across the different

  16. Effects of the Eastern Mediterranean Sea circulation on the thermohaline properties as recorded by fixed deep-ocean observatories

    Science.gov (United States)

    Bensi, Manuel; Velaoras, Dimitris; Meccia, Virna L.; Cardin, Vanessa

    2016-06-01

    Temperature and salinity time-series from three fixed observatories in the Eastern Mediterranean Sea (EMed) are investigated using multi-annual (2006-2014), high-frequency (up to 3 h sampling rate) data. Two observatories are deployed in the two dense water formation (DWF) areas of the EMed (Southern Adriatic Sea, E2-M3A; Cretan Sea, E1-M3A) and the third one (Southeast Ionian Sea, PYLOS) lays directly on the intermediate water masses pathway that connects the DWF sources. The long-term variations of the hydrological characteristics at the observatories reflect the oscillating large-scale circulation modes of the basin (i.e. BiOS-Bimodal Oscillating System and internal thermohaline pump theories). In particular, between 2006 and 2014 an anti-correlated behaviour of the intermediate layer (200-600 m) salinity between the Adriatic and Cretan Sea observatories is verified. This behaviour is directly linked to reversals of the North Ionian Gyre, which appeared cyclonic during 2006-2011 and turned anticyclonic after 2011. Statistical analysis suggests that the travel time of the intermediate salinity maximum signal between the Cretan and Adriatic Sea is roughly 1.5 years, in good agreement with the analysis of additionally presented ARGO data as well as previous literature references. We argue that the understanding of such oscillations provides important foresight on future DWF events, as increased salinity may act as a crucial preconditioning factor for DWF processes. Additionally, energy spectrum analysis of the time-series revealed interesting short-term variability connected to mesoscale activity at the observatories. Hence, the sustain of permanent observatories able to monitor oceanic parameters at high sampling rates may play a key role in understanding both climatic and oceanic processes and trends.

  17. Characterization of a deep-sea microbial mat from an active cold seep at the Milano mud volcano in the Eastern Mediterranean Sea.

    Science.gov (United States)

    Heijs, Sander K; Damsté, Jaap S Sinninghe; Forney, Larry J

    2005-09-01

    A white, filamentous microbial mat at the Milano mud volcano in the Eastern Mediterranean Sea was sampled during the Medinaut cruise of the R/V Nadir in 1998. The composition of the mat community was characterized using a combination of phylogenetic and lipid biomarker methods. The mat sample was filtered through 0.2 and 5-microm filters to coarsely separate unicellular and filamentous bacteria. Analyses of 16S rRNA gene sequences amplified from the total community DNA from these fractions showed that similar archaeal populations were present in both fractions. However, the bacterial populations in the fractions differed from one another, and were more diverse than the archaeal ones. Lipid analysis showed that bacteria were the dominant members of the mat microbial community and the relatively low delta(13)C carbon isotope values of bulk bacterial lipids suggested the occurrence of methane- and sulfide-based chemo(auto)trophy. Consistent with this, the bacterial populations in the fractions were related to Alpha-, Gamma- and Epsilonproteobacteria, most of which were chemoautotrophic bacteria that utilize hydrogen sulfide (or reduced sulfur compounds) and/or methane. The most common archaeal 16S rRNA gene sequences were related to those of previously identified Archaea capable of anaerobic methane oxidation. Although the filamentous organisms observed in the mat were not conclusively identified, our results indicated that the Eastern Mediterranean deep-sea microbial mat community might be sustained on a combination of methane- and sulfide-driven chemotrophy.

  18. Data from investigation on seismic Sea-waves events in the Eastern Mediterranean from the Birth of Christ to 500 A.D.

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    J. ANTONOPOULOS

    1980-06-01

    Full Text Available The Eastern Mediterranean has a long history of damaging seismic sea
    waves (Tsunamis but a great number of them which are locally generated are small. They have caused no serious damage to the coasts because their
    energy is confined by many islands of the Greek Archipelagos. However,
    some of them have been rather severe and destructive to property and
    human life.
    This paper is comprised of data from an investigation into the activity
    of seismic sea waves in the Eastern Mediterranean from the Birth of
    Christ to 500 A.D. It contains a great amount of information concerning
    earthquakes, volcanic eruptions and seismic sea waves.
    All the available information has been compiled from historical accounts,
    archives, press reports, magazines and related works.

  19. The presence of the Indo-Pacific symbiont-bearing foraminifer Amphistegina lobifera in Greek coastal ecosystems (Aegean Sea, Eastern Mediterranean

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    M.V. TRIANTAPHYLLOU

    2009-12-01

    Full Text Available During the last decades, hundreds of species of Indo-Pacific origin from the Red Sea have traversed the Suez Canal and settled in the Eastern Mediterranean. Nowadays, Amphistegina lobifera Larsen, is known to be a successful immigrant that is widely distributed in the coastal ecosystems of the Eastern Mediterranean Sea. Amphistegina is the most common epiphytic, symbiont- bearing large foraminifer. In this study we provide additional data on the presence of this species in the coastal ecosystems of Aegean Sea, Greece. The high relative abundance of A. lobifera is the result of very successful adaptation of this species to local conditions and suggests that it has become a significant part of the epiphytic foraminiferal fauna.

  20. Particle dynamics in the Eastern Mediterranean Sea: A synthesis based on light transmission, PMC, and POC archives (1991 2001)

    Science.gov (United States)

    Karageorgis, Aristomenis P.; Gardner, Wilford D.; Georgopoulos, Dimitris; Mishonov, Alexey V.; Krasakopoulou, Evangelia; Anagnostou, Christos

    2008-02-01

    During the last two decades light transmission (LT) data have been collected routinely in the Eastern Mediterranean Sea, within the framework of several research projects. A procedure was developed to obtain beam attenuation coefficient due to particles ( cp) at 660-670 nm adjusted for variations in mid-depth 'clear' water and instrumental drifts. Data from 3146 stations occupied between 1991 and 2001 were converted to a common format for the analysis of particulate matter (PM) temporal and spatial distribution patterns. The data were separated into 'wet' (December-May) and 'dry' (June-November) periods. The horizontal distribution of beam cp at various depths revealed clearly higher values in the surface nepheloid layer (SNL) in the vicinity of river mouths during the 'wet' period, whilst the increase was negligible during the 'dry' period. In contrast, the bottom nepheloid layer (BNL; 1-10 m above bottom) appeared to be turbid throughout the year, particularly on the continental shelves receiving riverine discharge. This feature is attributed to resuspension and advection of recently deposited bottom sediments due to waves and currents. However, the Eastern Mediterranean as a whole is impoverished in PM in the water column, particularly at depths >200 m. The behavior of surface-water cp revealed a strong relationship to mesoscale dynamic features. Cyclonic eddies, which upwell nutrient-rich waters toward the surface, favor primary production, which was identified as elevated beam cp values. Beam cp was correlated with PM concentration (PMC) and particulate organic carbon (POC) concentration obtained by bottle sampling. Although there were regional differences in the correlations, no significant seasonal variations were observed. Two generic equations were generated that can be used for a first-order estimate of PMC and POC from historical LT measurements conducted in the area, provided that data are handled according to the proposed methodology.

  1. Bathymetric zonation of modern shelf benthic foraminifera in the Levantine Basin, eastern Mediterranean Sea

    Science.gov (United States)

    Avnaim-Katav, Simona; Hyams-Kaphzan, Orit; Milker, Yvonne; Almogi-Labin, Ahuva

    2015-05-01

    Siliciclastic carbonate-poor sediments are common in southern and central parts of the inner Israeli shelf, part of the Nile littoral cell and in deeper water along the entire coast, while carbonate rich sediments occur in northern Israel and in submerged rocky environments. The distribution of benthic foraminifera, common components of these environments, was studied in surface sediment samples in order to identify their bathymetric zonation using multivariate statistical analyses. The dead foraminiferal assemblages exhibit a clear bathymetric zonation directly related to substrate type. A distinct faunal change has been found at approximately 40 m water depth coinciding with the shift from the shallow-water sand belt, distributed parallel to the Israeli coast up to Haifa Bay, to a silty-clayey belt relatively rich with organic matter extending westward along the entire SE Mediterranean shelf. Ammonia parkinsoniana, Ammonia sp. 1, Buccella granulata, Nubeculina divaricata and Adelosina sp. 1 predominating the shallow-water depths are positively related to sand content and negatively related to water depth. Other species, such as Asterigerinata mamilla, Hanzawaia rhodiensis, Reussella spinulosa, Triloculina marioni and Valvulineria bradyana, occurring between 40 and 100 m, exhibit a positive relationship with total organic carbon content and water depth. Beyond the Nile littoral cell and partly in its distal part Amphistegina lessonii, Peneroplis pertusus, Pseudoschlumbergerina ovata, Pseudoschlumbergerina sp. 1 and Quinqueloculina ungeriana dominate the rocky and coarse sand substrate, exhibiting a more positive relationship with higher carbonate content values. The distinct bathymetric zonation established in this study may prove to be useful in fossil records for accurate paleo-bathymetry reconstruction of Quaternary records in this dynamic system prone to frequent sea level fluctuations.

  2. On some rarely caught fish in the southeastern Aegean Sea (Greece, Eastern Mediterranean

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    Maria Corsini-Foka

    2015-11-01

    Full Text Available The marine region of the Dodecanese Islands (Greece is heavily affected by climate changes, intensification of anthropogenic interferences and biological invasions. Its ichthyofauna diversity is still poorly known, despite the development of marine research during the last decades, both in shallow and deep waters, and the increasing interest of fishermen to biodiversity knowledge and conservation. Regardless of its oligotrophic character, with only 1-3 % of the total Greek fishery production (ELSTAT, 2015, at least 60 % of the total fish species known in the Hellenic seas (510 has been recorded in the area (Papaconstantinou, 2014. Between 2009 and 2014, 14 uncommon species - Alopias superciliosus, Gymnura altavela, Aulopus filamentosus, Sudis hyalina, Gymnothorax unicolor, Ophisurus serpens, Nemichthys scolopaceus, Lophotus lacepede, Naucrates ductor, Alectis alexandrinus, Brama brama, Pomadasys incisus, Schedophilus ovalis and Mola mola - were captured. The first records of P. incisus and S. ovalis in the area significantly enlarge their known distribution in the Hellenic Aegean waters (Papaconstantinou, 2014. The capture of L. lacepede (approx. 140 cm total length in Patmos (2011 confirms the occurrence of this rare species in the Dodecanese, given that a juvenile is preserved at the Hydrobiological Station of Rhodes since the 1950s, and constitutes the third official record in the Aegean waters, after Gökova Bay and Chalkidiki findings (Bilecenoğlu et al., 2001; Minos et al., 2013. The captures of S. hyalina (2011 and N. scolopaceus (2014 confirm their occurrence some years after their first reports in the same area in 2004 and 2002 respectively (Corsini-Foka, 2009. The occurrence of A. superciliosus, a species infrequent in local fishery, is poorly documented in the Mediterranean and the species is considered scarce or rare in the basin (Madiraca and Davidov, 2015. The scattered records of the remaining above species contribute to monitor

  3. Sub-seasonally resolved coral records of northern Red Sea - eastern Mediterranean climate during the Holocene and the last interglacial

    Science.gov (United States)

    Felis, T.; Rimbu, N.; Al-Rousan, S.; Kuhnert, H.; Lohmann, G.; Kölling, M.; Pätzold, J.

    2012-04-01

    The northern Red Sea represents a unique location where ocean currents transport warm tropical waters northward, enabling coral reef growth at unusually high latitudes of up to 29 °N. Moreover, one of the world's northernmost complexes of uplifted Pleistocene reef terraces can be found here at Aqaba (Jordan). We present sub-seasonally resolved reconstructions of surface ocean conditions in the northern Red Sea derived from annually banded Porites corals. The Sr/Ca and δ18O variations in the aragonitic skeletons of our modern and fossil coral colonies provide proxy records of temperature, salinity and hydrologic balance at the sea surface during the last centuries and during time windows (40 to 100 years length) of the Holocene and the last interglacial period. Previous work has shown that seasonality and interannual to decadal climate variability in the northern Red Sea as documented in our coral records is strongly coupled to climate variations in the eastern Mediterranean, Middle East and Europe, reflecting the prominent role of atmospheric teleconnections of the Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) in controlling regional climate on these timescales. New coral Sr/Ca data, in combination with δ18O, reveal an abrupt regime shift toward fresher surface ocean conditions in northern Red Sea surface waters at the end of the Little Ice Age. Possible mechanisms include a re-organization of the Northern Hemisphere atmospheric circulation. Sr/Ca records from a large number of fossil corals indicate a trend of decreasing temperature seasonality over the last 6000 years toward present-day. Such a trend is expected in the higher latitudes of the Northern Hemisphere from insolation changes on orbital timescales. Coral δ18O and Sr/Ca records suggest an increased seasonality in the hydrologic balance during time intervals around 4400, 4600 and 6000 years ago, which could result from both enhanced winter evaporation or increased summer precipitation

  4. Mediterranean, our sea

    Science.gov (United States)

    Markaki, Foteini

    2017-04-01

    My school (1o EPAL Ymittos -Athens, Greece) is a technical school of secondary education and throughout this school year being drafted a program of environmental education. The main theme is the Mediterranean Sea, the biggest closed sea extending between three continents. Topics studied: 1. Biodiversity and the risks threat. 2. The geophysics that characterize (earthquakes, volcanoes explosions, etc). 3. The Mediterranean Sea as environment anthropogenesis, a mosaic of other cultures and even place current notions of social phenomena (refugees). Pedagogical Objectives: Cognitive/Enviromental: 1. To investigate and understand the biodiversity of the Mediterranean Sea and the risks to threaten and phenomena that characterize. 2. To understand the position of the Mediterranean Sea in the land and the role of the historical, cultural and social human environment. 3. To come in contact with texts literary, social, articles on the Mediterranean. Psychomotor: 1. To work together and collect information for the Mediterranean Sea. 2. Experiential approach to the natural environment. 3. Develop critical thinking. 4. Undertake responsibilities for the presentation of the program. Emotional: 1. To feel joy from participation in the program. 2. Being sensitized and configure attitudes and actions of respect towards the environment. Methodology implementation: Teamwork. Interdisciplinary - holistic to dissemination of program recordings to courses curriculum. Study in the field. Gathering information from newspapers, magazines, internet, maps, and photographs. Experiential method- Project. Assessment methods and self-assessment. Fields of courses: Greek language- History- Biology- Chemistry- Technology Dissemination of results: Make a page of social media (facebook), a blog, enhancing environmental awareness via video, make an electronic poster.

  5. Methanogenic diversity and activity in hypersaline sediments of the centre of the Napoli mud volcano, Eastern Mediterranean Sea.

    Science.gov (United States)

    Lazar, Cassandre Sara; Parkes, R John; Cragg, Barry A; L'Haridon, Stéphane; Toffin, Laurent

    2011-08-01

    Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out to assess the methanogenic activity rates, pathways and diversity in the hypersaline sediments of the centre of the Napoli mud volcano. Methylotrophic methanogenesis was the only significant methanogenic pathway in the shallow sediments (0-40 cm) but was also measured throughout the sediment core, confirming that methylotrophic methanogens could be well adapted to hypersaline environments. Hydrogenotrophic methanogenesis was the dominant pathway below 50 cm; however, low rates of acetoclastic methanogenesis were also present, even in sediment layers with the highest salinity, showing that these methanogens can thrive in this extreme environment. PCR-DGGE and methyl coenzyme M reductase gene libraries detected sequences affiliated with anaerobic methanotrophs (mainly ANME-1) as well as Methanococcoides methanogens. Results show that the hypersaline conditions in the centre of the Napoli mud volcano influence active biogenic methane fluxes and methanogenic/methylotrophic diversity.

  6. Eastern Mediterranean sea levels through the last interglacial from a coastal-marine sequence in northern Israel

    Science.gov (United States)

    Sivan, D.; Sisma-Ventura, G.; Greenbaum, N.; Bialik, O. M.; Williams, F. H.; Tamisiea, M. E.; Rohling, E. J.; Frumkin, A.; Avnaim-Katav, S.; Shtienberg, G.; Stein, M.

    2016-08-01

    A last interglacial (Marine Isotope Stage, MIS5e) marine-coastal sequence has been identified along the Galilee coast of Israel, with the type section located at Rosh Hanikra (RH). The microtidal regime and tectonic stability, along with the detailed stratigraphy of the RH shore, make the study region ideally suited for determining relative sea level (RSL) through the MIS5e interval in the eastern Mediterranean. The sequence contains fossilized microtidal subunits at a few meters above the current sea level. Unfortunately, all fossils were found to be altered, so that U-Th datings cannot be considered to represent initial deposition. We contend that U-Th dating of Strombus bubonius shells (recrystallized to calcite) suffices to indicate a lower limit of ∼110 ± 8 ka for the time sea level dropped below the RH sedimentary sequence. The RH-section comprises three main subunits of a previously determined member (the Yasaf Member): (a) a gravelly unit containing the diagnostic gastropod Strombus bubonius Lamarck (Persististrombus latus), which was deposited in the intertidal to super-tidal stormy zone; (b) Vermetidae reef domes indicating a shallow-water depositional environment; and (c) coarse to medium-sized, bioclastic sandstone, probably deposited in the shallow sub-tidal zone. The sequence overlies three abrasion platforms that are cut by tidal channels at elevations of +0.8 m, +2.6 m and +3.4 m, and which are filled with MIS5e sediments. We present a detailed study of the sequence, with emphasis on stratigraphic, sedimentological, and palaeontological characteristics that indicate sea-level changes. Although without precise absolute dating, the stratigraphic sequence of RH through MIS5e allows us to identify a time-series of RSL positions, using the elevations of three stratigraphic subunits. Reconstructed RSL values range from +1.0 m to +7 m (with uncertainly GIA) modelling using multiple ice histories suggests that GIA corrections range between about -1.8 m

  7. Applicability of the Decision Matrix of North Eastern Atlantic, Mediterranean and connected seas Tsunami Warning System to the Italian tsunamis

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    S. Tinti

    2012-03-01

    Full Text Available After the 2004 Indian Ocean tsunami catastrophe, UNESCO through the IOC (Intergovernmental Oceanographic Commission sponsored the establishment of Intergovernmental Coordination Groups (ICG with the aim to devise and implement Tsunami Warning Systems (TWSs in all the oceans exposed to tsunamis, in addition to the one already in operation in the Pacific (PTWS. In this context, since 2005, efforts have begun for the establishment of TWSs in the Indian Ocean (IOTWS, in the Caribbean area (CARIBE EWS and in the North Eastern Atlantic, the Mediterranean and Connected Seas (NEAMTWS.

    In this paper, we focus on a specific tool that was first introduced in the PTWS routine operations, i.e., the Decision Matrix (DM. This is an easy-to-use table establishing a link between the main parameters of an earthquake and the possible ensuing tsunami in order to make quick decision on the type of alert bulletins that a Tsunami Warning Center launches to its recipients. In the process of implementation of a regional TWS for the NEAM area, two distinct DMs were recently proposed by the ICG/NEAMTWS, one for the Atlantic and the other for the entire Mediterranean area.

    This work applies the Mediterranean NEAMTWS DM to the earthquakes recorded in Italy and compares the action predicted by the DM vs. the action that should be appropriate in view of the observed tsunami characteristics with the aim to establish how good the performance of the Italian TWS will be when it uses the DM for future events. To this purpose, we make use of the parametric catalogue of the Italian earthquakes (CPTI04 compiled in 2004 and the most recent compilation of the Italian tsunami, based on the Italian Tsunami Catalogue of 2004 and the subsequent revisions. In order to better compare the TWS actions, we have identified four different kinds of action coding them from 0 to 3 according to the tsunami severity and have further considered three different distance ranges where

  8. Geochemical characteristics of late Quaternary sediments from the southern Aegean Sea (Eastern Mediterranean)

    OpenAIRE

    A. SIOULAS; CH. ANAGNOSTOU; A.P. KARAGEORGIS; C.D. GARBE-SCHONBERG

    2012-01-01

    Ten cores from the southern Aegean Sea have been logged for their lithological composition and seventy-three sub-samples were analysed for the determination of major and trace elements concentrations. Four lithological units were identified, namely, mud, volcanic, turbidite and sapropel. On the basis of the “Z-2” Minoan ash layer radiocarbon age sedimentation rates for the southern Aegean Sea were estimated at 3.26 to 4.15 cm kyr -1. Simple correlation analysis revealed three groups of elemen...

  9. Ethnobotany of medicinal plants used in Eastern Mallorca (Balearic Islands, Mediterranean Sea).

    Science.gov (United States)

    Carrió, Esperança; Vallès, Joan

    2012-06-14

    This paper represents the first large-scale ethnobotanical study in the island of Mallorca, and provides significant information on pharmaceutical plant uses, built up from interviews with native people from this touristic hotspot, demonstrating its ethnopharmacological importance. To collect, analyse and evaluate the ethnobotanical knowledge concerning medicinal plants in a north-eastern Mallorcan area (municipalities of Artà, Capdepera and Son Servera; 298 km2, 31,764 inhabitants). We performed semi-structured interviews with 42 informants (mean age 77; 40% women, 60% men), identified the plant taxa reported and analysed the results, comparing them with those found in the current Mallorcan ethnobotanical information and in other territories. The informants reported data on 121 human medicinal plants representing 64 botanical families. Around 45 medicinal uses reported, concerning 37 species, have not or have very rarely been cited as medicinal. An index of medicinal importance is proposed. All efforts addressed to compiling ethnobotanical information in industrialised or touristised areas such as Eastern Mallorca are still valuable. New possibilities can be explored to give practical value to Mallorcan ethnobotanical data in the frame of considering traditional plant knowledge as part of the islanders’ lifestyle and healthy habits.

  10. Geochemical characteristics of late Quaternary sediments from the southern Aegean Sea (Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    A. SIOULAS

    2012-12-01

    Full Text Available Ten cores from the southern Aegean Sea have been logged for their lithological composition and seventy-three sub-samples were analysed for the determination of major and trace elements concentrations. Four lithological units were identified, namely, mud, volcanic, turbidite and sapropel. On the basis of the “Z-2” Minoan ash layer radiocarbon age sedimentation rates for the southern Aegean Sea were estimated at 3.26 to 4.15 cm kyr -1. Simple correlation analysis revealed three groups of elements associated with: (1 biogenic carbonates; (2 terrigenous alumino-silicates and (3 sapropelic layers. R-mode factor analysis applied on the carbonate-free corrected data-set defined four significant factors: (1 the “detrital alumino-silicate factor” represented by Si, Al, Na, K, Rb, Zr, Pb and inversely related to Ca, Mg, and Sr; (2 a “hydrothermal factor” loaded with Cr, Ni, Co, Cu, Fe; (3 the “volcanic ash factor” with high loadings for Ti, Al, Fe, Na and (4 a “sapropel factor” represented by Ba, Mo, and Zn. High factor scores for the “hydrothermal factor” were observed in sediment samples proximal to Nisyros Isl., suggesting a potential hydrothermal influence. Red-brown oxides and crusts dredged from this area support further this possibility. The use of factor analysis enabled for a better understanding of the chemical elements associations that remained obscured by correlation analysis.

  11. Geochemical characteristics of late Quaternary sediments from the southern Aegean Sea (Eastern Mediterranean

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    A. SIOULAS

    2000-12-01

    Full Text Available Ten cores from the southern Aegean Sea have been logged for their lithological composition and seventy-three sub-samples were analysed for the determination of major and trace elements concentrations. Four lithological units were identified, namely, mud, volcanic, turbidite and sapropel. On the basis of the “Z-2” Minoan ash layer radiocarbon age sedimentation rates for the southern Aegean Sea were estimated at 3.26 to 4.15 cm kyr -1. Simple correlation analysis revealed three groups of elements associated with: (1 biogenic carbonates; (2 terrigenous alumino-silicates and (3 sapropelic layers. R-mode factor analysis applied on the carbonate-free corrected data-set defined four significant factors: (1 the “detrital alumino-silicate factor” represented by Si, Al, Na, K, Rb, Zr, Pb and inversely related to Ca, Mg, and Sr; (2 a “hydrothermal factor” loaded with Cr, Ni, Co, Cu, Fe; (3 the “volcanic ash factor” with high loadings for Ti, Al, Fe, Na and (4 a “sapropel factor” represented by Ba, Mo, and Zn. High factor scores for the “hydrothermal factor” were observed in sediment samples proximal to Nisyros Isl., suggesting a potential hydrothermal influence. Red-brown oxides and crusts dredged from this area support further this possibility. The use of factor analysis enabled for a better understanding of the chemical elements associations that remained obscured by correlation analysis.

  12. Pelagic-benthic coupling and diagenesis of nucleic acids in a deep-sea continental margin and an open-slope system of the Eastern Mediterranean.

    Science.gov (United States)

    Dell'anno, Antonio; Corinaldesi, Cinzia; Stavrakakis, Spyros; Lykousis, Vasilis; Danovaro, Roberto

    2005-10-01

    Downward fluxes of nucleic acids adsorbed onto settling particles play a key role in the supply of organic phosphorus and genetic material to the ocean interior. However, information on pelagic-benthic coupling, diagenesis, and processes controlling nucleic acid preservation in deep-sea sediments is practically nonexistent. In this study, we compared nucleic acid fluxes, sedimentary DNA and RNA concentrations, and the enzymatically hydrolyzable fraction of DNA in a bathyal continental margin (North Aegean Sea) and an open-sea system (South Aegean Sea) of the Eastern Mediterranean. The two systems displayed contrasting patterns of nucleic acid fluxes, which increased significantly with depth in the North Aegean Sea and decreased with depth in the South Aegean Sea. These results suggest that in continental margin and open-ocean systems different processes control the nucleic acid supply to the sea floor. Differences in nucleic acid fluxes were reflected by nucleic acid concentrations in the sediments, which reached extremely high values in the North Aegean Sea. In this system, a large fraction of DNA may be buried, as suggested by the large fraction of DNA resistant to nuclease degradation and by estimates of burial efficiency (ca. eight times higher in the North than in the South Aegean Sea). Overall, the results reported here suggest that the preservation of DNA in deeper sediment layers may be favored in benthic systems characterized by high sedimentation rates.

  13. Sea surface temperatures and environmental conditions during the ;warm Pliocene; interval ( 4.1-3.2 Ma) in the Eastern Mediterranean (Cyprus)

    Science.gov (United States)

    Athanasiou, M.; Bouloubassi, I.; Gogou, A.; Klein, V.; Dimiza, M. D.; Parinos, C.; Skampa, E.; Triantaphyllou, M. V.

    2017-03-01

    Organic geochemical (alkenones) and micropaleontological (nannofossil) data from the Pissouri South section (PPS) in the island of Cyprus provided a detailed description of the paleoclimatic (sea surface temperature-SST) and paleoenvironmental conditions during the ;warm Pliocene; (c. 4.1-3.25 Ma) in the Eastern Mediterranean. We found that the suite of sapropel events recorded in the studied interval took place under conditions of increased SST, enhanced water column stratification and development of a productive deep chlorophyll maximum (DCM), as witnessed by the dominance of Florisphaera profunda species. Such conditions are similar to those prevailing during Quaternary sapropel formation, triggered by freshwater discharges from the N. African margin due to insolation-driven intensification of the African monsoon. The absence of F. profunda in Pliocene sapropels from central Mediterranean records highlights the sensitive response of the eastern basin to freshwater perturbations. Comparisons between alkenone and calcareous nannofossil assemblage patterns infer Pseudoemiliania lacunosa as the main alkenone producer in sapropel layers; yet Reticulofenestra spp. contribution cannot be ruled out. The first Pliocene alkenone-SST record in the E. Mediterranean presented here documents the ;warm Pliocene; period ( 4.1-3.25 Ma) characterized by mean SST of c. 26 °C. Distinct SST minima at 3.9 Ma, 3.58 Ma and between 3.34 and 3.31 Ma, correspond to the MIS Gi16, MIS MG12 and MIS M2 global cooling episodes, before the onset of the Northern Hemisphere glaciation. Our findings imply that the peak of the MIS M2 cooling in the Eastern Mediterranean may be up to 40 kyrs older than the age attributed before to benthic stable oxygen isotopes records of this event.

  14. Modelling tsunamis in the Eastern Mediterranean Sea. Application to the Minoan Santorini tsunami sequence as a potential scenario for the biblical Exodus

    Science.gov (United States)

    Periáñez, R.; Abril, J. M.

    2014-11-01

    A numerical model which simulates the propagation of tsunamis in the Eastern Mediterranean has been developed. Several tsunami sources have been considered: earthquakes associated to geological faults, submarine landslides, entry of pyroclastic flows into the sea and the collapse of a volcano caldera. The model has been applied to different past events for which historic data or previous simulations exist, to test its performance. Then it has been applied to simulate tsunamis triggered by the explosion of Santorini volcano (17th century BC) in the Aegean Sea. While the model accounts for run-ups in the Aegean coasts, it fails to explain the isochronous tsunamigenic deposits reported in eastern Sicily and the levantine coasts. A scenario of a sequence of intense tectonics strain release triggering a series of tsunamis could better fit the whole dataset. Thus, a submarine landslide at the Gulf of Sirte may explain the Augias megaturbidite and the sedimentary deposits reported in Augusta Bay (Sicily). Similarly, a sequential tsunami in the eastern Nile Delta may explain the tsunamigenic deposits found in Israel and Gaza. Considering the former coastline at 3500 years BP, it could also provide a plausible scenario for the biblical sea crossing related in the Exodus.

  15. Description of the first Lessepsian squid migrant, Sepioteuthis lessoniana (CEPHALOPODA: Loliginidae, in the Aegean Sea (Eastern Mediterranean

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    E. LEFKADITOU

    2012-12-01

    Full Text Available Loliginid squids of the Sepioteuthis lessoniana complex are widely spread in the Indo-Pacific Ocean, where they constitute a commercially important resource for neritic fisheries. Sepioteuthis lessoniana is the only Lessepsian squid migrant till now, recorded for the first time in the Mediterranean in 2002 along the Turkish Levantine coasts. Two maturing males, with mantle lengths 193 mm and 244 mm, have been recently caught near the coasts of Rhodes Island (SE Aegean, extending the species distribution northward, into Hellenic waters. Their identity was confirmed by comparison of the main body, beak characteristics and morphometric measurements with those available in the literature for this species. Suspected expansion of the Lessepsian loliginid into the Aegean Sea, due to the gradual warming of the sea, is discussed.

  16. Discovering where bluefin tuna, Thunnus thynnus, might go: using environmental and fishery data to map potential tuna habitat in the eastern Mediterranean Sea

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    Dimitrios Damalas

    2012-11-01

    Full Text Available Based on a dataset derived from commercial fisheries in the eastern Mediterranean Sea in 1998-2005, we applied generalized additive models (GAMs to investigate the relative influence of a range of environmental factors on catch rates of Atlantic bluefin tuna (Thunnus thynnus Linnaeus, 1785. GAM analyses were conducted by separately modelling (1 the probability of making a catch (encountering a school, and (2 the positive catch rates (school size. Results suggested intra-annual variations in tuna distribution and revealed interesting associations with some environmental features, lunar periodicity being the most distinctive one. Probability of encountering a school peaked in late spring months, eastwards, at water temperatures above 22°C and around the full moon. Size of school was more likely to be larger in northeasternmost regions and in the vicinity of land in late spring, when the percentage of lunar disc illumination was higher. A moderate but continuous annual decline in the probability of encountering a bluefin tuna school was detected from the models’ outputs. The models were used as an indication of preference or association for the selected environmental variables. Based on these associations, an indirect identification of the bluefin tuna potential habitat was obtained and used to map distributions in the eastern Mediterranean region.

  17. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

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    K. ANTONAKAKIS

    2012-12-01

    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  18. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

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    K. ANTONAKAKIS

    2011-06-01

    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  19. Comparative Reproduction Aspects of the Deep-water Shrimps Aristaeomorpha foliacea and Aristeus antennatus (Decapoda, Aristeidae in the Greek Ionian Sea (Eastern Mediterranean

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    K. Kapiris

    2009-01-01

    Full Text Available In the eastern Ionian Sea, the deep-water shrimps Aristaeomorpha foliacea and Aristeus antennatus constitute a virgin fishing resource, since their maximum abundance depth exceeds commercial exploitation depths. The two sympatric species share a number of common reproductive features, such as summer reproduction. A slight temporal shift in mating activity, ovarian maturation, and spawning period was observed between species. The most notable difference was the more pronounced seasonality in reproductive activity of Aristeus antennatus compared to that of A. foliacea as evidenced by the frequency of inseminated females and functionally mature males, as well as by the shorter ovarian maturation period. Nevertheless, regarding the whole life span, both sexes of Aristeus antennatus exhibit a more extended reproductive activity in comparison to A. foliacea. No notable differentiation of both species existed in comparison to other Mediterranean regions.

  20. The sea surface temperature field in the Eastern Mediterranean from advanced very high resolution radiometer (AVHRR) data. Part I. Seasonal variability

    Science.gov (United States)

    Marullo, S.; Santoleri, R.; Malanotte-Rizzoli, P.; Bergamasco, A.

    1999-04-01

    A ten-year dataset of Advanced Very High Resolution Radiometer-Sea Surface Temperature (AVHRR-SST) with 18-km space resolution and weekly frequency is used to study the seasonal variability of the Eastern Mediterranean Sea surface field. Three main objectives are addressed in this study. The first is to define the time and space scales of the surface temperature distributions. The second objective is to relate the SST features to the upper thermocline circulation and the third is to compare these features with the observational evidence of the Physical Oceanography of the Eastern Mediterranean (POEM) Programme. The time analysis reveals the presence of a strong seasonal signal characterized by two main seasonal extremes, winter and summer. The transition between the overall zonal distribution of the isotherms (winter) and the mostly meridional pattern of the fronts (summer) occurs very rapidly in May and October. The space analysis shows that the dominant scale is the sub-basin scale and the sub-basin gyres are very well resolved allowing the identification of permanent and semipermanent structures. The results for the two further objectives can be summarized together. The seasonal and monthly SST distributions are strongly correlated with the dynamical structure of the basin upper thermocline circulation. A direct comparison of the September 1987 SST pattern with the corresponding surface temperature map of the POEM-87 survey proves this correlation quantitatively. Furthermore, comparison of the SST monthly climatologies with the POEM circulation scheme shows that all the major currents and the sub-basin gyres are also found consistently in our patterns, with the only exception of the anticyclonic Mersa-Matruh Gyre.

  1. External N inputs and internal N cycling traced by isotope ratios of nitrate, dissolved reduced nitrogen, and particulate nitrogen in the eastern Mediterranean Sea

    Science.gov (United States)

    Emeis, Kay-Christian; Mara, Paraskevi; Schlarbaum, Tim; MöBius, Jürgen; DäHnke, Kirstin; Struck, Ulrich; Mihalopoulos, Nikolaos; Krom, Michael

    2010-12-01

    The eastern Mediterranean Sea is an unusually nutrient-poor ocean basin where the 15N/14N isotope ratios in many compartments of reactive nitrogen are lower than in comparable oceanic settings. To elucidate possible reasons, we determined stable isotope ratios in nitrate, suspended particulate nitrogen (PN), and total dissolved reduced nitrogen for stations across the eastern Mediterranean Sea occupied in January and February 2007; sinking PN was collected at one of the stations in the period from February to September 2007. The δ15N levels of all reactive N compartments in waters of the basin are very low (grand average 2.6‰) compared to other oceanic environments. Deep water nitrate below 500 m water depth (δ15N = 2.2 ± 0.3‰) was more depleted in 15N than nitrate generally found in deep water nitrate pools of other oceans (δ15N ranges from 4.7 to 5.4‰), whereas 15N was enriched in suspended particulate N (δ15N = 7.3 ± 0.8‰) and reduced dissolved N (δ15N = 5.7 ± 3.8‰) compared to nitrate and sinking particulate N intercepted in sediment traps (δ15N = 0.9 ± 0.8‰). We infer that extensive mineralization is the cause of the isotopic makeup of reactive N in deep water, in concert with the lack of water column denitrification. Nitrogen and oxygen isotope ratios in nitrate of the mixed layer suggest an external source of nitrate depleted in 15N, probably anthropogenic NOx rather than fixed nitrogen. To explain the observed isotope anomaly in the mixed layer, either the ammonium formed by the breakdown of organic matter must be predominantly nitrified, or atmospheric NOx characteristically enriched in 18O was present.

  2. Cold seep communities in the deep eastern Mediterranean Sea: composition, symbiosis and spatial distribution on mud volcanoes

    Science.gov (United States)

    Olu-Le Roy, Karine; Sibuet, Myriam; Fiala-Médioni, Aline; Gofas, Serge; Salas, Carmen; Mariotti, André; Foucher, Jean-Paul; Woodside, John

    2004-12-01

    Two mud volcano fields were explored during the French-Dutch MEDINAUT cruise (1998) with the submersible NAUTILE, one south of Crete along the Mediteranean Ridge at about 2000 m depth (Olimpi mud field) and the other south of Turkey between 1700 and 2000 m depth (Anaximander mud field) where high methane concentrations were measured. Chemosynthetic communities were observed and sampled on six mud volcanoes and along a fault scarp. The communities were dominated by bivalves of particularly small size, belonging to families commonly found at seeps (Mytilidae, Vesicomyidae, Thyasiridae) and to Lucinidae mostly encountered in littoral sulfide-rich sediments and at the shallowest seeps. Siboglinid polychaetes including a large vestimentiferan Lamellibrachia sp. were also associated. At least four bivalve species and one siboglinid are associated with symbiotic chemoautotrophic bacteria, as evidenced by Transmission Electronic Microscopy and isotopic ratio measurements. Among the bivalves, a mytilid harbors both methanotrophic and sulfide-oxidizing bacteria. Video spatial analysis of the community distribution on three volcanoes shows that dense bivalve shell accumulations (mainly lucinids) spread over large areas, from 10% to 38% of the explored areas (2500-15000 m 2) on the different volcanoes. Lamellibrachia sp. had different spatial distribution and variable density in the two mud volcano fields, apparently related with higher methane fluxes in the Anaximander volcanoes and maybe with the instability due to brines in the Olimpi area. The abundance and richness of the observed chemosynthetic fauna and the size of some of the species contrast with the poverty of the deep eastern Mediterranean. The presence of a specialized fauna, with some mollusk genera and species shared with other reduced environments of the Mediterranean, but not dominated by the large bivalves usually found at seeps, is discussed.

  3. Presence of Marphysa disjuncta (Polychaeta: Eunicidae in the Mediterranean Sea

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    G. KURT SAHIN

    2009-12-01

    Full Text Available An individual belonging to the eunicid polychaete species Marphysa disjuncta Hartman, 1961 was collected on muddy substratum at 100 m deep in Fethiye Bay (Levantine Sea, eastern Mediterranean. This species is new to the Mediterranean fauna. It closely resembles to Marphysa bellii, a native species, but it lacks compound falcigers and has unidentate subacicular hooks. This species was only reported from the eastern and western Pacific Ocean and could have been introduced to the Mediterranean Sea via ballast waters of vessels.

  4. Sprite Climatology in the Eastern Mediterranean Region

    Science.gov (United States)

    Yair, Yoav; Price, Colin; Katzenelson, Dor; Rosenthal, Neta; Rubanenko, Lior; Ben-Ami, Yuval; Arnone, Enrico

    2015-04-01

    We present statistical analysis of 436 sprites observed in 7 winter campaigns from 2006/7-2012/13. Results show a clear peak in the frequency of sprite detections, with maximum values (reports of winter sprites over the Sea of Japan and summer ones in central Europe. Other shapes such as trees, wishbones, etc. appear quite rarely. Single element events constitute 16.5% of observations, with 83.5% containing 2 elements or more. Clusters of homogeneous types are slightly more frequent than mixed ones (55%). Our observations suggest winter East Mediterranean thunderstorms to have a vertical structure that is an intermediate type between high tropical convective systems and the lower cloud-top cells in winter thunderstorms over the Sea of Japan. The climatology shows that the Eastern Mediterranean is a major sprite producer during Northern Hemisphere winter, and thus the existing and future optical observation infrastructure in Israel offers ground-based coverage for upcoming space missions that aim to map global sprite activity.

  5. Levels and congener profiles of PCBs and PCDD/Fs in blue shark (Prionace glauca) liver from the South-Eastern Mediterranean Sea (Italy).

    Science.gov (United States)

    Storelli, Maria Maddalena; Barone, Grazia; Storelli, Arianna; Marcotrigiano, Giuseppe Onofrio

    2011-01-01

    Liver of blue shark (Prionace glauca) specimens from the South-Eastern Mediterranean Sea were analyzed for the presence of polychlorinated biphenyls (PCBs), including coplanar congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). PCBs were the dominant chemicals, followed by PCDFs and PCDDs. The pattern of PCB congener concentrations in the hepatic tissue was dominated by higher chlorinated compounds. The specific profile of toxic PCDD/F congeners was characterized mainly by 2,3,7,8-TCDF and 2,3,7,8-TCDD, followed by 1,2,3,6,7,8-HxCDD and 2,3,4,6,7,8-HxCDF. The total 2,3,7,8-TCDD toxic equivalent (TEQs) was 149 pg g⁻¹ lipid wt. The profile of TEQ shows that PCDDs present the greatest risk to this species contributing to total toxicity with a percentage approximately of 60%, while the contribution of PCDFs and DL-PCBs is almost the same being 22.4% and 21.6%, respectively. Further investigations are urgently needed to characterize the PCDD/Fs contamination levels not only in elasmobranch fish but in all Mediterranean marine biota. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Shifts in microbial community structure and activity in the ultra-oligotrophic Eastern Mediterranean Sea driven by the deposition of Saharan dust and European aerosols

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    Cui Guo

    2016-09-01

    Full Text Available The atmospheric deposition of gases and particulates from the Sahara Desert and European landmass is an important source of nutrients for the Mediterranean Sea. In this study, we investigated how such atmospheric input might affect bacterial metabolic activities and community dynamics in the ultra-oligotrophic Eastern Mediterranean Sea. Thus a mesocosm simulation experiment was conducted using pure Saharan dust (SD and mixed aerosols (A, polluted and desert origin. The cell specific bacterial production (BP was stimulated soon after the addition of SD and A, with a higher degree of stimulation being observed in the activity of Alphaproteobacteria than in Gammaproteobacteria, and this lead to significant increases in community BP. Subsequently, a shift between these two dominating classes was observed (such that the proportion of Gammaproteobacteria increased while that of Alphaproteobacteria decreased, along with significant increases in bacterial abundance and chlorophyll a concentration. After a few days, although the abundance of bacteria was still significantly higher in the SD- or A-treated groups, differences in the active community composition between the treatment and control groups were reduced. The altered activity of the two dominating Proteobacteria classes observed, might reflect their different strategies in responding to external nutrient input: with Alphaproteobacteria being more responsive to the direct dust input, whereas Gammaproteobacteria seemed to benefit more from the increase in phytoplankton biomass. In addition, the input of A had a stronger immediate effect and longer lasting influence on changing the active bacterial community composition than did that of SD. Our findings show that episodic atmospheric deposition events might affect the microbial community with regards to their abundance, activity and composition over a short period of time, and thus regulate the function of the microbial community and carbon cycling

  7. Upper ocean climate of the Eastern Mediterranean Sea during the Holocene Insolation Maximum – a model study

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    G. Schmiedl

    2011-05-01

    Full Text Available Nine thousand years ago, the Northern Hemisphere experienced enhanced seasonality caused by an orbital configuration with a minimum of the precession index. To assess the impact of the "Holocene Insolation Maximum" (HIM on the Mediterranean Sea, we use a regional ocean general circulation model forced by atmospheric input derived from global simulations. A stronger seasonal cycle is simulated in the model, which shows a relatively homogeneous winter cooling and a summer warming with well-defined spatial patterns, in particular a subsurface warming in the Cretan and Western Levantine areas. The comparison between the SST simulated for the HIM and the reconstructions from planktonic foraminifera transfer functions shows a poor agreement, especially for summer, when the vertical temperature gradient is strong. However, a reinterpretation of the reconstructions is proposed, to consider the conditions throughout the upper water column. Such a depth-integrated approach accounts for the vertical range of preferred habitat depths of the foraminifera used for the reconstructions and strongly improves the agreement between modelled and reconstructed temperature signal. The subsurface warming is recorded by both model and proxies, with a light shift to the south in the model results. The mechanisms responsible for the peculiar subsurface pattern are found to be a combination of enhanced downwelling and wind mixing due to strengthened Etesian winds, and enhanced thermal forcing due to the stronger summer insolation in the Northern Hemisphere. Together, these processes induce a stronger heat transfer from the surface to the subsurface during late summer in the Western Levantine; this leads to an enhanced heat piracy in this region.

  8. Upper ocean climate of the Eastern Mediterranean Sea during the Holocene Insolation Maximum – a model study

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    F. Adloff

    2011-10-01

    Full Text Available Nine thousand years ago (9 ka BP, the Northern Hemisphere experienced enhanced seasonality caused by an orbital configuration close to the minimum of the precession index. To assess the impact of this "Holocene Insolation Maximum" (HIM on the Mediterranean Sea, we use a regional ocean general circulation model forced by atmospheric input derived from global simulations. A stronger seasonal cycle is simulated by the model, which shows a relatively homogeneous winter cooling and a summer warming with well-defined spatial patterns, in particular, a subsurface warming in the Cretan and western Levantine areas.

    The comparison between the SST simulated for the HIM and a reconstruction from planktonic foraminifera transfer functions shows a poor agreement, especially for summer, when the vertical temperature gradient is strong. As a novel approach, we propose a reinterpretation of the reconstruction, to consider the conditions throughout the upper water column rather than at a single depth. We claim that such a depth-integrated approach is more adequate for surface temperature comparison purposes in a situation where the upper ocean structure in the past was different from the present-day. In this case, the depth-integrated interpretation of the proxy data strongly improves the agreement between modelled and reconstructed temperature signal with the subsurface summer warming being recorded by both model and proxies, with a small shift to the south in the model results.

    The mechanisms responsible for the peculiar subsurface pattern are found to be a combination of enhanced downwelling and wind mixing due to strengthened Etesian winds, and enhanced thermal forcing due to the stronger summer insolation in the Northern Hemisphere. Together, these processes induce a stronger heat transfer from the surface to the subsurface during late summer in the western Levantine; this leads to an enhanced heat piracy in this region, a process never

  9. Live (Rose-bengal stained) foraminifera from deep-sea anoxic salt brine in the Eastern Mediterranean: toward understanding limit of life for single-celled eukaryotes (foraminifera)

    Science.gov (United States)

    Kitazato, H.; Ohkawara, N.; Iwasaki, A.; Nomaki, H.; Akoumianaki, I.; Tokuyama, H.

    2012-04-01

    What is a limit of life for the eukaryotes? Eukaryotes are thought to adapt and evolve under oxic environmental conditions. Recently, there are many exceptions for this hypothesis, as many eukaryotes including metazoan groups are found in anoxic environmental conditions. We found many rose-bengal stained foraminifera from a deep-hypersaline anoxic basin (DHAB) in the eastern Mediterranean. During KH06-04 cruise, we conducted oceanographic research at Medée Lake, the largest DHAB, that is located 100km southwest of Crete Island in the eastern Mediterranean. The lake situates at 2920m in water depth. Depth of saline water is 120m in maximum. Both water and sediment samplings were carried out both with Niskin bottles and multiple corer attached to camera watching sampling system at three sites, inside of the lake (CS), the edge of the lake (OMS) and the normal deep-sea floor (RS). Temperature, salinity, and dissolved oxygen concentrations at central saline lake are 15.27 oC, 328PSU, and 0.0 ml/L, respectively. Strong smell of hydrogen sulfide was detected from the lake sediment. Subsamples were conducted for multiple core samples using 3 subcores(φ 2.9cm) from each core tube (φ 8.2cm). Sediment samples were fixed with 4% formalin Rose Bengal solution on board. In laboratory, samples were washed with 32μm sieve. Rose Bengal stained specimens were picked under binocular stereomicroscope (Zeiss Stemi SV11) for surface 0.5cm layer, and identified with inverted microscope (Nikon ECLIPSE TE300). In total, 26 species belonging to 9 genera were identified from three sites. Six species belonging to two genera were identified in the center of the salt brine. Only a few species are common among three sites, even though the numbers of common species were 10 between OMS and RS sites. In DHAB, spherical organic-walled species, such as allogromiid and psammosphaerid, are dominant. In contrast, tube-like chitinous foraminifera, such as Resigella, Conicotheca and Nodellum, are

  10. Relationships between lake-level changes and water and salt budgets in the Dead Sea during extreme aridities in the Eastern Mediterranean

    Science.gov (United States)

    Kiro, Yael; Goldstein, Steven L.; Garcia-Veigas, Javier; Levy, Elan; Kushnir, Yochanan; Stein, Mordechai; Lazar, Boaz

    2017-04-01

    Thick halite intervals recovered by the Dead Sea Deep Drilling Project cores show evidence for severely arid climatic conditions in the eastern Mediterranean during the last three interglacials. In particular, the core interval corresponding to the peak of the last interglacial (Marine Isotope Stage 5e or MIS 5e) contains ∼30 m of salt over 85 m of core length, making this the driest known period in that region during the late Quaternary. This study reconstructs Dead Sea lake levels during the salt deposition intervals, based on water and salt budgets derived from the Dead Sea brine composition and the amount of salt in the core. Modern water and salt budgets indicate that halite precipitates only during declining lake levels, while the amount of dissolved Na+ and Cl- accumulates during wetter intervals. Based on the compositions of Dead Sea brines from pore waters and halite fluid inclusions, we estimate that ∼12-16 cm of halite precipitated per meter of lake-level drop. During periods of halite precipitation, the Mg2+ concentration increases and the Na+/Cl- ratio decreases in the lake. Our calculations indicate major lake-level drops of ∼170 m from lake levels of 320 and 310 m below sea level (mbsl) down to lake levels of ∼490 and ∼480 mbsl, during MIS 5e and the Holocene, respectively. These lake levels are much lower than typical interglacial lake levels of around 400 mbsl. These lake-level drops occurred as a result of major decreases in average fresh water runoff, to ∼40% of the modern value (pre-1964, before major fresh water diversions), reflecting severe droughts during which annual precipitation in Jerusalem was lower than 350 mm/y, compared to ∼600 mm/y today. Nevertheless, even during salt intervals, the changes in halite facies and the occurrence of alternating periods of halite and detritus in the Dead Sea core stratigraphy reflect fluctuations between drier and wetter conditions around our estimated average. The halite intervals include

  11. Comparison of the level of organic contaminants in bile and muscle of Mugil spp. following a major oil spill in the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Elie K. Barbour

    2009-09-01

    Full Text Available The total polyaromatic hydrocarbons (TPAH and the total polychlorinated biphenyls (TPCB that originate from oil spills in sea and ocean waters are toxic to fish and their offspring. The authors compare the levels of organic contaminants (TPAH and TPCB recovered from the bile versus the dorsal muscles of 120 individual Mugil spp. that were harvested from six sites in the eastern Mediterranean following a significant heavy oil spill. Results showed an insignificant difference between the mean of means of TPAH and TPCB (six means of individual Mugil spp. from six respective sites in bile versus dorsal muscle. In addition, the correlation equation between the level of bile TPAH and the level of bile carcinogenic polyaromatic hydrocarbons (cPAH was established. This data suggests the possibility of substituting the analysis of organic contaminants in muscles by using the liquid bile of Mugil spp., thus eliminating the time-consuming steps of lyophilisation and homogenisation of muscle. In addition, the bile cPAH could be predicted from the bile TPAH by a regression relationship.

  12. Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.

    Science.gov (United States)

    Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos

    2014-07-01

    Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (ΣAH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (ΣPAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, β-hexachlorocyclohexane (β-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (ΣPCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases.

  13. Draft Genome Sequence of the Hydrocarbon-Degrading Bacterium Alcanivorax dieselolei KS-293 Isolated from Surface Seawater in the Eastern Mediterranean Sea

    KAUST Repository

    Barbato, Marta

    2015-12-10

    We report here the draft genome sequence of Alcanivorax dieselolei KS-293, a hydrocarbonoclastic bacterium isolated from the Mediterranean Sea, by supplying diesel oil as the sole carbon source. This strain contains multiple putative genes associated with hydrocarbon degradation pathways and that are highly similar to those described in A. dieselolei type strain B5.

  14. Ecological characteristics of the invasive pufferfish Lagocephalus sceleratus (Gmelin, 1789 in the eastern Mediterranean Sea – a case study from Rhodes

    Directory of Open Access Journals (Sweden)

    S. KALOGIROU

    2013-04-01

    Full Text Available In this study, the ecological and societal impact of the invasive pufferfish Lagocephalus sceleratus on coastal habitats of an area of the eastern Mediterranean Sea (Rhodes Island was investigated. Seasonal quantitative samplings in two common coastal habitats were used to investigate habitat use of different life-stages. Sandy areas were found to be highly important for the early life stages of L. sceleratus. In contrast, Posidonia oceanica habitats were mainly preferred by larger (> 29 cm reproductive adults, not exceeding 64 cm. Lagocephalus sceleratus was found to feed on invertebrates and fish while size classification revealed a tendency for a diet shift with increased size. During early life stages, L. sceleratus inhabits sandy bottoms where it feeds on various invertebrates. The predominant molluscan species found in the diet of larger (> 20 cm L. sceleratus individuals were the economically important Sepia officinalis and Octopus vulgaris. The size at which 50% of individuals reach maturity was estimated to 19 cm. With increased size, habitat shift to seagrass meadows most possibly occurs to meet both the increased demand in prey availability and requirement of appropriate spawning ground. Condition factor of L. sceleratus showed significantly higher values during summer than all other seasons and this was attributed to spawning season and increase in feeding. Societal impacts were alarming due to increased public attention concerning its lethal effects (presence of tetrodotoxin, if consumed. Its high abundance in the coastal fish communities of the studied area combined with ecological and societal impacts, clearly classify L. sceleratus a pest for fisheries and potential threat for biodiversity.

  15. Ecological characteristics of the invasive pufferfish Lagocephalus sceleratus (Gmelin, 1789 in the eastern Mediterranean Sea – a case study from Rhodes

    Directory of Open Access Journals (Sweden)

    S. KALOGIROU

    2013-07-01

    Full Text Available In this study, the ecological and societal impact of the invasive pufferfish Lagocephalus sceleratus on coastal habitats of an area of the eastern Mediterranean Sea (Rhodes Island was investigated. Seasonal quantitative samplings in two common coastal habitats were used to investigate habitat use of different life-stages. Sandy areas were found to be highly important for the early life stages of L. sceleratus. In contrast, Posidonia oceanica habitats were mainly preferred by larger (> 29 cm reproductive adults, not exceeding 64 cm. Lagocephalus sceleratus was found to feed on invertebrates and fish while size classification revealed a tendency for a diet shift with increased size. During early life stages, L. sceleratus inhabits sandy bottoms where it feeds on various invertebrates. The predominant molluscan species found in the diet of larger (> 20 cm L. sceleratus individuals were the economically important Sepia officinalis and Octopus vulgaris. The size at which 50% of individuals reach maturity was estimated to 19 cm. With increased size, habitat shift to seagrass meadows most possibly occurs to meet both the increased demand in prey availability and requirement of appropriate spawning ground. Condition factor of L. sceleratus showed significantly higher values during summer than all other seasons and this was attributed to spawning season and increase in feeding. Societal impacts were alarming due to increased public attention concerning its lethal effects (presence of tetrodotoxin, if consumed. Its high abundance in the coastal fish communities of the studied area combined with ecological and societal impacts, clearly classify L. sceleratus a pest for fisheries and potential threat for biodiversity.

  16. Evaluation of the twenty-first century RCM simulations driven by multiple GCMs over the Eastern Mediterranean-Black Sea region

    Science.gov (United States)

    Önol, Barış; Bozkurt, Deniz; Turuncoglu, Ufuk Utku; Sen, Omer Lutfi; Dalfes, H. Nuzhet

    2014-04-01

    In this study, human-induced climate change over the Eastern Mediterranean-Black Sea region has been analyzed for the twenty-first century by performing regional climate model simulations forced with large-scale fields from three different global circulation models (GCMs). Climate projections have been produced with Special Report on Emissions Scenarios A2, A1FI and B1 scenarios, which provide greater diversity in climate information for future period. The gradual increases for temperature are widely apparent during the twenty-first century for each scenario simulation, but ECHAM5-driven simulation generally has a weaker signal for all seasons compared to CCSM3 simulations except for the Fertile Crescent. The contrast in future temperature change between the winter and summer seasons is very strong for CCSM3-A2-driven and HadCM3-A2-driven simulations over Carpathians and Balkans, 4-5 °C. In addition, winter runoff over mountainous region of Turkey, which feeds many river systems including the Euphrates and Tigris, increases in second half of the century since the snowmelt process accelerates where the elevation is higher than 1,500 m. Moreover, analysis of daily temperature outputs reveals that the gradual decrease in daily minimum temperature variability for January during the twenty-first century is apparent over Carpathians and Balkans. Analysis of daily precipitation extremes shows that positive trend is clear during the last two decades of the twenty-first century over Carpathians for both CCSM3-driven and ECHAM5-driven simulations. Multiple-GCM driven regional climate simulations contribute to the quantification of the range of climate change over a region by performing detailed comparisons between the simulations.

  17. 3D modelling of the active normal fault network in the Apulian Ridge (Eastern Mediterranean Sea): Integration of seismic and bathymetric data with implicit surface methods

    Science.gov (United States)

    Bistacchi, Andrea; Pellegrini, Caludio; Savini, Alessandra; Marchese, Fabio

    2016-04-01

    The Apulian ridge (North-eastern Ionian Sea, Mediterranean), interposed between the facing Apennines and Hellenides subduction zones (to the west and east respectively), is characterized by thick cretaceous carbonatic sequences and discontinuous tertiary deposits crosscut by a penetrative network of NNW-SSE normal faults. These are exposed onshore in Puglia, and are well represented offshore in a dataset composed of 2D seismics and wells collected by oil companies from the '60s to the '80s, more recent seismics collected during research projects in the '90s, recent very high resolution seismics (VHRS - Sparker and Chirp-sonar data), multibeam echosounder bathymetry, and sedimentological and geo-chronological analyses of sediment samples collected on the seabed. Faults are evident in 2D seismics at all scales, and their along-strike geometry and continuity can be characterized with multibeam bathymetric data, which show continuous fault scarps on the seabed (only partly reworked by currents and covered by landslides). Fault scarps also reveal the finite displacement accumulated in the Holocene-Pleistocene. We reconstructed a 3D model of the fault network and suitable geological boundaries (mainly unconformities due to the discontinuous distribution of quaternary and tertiary sediments) with implicit surface methods implemented in SKUA/GOCAD. This approach can be considered very effective and allowed reconstructing in details complex structures, like the frequent relay zones that are particularly well imaged by seafloor geomorphology. Mutual cross-cutting relationships have been recognized between fault scarps and submarine mass-wasting deposits (Holocene-Pleistocene), indicating that, at least in places, these features are coeval, hence the fault network should be considered active. At the regional scale, the 3D model allowed measuring the horizontal WSW-ENE stretching, which can be associated to the bending moment applied to the Apulian Plate by the combined effect

  18. Assessment of island beach erosion due to sea level rise: the case of the Aegean archipelago (Eastern Mediterranean)

    Science.gov (United States)

    Monioudi, Isavela N.; Velegrakis, Adonis F.; Chatzipavlis, Antonis E.; Rigos, Anastasios; Karambas, Theophanis; Vousdoukas, Michalis I.; Hasiotis, Thomas; Koukourouvli, Nikoletta; Peduzzi, Pascal; Manoutsoglou, Eva; Poulos, Serafim E.; Collins, Michael B.

    2017-03-01

    The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths economic resource of the Aegean archipelago.

  19. New Fisheries-related data from the Mediterranean Sea (October 2015

    Directory of Open Access Journals (Sweden)

    K. TSAGARAKIS

    2015-11-01

    Full Text Available In this third Collective Article, with fisheries-related data from the Mediterranean Sea, we present the historical length distribution of Lophius budegassa in the catch of commercial trawlers in the Greek seas; length-weight and length-length relationships of five flatfish species (Lepidorhombus boscii, L. whiffiagonis, Platichthys flesus, Pegusa lascaris and Solea solea from different coastal areas of Turkey (Black Sea and Eastern Mediterranean Sea; growth of settled Polyprion americanus and length-weight relationships of this species and of Deltentosteus quadrimaculatus, Capros aper and three commercially important groupers in the Eastern Mediterranean Sea; the age, growth and mortality of Zosterisessor ophiocephalus in the Eastern Adriatic Sea; the length-weight relationship and condition factor of Atherina boyeri in a Central Mediterranean semi-isolated lagoon, and also the length-weight and length-length relationships of three Alburnus species from different inland waters in Turkey.

  20. Microplastic sampling in the Mediterranean Sea

    DEFF Research Database (Denmark)

    Biginagwa, Fares; Sosthenes, Bahati; Syberg, Kristian

    The extent of microplastic pollution in the Southwestern Mediterranean Sea is not yet known, although on Northwestern part has been previously studied. Plastic samples were collected at 7 transects during a 10 day expedition from Sicily (Italy) to Malaga (Spain) in September 2014. A 330 µM mesh....... This is the first study to assess plastic pollution levels in SW Mediterranean Sea....

  1. Quasi-Stationary SST Estimation in the Eastern Mediterranean Sea Using Marine Gravity, GOCE/GRACE Gravity Information and Recent Altimetry Missions Through the Multiple Input/Multiple Output System Theory

    Science.gov (United States)

    Andritsanos, Vassilios D.; Tziavos, Ilias N.

    2016-08-01

    The Multiple Input / Multiple Output System (MIMOS) Theory is used in the spectral combination of marine and satellite data for Quasi-stationary Sea Surface Topography (QSST) estimation. 15 years (2000 - 2015) of altimetric data from ERS2, GEOSAT FOLLOW-ON, ENVISAT and SARAL / Altika satellites are optimally combined with in situ marine gravity observations. The repeated character of the altimetric missions provides more than one sample of Sea Surface Height (SSH) data sets, and the approximation of the input signal and output error power spectral densities is feasible using this successive information. The assimilation of low frequency global gravity information from GOCE/GRACE satellites is considered in data reductions. The geodynamically active area of the Eastern Mediterranean Sea is chosen as test area and the evolution of yearly SST is presented.

  2. Simulating anchovy's full life cycle in the northern Aegean Sea (eastern Mediterranean): A coupled hydro-biogeochemical-IBM model

    Science.gov (United States)

    Politikos, D.; Somarakis, S.; Tsiaras, K. P.; Giannoulaki, M.; Petihakis, G.; Machias, A.; Triantafyllou, G.

    2015-11-01

    A 3-D full life cycle population model for the North Aegean Sea (NAS) anchovy stock is presented. The model is two-way coupled with a hydrodynamic-biogeochemical model (POM-ERSEM). The anchovy life span is divided into seven life stages/age classes. Embryos and early larvae are passive particles, but subsequent stages exhibit active horizontal movements based on specific rules. A bioenergetics model simulates the growth in both the larval and juvenile/adult stages, while the microzooplankton and mesozooplankton fields of the biogeochemical model provide the food for fish consumption. The super-individual approach is adopted for the representation of the anchovy population. A dynamic egg production module, with an energy allocation algorithm, is embedded in the bioenergetics equation and produces eggs based on a new conceptual model for anchovy vitellogenesis. A model simulation for the period 2003-2006 with realistic initial conditions reproduced well the magnitude of population biomass and daily egg production estimated from acoustic and daily egg production method (DEPM) surveys, carried out in the NAS during June 2003-2006. Model simulated adult and egg habitats were also in good agreement with observed spatial distributions of acoustic biomass and egg abundance in June. Sensitivity simulations were performed to investigate the effect of different formulations adopted for key processes, such as reproduction and movement. The effect of the anchovy population on plankton dynamics was also investigated, by comparing simulations adopting a two-way or a one-way coupling of the fish with the biogeochemical model.

  3. Gaia and the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Kenneth J. Hsü

    2001-12-01

    Full Text Available The Earth is a self-organizing system liking a living organism. Lovelock proposed Gaia as a metaphor to designate the check and balance ofterrestrial temperatures: the Earth is never too hot so that the ocean could boil, and the Earth is never too cold that the ocean could freeze from top to bottom. Hsü proposed that Gaia is endothermic because the life on Earth has been alternate successions of air-conditioners and heaters which evolved and deactivate or reinforce the terrestial greenhouse of carbon dioxide in atmosphere. When Earth was heating up too much, the air-conditioneers, such as anaerobic bacteria, cyanobacteria, skeletal organisms and trees, and finally calcareous plankton, went to work to bring the terrestrial temperature down. When the Earth was freezing at times of continental glaciation, heaters went to work, such as methanogenic bacteria, Ediacaran faunas, tundra and desert plants, and now Homo sapiens. Gaia has to have other organs to keep the self-organizing system vital. This paper presents a postulate that the Miocene Mediterranean Sea acted as Gaia´s kidney. The steady influx of dissolved ions and debris into the ocean causes inevitable increase of ocean´s salinity. The fossil and geochemicl records indicate that the ocean has never been too saline nor too brackish for the survival of normal marine organisms: the salinity ranged from about 32 to 36 pro mil during the last billion years. Ocean-drilling cruises to the Mediterranean discovered a very large salt formation, deposited during some 5 million years ago when the Mediterranean dried up. A study of the geochemical balance of the oceans indicates that the deposition of very large salt bodies in isolated basins such as the Miocene Mediterranean every 100 million years or so. The saline giants have the function of Gaia´s kidney. With periodical removals of the salt ions and the heavy metals from seawater, the world´s ocean have been rendered forever habitable. Gaia

  4. THE EARTHQUAKE AND TSUNAMI OF JULY 21, 365 AD IN THE EASTERN MEDITERRANEAN SEA - Review of Impact on the Ancient World - Assessment of Recurrence and Future Impact

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2011-01-01

    Full Text Available There is ample evidence indicating that on July 21, 365 AD a great earthquake near the west coast of the Island of Crete generated a mega-tsunami, which was responsible for extensive destruction throughout the Eastern Mediterranean, but particularly on Peloponnesus, the Greek Islands, Sicily, Libya, Cyprus, Palestine and Egypt. It is believed that the combined catastrophic impacts of the earthquake and tsunami were significant catalysts in furthering the declination of the Roman Empire and contributing to its subsequent final division between the East Roman and the West (Byzantine empires in 395 A.D. In view of subsequent earthquakes and tsunamis in the region and the high probability that a similar great disaster will occur again, the present study reviews and summarizes the seismo-tectonic and kinematic characteristics of the Aegean and Anatolian micro-plates, their interaction with the African and Eurasian tectonic plates and examines and evaluates the historical records pertaining to this 4th Century AD disaster as to the destructive impact it had on the ancient world. Additionally, the study reconciles the impact described in historical and recent records with results obtained by numerical modeling studies, provides a rough estimate of the recurrence frequency of great tsunamigenic earthquakes in the Eastern Mediterranean region and assesses what the future impact may be in view of great increases in population densities along coastal areas.

  5. The Mediterranean and Black Sea fisheries at risk from overexploitation.

    Directory of Open Access Journals (Sweden)

    Athanassios C Tsikliras

    Full Text Available The status of the Mediterranean and Black Sea fisheries was evaluated for the period 1970-2010 on a subarea basis, using various indicators including the temporal variability of total landings, the number of recorded stocks, the mean trophic level of the catch, the fishing-in-balance index and the catch-based method of stock classification. All indicators confirmed that the fisheries resources of the Mediterranean and Black Sea are at risk from overexploitation. The pattern of exploitation and the state of stocks differed among the western (W, central (C and eastern (E Mediterranean subareas and the Black Sea (BS, with the E Mediterranean and BS fisheries being in a worst shape. Indeed, in the E Mediterranean and the BS, total landings, mean trophic level of the catch and fishing-in-balance index were declining, the cumulative percentage of overexploited and collapsed stocks was higher, and the percentage of developing stocks was lower, compared to the W and C Mediterranean. Our results confirm the need for detailed and extensive stock assessments across species that will eventually lead to stocks recovering through conservation and management measures.

  6. The Mediterranean and Black Sea Fisheries at Risk from Overexploitation

    Science.gov (United States)

    Tsikliras, Athanassios C.; Dinouli, Anny; Tsiros, Vasileios-Zikos; Tsalkou, Eleni

    2015-01-01

    The status of the Mediterranean and Black Sea fisheries was evaluated for the period 1970-2010 on a subarea basis, using various indicators including the temporal variability of total landings, the number of recorded stocks, the mean trophic level of the catch, the fishing-in-balance index and the catch-based method of stock classification. All indicators confirmed that the fisheries resources of the Mediterranean and Black Sea are at risk from overexploitation. The pattern of exploitation and the state of stocks differed among the western (W), central (C) and eastern (E) Mediterranean subareas and the Black Sea (BS), with the E Mediterranean and BS fisheries being in a worst shape. Indeed, in the E Mediterranean and the BS, total landings, mean trophic level of the catch and fishing-in-balance index were declining, the cumulative percentage of overexploited and collapsed stocks was higher, and the percentage of developing stocks was lower, compared to the W and C Mediterranean. Our results confirm the need for detailed and extensive stock assessments across species that will eventually lead to stocks recovering through conservation and management measures. PMID:25793975

  7. Hydrothermalism in the Mediterranean Sea

    Science.gov (United States)

    Dando, P. R.; Stüben, D.; Varnavas, S. P.

    1999-08-01

    Hydrothermalism in the Mediterranean Sea results from the collision of the African and European plates, with the subduction of the oceanic part of the African plate below Europe. High heat flows in the resulting volcanic arcs and back-arc extensional areas have set-up hydrothermal convection systems. Most of the known hydrothermal sites are in shallow coastal waters, <200 m depth, so that much of the reported fluid venting is of the gasohydrothermal type. The hydrothermal liquids are of varying salinities, both because of phase separation as a result of seawater boiling at the low pressures and because of significant inputs of rainfall into the hydrothermal reservoirs at some sites. The major component of the vented gas is carbon dioxide, with significant quantities of sulphur dioxide, hydrogen sulphide, methane and hydrogen also being released. Acid leaching of the underlying rocks leads to the mobilisation of heavy metals, many of which are deposited sub-surface although there is a conspicuous enrichment of metals in surficial sediments in venting areas. Massive polymetalic sulphides have been reported from some sites. No extant vent-specific fauna have been described from Mediterranean sites. There is a reduced diversity of fauna within the sediments at the vents. In contrast, a high diversity of epifauna has been reported and the vent sites are areas of settlement for exotic thermophilic species. Large numbers of novel prokaryotes, especially hyperthermophilic crenarchaeota, have been isolated from Mediterranean hydrothermal vents. However, their distribution in the subsurface biosphere and their role in the biogeochemistry of the sites has yet to be studied.

  8. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from METEOR in the Aegean Sea, Mediterranean Sea and others from 2001-10-18 to 2001-11-11 (NODC Accession 0084620)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0084620 includes discrete sample and profile data collected from METEOR in the Aegean Sea, Mediterranean Sea, Mediterranean Sea - Eastern Basin,...

  9. Revision of Chone Krøyer, 1856 (Polychaeta: Sabellidae from the eastern central Atlantic and Mediterranean Sea with descriptions of two new species

    Directory of Open Access Journals (Sweden)

    María Ana Tovar-Hernández

    2007-06-01

    Full Text Available A neotype specimen is designated for Chone acustica (Claparède, 1870 with a full description. The original descriptions of Chone arenicola Langerhans, 1880 and Chone collaris Langerhans, 1880, both from Madeira, did not include some details and incomplete or misleading information was provided, so both species are redescribed. Amendments to the description of Chone longiseta Giangrande, 1992 are also given together with the methyl green staining pattern of Chone usticensis Giangrande et al. 2006. Two new species are described: Chone gambiae sp. nov., from the Gulf of Naples and Chone dunerificta sp. nov., from the Gulf of Salerno. This study shows the distribution of Chone duneri Krøyer, 1856, and Chone filicaudata Southern, 1914, to be restricted to the Arctic seas and North Atlantic Ocean, respectively. Records from the Mediterranean Sea are found to be erroneous.

  10. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    NARCIS (Netherlands)

    Grant, K. M.; Grimm, R.; Mikolajewicz, U.; Marino, G.; Ziegler, M.; Rohling, E. J.

    2016-01-01

    The Mediterranean basin is sensitive to global sea-level changes and African monsoon variability on orbital timescales. Both of these processes are thought to be important to the deposition of organic-rich sediment layers or 'sapropels' throughout the eastern Mediterranean, yet their relative

  11. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    NARCIS (Netherlands)

    Grant, K. M.; Grimm, R.; Mikolajewicz, U.; Marino, G.; Ziegler, M.; Rohling, E. J.

    2016-01-01

    The Mediterranean basin is sensitive to global sea-level changes and African monsoon variability on orbital timescales. Both of these processes are thought to be important to the deposition of organic-rich sediment layers or 'sapropels' throughout the eastern Mediterranean, yet their relative influe

  12. Sediment reworking rates in deep sediments of the Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Barsanti, M., E-mail: mattia.barsanti@enea.it [ENEA, Marine Environment Research Centre, La Spezia (Italy); Delbono, I., E-mail: ivana.delbono@enea.it [ENEA, Marine Environment Research Centre, La Spezia (Italy); Schirone, A., E-mail: antonio.schirone@enea.it [ENEA, Marine Environment Research Centre, La Spezia (Italy); Langone, L., E-mail: leonardo.langone@bo.ismar.cnr.it [CNR, ISMAR Istituto di Scienze Marine, U.O.S. Bologna (Italy); Miserocchi, S., E-mail: stefano.miserocchi@bo.ismar.cnr.it [CNR, ISMAR Istituto di Scienze Marine, U.O.S. Bologna (Italy); Salvi, S., E-mail: stefano.salvi@enea.it [ENEA, Research Centre Brasimone, Camugnano (Italy); Delfanti, R., E-mail: roberta.delfanti@enea.it [ENEA, Marine Environment Research Centre, La Spezia (Italy)

    2011-07-01

    Different pelagic areas of the Mediterranean Sea have been investigated in order to quantify physical and biological mixing processes in deep sea sediments. Herein, results of eleven sediment cores sampled at different deep areas (> 2000 m) of the Western and Eastern Mediterranean Sea are presented. {sup 210}Pb{sub xs} and {sup 137}Cs vertical profiles, together with {sup 14}C dating, are used to identify the main processes characterising the different areas and, finally, controlling mixing depths (SML) and bioturbation coefficients (D{sub b}). Radionuclide vertical profiles and inventories indicate that bioturbation processes are the dominant processes responsible for sediment reworking in deep sea environments. Results show significant differences in sediment mixing depths and bioturbation coefficients among areas of the Mediterranean Sea characterised by different trophic regimes. In particular, in the Oran Rise area, where the Almeria-Oran Front induces frequent phytoplankton blooms, we calculate the highest values of sediment mixing layers (13 cm) and bioturbation coefficients (0.187 cm{sup 2} yr{sup -1}), and the highest values of {sup 210}Pb{sub xs} and {sup 137}Cs inventories. Intermediate values of SML and D{sub b} ({approx} 6 cm and {approx} 0.040 cm{sup 2} yr{sup -1}, respectively) characterise the mesothrophic Algero-Balearic basin, while in the Southern Tyrrhenian Sea mixing parameters (SML of 3 cm and D{sub b} of 0.011 cm{sup 2} yr{sup -1}) are similar to those calculated for the oligotrophic Eastern Mediterranean (SML of 2 cm and D{sub b} of {approx} 0.005 cm{sup 2} yr{sup -1}). - Research highlights: {yields} Physical and biological mixing processes in the Mediterranean Sea are investigated. {yields} Results of 11 sediment cores in deep areas of the Mediterranean Sea are shown. {yields} {sup 210}Pb{sub xs} and {sup 137}Cs vertical profiles are analysed. {yields} New data on {sup 210}Pb and {sup 137}Cs inventories of Mediterranean deep sediments are

  13. Genetic homogeneity of dolphinfish (Coryphaena hippurus) in the western Mediterranean and the eastern Atlantic

    OpenAIRE

    Pla Zanuy, Carles; Pujolar, Josep Martí

    1998-01-01

    Dolphinfish (Coryphaena hippurus) is an epipelagic, highly migratory species distributed worldwide in tropical and temperate waters including the Mediterranean Sea. Protein electrophoresis analyses can provide knowledge of the genetic population structure of the species and therefore be used as a tool for fishery management. Areas sampled include the islands of Majorca and Sicily in the western Mediterranean and the Canary Islands in the eastern Atlantic. The results of the protein electropho...

  14. Histological and Morphological Aspects of Reproduction in Male Blackspotted Smooth-Hound Mustelus punctulatus in the Adriatic Sea (Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Romana Gračan

    2016-01-01

    Full Text Available We present first data on reproductive biology of male blackspotted smooth-hound Mustelus punctulatus in the Adriatic Sea and first histological examination of gonads at different maturation stages and seasonal cycles for this species. We collected samples from 117 male specimens of M. punctulatus ranging in length from 44.6 to 126.5 cm, caught by commercial bottom trawls in the North-Central Adriatic Sea. Microscopic observation revealed a diametric development of testes, in which round-shaped spermatocysts have zonal arrangement, showing seven different stages of development. Males began to mature when they were between 61 and 88 cm body length, which was indicated by the presence of functional claspers or appearance of the spermatogenic cysts. While the smallest mature shark was only 80 cm long, all animals longer than 89 cm were sexually mature. The seasonal analysis of the testes indicated that mature spermatozoa dominated in testes during the first half of the year with a peak in May and June, after which followed less active period during July and August.

  15. Niche differentiation among mat-forming, sulfide-oxidizing bacteria at cold seeps of the Nile Deep Sea Fan (Eastern Mediterranean Sea).

    Science.gov (United States)

    Grünke, S; Felden, J; Lichtschlag, A; Girnth, A-C; De Beer, D; Wenzhöfer, F; Boetius, A

    2011-07-01

    Sulfidic muds of cold seeps on the Nile Deep Sea Fan (NDSF) are populated by different types of mat-forming sulfide-oxidizing bacteria. The predominant sulfide oxidizers of three different mats were identified by microscopic and phylogenetic analyses as (i) Arcobacter species producing cotton-ball-like sulfur precipitates, (ii) large filamentous sulfur bacteria including Beggiatoa species, and (iii) single, spherical Thiomargarita species. High resolution in situ microprofiles revealed different geochemical settings selecting for the different mat types. Arcobacter mats occurred where oxygen and sulfide overlapped above the seafloor in the bottom water interface. Filamentous sulfide oxidizers were associated with steep gradients of oxygen and sulfide in the sediment. A dense population of Thiomargarita was favored by temporarily changing supplies of oxygen and sulfide in the bottom water. These results indicate that the decisive factors in selecting for different mat-forming bacteria within one deep-sea province are spatial or temporal variations in energy supply. Furthermore, the occurrence of Arcobacter spp.-related 16S rRNA genes in the sediments below all three types of mats, as well as on top of brine lakes of the NDSF, indicates that this group of sulfide oxidizers can switch between different life modes depending on the geobiochemical habitat setting. © 2011 Blackwell Publishing Ltd.

  16. Mediterranean circulation perturbations over the last five centuries: Relevance to past Eastern Mediterranean Transient-type events

    Science.gov (United States)

    Incarbona, Alessandro; Martrat, Belen; Mortyn, P. Graham; Sprovieri, Mario; Ziveri, Patrizia; Gogou, Alexandra; Jordà, Gabriel; Xoplaki, Elena; Luterbacher, Juerg; Langone, Leonardo; Marino, Gianluca; Rodríguez-Sanz, Laura; Triantaphyllou, Maria; di Stefano, Enrico; Grimalt, Joan O.; Tranchida, Giorgio; Sprovieri, Rodolfo; Mazzola, Salvatore

    2016-07-01

    The Eastern Mediterranean Transient (EMT) occurred in the Aegean Sea from 1988 to 1995 and is the most significant intermediate-to-deep Mediterranean overturning perturbation reported by instrumental records. The EMT was likely caused by accumulation of high salinity waters in the Levantine and enhanced heat loss in the Aegean Sea, coupled with surface water freshening in the Sicily Channel. It is still unknown whether similar transients occurred in the past and, if so, what their forcing processes were. In this study, sediments from the Sicily Channel document surface water freshening (SCFR) at 1910 ± 12, 1812 ± 18, 1725 ± 25 and 1580 ± 30 CE. A regional ocean hindcast links SCFR to enhanced deep-water production and in turn to strengthened Mediterranean thermohaline circulation. Independent evidence collected in the Aegean Sea supports this reconstruction, showing that enhanced bottom water ventilation in the Eastern Mediterranean was associated with each SCFR event. Comparison between the records and multi-decadal atmospheric circulation patterns and climatic external forcings indicates that Mediterranean circulation destabilisation occurs during positive North Atlantic Oscillation (NAO) and negative Atlantic Multidecadal Oscillation (AMO) phases, reduced solar activity and strong tropical volcanic eruptions. They may have recurrently produced favourable deep-water formation conditions, both increasing salinity and reducing temperature on multi-decadal time scales.

  17. Important Conclusions on the Messinian Salinity Crisis Depositional History of the Eastern Mediterranean Basin

    Science.gov (United States)

    Gunes, Pinar; Aksu, Ali; Hall, Jeremy

    2017-04-01

    The interpretation of a comprehensive set of high-resolution multi-channel seismic reflection profiles, multibeam bathymetry data and the litho- and bio-stratigraphic information from exploration wells across the Antalya Basin and Florence Rise revealed important conclusions on the Miocene to Recent tectonic evolution and the Messinian Salinity Crisis depositional history of the eastern Mediterranean Basin. This study clearly demonstrated the presence of a 4-division Messinian evaporite stratigraphy in the eastern Mediterranean, similar to that observed in the western Mediterranean, suggesting the existence of a similar set of depositional processes across the Mediterranean during the Messinian Salinity Crisis. However, the stratigraphic and depositional similarities of the evaporites between the eastern and western basins do not necessitate synchroneity in their depositional histories. The fact that the only saline water source for the eastern Mediterranean is the Atlantic Ocean and that the Sicily sill creates a physical barrier between the eastern and western Mediterranean impose several critical conditions. A simple 2-D model is developed which satisfies these conditions. The synchroneity of evaporite deposition across the eastern and western basins broke down as the Sicily Gateway became largely subaerial during a period when the Calabrian Arc area experienced uplift associated with slab break-off: the Sicily sill must have remained within a "goldilocks" zone to allow the right amount of saline water inflow into the eastern Mediterranean so that evaporites (massive halite) could be deposited. During this time, the sea level in western Mediterranean was at the breach-level of the Sicily sill, thus no evaporite deposition took place there. The model suggests that the eastern and western basin margins experienced a nearly synchronized gypsum deposition associated with the initial drawdown of the Mediterranean level, followed by the resedimentation in the deep

  18. On the occurrence of the fireworm Eurythoe complanata complex (Annelida, Amphinomidae in the Mediterranean Sea with an updated revision of the alien Mediterranean amphinomids

    Directory of Open Access Journals (Sweden)

    Andrés Arias

    2013-09-01

    Full Text Available The presence of two species within the Eurythoe complanata complex in the Mediterranean Sea is reported, as well as their geographical distributions. One species, Eurythoe laevisetis, occurs in the eastern and central Mediterranean, likely constituting the first historical introduction to the Mediterranean Sea and the other, Eurythoe complanata, in both eastern and Levantine basins. Brief notes on their taxonomy are also provided and their potential pathways for introduction to the Mediterranean are discussed. A simplified key to the Mediterranean amphinomid genera and species of Eurythoe and Linopherus is presented plus an updated revision of the alien amphinomid species reported previously from the Mediterranean Sea. A total of five exotic species have been included; information on their location, habitat, date of introduction and other relevant features is also provided.

  19. Patterns in planktonic metabolism in the Mediterranean Sea

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    A. Regaudie-de-Gioux

    2009-12-01

    Full Text Available Planktonic gross community production (GPP, net community production (NCP and community respiration (CR across the Mediterranean Sea was examined in two cruises, Thresholds 2006 and 2007, each crossing the Mediterranean from West to East to test for consistent variation along this longitudinal gradient in late spring to early summer. GPP averaged 2.4±0.4 mmol O2 m−3 d−1, CR averaged 3.8±0.5 mmol O2 m−3 d−1, and NCP averaged – 0.8±0.6 mmol O2 m−3 d−1 across the studied sections, indicative of a tendency for a net heterotrophic metabolism in late spring to early summer, prevalent across studied sections of the Mediterranean Sea as reflected in 70% of negative NCP estimates. The median P/R ratio was 0.6, also indicating a strong prevalence of heterotrophic communities (P/R<1 along the studied sections of the Mediterranean Sea. The communities tended to be net heterotrophic (i.e. P/R<1 at GPP less than 2.8 mmol O2 m−3 d−1. The Western Mediterranean tended to support a higher gross primary production and community respiration than the Eastern basin did, but these differences were not statistically significant (t-test, p>0.05. The net heterotrophy of the studied sections of the Mediterranean Sea indicates that allochthonous carbon should be important to subsidise planktonic metabolism during the late spring.

  20. Heat Wave Changes in the Eastern Mediterranean since 1960

    Science.gov (United States)

    Kuglitsch, Franz G.; Toreti, Andrea; Xoplaki, Elena; Della-Marta, Paul M.; Zerefos, Christos S.; Türkes, Murat; Luterbacher, Jürg

    2010-05-01

    Heat waves have discernible impacts on mortality and morbidity, infrastructure, agricultural resources, the retail industry, ecosystem and tourism and consequently affect human societies. A new definition of socially relevant heat waves is presented and applied to new data sets of high-quality homogenized daily maximum and minimum summer air temperature series from 246 stations in the eastern Mediterranean region (including Albania, Bosnia-Herzegovina, Bulgaria, Croatia, Cyprus, Greece, Israel, Romania, Serbia, Slovenia, Turkey). Changes in heat wave number, length and intensity between 1960 and 2006 are quantified. Daily temperature homogeneity analysis suggest that many instrumental measurements in the 1960s are warm-biased, correcting for these biases regionally averaged heat wave trends are up to 8% higher. We find significant changes across the western Balkans, southwestern and western Turkey, and along the southern Black Sea coastline. Since the 1960s, the mean heat wave intensity, heat wave length and heat wave number across the eastern Mediterranean region have increased by a factor 7.6 ±1.3, 7.5 ±1.3 and 6.2 ±1.1, respectively. These findings suggest that the heat wave increase in this region is higher than previously reported.

  1. Prokaryotic abundance and heterotrophic metabolism in the deep Mediterranean Sea

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    Rosabruna La Ferla

    2010-06-01

    Full Text Available A synthesis of field data carried out in the Mediterranean Sea are presented, aimed at contributing to the knowledge of three prokaryotic-mediated processes and their implications on the Carbon cycle. The distribution of exoenzymatic activities, secondary production and respiration rates was studied together with the prokaryotic abundances. Particular attention was paid to the meso- and bathypelagic layers which play an important role in the Mediterranean carbon cycle. The study is noteworthy because of its large spatial scale spanning the entire Mediterranean Sea over 4 years. In addition, two Atlantic stations in front of the Gibraltar Strait were investigated. The longitudinal distribution of prokaryotic activities and abundance along the MED showed different trends along the depthlayers. In particular, higher exoenzymatic rates were detected in the Eastern basin compared to the Western one; carbon respiration rate showed patterns variable with the sampling periods in the epipelagic and bathypelagic layers, while a consistent Westwards decreasing trend at the mesopelagic layers occurred. Specific enzyme activities per cell showed high values in the deepest layers for leucine aminopeptidase. Comparison with Carbon respiration rate data collected before the 2000s showed changing patterns of microbial heterotrophic processes in the Mediterranean Sea.

  2. The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

    Science.gov (United States)

    Coll, Marta; Piroddi, Chiara; Steenbeek, Jeroen; Kaschner, Kristin; Ben Rais Lasram, Frida; Aguzzi, Jacopo; Ballesteros, Enric; Bianchi, Carlo Nike; Corbera, Jordi; Dailianis, Thanos; Danovaro, Roberto; Estrada, Marta; Froglia, Carlo; Galil, Bella S.; Gasol, Josep M.; Gertwagen, Ruthy; Gil, João; Guilhaumon, François; Kesner-Reyes, Kathleen; Kitsos, Miltiadis-Spyridon; Koukouras, Athanasios; Lampadariou, Nikolaos; Laxamana, Elijah; López-Fé de la Cuadra, Carlos M.; Lotze, Heike K.; Martin, Daniel; Mouillot, David; Oro, Daniel; Raicevich, Saša; Rius-Barile, Josephine; Saiz-Salinas, Jose Ignacio; San Vicente, Carles; Somot, Samuel; Templado, José; Turon, Xavier; Vafidis, Dimitris; Villanueva, Roger; Voultsiadou, Eleni

    2010-01-01

    The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of

  3. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats.

    Directory of Open Access Journals (Sweden)

    Marta Coll

    Full Text Available The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet-undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular

  4. Segmentation of the Levant continental margin, eastern Mediterranean

    Science.gov (United States)

    Ben-Avraham, Z.; Schattner, U.; Lazar, M.; Hall, J. K.; Ben-Gai, Y.; Neev, D.; Reshef, M.

    2006-10-01

    The Levant continental margin is divided into two major segments by the Carmel structure, which extends from the Dead Sea fault into the eastern Mediterranean. New seismic reflection data over the unexplored northern segment are used for completing the structural framework of the Levant area, together with existing data south of it. Inclusive depth structural maps of the area were produced for the base Pliocene and base Messinian evaporites. Previous studies indicate that differences between the two segments are well expressed in the deep crustal structure. The present study, which focuses mainly on the shallow section, shows that these differences are maintained throughout the accumulation of young sedimentary units, and even in the bathymetry. This preservation of segmentation, both in the shallow and in the deep structure, insinuates that the two segments were formed through different continental breakup processes, which continue to dictate the style of sediment accumulation.

  5. Does by-catch pose a threat for the conservation of seabird populations in the southern Ionian Sea (eastern Mediterranean? A questionnaire based survey of local fisheries

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    G. KARRIS

    2013-09-01

    Full Text Available A significant number of studies worldwide have shown that incidental catches (by-catch of seabirds in fishing gear might pose a considerable risk for the conservation of their populations. Nevertheless reliable data on by-catch rates of seabirds in European marine ecosystems are patchy and need to be improved. This study constitutes a first attempt at the evaluation of by-catch rates in the southern Ionian Sea. Data were obtained by distributing a specific questionnaire to the fishers of Zakynthos Island. 150 professional fishers (representing 90% of the local fishing fleet participated in the research, and were interviewed during July-December 2010. The information collected showed that commercial longline and (to a lesser extent gillnet fishery gears caused incidental catches mostly of Scopoli’s Shearwater and Mediterranean Shag. The temporal analysis of the incidental bird mortality showed that seabirds were more susceptible to be trapped in fishery gears set around sunrise during spring and summer whereas spatial analysis of by-catch data indicated variations in the number of seabirds caught in different fishery areas.

  6. Does by-catch pose a threat for the conservation of seabird populations in the southern Ionian Sea (eastern Mediterranean? A questionnaire based survey of local fisheries

    Directory of Open Access Journals (Sweden)

    G. KARRIS

    2013-07-01

    Full Text Available A significant number of studies worldwide have shown that incidental catches (by-catch of seabirds in fishing gear might pose a considerable risk for the conservation of their populations. Nevertheless reliable data on by-catch rates of seabirds in European marine ecosystems are patchy and need to be improved. This study constitutes a first attempt at the evaluation of by-catch rates in the southern Ionian Sea. Data were obtained by distributing a specific questionnaire to the fishers of Zakynthos Island. 150 professional fishers (representing 90% of the local fishing fleet participated in the research, and were interviewed during July-December 2010. The information collected showed that commercial longline and (to a lesser extent gillnet fishery gears caused incidental catches mostly of Scopoli’s Shearwater and Mediterranean Shag. The temporal analysis of the incidental bird mortality showed that seabirds were more susceptible to be trapped in fishery gears set around sunrise during spring and summer whereas spatial analysis of by-catch data indicated variations in the number of seabirds caught in different fishery areas.

  7. The controversial path of Atlantic Water in the Eastern Mediterranean

    Science.gov (United States)

    Ciappa, Achille Carlo

    2014-04-01

    The Atlantic Water (AW) path suggested by two decades of thermal satellite data observations in the Eastern Mediterranean is similar to the path followed by the AW in the Western Mediterranean but is in contrast with the scheme proposed after the Physical Oceanography of the Eastern Mediterranean (POEM) experiment during the 1990s. Evidence of the AW path along the Libyo-Egyptian coast (Libyo-Egyptian Current; LEC) and around anti-cyclonic eddies of variable size and position (Libyo-Egyptian Eddies; LEEs) is reported in XBT transects, high resolution models and drifter trajectories. In the POEM scheme, the AW was carried eastwards by the Mid-Mediterranean Jet (MMJ) flowing in the middle of the Levantine basin. The MMJ is still noted in recent drifter trajectory analyses, and seasonal surveys and glider missions report that the AW is transferred towards the Levantine basin by the MMJ in subsurface layers. The issue is investigated in this study by considering whether the determination of the AW path and the resolution of the surface circulation are, unlike in the Western Mediterranean, two distinct problems. Historical hydrographic datasets and numerical experiments illustrated in this study demonstrate that satellite observations in the Eastern Mediterranean reveal the path of the surface water of Atlantic origin, which is modified by heating and evaporation into the saltier and warmer Levantine Surface Water (LSW), but do not reveal the path of the submerged AW that maintains the distinctive character of fresh AW in the Levantine basin. Differences between the surface and the submerged circulation in the Mersa-Matruh area explain the reason for the discrepancy. In summer the AW departs from the Sicily Channel at the sea surface and crosses the Ionian Sea in a surface layer 30 m deep. At the entrance to the Levantine basin, part of the AW re-circulates westwards in two separate branches, one directed to the Southern Ionian and the other towards the Central Ionian

  8. Corrigendum to "Upper ocean climate of the Eastern Mediterranean Sea during the Holocene Insolation Maximum – a model study" published in Clim. Past, 7, 1103–1122, 2011

    Directory of Open Access Journals (Sweden)

    G. Schmiedl

    2011-11-01

    Full Text Available Nine thousand years ago (9 ka BP, the Northern Hemisphere experienced enhanced seasonality caused by an orbital configuration close to the minimum of the precession index. To assess the impact of this "Holocene Insolation Maximum" (HIM on the Mediterranean Sea, we use a regional ocean general circulation model forced by atmospheric input derived from global simulations. A stronger seasonal cycle is simulated by the model, which shows a relatively homogeneous winter cooling and a summer warming with well-defined spatial patterns, in particular, a subsurface warming in the Cretan and western Levantine areas. The comparison between the SST simulated for the HIM and a reconstruction from planktonic foraminifera transfer functions shows a poor agreement, especially for summer, when the vertical temperature gradient is strong. As a novel approach, we propose a reinterpretation of the reconstruction, to consider the conditions throughout the upper water column rather than at a single depth. We claim that such a depth-integrated approach is more adequate for surface temperature comparison purposes in a situation where the upper ocean structure in the past was different from the present-day. In this case, the depth-integrated interpretation of the proxy data strongly improves the agreement between modelled and reconstructed temperature signal with the subsurface summer warming being recorded by both model and proxies, with a small shift to the south in the model results. The mechanisms responsible for the peculiar subsurface pattern are found to be a combination of enhanced downwelling and wind mixing due to strengthened Etesian winds, and enhanced thermal forcing due to the stronger summer insolation in the Northern Hemisphere. Together, these processes induce a stronger heat transfer from the surface to the subsurface during late summer in the western Levantine; this leads to an enhanced heat piracy in this region, a process never identified before

  9. Index medicus for the Eastern Mediterranean region

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    Al-Shorbaji Najeeb

    2008-09-01

    Full Text Available Abstract The study provides the rationale, history and current status of the Index Medicus for the World Health Organization Eastern Mediterranean Region. The Index is unique in combining the geographic coverage of peer-reviewed health and biomedical journals (408 titles from the 22 countries of the Region. Compiling and publishing the Index coupled with a document delivery service is an integral part of the WHO Regional Office's knowledge management and sharing programme. In this paper, bibliometric indicators are presented to demonstrate the distribution of journals, articles, languages, subjects and authors as well as availability in printed and electronic formats. Two countries in the Region (Egypt and Pakistan contribute over 50% of the articles in the Index. About 90% of the articles are published in English. Epidemiology articles represent 8% of the entire Index. 15% of the journals in the Index are also indexed in MEDLINE, while 7% are indexed in EMBASE. Future developments of the Index will include covering more journals and adding other types of health and biomedical literature, including reports, theses, books and current research. The challenges and lessons learnt are discussed.

  10. Lightning flash multiplicity in eastern Mediterranean thunderstorms

    Science.gov (United States)

    Yair, Y.; Shalev, S.; Erlich, Z.; Agrachov, A.; Katz, E.; Saaroni, H.; Price, C.; Ziv, B.

    2014-02-01

    Cloud-to-ground lightning flashes usually consist of one or several strokes coming in very short temporal succession and close spatial proximity. A commonly used method for converting stroke data into flashes is using the National Lightning Detection Network (NLDN) thresholds of maximum temporal separation of 0.5 s and maximum lateral distance of 10 km radius between successive strokes. In the present study, we tested a location-based algorithm with several spatial and temporal ranges, and analyzed stroke data obtained by the Israel Lightning Location System (ILLS) during one year (1.8.2009-31.7.2010). We computed the multiplicity, the percentage of single stroke flashes and the geographical distribution of average multiplicity values for thunderstorms in the Eastern Mediterranean region. Results show that for the NLDN thresholds, the percentage of single stroke flashes in Israel was 37% and the average multiplicity was 1.7. We reanalyzed the data with a spatial range that equals twice the ILLS location error and shorter times. For the new thresholds of maximum distance of 2.5 km and maximum allowed temporal separation of 0.2 s we find that the mean multiplicity of negative CGs is lowered to 1.4 and find a percentage of 58% of single stroke flashes. A unique severe storm from 30 October 2009 is analyzed and compared with the annual average of 2009/2010, showing that large deviations from the mean values can occur in specific events.

  11. Ozone and carbon monoxide budgets over the Eastern Mediterranean

    NARCIS (Netherlands)

    Myriokefalitakis, S.; Daskalakis, N.; Fanourgakis, G.S.; Voulgarakis, A.; Krol, M.C.; Brugh, Aan de J.M.J.; Kanakidou, M.

    2016-01-01

    The importance of the long-range transport (LRT) on O3 and CO budgets over the Eastern Mediterranean has been investigated using the state-of-the-art 3-dimensional global chemistry-transport model TM4-ECPL. A 3-D budget analysis has been performed separating the Eastern from the

  12. Plastic Accumulation in the Mediterranean Sea

    Science.gov (United States)

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  13. Plastic accumulation in the Mediterranean sea.

    Directory of Open Access Journals (Sweden)

    Andrés Cózar

    Full Text Available Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2, as well as its frequency of occurrence (100% of the sites sampled, are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  14. Plastic accumulation in the Mediterranean sea.

    Science.gov (United States)

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  15. Plastic Accumulation in the Mediterranean Sea

    KAUST Repository

    Cózar, Andrés

    2015-04-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  16. The Eastern Sardinian Margin (Tyrrhenian Sea, Western Mediterranean) : a key area to study the rifting and post-breakup evolution of a back-arc passive continental margin

    Science.gov (United States)

    Gaullier, Virginie; Chanier, Frank; Vendeville, Bruno; Maillard, Agnès; Thinon, Isabelle; Graveleau, Fabien; Lofi, Johanna; Sage, Françoise

    2016-04-01

    The Eastern Sardinian passive continental margin formed during the opening of the Tyrrhenian Sea, which is a back-arc basin created by continental rifting and oceanic spreading related to the eastward migrating Apennine subduction system (middle Miocene to Pliocene). Up to now, rifting in this key area was considered to be pro parte coeval with the Messinian Salinity Crisis (MSC, 5.96-5.32 Ma). We use the MSC seismic markers and the deformation of viscous salt and its brittle overburden as proxies to better delineate the timing of rifting and post-rift reactivation, and especially to quantify vertical and horizontal movements. On this young, highly-segmented margin, the Messinian Erosion Surface and the Upper and Mobile Units are systematically associated, respectively, to basement highs and deeper basins, showing that a rifted deep-sea domain already existed by Messinian times, therefore a major pre-MSC rifting episode occurred across the entire domain. Data show that there are no signs of Messinian syn-rift sediments, hence no evidence for rifting after Late Tortonian times. Moreover, because salt tectonics creates fan-shaped geometries in sediments, syn-rift deposits have to be carefully re-examined to distinguish the effects of crustal tectonics (rifting) and salt tectonics. We also precise that rifting is clearly diachronous from the upper margin (East-Sardinia Basin) to the lower margin (Cornaglia Terrace) with two unconformities, attributed respectively to the necking and to the lithospheric breakup unconformities. The onshore part of the upper margin has been recently investigated in order to characterize the large crustal faults affecting the Mesozoic series (geometry, kinematics and chronology) and to decipher the role of the structural inheritance and of the early rifting. Seaward, we also try to constrain the architecture and timing of the continent-ocean transition, between the hyper-extended continental crust and the first oceanic crust. Widespread

  17. Ozone and carbon monoxide budgets over the Eastern Mediterranean.

    Science.gov (United States)

    Myriokefalitakis, S; Daskalakis, N; Fanourgakis, G S; Voulgarakis, A; Krol, M C; Aan de Brugh, J M J; Kanakidou, M

    2016-09-01

    The importance of the long-range transport (LRT) on O3 and CO budgets over the Eastern Mediterranean has been investigated using the state-of-the-art 3-dimensional global chemistry-transport model TM4-ECPL. A 3-D budget analysis has been performed separating the Eastern from the Western basins and the boundary layer (BL) from the free troposphere (FT). The FT of the Eastern Mediterranean is shown to be a strong receptor of polluted air masses from the Western Mediterranean, and the most important source of polluted air masses for the Eastern Mediterranean BL, with about 40% of O3 and of CO in the BL to be transported from the FT aloft. Regional anthropogenic sources are found to have relatively small impact on regional air quality in the area, contributing by about 8% and 18% to surface levels of O3 and CO, respectively. Projections using anthropogenic emissions for the year 2050 but neglecting climate change calculate a surface O3 decrease of about 11% together with a surface CO increase of roughly 10% in the Eastern Mediterranean.

  18. The wind power potential of the eastern Mediterranean region of Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Besir; Bilgili, Mehmet; Akilli, Huseyin [Mechanical Engineering Department, Faculty of Engineering and Arhitecture, & amp; Ccedil; ukurova University, 01330 Adana (Turkey)

    2005-02-01

    The wind energy potential in the eastern Mediterranean region has been investigated using hourly wind data taken from seven stations during 1992-2001 periods by the Turkish Meteorological Service. The present work suggests that in the east Mediterranean Sea coast of Turkey, wind energy sources are convenient for electricity generation. The mean power density was determined as 500W/m{sup 2} in many areas of this region at 25m from the ground level. The most promising locations in terms of wind power generation are identified. The contours of constant wind speed and power potential could lead the private power developers to decide the locations of appropriate wind farms.

  19. Flabelliderma cinari (Polychaeta: Flabelligeridae, a new species from the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    S.U. KARHAN

    2013-01-01

    Full Text Available A new species of flabelligerid polychaete, Flabelliderma cinari, is described from the Turkish coast of the Eastern MediterraneanSea. This represents the first occurrence of the genus Flabelliderma in the Mediterranean. Flabelliderma cinari sp. nov. isclosely allied to F. claparedei in having dorsal tubercles of two different sizes; however, these species differ in the relative shapeand number of dorsal tubercles, the number of capillaries per fascicle in the notopodia and the shape of the curved distal articlesin the neuropodial hooks.

  20. The history and transitent nature of salinity anomalies in the Mediterranean Sea from advanced reanalysis

    Science.gov (United States)

    Pinardi, Nadia; Fratianni, Claudia; Lyubartsev, Vladyslav

    2015-04-01

    Long term, high resolution re-analyses of the Mediterranean Sea circulation and thermohaline structure are now available from the NextData and MyOcean projects. The first is a 60 years re-analysis (1953-2012) done with atmospheric AMIP forcing and the second is 25 years re-analysis (1987-2012) done with ECMWF atmospheric forcing re-analysis. Both concur to have a representation of the longest time series of salinity anomalies in the Mediterranean Sea, the highest space-time reconstruction ever done for the whole basin. The salinity anomalies of the Mediterranean Sea below seven hundred meters of the past 60 years are examined in comparison with the Eastern Mediterranean Transient, a phenomenon Dr. A.Hecht contributed to discover during POEM. Deep water salinity changes and Gibraltar Strait anomalies are also examined in the light of possible feedback mechanisms, as well as the structure and correlation of such salinity anomalies with atmospheric forcing.

  1. Tectonic isolation of the Levant basin offshore Galilee-Lebanon effects of the Dead Sea fault plate boundary on the Levant continental margin, eastern Mediterranean

    Science.gov (United States)

    Schattner, U.; Ben-Avraham, Z.; Lazar, M.; Hüebscher, C.

    2006-11-01

    The continental margin of the central Levant, offshore northern Israel and southern Lebanon is characterized by a sharp continental-oceanic crustal transition, exhibited on the bathymetry as a steep continental slope. At the base of the slope a narrow zone of faulting deforms the upper Messinian-recent sedimentary sequence. Further into the basin no major deformations are observed. However, onland a restraining bend along the Dead Sea fault plate boundary results in the formation of the Lebanon and anti-Lebanon mountain ranges, which exhibit a large positive isostatic anomaly not compensated at depth. All these geologic features follow a NNE-SSW trend. A dense network of multi-channel and single-channel seismic profiles, covering 5000 km of ship-track offshore northern Israel and southern Lebanon, was analyzed for the purpose of characterizing the continental margin. Additional seismic surveys covering the area between the Levant margin and the Cyprean arc were examined. Data were then incorporated with magnetic, gravity and earthquake measurements to reveal the deep crustal structure of the area and integrated with bathymetry data to describe the behavior of the young sedimentary basin fill. Results indicate that the Levant basin, offshore northern Israel and southern Lebanon (up to Beirut) is more-or-less unaffected by the intense tectonic deformation occurring onland. The transition between the deformed area onland and the undeformed Levant basin occurs along the base of the continental slope. Along the base, the upper Messinian-recent sedimentary sequence is cut by two sets of faults: shallow growth faults resulting from salt tectonics and high angle faults, marking the surface expression of a deeper crustal discontinuity - the marine extension of the Carmel fault zone. The central Levant continental margin is being reactivated by transpressional faulting of the marine continuation of the Carmel fault, at the base of the continental slope. This fault system

  2. Radioactivity in three species of eastern Mediterranean jellyfish.

    Science.gov (United States)

    Mamish, S; Al-Masri, M S; Durgham, H

    2015-11-01

    Activity concentrations of (137)Cs, (40)K, (210)Po, (210)Pb, (234)U and (238)U were determined in umbrella and oral arms of three widely distributed jellyfish species; namely Rhopilema nomadica Galil, 1990, Aurelia aurita Linne, 1758 and Aequorea forskalea Péron & Lesueur, 1810 collected from February 2011 to January 2012 in four sampling locations along the Syrian coast (Eastern Mediterranean Sea). The results have shown significant variations in radionuclides activity concentrations amongst the species. The average activity concentrations of (40)K, (210)Po, (210)Pb, (234)U and (238)U in the umbrella of R. nomadica species were higher than the average activity concentrations in the umbrella of A. aurita species by about 3.2, 1.4, 1.8, 3.2 and 3.2 folds, and A. forskalea species by about 45.5, 15.4, 19, 7.4 and 7.6 folds, respectively. The average activity concentrations of (40)K, (210)Po, (210)Pb, (234)U and (238)U in oral arms of R. nomadica species were higher than the average activity concentrations in oral arms of A. aurita species by about 3.8, 1.7, 1.9, 2.8 and 2.9 folds, respectively. (137)Cs activity concentrations were below the detection limit in all measured samples. In addition, activity concentrations of (137)Cs, (40)K, (210)Po, (210)Pb, (234)U and (238)U were also determined in 44 surface seawater samples and the activity concentrations ranged between 10.6 and 11.9 Bq l(-1) for (40)K, 1.1 and 1.4 mBq l(-1) for (210)Po, 0.5 and 0.7 mBq l(-1) for (210)Pb, 40.8 and 44.5 mBq l(-1) for (234)U, and 36.9 and 38.4 mBq l(-1) for (238)U, while (137)Cs activity concentrations were below the detection limit in all measured samples. Moreover, the umbrella and oral arms readily accumulated (40)K, (210)Po, (210)Pb, (234)U and (238)U above ambient seawater levels in the sequence of (210)Po > (210)Pb > (4) K > (234)U and (238)U. Concentration ratio (CR) values were relatively high for (210)Po and (210)Pb and reached 10(3) and 10(2), respectively for the jellyfish R

  3. National health research system mapping in 10 Eastern Mediterranean countries.

    Science.gov (United States)

    Kennedy, A; Khoja, T A M; Abou-Zeid, A H; Ghannem, H; IJsselmuiden, C

    2008-01-01

    Health research systems in the Eastern Mediterranean Region are not well developed to generate and use knowledge to improve health, reduce inequity and contribute to economic development. This study aimed to provide core data on National Health Research Systems (NHRS) in 10 Eastern Mediterranean countries in order to inform actions to strengthen health research system governance and management. Whilst there were examples of good practice, few countries had a formal NHRS and many basic building blocks needed for an effective system had not been put in place. Although limited in focus, the study provides useful information for countries to initiate action to strengthen their NHRS.

  4. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    Directory of Open Access Journals (Sweden)

    Roberto Danovaro

    Full Text Available Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth, including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components

  5. Deep-Sea Biodiversity in the Mediterranean Sea: The Known, the Unknown, and the Unknowable

    Science.gov (United States)

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J.; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  6. Large-scale response of the Eastern Mediterranean thermohaline circulation to African monsoon intensification during sapropel S1 formation

    Science.gov (United States)

    Tesi, T.; Asioli, A.; Minisini, D.; Maselli, V.; Dalla Valle, G.; Gamberi, F.; Langone, L.; Cattaneo, A.; Montagna, P.; Trincardi, F.

    2017-03-01

    The formation of Eastern Mediterranean sapropels has periodically occurred during intensification of northern hemisphere monsoon precipitation over North Africa. However, the large-scale response of the Eastern Mediterranean thermohaline circulation during these monsoon-fuelled freshening episodes is poorly constrained. Here, we investigate the formation of the youngest sapropel (S1) along an across-slope transect in the Adriatic Sea. Foraminifera-based oxygen index, redox-sensitive elements and biogeochemical parameters reveal - for the first time - that the Adriatic S1 was synchronous with the deposition of south-eastern Mediterranean S1 beds. Proxies of paleo thermohaline currents indicate that the bottom-hugging North Adriatic Dense Water (NAdDW) suddenly decreased at the sapropel onset simultaneously with the maximum freshening of the Levantine Sea during the African Humid Period. We conclude that the lack of the "salty" Levantine Intermediate Water hampered the preconditioning of the northern Adriatic waters necessary for the NAdDW formation prior to the winter cooling. Consequently, a weak NAdDW limited in turn the Eastern Mediterranean Deep Water (EMDWAdriatic) formation with important consequences for the ventilation of the Ionian basin as well. Our results highlight the importance of the Adriatic for the deep water ventilation and the interdependence among the major eastern Mediterranean water masses whose destabilization exerted first-order control on S1 deposition.

  7. Guo Dantong, Intercourse between Egypt and Eastern Mediterranean World

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    With growing interests in the studies of global history, scholars around the worldhave since the 1970s increasingly focused their attentions on the relationship between the ancient civilizations in the Eastern Mediterranean world. Guo Dantong has takenpart in the academic discussions on this subject in China in recent years, and publishedone of her important research results in 2011.

  8. Pre-collisional geodynamics of the Mediterranean Sea: the Mediterranean Ridge and the Tyrrhenian Sea

    Directory of Open Access Journals (Sweden)

    E. Chaumillon

    1997-06-01

    Full Text Available Today the Mediterranean Sea consists of a series of small-sized and almost geographically disconnected oceanic or continental crust rooted marine basins. It is also an area almost totally surrounded by mountain ranges, which chiefly belong to the alpine realm. This overall geodynamic setting results from a long term convergence between the two major, African and European, plates. Previous collisions have led to the edification of surrounding chains, while subduction and new-collisional processes tend to create new extensional back-arc basins and wide tectonized accretionary prisms. In this paper we briefly outline the most recent and almost land-locked back-arc basin that has developed in the Mediterranean,i.e., the Tyrrhenian Sea, and the Mediterranean Ridge, which may be regarded as a collisional sedimentary wedge predating a future mountain chain.

  9. Contribution of mono and polysaccharides to heterotrophic N2 fixation at the eastern Mediterranean coastline.

    Science.gov (United States)

    Rahav, E; Giannetto, M J; Bar-Zeev, E

    2016-06-16

    N2 fixation should be a critical process in the nitrogen-poor surface water of the eastern Mediterranean Sea. Despite favorable conditions, diazotroph abundance and N2 fixation rates remains low for reasons yet explained. The main goal of this study was to investigate the limiting nutrients for diazotrophy in this oligotrophic environment. Hence, we conducted dedicated bottle-microcosms with eastern Mediterranean Sea water that were supplemented with mono and polysaccharides as well as inorganic nitrogen and phosphorous. Our results indicate that the diazotrophic community expressing nifH was primarily represented by heterotrophic Proteobacteria. N2 fixation and heterotrophic bacterial activity increased up-to tenfold following two days of dark incubations, once seawater was supplemented with organic carbon substrate in the form of glucose (monosaccharides) or gum-xanthan (polysaccharide surrogate). Furthermore, our results point that carbon-rich polysaccharides, such as transparent exopolymer particles, enhance heterotrophic N2 fixation, by forming microenvironments of intense metabolic activity, high carbon: nitrogen ratio, and possibly low O2 levels. The conclusions of this study indicate that diazotrophs in the eastern Mediterranean coast are primarily limited by organic carbon substrates, as possibly in many other marine regions.

  10. Sugars in atmospheric aerosols over the Eastern Mediterranean

    Science.gov (United States)

    Theodosi, Christina; Panagiotopoulos, Christos; Nouara, Amel; Zarmpas, Pavlos; Nicolaou, Panagiota; Violaki, Kalliopi; Kanakidou, Maria; Sempéré, Richard; Mihalopoulos, Nikolaos

    2017-04-01

    The role of biomass combustion and primary bio-particles in atmospheric PM10 aerosols in the Eastern Mediterranean over a two-year period was estimated by studying sugar tracers. Sugar concentrations ranged from 6 to 334 ng m-3, while their contributions to the organic carbon (OC) and water soluble organic carbon (WSOC) pools were 3 and 11%, respectively. Over the studied period, glucose and levoglucosan were the two most abundant sugars accounting equally about 25% of the total sugar concentration in PM10 aerosols whereas fructose, sucrose, and mannitol represented 18%, 15% and 10%, respectively. Primary saccharides (glucose, fructose, and sucrose) peaked at the beginning of spring (21, 17 and 15 ng m-3, respectively), indicating significant contributions of bioaerosols to the total organic aerosol mass. On the other hand, higher concentrations of anhydrosugars (burning biomass tracers including levoglucosan, mannosan and galactosan) were recorded in winter (19, 1.4 and 0.2 ng m-3, respectively) than in summer (9.1, 1.1 and 0.5 ng m-3, respectively). Levoglucosan was the dominant monosaccharide in winter (37% of total sugars) with less contribution in summer (19%) probably in relation with enhanced photochemical oxidation reactions by hydroxyl (ṡOH) radicals impacting anhydrosugars. We estimate that atmospheric oxidation by ṡOH decreases levoglucosan levels by 54% during summer. Biomass burning, based on levoglucosan observations, was estimated to contribute up to 13% to the annual average OC measured at Finokalia. Annual OC, WSOC, and carbohydrate dry deposition fluxes for the studied period were estimated to 414, 175, and 9 mg C m-2 y-1, respectively. Glucose and levoglucosan accounted for 34% and 2% of the total sugar fluxes. According to our estimations, atmospheric OC and WSOC inputs account for ˜0.70% of the carbon produced by annual primary production (PP) in the Cretan Sea. Considering the entire Mediterranean, dry deposition of OC could provide at

  11. Zonal distribution of dissolved aluminium in the Mediterranean Sea

    NARCIS (Netherlands)

    Rolison, J. M.; Middag, R.; Stirling, C. H.; Rijkenberg, M. J. A.; de Baar, H. J. W.

    2015-01-01

    Dissolved aluminium (Al) is an important tracer of atmospheric dust input to the oceans. The GEOTRACES expedition to the highly dust impacted Mediterranean Sea afforded the opportunity to study the distribution of dissolved Al in the Mediterranean Sea in detail. Interestingly, the elevated concentra

  12. Wild fire effects on floristic diversity in three thermo-Mediterranean vegetation types in a small islet of eastern Aegean sea

    Science.gov (United States)

    Abraham, Eleni; Kyriazopoulos, Apostolos; Korakis, George; Parissi, Zoi; Chouvardas, Dimitrios

    2014-05-01

    Sclerophyllus scrub formations, the main vegetation type in many islands of the Aegean area, are characterized by their high biodiversity. Dominant shrub species of sclerophyllus formations are well adapted to dry season conditions by various anatomical and physiological mechanisms. As a result, their biomass acts as very flammable fine fuel, and consequently wild fires are very common in these ecosystems. Wildfire effects on vegetation and biodiversity in the Mediterranean basin have been studied and the results are diverse depending mainly on vegetation type and frequency of fire. The aim of this study was to evaluate the effects of wildfire on floristic diversity and species composition in three thermo-Mediterranean vegetation types 1) Sacropoterium spinosum phrygana, 2) low formations of Cistus creticus and 3) low formations of Cistus creticus in abandoned terraces. The research was conducted in Enoussa islet, which is located northeastern of Chios Island, in May 2013 (one year after the fire). Vegetation sampling was performed along five transects placed in recently burned and in adjacent unburned sites of each vegetation type. The plant cover and the floristic composition were measured, while diversity, evenness and dominance indices were determined for the vegetation data. Vegetation cover and the floristic diversity were significant lower and higher respectively in burned areas in comparison to the unburned. The woody species followed by the annual grasses and the annual forbs dominated in both burned and unburned areas. However, the woody species were significantly decreased in the burned areas in all vegetation types, while the annual grasses only in the burned areas of Sacropoterium spinosum phrygana and Cistus creticus in abandoned terraces. Inversely, the annual forbs significantly increased in the burned sites of Cistus creticus formations. The highest value of Morisita-Horn Index of similarity between burned and unburned sites (beta diversity) was

  13. New Fisheries-related data from the Mediterranean Sea (April 2014

    Directory of Open Access Journals (Sweden)

    K. STERGIOU

    2013-12-01

    Full Text Available As part of its policy, Mediterranean Marine Science started from 2014 to publish a new series of collective article with fisheries-related data from the Mediterranean Sea. In this first collective article we present length frequencies and weight-length relationships for the northern brown shrimp Farfantepenaeus aztecus in the eastern Mediterranean, length-weight relationships for 10 fish species in the North Aegean Sea, the feeding habits for 11 sparid fishes in the North Aegean Sea, a review of the existing literature on the feeding and reproduction of common carp Cyprinus carpio in Anatolia (Turkey and mouth dimensions and the relationships between mouth area and length for seven freshwater fishes from Lake Volvi (Northern Greece.

  14. Eastern Mediterranean Natural Gas: Analyzing Turkey's Stance

    Directory of Open Access Journals (Sweden)

    Abdullah Tanriverdi

    2016-02-01

    Full Text Available Recent large-scale natural gas discoveries in East Mediterranean have drawn attention to the region. The discoveries caused both hope and tension in the region. As stated, the new resources may serve as a new hope for all relevant parties as well as the region if managed in a collaborative and conciliatory way. Energy may be a remedy to Cyprus' financial predicament, initiate a process for resolving differences between Turkey and Cyprus, normalize Israel-Turkey relations and so on. On the contrary, adopting unilateral and uncooperative approach may aggravate the tension and undermine regional stability and security. In this sense, the role of energy in generating hope or tension is dependent on the approaches of related parties. The article will analyze Turkey's attitude in East Mediterranean case in terms of possible negative and positive implications for Turkey in the energy field. The article examines Turkey's position and the reasons behind its stance in the East Mediterranean case. Considering Turkey's energy profile and energy policy goals, the article argues that the newly found hydrocarbons may bring in more stakes for Turkey if Turkey adopts a cooperative approach in this case.

  15. Hydrodynamic, neotectonic and climatic control of the evolution of a barrier beach in the microtidal environment of the NE Ionian Sea (eastern Mediterranean)

    Science.gov (United States)

    Poulos, Serafim E.; Ghionis, George; Verykiou, Efthymia; Roussakis, Grigoris; Sakellariou, Dimitrios; Karditsa, Aikaterini; Alexandrakis, George; Petrakis, Stelios; Sifnioti, Dafni; Panagiotopoulos, Ioannis P.; Andris, Periklis; Georgiou, Panos

    2015-02-01

    The existence of barrier beaches is crucial, as they act as a buffer zone to the associated wetlands, whilst they are sensitive to climate change. The present study offers an insight into the processes controlling the formation and evolution of the Gyra barrier beach (NW coast of the island of Lefkada) in the microtidal, tectonically very active Ionian Sea under the influence of regional climate change and human interference. Such investigations are sparse in the literature. Existing information regarding regional geology, sediment availability and human intervention is combined with the collection of geophysical data, field observations and simulations of nearshore hydro- and sediment dynamics, analysis of climatic variations with respect to offshore wind/wave patterns (including storminess), in situ measurements of recent morphometric changes (2006-2008) and historical shoreline changes (since the 1960s). The recent formation and evolution (mostly under retreat) of the Gyra barrier beach is shown to be the combined result of the regional seismotectonic setting, relative increase of sea level, coastal sediment transport patterns, as well as human impact (negative) on primarily terrestrial sediment influxes. The current erosional trend of the barrier beach is associated with a shift in the wind and wave direction (from SW to NW) of extreme storm events in the Ionian Sea since the 1980s. The regional climatic variations of the last decades are well correlated with the trend of the North Atlantic Oscillation.

  16. Polychlorinated Biphenyl Levels and its Correlation to Size of Marine Organisms Harvested from a War-Induced Oil Spill Zone of the Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    E.K. BARBOUR

    2012-12-01

    Full Text Available This is the first work establishing a base-line data of the level of total Polychlorinated Biphenyl (PCB contaminants in selected marine organisms (Siganus rivulatus, Mullet spp., and oysters and its relationship to organism size and the harvest distance from the oil spill source. Six locations across the Lebanese Mediterranean were included for sampling. Oysters and the two fish types were collected after 72 days of the spill. The length, maximum width, and whole weight of individual organisms were recorded. Methanol extracts of the samples were analyzed for total PCB using a Competitive Enzyme-linked Immunosorbent Assay (ELISA based Spectrophotometry.All means of PCB in the three selected marine organisms were below the guidance level set by USFDA (2 ppm. A total of 6 significant regression equations were established between the total PCB level and certain size dimensions of specific selected marine species, with values of R2 ranging between 0.719 – 0.909 and P values ranging from 0.038 – 0.099.In addition, the total PCB level in Siganus rivulatus correlated with the harvest distance north of the oil spill source, signifying a drop in total PCB level with an increase in harvest distance from the oil spill source.

  17. Polychlorinated Biphenyl Levels and its Correlation to Size of Marine Organisms Harvested from a War-Induced Oil Spill Zone of the Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    E.K. BARBOUR

    2009-12-01

    Full Text Available This is the first work establishing a base-line data of the level of total Polychlorinated Biphenyl (PCB contaminants in selected marine organisms (Siganus rivulatus, Mullet spp., and oysters and its relationship to organism size and the harvest distance from the oil spill source. Six locations across the Lebanese Mediterranean were included for sampling. Oysters and the two fish types were collected after 72 days of the spill. The length, maximum width, and whole weight of individual organisms were recorded. Methanol extracts of the samples were analyzed for total PCB using a Competitive Enzyme-linked Immunosorbent Assay (ELISA based Spectrophotometry.All means of PCB in the three selected marine organisms were below the guidance level set by USFDA (2 ppm. A total of 6 significant regression equations were established between the total PCB level and certain size dimensions of specific selected marine species, with values of R2 ranging between 0.719 – 0.909 and P values ranging from 0.038 – 0.099.In addition, the total PCB level in Siganus rivulatus correlated with the harvest distance north of the oil spill source, signifying a drop in total PCB level with an increase in harvest distance from the oil spill source.

  18. Reducing maternal mortality in the eastern Mediterranean region.

    Science.gov (United States)

    Mahaini, R; Mahmoud, H

    2005-07-01

    Current efforts in some countries of the Eastern Mediterranean Region are still insufficient to achieve the fifth Millennium Development Goal on improving maternal health. Strong commitment, intensive efforts and effective national policies and strategies are now urgently required in order to translate vision into action. Such efforts and plans should target the strengthening of health systems, the expansion in the coverage of effective integrated interventions, and the recognition of the essential role of individuals, families and communities in making pregnancy safer. This article provides a background on the current situation of maternal health in the Eastern Mediterranean Region, including underlying causes and contributing factors, and describes strategic directions aimed at accelerating the reduction of maternal mortality in the Region and moving closer to the achievement of the Millennium Development Goals.

  19. Observations of smoke and mineral dust over Eastern Mediterranean

    Science.gov (United States)

    Nisantzi, Argyro; Elisavet Mamouri, Rodanthi; Hadjimitsis, Diofandos; Ansmann, Albert

    2016-04-01

    Four-year combined observations (2010-2014) with EARLINET polarization lidar and AERONET sun/sky photometer at Limassol (34.7 N, 33 E), Cyprus, Eastern Mediterranean, were used in order to study the soil dust content in lofted fire smoke plumes. This study focuses on air masses advected from Turkey as well regions further north of Black Sea during the main burning season (summer half year). Cases with strong impact of smoke events (occurring over Turkey during 1-3 days before arrival at Limassol) and observations with more background-like aerosol signatures (not influenced by Turkish fire smoke) were separated. This first systematic attempt to characterize less than 3-day-old smoke plumes in terms of particle linear depolarization ratio (PDR), measured with lidar, shown that PDR was typically 10-15% when Turkish fires contributed to the aerosol burden in the free troposphere and considerably lower with values 3-8% when fires over Turkey were absent while the air masses cross this country. High Ångström exponents of 1.4-2.2 during all these events with lofted smoke layers, occurring between 1 and 3 km height, suggest the absence of a pronounced particle coarse mode. When PDR plotted vs. travel time (spatial distance between Limassol and last fire area), PDR decreased strongly from initial values around 16-18% (1 day travel) to 4-8% after 4 days of travel caused by deposition processes. This behavior was found to be in close agreement with findings described in the literature. Biomass burning should therefore be considered as another source of free tropospheric soil dust.

  20. Improving sea level simulation in Mediterranean regional climate models

    Science.gov (United States)

    Adloff, Fanny; Jordà, Gabriel; Somot, Samuel; Sevault, Florence; Arsouze, Thomas; Meyssignac, Benoit; Li, Laurent; Planton, Serge

    2017-08-01

    For now, the question about future sea level change in the Mediterranean remains a challenge. Previous climate modelling attempts to estimate future sea level change in the Mediterranean did not meet a consensus. The low resolution of CMIP-type models prevents an accurate representation of important small scales processes acting over the Mediterranean region. For this reason among others, the use of high resolution regional ocean modelling has been recommended in literature to address the question of ongoing and future Mediterranean sea level change in response to climate change or greenhouse gases emissions. Also, it has been shown that east Atlantic sea level variability is the dominant driver of the Mediterranean variability at interannual and interdecadal scales. However, up to now, long-term regional simulations of the Mediterranean Sea do not integrate the full sea level information from the Atlantic, which is a substantial shortcoming when analysing Mediterranean sea level response. In the present study we analyse different approaches followed by state-of-the-art regional climate models to simulate Mediterranean sea level variability. Additionally we present a new simulation which incorporates improved information of Atlantic sea level forcing at the lateral boundary. We evaluate the skills of the different simulations in the frame of long-term hindcast simulations spanning from 1980 to 2012 analysing sea level variability from seasonal to multidecadal scales. Results from the new simulation show a substantial improvement in the modelled Mediterranean sea level signal. This confirms that Mediterranean mean sea level is strongly influenced by the Atlantic conditions, and thus suggests that the quality of the information in the lateral boundary conditions (LBCs) is crucial for the good modelling of Mediterranean sea level. We also found that the regional differences inside the basin, that are induced by circulation changes, are model-dependent and thus not

  1. An overlooked alien species present on the coasts of Greece (Eastern Mediterranean: the polychaete Polycirrus twisti Potts (Polychaeta: Terebellidae

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    N. SIMBOURA

    2012-12-01

    Full Text Available The Terebellidae polychaete Polycirrus twisti Potts, 1928 had been confused in several previous records the Eastern Mediterranean with the co-generic species Polycirrus plumosusWollebaeck, 1912, because of incomplete specimens or unclear descriptions; therefore its presence in Greek seas had been overlooked. Specimens of Polycirrus twisti were currently identified from the Korinthiakos Gulf (Greece, Eastern Mediterranean, while older records from the Hellenic marine area, erroneously assigned toPolycirrus plumosus and recorded since 1983 (Rhodos island, Dodekanesse were emended. Polycirrus twisti is an alien species, most likely introduced to the Mediterranean from the Suez Canal, while it was recently reported from the Southern coasts of Turkey (Levantine Sea. Its identification and report in Greek Seas increases the number of alien polychaete species in this area to 37 and offers a further evidence and link of its introduction and dispersion dynamics from the Suez Canal to the Levantine and Aegean Sea. The presence of the previously reported species Polycirrus plumosus in the Mediterranean Sea is therefore strongly questionable.

  2. Mean sea level and surface circulation variability of the Mediterranean Sea from 2 years of TOPEX/POSEIDON altimetry

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    Larnicol, Gilles; Le Traon, Pierre-Yves; Ayoub, Nadia; de Mey, Pierre

    1995-12-01

    We describe the circulation and mean sea level variations of the Mediterranean Sea from 2 years of TOPEX/POSEIDON altimetric data. It is first shown that the response of the Mediterranean Sea to atmospheric pressure forcing is close to an inverse barometer (except at high frequencies) which means that the adjustment is accompanied by a flow through the Straits of Sicily and Gibraltar. We then use TOPEX/POSEIDON to study the mean sea level variations, representing steric effects and integrated large-scale changes of the mass of the Mediterranean Sea. We observe an annual cycle with a fast drop during winter. Steric effects account for about half of the observed variations. The remaining signal is believed to be driven by evaporation minus precipitation (E - P) forcing and internal hydraulic control in the Straits of Gibraltar. Using suboptimal space-time objective analysis, the classic components of the Mediterranean surface circulation are recovered, despite low signal-to-noise ratio (the rms of sea level variability is less than 10 cm). The variable Mediterranean circulation is seen as a complex combination of mesoscale and large-scale variations. The surface circulation is more complex in the eastern basin than in the western basin. In the east it is composed of subbasin-scale gyres, such as the so-called Mersa-Matruh and Shikmona gyres, which do not have an obvious recurrence period. We also observe an intensification of the large-scale cyclonic winter circulation in the western and in the Ionian basins. Several mesoscale structures, such as the Alboran gyres and the Ierepetra gyre, show a clear seasonal cycle, with a maximum in summer. The good qualitative and quantitative agreement of the results with previous data from the Mediterranean illustrates the improved accurary of TOPEX/POSEIDON over its predecessors.

  3. Marine caves of the Mediterranean Sea: a sponge biodiversity reservoir within a biodiversity hotspot.

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    Vasilis Gerovasileiou

    Full Text Available Marine caves are widely acknowledged for their unique biodiversity and constitute a typical feature of the Mediterranean coastline. Herein an attempt was made to evaluate the ecological significance of this particular ecosystem in the Mediterranean Sea, which is considered a biodiversity hotspot. This was accomplished by using Porifera, which dominate the rocky sublittoral substrata, as a reference group in a meta-analytical approach, combining primary research data from the Aegean Sea (eastern Mediterranean with data derived from the literature. In total 311 species from all poriferan classes were recorded, representing 45.7% of the Mediterranean Porifera. Demospongiae and Homoscleromorpha are highly represented in marine caves at the family (88%, generic (70%, and species level (47.5%, the latter being the most favored group along with Dictyoceratida and Lithistida. Several rare and cave-exclusive species were reported from only one or few caves, indicating the fragmentation and peculiarity of this unique ecosystem. Species richness and phylogenetic diversity varied among Mediterranean areas; the former was positively correlated with research effort, being higher in the northern Mediterranean, while the latter was generally higher in caves than in the overall sponge assemblages of each area. Resemblance analysis among areas revealed that cavernicolous sponge assemblages followed a pattern quite similar to that of the overall Mediterranean assemblages. The same pattern was exhibited by the zoogeographic affinities of cave sponges: species with Atlanto-Mediterranean distribution and Mediterranean endemics prevailed (more than 40% each, 70% of them having warm-water affinities, since most caves were studied in shallow waters. According to our findings, Mediterranean marine caves appear to be important sponge biodiversity reservoirs of high representativeness and great scientific interest, deserving further detailed study and protection.

  4. Probabilistic Tsunami Hazard Assessment - Application to the Mediterranean Sea

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    Sorensen, M. B.; Spada, M.; Babeyko, A.; Wiemer, S.; Grünthal, G.

    2009-12-01

    Following several large tsunami events around the world in the recent years, the tsunami hazard is becoming an increasing concern. The traditional way of assessing tsunami hazard has been through deterministic scenario calculations which provide the expected wave heights due to a given tsunami source, usually a worst-case scenario. For quantitative hazard and risk assessment, however, it is necessary to move towards a probabilistic framework. In this study we focus on earthquake generated tsunamis and present a scheme for probabilistic tsunami hazard assessment (PTHA). Our PTHA methodology is based on the use of Monte-Carlo simulations and follows probabilistic seismic hazard assessment methodologies closely. The PTHA is performed in four steps. First, earthquake and tsunami catalogues are analyzed in order to define a number of potential tsunami sources in the study area. For each of these sources, activity rates, maximum earthquake magnitude and uncertainties are assigned. Following, a synthetic earthquake catalogue is established, based on the information about the sources. The third step is to calculate multiple synthetic tsunami scenarios for all potentially tsunamigenic earthquakes in the synthetic catalogue. The tsunami scenarios are then combined at the fourth step to generate hazard curves and maps. We implement the PTHA methodology in the Mediterranean Sea, where numerous tsunami events have been reported in history. We derive a 100000 year-long catalog of potentially tsunamigenic earthquakes and calculate tsunami propagation scenarios for ca. 85000 M6.5+ earthquakes from the synthetic catalog. Results show that the highest tsunami hazard is attributed to the Eastern Mediterranean region, but that also the Western Mediterranean can experience significant tsunami waves for long return periods. Hazard maps will be presented for a range of probability levels together with hazard curves for selected critical locations.

  5. Impact of the Minoan tsunami of Santorini: Simulated scenarios in the eastern Mediterranean

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    Pareschi, Maria Teresa; Favalli, Massimiliano; Boschi, Enzo

    2006-09-01

    We have simulated the impact of the tsunami generated by the Late Bronze Age (LBA) volcanic eruption of Santorini on the Eastern Mediterranean. Two different tsunami triggering mechanisms were considered: a caldera collapse and pyroclastic flows/surges entering the sea. Simulations include the "worst" input conditions in order to evaluate the maximum possible impacts, but also "lighter" input conditions, compatible with the lack of any tsunami trace on the Northern coasts of Crete. In all the simulations, tsunami propagation is mainly confined to the Southern Aegean. Outside the Aegean, the tsunami impact was negligible and not responsible for the slide-slumping of fine-grained pelagic and/or hemipelagic sediments considered the sources of the sporadically located sea-deposits in the Ionian Sea and of the widespread megaturbidite deposits localized in the Ionian and Sirte Abyssal Plains.

  6. FEATURES AND PROBLEMS WITH HISTORICAL GREAT EARTHQUAKES AND TSUNAMIS IN THE MEDITERRANEAN SEA

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    Lobkovsky L.

    2016-11-01

    Full Text Available The present study examines the historical earthquakes and tsunamis of 21 July 365 and of 9 February 1948 in the Eastern Mediterranean Sea. Numerical simulations were performed for the tsunamis generated by underwater seismic sources in frames of the keyboard model, as well as for their propagation in the Mediterranean Sea basin. Similarly examined were three different types of seismic sources at the same localization near the Island of Crete for the earthquake of 21 July 365, and of two different types of seismic sources for the earthquake of 9 February 1948 near the Island of Karpathos. For each scenario, the tsunami wave field characteristics from the earthquake source to coastal zones in Mediterranean Sea’s basin were obtained and histograms were constructed showing the distribution of maximum tsunami wave heights, along a 5-m isobath. Comparison of tsunami wave characteristics for all the above mentioned scenarios, demonstrates that underwater earthquakes with magnitude M > 7 in the Eastern Mediterranean Sea basin, can generate waves with coastal runup up to 9 m.

  7. Mitochondrial DNA Reveals Genetic Structuring of Pinna nobilis across the Mediterranean Sea

    Science.gov (United States)

    Sanna, Daria; Cossu, Piero; Dedola, Gian Luca; Scarpa, Fabio; Maltagliati, Ferruccio; Castelli, Alberto; Franzoi, Piero; Lai, Tiziana; Cristo, Benedetto; Curini-Galletti, Marco; Francalacci, Paolo; Casu, Marco

    2013-01-01

    Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima’s and Fu’s neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units. PMID:23840684

  8. Distribution of artificial radionuclides in deep sediments of the Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Orellana, J. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Institut de Ciencia i Tecnologia Ambientals (ICTA), Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)], E-mail: jordi.garcia@uab.cat; Pates, J.M. [Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ (United Kingdom); Masque, P. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Institut de Ciencia i Tecnologia Ambientals (ICTA), Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Bruach, J.M. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Sanchez-Cabeza, J.A. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Institut de Ciencia i Tecnologia Ambientals (ICTA), Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); International Atomic Energy Agency, Marine Environment Laboratories, MC-98000 (Monaco)

    2009-01-01

    Artificial radionuclides enter the Mediterranean Sea mainly through atmospheric deposition following nuclear weapons tests and the Chernobyl accident, but also through the river discharge of nuclear facility effluents. Previous studies of artificial radionuclides impact of the Mediterranean Sea have focussed on shallow, coastal sediments. However, deep sea sediments have the potential to store and accumulate pollutants, including artificial radionuclides. Deep sea marine sediment cores were collected from Mediterranean Sea abyssal plains (depth > 2000 m) and analysed for {sup 239,240}Pu and {sup 137}Cs to elucidate the concentrations, inventories and sources of these radionuclides in the deepest areas of the Mediterranean. The activity - depth profiles of {sup 210}Pb, together with {sup 14}C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2.5 cm of the sedimentary column. The excess {sup 210}Pb inventory was used to normalize {sup 239,240}Pu and {sup 137}Cs inventories for variable sediment fluxes. The {sup 239,240}Pu/{sup 210}Pb{sub xs} ratio was uniform across the entire sea, with a mean value of 1.24 x 10{sup -3}, indicating homogeneous fallout of {sup 239,240}Pu. The {sup 137}Cs/{sup 210}Pb{sub xs} ratio showed differences between the eastern (0.049) and western basins (0.030), clearly significant impact of deep sea sediments from the Chernobyl accident. The inventory ratios of {sup 239,240}Pu/{sup 137}Cs were 0.041 and 0.025 in the western and eastern basins respectively, greater than the fallout ratio, 0.021, showing more efficient scavenging of {sup 239,240}Pu in the water column and major sedimentation of {sup 137}Cs in the eastern basin. Although areas with water depths of > 2000 m constitute around 40% of the entire Mediterranean basin, the sediments in these regions only contained 2.7% of the {sup 239,240}Pu and 0.95% of the {sup 137}Cs deposited across the Sea in 2000. These data show that the

  9. Cyclone contribution to the Mediterranean Sea water budget

    Science.gov (United States)

    Flaounas, E.; Di Luca, A.; Drobinski, P.; Mailler, S.; Arsouze, T.; Bastin, S.; Beranger, K.; Lebeaupin Brossier, C.

    2016-02-01

    This paper analyzes the impact of cyclones to the atmospheric components on the Mediterranean Sea Water Budget, namely the cyclones contribution to precipitation and evaporation over the Mediterranean Sea. Three regional simulations were performed with the WRF model for the period 1989-2008. The model was run (1) as a standalone model, (2) coupled with the oceanic model NEMO-MED12 and (3) forced by the smoothed Sea Surface Temperature (SST) fields from the second simulation. Cyclones were tracked in all simulations, and their contribution to the total rainfall and evaporation was quantified. Results show that cyclones are mainly associated with extreme precipitation, representing more than 50 % of the annual rainfall over the Mediterranean Sea. On the other hand, we found that cyclone-induced evaporation represents only a small fraction of the annual total, except in winter, when the most intense Mediterranean cyclones take place. Despite the significant contribution of cyclones to rainfall, our results show that there is a balance between cyclone-induced rainfall and evaporation, suggesting a weak net impact of cyclones on the Mediterranean Sea water budget. The sensitivity of our results with respect to rapid SST changes during the development of cyclones was also investigated. Both rainfall and evaporation are affected in correlation with the SST response to the atmosphere. In fact, air feedbacks to the Mediterranean Sea during the cyclones occurrence were shown to cool down the SST and consequently to reduce rainfall and evaporation at the proximity of cyclone centers.

  10. Sustainable management for the eastern Mediterranean coast of Turkey.

    Science.gov (United States)

    Berberoglu, Süha

    2003-03-01

    The objective of this article is to propose a program for the integrated coastal zone management that is required to stimulate and guide sustainable development of the Mediterranean coastal zone of Turkey. Improved data collection, quality control, analysis, and data management will provide a firm basis for future scientific understanding of the East Mediterranean coast of Turkey and will support long-term management. Various innovative procedures were proposed for a promising ecosystem-based approach to manage coastal wetlands in the Mediterranean: remote data acquisition with new technologies; environmental quality monitoring program that will provide a baseline for monitoring; linking a Geographic Information System (GIS) with natural resource management decision routines in the context of operational wetlands, fisheries, tourism management system; environmental sensitivity analysis to ensure that permitted developments are environmentally sustainable; and use of natural species to restore the wetlands and coastal dunes and sustain the system processes. The proposed management scheme will benefit the scientific community in the Mediterranean and the management/planning community in Eastern Turkey.

  11. Speciation of mercury in surface and deep-sea waters in the Mediterranean Sea

    Science.gov (United States)

    Horvat, Milena; Kotnik, Jože; Logar, Martina; Fajon, Vesna; Zvonarić, Tomislav; Pirrone, Nicola

    A summary of data recently obtained for mercury analysis and speciation (reactive Hg, total Hg and monomethylmercury (MMHg)) in filtered and non-filtered seawater samples, dissolved gaseous mercury (DGM) and dimethylmercury (DMHg) in open and coastal waters of the Mediterranean Sea is presented. The majority of the results were obtained during an oceanographic cruise aboard the research vessel Urania from 14 July to 9 August, 2000, as part of the MED-OCEANOR Project funded by the National Research Council of Italy. The results are compared with those obtained in contaminated coastal environments of the Adriatic (The Gulf of Trieste and Kaštela Bay) and non-contaminated coastal waters of the eastern Adriatic coast obtained in 1998. Total mercury concentrations in surface ocean waters are relatively low with an average of 0.81 pM (0.49-1.91 pM). Reactive Hg represents a substantial part with an average of 57% of total Hg (15-97%). Most mercury in open ocean waters was present in the dissolved form (32-95%, av. 70%), which is mainly due to the low abundance of particulate matter, a phenomenon well known for the Mediterranean open ocean waters. On average the percentage of Hg as MMHg was about 20%, of which about 66% was present in the dissolved form. The percentage of DGM in the surface ocean waters represents about 9% of total Hg (2.5-24.5%) and may originate from photochemical, biologically mediated mechanisms or diffusion from deeper layer either due to biological and/or to tectonic activity which is typical of the Mediterranean region. The presence of DMHg was confirmed only in waters below 20 m (up to 12 fM), while in surface waters DMHg was below the limit of detection (<0.1 fM). Surface concentrations of Hg in the eastern and western parts are comparable, except for DGM which shows significantly higher concentrations in the eastern part (mean value: 0.22 pM) as compared to the western Mediterranean (mean value: 0.09 pM). The distribution of Hg species with

  12. Saharan dust deposition may affect phytoplankton growth in the Mediterranean sea at ecological time scales.

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    Rachele Gallisai

    Full Text Available The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5% of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layer.

  13. Saharan Dust Deposition May Affect Phytoplankton Growth in the Mediterranean Sea at Ecological Time Scales

    Science.gov (United States)

    Gallisai, Rachele; Peters, Francesc; Volpe, Gianluca; Basart, Sara; Baldasano, José Maria

    2014-01-01

    The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5%) of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layer. PMID:25333783

  14. Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

    Science.gov (United States)

    Adloff, Fanny; Somot, Samuel; Sevault, Florence; Jordà, Gabriel; Aznar, Roland; Déqué, Michel; Herrmann, Marine; Marcos, Marta; Dubois, Clotilde; Padorno, Elena; Alvarez-Fanjul, Enrique; Gomis, Damià

    2015-11-01

    The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air-sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961-2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001-2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air-sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070-2099 period compared to 1961-1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in

  15. Travelling in the eastern Mediterranean with landscape character assessment

    Science.gov (United States)

    Abu Jaber, N.; Abunnasr, Y.; Abu Yahya, A.; Boulad, N.; Christou, O.; Dimitropoulos, G.; Dimopoulos, T.; Gkoltsiou, K.; Khreis, N.; Manolaki, P.; Michael, K.; Odeh, T.; Papatheodoulou, A.; Sorotou, A.; Sinno, S.; Suliman, O.; Symons, N.; Terkenli, T.; Trigkas, Vassilis; Trovato, M. G.; Victora, M.; Zomeni, M.; Vogiatzakis, I. N.

    2015-06-01

    Following its application in Northern Europe, Landscape Character Assessment has also been implemented in Euro-Mediterranean countries as a tool for classifying, describing and assessing landscapes. Many landscape classifications employed in the Euro-Mediterranean area are similar in philosophy and application to the ones developed in Northern Europe. However, many aspects of landform, climate, land-use and ecology, as well as socio-economic context are distinctive of Mediterranean landscapes. The paper discusses the conceptual and methodological issues faced during landscape mapping and characterisation in four East-Mediterranean countries (within the MEDSCAPES project): Cyprus, Greece, Jordan and Lebanon. The major hurdles to overcome during the first phase of methodology development include variation in availability, quality, scale and coverage of spatial datasets between countries and also terminology semantics around landscapes. For example, the concept of landscape - a well-defined term in Greek and English - did not exist in Arabic. Another issue is the use of relative terms like 'high mountains,' `uplands' `lowlands' or ' hills'. Such terms, which are regularly used in landscape description, were perceived slightly differently in the four participating countries. In addition differences exist in nomenclature and classification systems used by each country for the dominant landscape-forming factors i.e. geology, soils and land use- but also in the cultural processes shaping the landscapes - compared both to each other and to the Northern-European norms. This paper argues for the development of consistent, regionally adapted, relevant and standardised methodologies if the results and application of LCA in the eastern Mediterranean region are to be transferable and comparable between countries.

  16. Genetic connectivity between land and sea: the case of the beachflea Orchestia montagui (Crustacea, Amphipoda, Talitridae) in the Mediterranean Sea.

    Science.gov (United States)

    Pavesi, Laura; Tiedemann, Ralph; De Matthaeis, Elvira; Ketmaier, Valerio

    2013-04-25

    We examined patterns of genetic divergence in 26 Mediterranean populations of the semi-terrestrial beachflea Orchestia montagui using mitochondrial (cytochrome oxidase subunit I), microsatellite (eight loci) and allozymic data. The species typically forms large populations within heaps of dead seagrass leaves stranded on beaches at the waterfront. We adopted a hierarchical geographic sampling to unravel population structure in a species living at the sea-land transition and, hence, likely subjected to dramatically contrasting forces. Mitochondrial DNA showed historical phylogeographic breaks among Adriatic, Ionian and the remaining basins (Tyrrhenian, Western and Eastern Mediterranean Sea) likely caused by the geological and climatic changes of the Pleistocene. Microsatellites (and to a lesser extent allozymes) detected a further subdivision between and within the Western Mediterranean and the Tyrrhenian Sea due to present-day processes. A pattern of isolation by distance was not detected in any of the analyzed data set. We conclude that the population structure of O. montagui is the result of the interplay of two contrasting forces that act on the species population genetic structure. On one hand, the species semi-terrestrial life style would tend to determine the onset of local differences. On the other hand, these differences are partially counter-balanced by passive movements of migrants via rafting on heaps of dead seagrass leaves across sites by sea surface currents. Approximate Bayesian Computations support dispersal at sea as prevalent over terrestrial regionalism.

  17. Community structure and population genetics of Eastern Mediterranean polychaetes

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    Giorgos eChatzigeorgiou

    2014-10-01

    Full Text Available Species and genetic diversity are often found to co-vary since they are influenced by external factors in similar ways. In this paper, we analyse the genetic differences of the abundant polychaete Hermodice carunculata (Pallas, 1776 during two successive years at two locations in northern Crete (Aegean Sea and compare them to other populations in the Mediterranean Sea and the Atlantic Ocean. The genetic analysis is combined with an analysis of ecological divergence of the total polychaete community structure (beta diversity at these locations. The phylogenetic analysis of all included H. carunculata populations revealed two main clades, one exclusively found in the Mediterranean and a second occurring in both the Mediterranean and the Atlantic. Genetic diversity indices reveal unexpectedly high differences between the two Cretan populations, despite the absence of apparent oceanographic barriers. A similarly high divergence, represented by a high beta diversity index, was observed between the polychaete communities at the two locations. This comparatively high divergence of the genetic structure of a dominant species and the total polychaete community might be explained by the strong influence of local environmental factors as well as inter-specific interactions between the dominance of a single species and the members of the community.

  18. Highlights and conclusions from the Eastern Mediterranean Public Health Network (EMPHNET) conference 2011.

    Science.gov (United States)

    Al Nsour, M; Kaiser, R; Abd Elkreem, E; Walke, H; Kandeel, A; Bloland, R

    2012-02-01

    As a follow up of a short communication that the Eastern Mediterranean Health journal published in December 2011, this article reports on highlights and conclusions from scientific abstracts, methodology workshops and plenary sessions that were presented as part of the Eastern Mediterranean Public Health Network (EMPHNET) conference held from 6 to 9 December 2011 in Sharm Al Sheikh, Egypt.

  19. A Historical, Cultural and Geoscientific approach of the Mediterranean Sea

    Science.gov (United States)

    Varouta, Panagiota

    2017-04-01

    Students' knowledge about geosciences is often limited to their country's geographical elements. The way geosciences are connected to their everyday lives, their history and their culture is something that they do not easily grasp. Thus, the development of a Project-Based Learning activity where 11 year-olds are asked to explore the Mediterranean Sea came as a result. The title of the activity is "An enclosed sea, an open mind, an amazing journey in STEAM". The main purpose of choosing the module of "The Mediterranean" is for the students to become aware of the special natural and cultural features of the Mediterranean region and to be able to connect the Mediterranean's geographical position and characteristics with its historical and social value. The activity aims to develop scientific skills and attitudes, to practice the students' scientific and critical thought, to foster the co-operative spirit among them and to make them aware of how the geography of the Mediterranean affects the relationships that form around it. In this activity, students study geological features (e.g. Orogenesis, Corinthian Rift, Islands, earthquakes, volcanoes), they experiment about the water flow and they examine the Mediterranean field and climate. In Odysseus' footsteps, they navigate using GPS, they research about the culture and the history of the people around the Mediterranean Sea and they present their findings. They focus on the historical, geological, geographical, cultural and environmental aspects of the Mediterranean Sea. On this poster, there will be a presentation of the goals, the methodology, the series of activities and the evaluation of the program. Key Words Mediterranean, Project-Based Learning, Geosciences, Culture

  20. Connectivity controls on the late Miocene eastern Mediterranean fish fauna

    Science.gov (United States)

    Agiadi, Konstantina; Antonarakou, Assimina; Kontakiotis, George; Kafousia, Nefeli; Moissette, Pierre; Cornée, Jean-Jacques; Manoutsoglou, Emmanouil; Karakitsios, Vasileios

    2016-06-01

    Environmental change significantly affects the production of fish resources and their dependent societies. The paleontological record offers unique insight into the effects of long-term paleoenvironmental variability on the fish species' distributions and abundances. In the present study, we investigate the late Miocene (7.5-6.5 Ma) fish assemblages of the Potamida section in western Crete (eastern Mediterranean). The determined fish taxa are examined in a paleobiogeographic context, with regard to their geographic and stratigraphic distribution from the early Miocene (~13 Ma) through today. In addition, present-day ecological data are used to reconstruct the paleoenvironmental conditions in the study area. Planktonic foraminifer biostratigraphy significantly improves the earlier dating of the studied sequence. The late Miocene fish fauna of Potamida includes 35 taxa (seven in open nomenclature) from 13 teleost families. The eastern Mediterranean biostratigraphic and geographic distribution of 32 taxa is significantly expanded into the Tortonian, whereas 13 species are recorded for the first time from the Messinian. Four stages are distinguished in the area's paleoenvironmental evolution. (1) The Potamida area was an open marine environment with depths exceeding 150 m between ~7.5-7.45 Ma. (2) Between 7.45-7.36 Ma, the results suggest depths between 300-400 m. (3) The depositional depth increases between 7.36-7.28 Ma to 400-550 m. (4) Later on, approximately between 6.8-6.6 Ma, the depth is again estimated around 100-150 m.

  1. Alien marine fishes deplete algal biomass in the Eastern Mediterranean.

    Science.gov (United States)

    Sala, Enric; Kizilkaya, Zafer; Yildirim, Derya; Ballesteros, Enric

    2011-02-22

    One of the most degraded states of the Mediterranean rocky infralittoral ecosystem is a barren composed solely of bare rock and patches of crustose coralline algae. Barrens are typically created by the grazing action of large sea urchin populations. In 2008 we observed extensive areas almost devoid of erect algae, where sea urchins were rare, on the Mediterranean coast of Turkey. To determine the origin of those urchin-less 'barrens', we conducted a fish exclusion experiment. We found that, in the absence of fish grazing, a well-developed algal assemblage grew within three months. Underwater fish censuses and observations suggest that two alien herbivorous fish from the Red Sea (Siganus luridus and S. rivulatus) are responsible for the creation and maintenance of these benthic communities with extremely low biomass. The shift from well-developed native algal assemblages to 'barrens' implies a dramatic decline in biogenic habitat complexity, biodiversity and biomass. A targeted Siganus fishery could help restore the macroalgal beds of the rocky infralittoral on the Turkish coast.

  2. Alien marine fishes deplete algal biomass in the Eastern Mediterranean.

    Directory of Open Access Journals (Sweden)

    Enric Sala

    Full Text Available One of the most degraded states of the Mediterranean rocky infralittoral ecosystem is a barren composed solely of bare rock and patches of crustose coralline algae. Barrens are typically created by the grazing action of large sea urchin populations. In 2008 we observed extensive areas almost devoid of erect algae, where sea urchins were rare, on the Mediterranean coast of Turkey. To determine the origin of those urchin-less 'barrens', we conducted a fish exclusion experiment. We found that, in the absence of fish grazing, a well-developed algal assemblage grew within three months. Underwater fish censuses and observations suggest that two alien herbivorous fish from the Red Sea (Siganus luridus and S. rivulatus are responsible for the creation and maintenance of these benthic communities with extremely low biomass. The shift from well-developed native algal assemblages to 'barrens' implies a dramatic decline in biogenic habitat complexity, biodiversity and biomass. A targeted Siganus fishery could help restore the macroalgal beds of the rocky infralittoral on the Turkish coast.

  3. Airborne expendable bathythermograph surveys of the eastern Mediterranean

    Science.gov (United States)

    Horton, C.; Kerling, J.; Athey, G.; Schmitz, J.; Clifford, M.

    1994-05-01

    Two extensive airborne expendable bathythermograph (AXBT) surveys of the eastern Mediterranean were conducted during December 1991 and July 1992 from a Naval Oceanographic Office RP-3 aircraft. Larger areas were sampled over shorter periods of time than is possible with conventional surveys carried out by ships. The circulation of the eastern Mediterranean consists of a collection of subgyres and fronts which show surprising seasonal and interannual variability. These surveys help to describe further this variability which is only partially understood. In particular, the surveys provide additional evidence that a relatively strong anticyclone located adjacent to the southeast corner of Crete during the late summer and through fall is a consequence of strong north winds from the Aegean, the Etesians, being blocked by Crete. Also notable in both surveys was the absence of "a" strong Mersa-Matruh gyre, an anticyclone or anticyclonic subgyre off the Egyptian coast generally considered to be permanent. In contrast to published earlier observations, the Mersa Matruh gyre system was more a collection of weaker anticyclones rather than a single, sometimes double centered, strong feature. In both surveys we saw a string of anticyclones off the African coast between about 24° and 32°E. In general, these eddies did not exhibit a significant surface thermal structure, but were most evident in the 200 m to 300 m-depth depictions. It may be that the formation of a strong southeast Crete anticyclone inhibits the formation of a large, relatively strong Mersa-Matruh subgyre by interacting with the mid-Mediterranean jet. If so, then both the southeast Crete anticyclone and the Mersa-Matruh anticyclone could both be recurrent but tend to occur at different times.

  4. Biology and new records of the invasive species Branchiomma bairdi (Annelida: Sabellidae in the Mediterranean Sea

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    A. ARIAS

    2013-04-01

    Full Text Available First observations on the reproductive biology of the alien polychaete Branchiomma bairdi (McIntosh, 1885 (Sabellidae in the Mediterranean Sea are provided as well as additional Mediterranean records of the species which can help to understand its introduction and spreading. Re-examination of the specimens from Miseno harbour (Tyrrhenian Sea, Italy revealed the presence of B. bairdi in the central-Mediterranean since September 2004. The histological study of individuals collected in Malta revealed that the species is a simultaneous hermaphrodite, developing male and female gametes in the same body segments; embryos are brooded inside the parent tube. However, there is evidence also for asexual reproduction. The species shows a different reproductive pattern from the previously reported population from the eastern-Pacific; this demonstrates its great plasticity and adaptability. Branchiomma bairdi has an invasive behaviour, colonizing large areas in relatively short-time, and reaching relatively high densities (c.a. 50 individuals/m2. Its expansion throughout several Mediterranean localities is largely a consequence of the high capacity of this species to colonize extremely different habitats and substrates, to the occurrence of sexual and asexual reproductive strategies, and the combination of both. Further, B. bairdi appears to be particularly abundant in confined and anthropogenic degraded areas. Finally, our findings strongly suggest that the pathway of introduction in the Mediterranean, previously hypothesized as the Suez Canal (Lessepsian migration, is most likely via the Gibraltar Strait.

  5. The circulation of the Mediterranean Sea: a historical review of experimental investigations

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    A. Bergamasco

    2010-06-01

    Full Text Available The Mediterranean Sea is an enclosed basin composed of two similar basins and different sub-basins. It is a concentration basin, where evaporation exceeds precipitation. In the surface layer there is an inflow of Atlantic water which is modified along its path to the Eastern basin. This transformation occurs through surface heat loss and evaporation specifically in the Levantine basin. The Mediterranean is furthermore the site of water mass formation processes, which can be studied experimentally because of their easy accessibility. There are two main reasons why the Mediterranean is important. The first one is the impact of the Mediterranean on the global thermohaline circulation, the second reason is that the Mediterranean basin can be considered as Laborartory for investigating processes occurring on the global scale of the world ocean. In this paper we want to provide a short historical review of the evolving knowledge of the Mediterranean circulation that has emerged from experimental investigations over the last decades. We start by describing the old picture of the basin circulation which had stationary, smooth large scale patterns. Then we show the major experiments that led to the discovery of the sub-basin scale circulation and its mesoscale features. We conclude with the dynamical discovery of EMT in the 1990s and the most exciting ongoing new research programmes.

  6. Mesoscale modeling of combined aerosol and photo-oxidant processes in the Eastern Mediterranean

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    M. Lazaridis

    2005-01-01

    Full Text Available Particulate matter and photo-oxidant processes in the Eastern Mediterranean have been studied using the UAM-AERO mesoscale air quality model in conjunction with the NILU-CTM regional model. Meteorological data were obtained from the RAMS prognostic meteorological model. The modeling domain includes the eastern Mediterranean area between the Greek mainland and the island of Crete. The modeling system is applied to study the atmospheric processes in three periods, i.e. 13–16 July 2000, 26–30 July 2000 and 7–14 January 2001. The spatial and temporal distributions of both gaseous and particulate matter pollutants have been extensively studied together with the identification of major emission sources in the area. The modeling results were compared with field data obtained in the same period. The objective of the current modeling work was mainly to apply the UAM-AERO mesoscale model in the eastern Mediterranean in order to assess the performed field campaigns and determine that the applied mesoscale model is fit for this purpose. Comparison of the modeling results with measured data was performed for a number of gaseous and aerosol species. The UAM-AERO model underestimates the PM10 measured concentrations during summer and winter campaigns. Discrepancies between modeled and measured data are attributed to unresolved particulate matter emissions. Particulate matter in the area is mainly composed by sulphate, sea salt and crustal materials, and with significant amounts of nitrate, ammonium and organics. During winter the particulate matter and oxidant concentrations were lower than the summer values.

  7. Footprints of climate change on Mediterranean Sea biota

    Directory of Open Access Journals (Sweden)

    Núria eMarbà

    2015-08-01

    Full Text Available The Mediterranean Sea ranks among the ocean regions warming fastest. There is evidence for impacts of climate change on marine Mediterranean organisms but a quantitative assessment is lacking. We compiled the impacts of warming reported in the literature to provide a quantitative assessment for the Mediterranean Sea. During the last three decades the summer surface temperature has increased 1.15 oC. Strong heat wave events have occurred in years 1994, 2003 and 2009. Impacts of warming are evident on growth, survival, fertility, migration and phenology of pelagic and benthic organisms, from phytoplankton to marine vegetation, invertebrates and vertebrates. Overall, 50 % of biological impacts in the Mediterranean Sea occur at summer surface temperature anomaly ≤ 4.5 ºC and at summer surface temperature of 27.5 ºC. The activation energy (geometric mean 1.58 ± 0.48 eV, the slope of the Arrhenius equation describing the temperature-dependence of biological processes, for the response of Mediterranean marine biota to warming reveals that these responses in the Mediterranean are far steepest than possibly explained by the direct effect of warming alone. The observations are biased toward the northern and western sectors of the basin, likely underestimating the impacts of warming in areas where warming is particularly intense.

  8. Footprints of climate change on Mediterranean Sea biota

    KAUST Repository

    Marbà, Núria

    2015-08-13

    The Mediterranean Sea ranks among the ocean regions warming fastest. There is evidence for impacts of climate change on marine Mediterranean organisms but a quantitative assessment is lacking. We compiled the impacts of warming reported in the literature to provide a quantitative assessment for the Mediterranean Sea. During the last three decades the summer surface temperature has increased 1.15°C. Strong heat wave events have occurred in years 1994, 2003, and 2009. Impacts of warming are evident on growth, survival, fertility, migration and phenology of pelagic and benthic organisms, from phytoplankton to marine vegetation, invertebrates and vertebrates. Overall, 50% of biological impacts in the Mediterranean Sea occur at summer surface temperature anomaly ≤ 4.5°C and at summer surface temperature of 27.5°C. The activation energy (geometric mean 1.58 ± 0.48 eV), the slope of the Arrhenius equation describing the temperature-dependence of biological processes, for the response of Mediterranean marine biota to warming reveals that these responses in the Mediterranean are far steepest than possibly explained by the direct effect of warming alone. The observations are biased toward the northern and western sectors of the basin, likely underestimating the impacts of warming in areas where warming is particularly intense.

  9. Comparison of Several Geoid Models over the Western Mediterranean Sea

    Science.gov (United States)

    Termens, A.; Martinez-Benjamin, J. J.

    2011-07-01

    The Mediterranean Sea is a semi-enclosed true ocean. Recent Mediterranean circulation and sea level studies using various observations and ocean general circulation models show good coherence and agreement. The satellite altimetry and tide gauge observed and model predicted sea level show good coherent with correlation coefficient of 0.6. The barotropic pressure response accounts for about 66% of the Mediterranean sea level rise (1948-2001). The estimated sea level trend (1.54 ± 0.75 mm/yr) using decadal altimetry (1985-2001) after correcting the interannual/decadal signals reconstructed using tide gauge data, agrees well with the long term trend (1948-2001) estimated using tide gauges (1.43 ± 0.09 mm/yr) in the Mediterranean Sea, and is in better agreement than before with the global long-term sea level trend (1.7 - 1.8 mm/yr). Simulation studies indicate that the time-varying mass variations of Mediterranean Sea likely are sensitive to GOCE at the few mEötvös level. One of GOCE's primary high-level data products is the global gravity model with anticipated geoid accuracy of 1 cm RMS and a spatial resolution of 130 km or longer. Actually, the International Centre for Global Earth Models (ICGEM) distributes some GOCE's Global Gravity field Models (GGMs) like GO_CONS_GCF_2_DIR (Bruinsma et al, 2010), GO_CONS_GCF_2_TIM (Pail et al, 2010a), GO_CONS_GCF_2_SPW (Migliaccio et al, 2010), GOCO01S (Pail et al, 2010b). The work focuses on the comparison between these GOCE's GGMs, EGM2008 and EIGEN-51C, with sea gravity anomalies and geoid undulations provided by existing local and regional geoids - like IBERGEO (Sevilla, 2008), IGG (Corchete et al, 2005), etc. - in the Western Mediterranean Sea in order to find the GGM that best fits this area. We also try to estimate how the GOCE geoid data, provided by ESA, works on the Western Mediterranean Sea in order to prepare future geomatic issues.

  10. Seasonal patterns of wind-induced upwelling/downwelling in the Mediterranean Sea

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    Andrew Bakun

    2001-09-01

    Full Text Available The historical file of wind observations from maritime weather reports is summarized to identify the characteristic seasonal distributions of wind-induced Ekman upwelling and downwelling in the Mediterranean Sea. Both coastal upwelling/downwelling and wind-stress curl-driven open ocean upwelling/downwelling are treated in a unified description. Vigorous upwelling zones are found in the eastern Aegean Sea, off the west coast of Greece, and in the Gulf of Lyons. The southern coast of the Mediterranean is found to be primarily a downwelling area, although significant coastal upwelling does appear in the Gulf of Sidra during the spring and summer seasons, and along the Algerian coast during summer.

  11. Environmental Assessment for Selected Regions in the Mediterranean Sea

    Science.gov (United States)

    1992-01-01

    shallow sill and travel eastward along the interface between the dissimilar water masses at a speed of 3 to 4 kt. Temperature differences on the order of...the eastern Mediterranean. OceanoL Acta 9(3): 239-248. Arevalo, L. and T. Garcia (1982). Corrientes de la Costa de Malaga, metodos y resultados. Inf

  12. First record of the moray eel Gymnothorax reticularis, Bloch, 1795 in the Mediterranean Sea, with a note on its taxonomy and distribution.

    Science.gov (United States)

    Stern, Nir; Goren, Menachem

    2013-01-01

    The first Red-Sea Indo-Pacific alien moray eel in the Eastern Mediterranean is reported here. A single specimen ot Gymnothorax reticularis was captured by a commercial bottom-trawl vessel off the northern coast of Israel. Morphological and anatomical similarities with the single known Red-Sea specimen raise an old taxonomic dilemma.

  13. Interactions between climate change and human activities during the early to mid-Holocene in the eastern Mediterranean basins

    Science.gov (United States)

    Berger, Jean-Francois; Lespez, Laurent; Kuzucuoğlu, Catherine; Glais, Arthur; Hourani, Fuad; Barra, Adrien; Guilaine, Jean

    2016-09-01

    This paper focuses on early Holocene rapid climate change (RCC) records in the Mediterranean zone, which are under-represented in continental archives (9.2 to 8.2 ka events) and on their impact on prehistoric societies. This lack of data handicaps the general interpretation of climate impacts on human societies, which flourished in recent years. Key questions remain about the impact of early Holocene cooling events on the Mediterranean climate, ecosystems and human societies. In this paper, we discuss some examples from river and lake systems from the eastern to central Mediterranean area (central Anatolia, Cyprus, northeastern and northwestern Greece) that illustrate some palaeohydrological and erosion variations that modified the sustainability of the first Neolithic populations in this region. Results allow us to present direct land-sea correlations and to reconstruct regional long-term trends as well as millennial- to centennial-scale climatic changes. In this context, we question the socio-economic and geographical adaptation capacities of these societies (mobility, technology, economic practices, social organisation) during the "early Holocene" interval (11.7 to 8.2 ka), which corresponds partly to the Sapropel 1 deposition in the eastern Mediterranean sea.

  14. Recent findings of Ommastrephes bartramii (Cephalopoda: Ommastrephidae in the eastern Mediterranean and the implication on its range expansion

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    E. LEFKADITOU

    2012-12-01

    Full Text Available The neon flying squid Ommastrephes bartramii is found circumglobally in subtropical, temperate waters and sustains important fisheries in the North Pacific, but it is rarely encountered in the Mediterranean Sea. During the last decade, and particularly since 2004, the frequency of its presence in the Aegean Sea and nearby regions has increased, raising a question about a change in the species distribution and abundance in this area. In this study, we reviewed the literature on O. bartramii findings in the Mediterranean Sea and present new data describing body and beak morphometry, diet and the maturity of specimens recently collected from the easternmost basins. According to data from the entire Mediterranean Sea, collected individuals reached 66 cm in mantle length (ML, wherein only females were larger than 32 cm in ML. An isometric growth in body weight (BW was shown, whereas the lower beak rostral length (LRL was allometrically positive in relation to the ML. Occasional catches by jigs during experimental cruises provided most of the individuals recorded in the period from 1982-1992. In contrast, the most recent records are primarily comprised of mature females collected on or near the shore in the eastern basin and of predominantly smaller individuals from the western basin caught by professional jigging fisheries. The distribution of the specimen recorded from the Aegean Sea indicates an association between the species distribution and the circulation of the warm Levantine Intermediate Water. The more frequent observations of moribund spawning females at the periphery of the Cretan Sea are indicative of a spawning ground at this area. The suspected recent increase of O. bartramii abundance in both the northeastern and northwestern basins might be due to the warming of upper sea layers, which has been observed since the mid-1980s and is considered to be the main factor driving the northward expansion of the warm-water species’ range within

  15. Recent findings of Ommastrephes bartramii (Cephalopoda: Ommastrephidae in the eastern Mediterranean and the implication on its range expansion

    Directory of Open Access Journals (Sweden)

    E. LEFKADITOU

    2011-09-01

    Full Text Available The neon flying squid Ommastrephes bartramii is found circumglobally in subtropical, temperate waters and sustains important fisheries in the North Pacific, but it is rarely encountered in the Mediterranean Sea. During the last decade, and particularly since 2004, the frequency of its presence in the Aegean Sea and nearby regions has increased, raising a question about a change in the species distribution and abundance in this area. In this study, we reviewed the literature on O. bartramii findings in the Mediterranean Sea and present new data describing body and beak morphometry, diet and the maturity of specimens recently collected from the easternmost basins. According to data from the entire Mediterranean Sea, collected individuals reached 66 cm in mantle length (ML, wherein only females were larger than 32 cm in ML. An isometric growth in body weight (BW was shown, whereas the lower beak rostral length (LRL was allometrically positive in relation to the ML. Occasional catches by jigs during experimental cruises provided most of the individuals recorded in the period from 1982-1992. In contrast, the most recent records are primarily comprised of mature females collected on or near the shore in the eastern basin and of predominantly smaller individuals from the western basin caught by professional jigging fisheries. The distribution of the specimen recorded from the Aegean Sea indicates an association between the species distribution and the circulation of the warm Levantine Intermediate Water. The more frequent observations of moribund spawning females at the periphery of the Cretan Sea are indicative of a spawning ground at this area. The suspected recent increase of O. bartramii abundance in both the northeastern and northwestern basins might be due to the warming of upper sea layers, which has been observed since the mid-1980s and is considered to be the main factor driving the northward expansion of the warm-water species’ range within

  16. Two new species of Dendrobrachia Brook, 1889 (Cnidaria: Octocorallia: Dendrobrachiidae from the north-eastern Atlantic and western Mediterranean

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    Pablo J. López-González

    2010-08-01

    Full Text Available Examination of recent benthic material collected during several cruises in the Gulf of Cadiz (NE Atlantic and the Strait of Sicily (Mediterranean has allowed the taxonomic reassessment of some previously identified specimens belonging to the monogeneric gorgonian family Dendrobrachiidae Brook, 1889. Dendrobrachia fallax Brook, 1889 is the type species of the single genus in this family, and was originally described from Ascension Island (South Atlantic. Subsequently, other authors reported the presence of this species in Cape Verde Islands (north-eastern Atlantic and some Mediterranean localities (Alboran Sea and the Strait of Sicily. The study of the specimen from the Prince of Monaco collections in Cape Verde Islands, and recently collected material from the Gulf of Cadiz (north-eastern Atlantic and in the south of Malta (Mediterranean, materials previously considered as D. fallax, allow us to recognize two undescribed species in this genus. All previous records of D. fallax from the north-eastern Atlantic and Mediterranean should be considered incorrect. Opresko and Bayer (1991 added two additional species of Dendrobrachia. Two new species are described here and compared with their congeners.

  17. The Impact of Rapid Climate Change on Prehistoric Societies during the Holocene in the Eastern Mediterranean

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    Bernhard Weninger

    2009-12-01

    Full Text Available In this paper we explore the impact of Rapid Climate Change (RCC on prehistoric communities in the Eastern Mediterranean during the Early and Middle Holocene. Our focus is on the social implications of the four major climate cold anomalies that have recently been identified as key time-windows for global RCC (Mayewski et al. 2004. These cooling anomalies are well-dated, with Greenland ice-core resolution, due to synchronicity between warm/cold foraminifera ratios in Mediterranean core LC21 as a proxy for surface water temperature, and Greenland GISP2 non sea-salt (nss [K+] ions as a proxy for the intensification of the Siberian High and for polar air outbreaks in the northeast Mediterranean (Rohling et al. 2002. Building on these synchronisms, the GISP2 agemodel supplies the following precise time-intervals for archaeological RCC research: (i 8.6–8.0 ka, (ii 6.0–5.2 ka, (iii 4.2–4.0 ka and (iv 3.1–2.9 ka calBP. For each of these RCC time intervals, based on detailed 14C-based chronological studies, we investigate contemporaneous cultural developments. From our studies it follows that RCC-related climatic deterioration is a major factor underlying social change, although always at work within a wide spectrum of social, cultural, economic and religious factors.

  18. Oil families in the eastern Mediterranean offshore and southern Israel: Biomarker and trace element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Feinstein, S.; Brooks, P.W.; Fowler, M.G.; Snowdon, L.R.; Goldberg, M.; Aizenshtat, Z.

    1988-08-01

    Oil samples were obtained from producing wells and DSTs from the eastern Mediterranean offshore and the southern coastal plain and Dead Sea area in Israel. The oil samples were fractionated by liquid chromatography and analyzed by capillary gas chromatography and gas chromatography-mass spectrometry to define their gross chemical and biomarker composition. The nickel and vanadium content of the samples was analyzed by emission spectrography. The oils may be classified into three different families which agree with their geographical distribution. The biomarker distributions and nickel/vanadium ratios of the oils from the Dead Sea region suggest they were derived from a carbonate-rich source rock deposited in a highly reducing hypersaline environment. The oils from the coastal plain Helez-Kokhav field were also generated from a predominantly carbonate-rich source rock. However, they probably were contributed from a clastic rock deposited in a slightly less reducing depositional environment, as indicated by the presence of diasteranes and higher pristane/phytane and nickel/vanadium ratios. The Ziv 1 oil from the eastern Mediterranean offshore was probably generated from a predominantly clastic, marine source rock. All the oils analyzed seem to have been generated from mature source rocks. The maturity of their host rocks is much lower, indicating the oils reached their present location by lateral and/or vertical migration. The Dead Sea region oils have suffered varying amounts of water-washing and biodegradation, whereas the Helez-Kokhav and Ziv 1 oils have suffered limited water-washing and only little (if any) biodegradation.

  19. Climate Data Homogenization and its Impact on Heatwave Changes in the Eastern Mediterranean

    Science.gov (United States)

    Kuglitsch, F. G.; Toreti, A.; Xoplaki, E.; Della-Marta, P. M.; Zerefos, C. S.; Turkes, M.; Luterbacher, J.

    2010-12-01

    Heatwaves have discernible impacts on mortality and morbidity, infrastructure, agricultural resources, the retail industry, ecosystem and tourism and consequently affect human societies. A new definition of socially relevant heatwaves is presented and applied to new data sets of high-quality homogenized daily maximum and minimum summer air temperature series from 246 stations in the eastern Mediterranean region (including Albania, Bosnia-Herzegovina, Bulgaria, Croatia, Cyprus, Greece, Israel, Romania, Serbia, Slovenia, Turkey). Changes in heatwave number, length and intensity between 1960 and 2006 are quantified before and after data homogenization. Daily temperature homogeneity analyses suggest that many instrumental measurements in the 1960s are warm-biased, correcting for these biases regionally averaged heatwave trends are up to 8% higher. We find significant changes across the western Balkans, southwestern and western Turkey, and along the southern Black Sea coastline. Since the 1960s, the mean heatwave intensity, heatwave length and heatwave number across the eastern Mediterranean region have increased by a factor of 7.6 ± 1.3, 7.5 ± 1.3 and 6.2 ± 1.1, respectively. These findings suggest that the heatwave increase in this region is higher than previously reported.

  20. Developing a Virtual Museum for the Ancient Wine Trade in Eastern Mediterranean

    Science.gov (United States)

    Kazanis, S.; Kontogianni, G.; Chliverou, R.; Georgopoulos, A.

    2017-08-01

    Digital technologies for representing cultural heritage assets of any size are already maturing. Technological progress has greatly enhanced the art of virtual representation and, as a consequence, it is all the more appealing to the general public and especially to younger generations. The game industry has played a significant role towards this end and has led to the development of edutainment applications. The digital workflow implemented for developing such an application is presented in this paper. A virtual museum has been designed and developed, with the intention to convey the history of trade in the Eastern Mediterranean area, focusing on the Aegean Sea and five productive cities-ports, during a period of more than 500 years. Image based modeling methodology was preferred to ensure accuracy and reliability. The setup in the museum environment, the difficulties encountered and the solutions adopted are discussed, while processing of the images and the production and finishing of the 3D models are described in detail. The virtual museum and edutainment application, MEDWINET, has been designed and developed with the intention to convey the essential information of the wine production and trade routes in the Eastern Mediterranean basin. The user is able to examine the 3D models of the amphorae, while learning about their production and use for trade during the centuries. The application has been evaluated and the results are also discussed.

  1. Earthquake and the Catastrophic End of the Late Bronze Age in the Eastern Mediterranean

    Science.gov (United States)

    Nur, A.

    2009-04-01

    The reasons for the catastrophic and wide spread political as well as physical collapse in the Aegean and Eastern Mediterranean areas that define the end of the Bronze age ca. 1225 BC to 1175 BC remain a major enigma. It has been attributed by historian to attacks by outsiders with the most favored group being the (enigmatic) so-called sea people. Unfortunately there is no real evidence for this. However combined geological, geophysical and archaeological evidence suggests that earthquakes may have played a key role in this extraordinary collapse during the late 13th and early 12th centuries . Based on the instrumentally recorded earthquakes occurring in the Aegean and Eastern Mediterranean region during the 20th century, several events that have clear historical information, and the geography of seismically active faults it is obvious that numerous earthquakes of magnitude 6·5 or greater (enough to destroy modern buildings, let alone those of antiquity) occurred here frequently in the past. Furthermore major earthquakes often occur in this region in groups, known as ‘‘sequences'' or ‘‘storms'', in which one large quake is followed days, months, or a few years later by others elsewhere on the plate boundary fault lines. When a map of the areas in the Aegean and Eastern Mediterranean region shaken by 20th century  earthquakes of magnitude 6·5 and greater and with an intensity of VII or greater is overlaid on Robert Drews' map of sites destroyed in these same regions during the so-called ‘‘Catastrophe'' near the end of the Late Bronze Age, it is readily apparent that virtually all of these LBA sites lie within the affected (‘‘high-shaking'') areas. This would suggest that a major ‘‘earthquake storm'' may have occurred in the Late Bronze Age Aegean and Eastern Mediterranean during the years 1225-1175 . This ‘‘storm'' may have interacted with societal, political and economic forces at work in these areas c. 1200  and

  2. Future trends of the Sea Surface Temperature for the Caribbean and the Western Mediterranean Seas

    Directory of Open Access Journals (Sweden)

    L. Garcies

    2006-01-01

    Full Text Available Global Climate Models foresee a general warming of the atmosphere, with varying intensity depending on the characteristics of each model and the hypotheses made on the release of gases of antropic origin. The warming is not expected to be homogeneous over the planet. In this work we focus on the evolution of the sea surface temperature of the Caribbean and the Mediterranean seas, and its linked with the likely prolongation of the hurricane season and the increase of strength of the hurricanes in the Caribbean, as well as with the more apt conditions for severe weather in the Mediterranean sea. In both areas more frequent occurence and intensity of severe weather events are expected due to the predicted increment of the sea surface temperature, 1.5ºC for the Caribbean sea and 2.5ºC for the Mediterranean sea.

  3. POP levels in blue crab (Callinectes sapidus) and edible fish from the eastern Mediterranean coast.

    Science.gov (United States)

    Tekin, Serkan; Pazi, Idil

    2017-01-01

    Organochlorinated pesticides and Aroclors were measured in the muscle of two edible fish species (gray mullet, sea bream) and blue crab, collected from eastern Mediterranean coast in 2013. The concentration of organochlorinated pesticides (OCPs) and Aroclors in biota samples which were collected at six sites ranged from 1.0-8.6 and 9-47.5 ng g(-1) wet weight, respectively. Total DDT concentrations in seafood samples were compared to tolerance level established by the US Food and Drug Administration (FDA); the concentrations were detected below the tolerence level. Health risk assessment was conducted related to the consumption of chemically contaminated seafood. The estimated daily intake of OCPs calculated by using the estimated daily fish consumption in Turkey was far below the acceptable daily intake as established by FAO/WHO. Our data indicated that consumption of blue crab, gray mullet, and sea bream collected from the Mediterranean coast of Turkey could pose "no risk" for human health in terms of OCPs.

  4. An account of the taxonomy and distribution of Syllidae (Annelida, Polychaetes in the eastern Mediterranean, with notes on the genus Prosphaerosyllis San Martín, 1984 in the Mediterranean

    Directory of Open Access Journals (Sweden)

    Sarah Faulwetter

    2011-11-01

    Full Text Available The syllid fauna of three locations in Crete and Israel (eastern Mediterranean Sea was studied, yielding 82 syllid species, many of which were found for the first time in the respective areas: Seventeen species were recorded for the first time on the Israeli coasts and 20 in Greek waters. Perkinsyllis augeneri (Hartmann-Schröder, 1979 and Prosphaerosyllis chauseyensis Olivier et al., 2011 are new records for the Mediterranean Sea. Detailed information is given on the morphology, ecology and distribution of the species recorded for the first time in the studied areas. In addition, an update on the distribution of the genus Prosphaerosyllis San Martín, 1984 in the Mediterranean is given and an identification key to the Mediterranean species is provided.

  5. Imaging density and seismic velocities in the Eastern Mediterranean

    Science.gov (United States)

    Blom, Nienke; Gokhberg, Alexey; Fichtner, Andreas

    2017-04-01

    The Mediterranean domain is a geologically complicated region, a result of its complex tectonic and geodynamic evolution. Our understanding of it draws from surface geology, modeling and imaging of the subsurface. Here, we present the first results of seismic waveform inversion of the Eastern Mediterranean region. While computationally much more expensive than more traditional ray-based imaging methods, the advantage of waveform tomography lies in its ability to incorporate in a consistent manner all the information in seismograms - not just the arrivals of certain, specified phases. As a result, body and multimode surface waves, source effects, frequency-dependence, wavefront healing, anisotropy and attenuation are naturally and coherently incorporated. This not only allows us to image P- and S-wave velocity jointly for the crust and mantle, but also makes it possible to put additional constraints on density that ray tomography cannot provide. This is of special interest because heterogeneities in density drive geodynamics, and the combined knowledge of all parameters would help to distinguish between thermal and compositional effects in the subsurface, where no direct measurements can be made. Our tomography makes use of a multi-scale approach, initially using only the very lowest frequency signals of periods of around 100-150 seconds which corresponds to structures of 200 km size in the crust. Slowly, higher-frequency data is added as the model is updated and more of the data is explained by it. Our ultimate aim is to go down to periods of 10 seconds, which corresponds to structures of about 15 km size in the crust to 25 km in the mantle. Only those parts of the seismograms are used in which data and synthetics are similar enough to allow for meaningful comparison. As iterations progress and synthetics become more similar to the data, more parts of the seismogram can be included. Resolution of the final model is assessed using a resolution analysis strategy

  6. Strangers in Paradise: The biogeographic range expansion of the foraminifera Amphistegina in the Mediterranean Sea

    Science.gov (United States)

    Langer, M. R.; Weinmann, A. E.; Rödder, D.; Lötters, S.

    2012-04-01

    Species distribution models (SDMs) have become important tools in biogeography and biodiversity research over the last decades. They are mainly based on the fundamental niche concept and allow the correlative prediction of species' potential distributional ranges by combining occurrence records with information on environmental (e.g. climatic) conditions. The generated environmental envelope of a species is projected into geographic space, thus defining areas of adequate habitat suitability. Here we apply a species distribution model (SDM) to assess potential range expansions of Amphistegina spp. in the Mediterranean Sea under current und future climate conditions. The model uses an environmental envelope of information from localities where amphisteginids are currently known to occur. Amphisteginid foraminifers are a group of circumtropically distributed, larger symbiont-bearing, calcareous foraminifera that have a well-documented record as detectors of historical climate change. They are currently expanding their biogeographic range in the Mediterranean Sea and rapidly progressing northwestward, closely approaching the Adriatic and the Tyrrhenian Sea. The shift in range locally leads to profound ecological changes where amphisteginids have become the dominant species along entire stretches of coastline. Mass deposits of amphisteginids reflect an increased carbonate production and reduced assemblage diversity, and these are likely to trigger major changes in ecosystem functioning. It is anticipated that the ongoing warming trend will convey the northwestward migration of amphisteginid foraminifers. Our model indicates that further warming is likely to cause a northwestward range extension and predicts dispersal through the straits of Sicily, Messina and Otranto into the Tyrrhenian and Adriatic Sea. Rapid proliferation and the extreme abundances of amphisteginid foraminifera affect the dynamic equilibrium of established foraminiferal biotas. In the eastern

  7. Space-time variability of alkalinity in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. Cossarini

    2014-09-01

    Full Text Available The paper provides a basin assessment of the spatial distribution of ocean alkalinity in the Mediterranean Sea. The assessment is made using a 3-D transport-biogeochemical-carbonate model to integrate the available experimental findings, which also constrains model output. The results indicate that the Mediterranean Sea shows alkalinity values that are much higher than those observed in the Atlantic Ocean on a basin-wide scale. A marked west-to-east surface gradient of alkalinity is reproduced as a response to the terrestrial discharges, the mixing effect with the Atlantic water entering from the Gibraltar Strait and the Black Sea water from Dardanelles, and the surface flux of evaporation minus precipitation. Dense water production in marginal seas (Adriatic and Aegean Seas, where alkaline inputs are relevant, and the Mediterranean thermohaline circulation sustains the west-to-east gradient along the entire water column. In the surface layers, alkalinity has a relevant seasonal cycle (up to 40 μmol kg−1 that is driven both by physical and biological processes. A comparison of alkalinity vs. salinity indicates that different regions present different relationships. In regions of freshwater influence, the two measures are negatively correlated due to riverine alkalinity input, whereas they are positively correlated in open seas. Alkalinity always is much higher than in the Atlantic waters, which might indicate a higher than usual buffering capacity towards ocean acidification, even at high concentrations of dissolved inorganic carbon.

  8. Loss of large predatory sharks from the Mediterranean Sea.

    Science.gov (United States)

    Ferretti, Francesco; Myers, Ransom A; Serena, Fabrizio; Lotze, Heike K

    2008-08-01

    Evidence for severe declines in large predatory fishes is increasing around the world. Because of its long history of intense fishing, the Mediterranean Sea offers a unique perspective on fish population declines over historical timescales. We used a diverse set of records dating back to the early 19th and mid 20th century to reconstruct long-term population trends of large predatory sharks in the northwestern Mediterranean Sea. We compiled 9 time series of abundance indices from commercial and recreational fishery landings, scientific surveys, and sighting records. Generalized linear models were used to extract instantaneous rates of change from each data set, and a meta-analysis was conducted to compare population trends. Only 5 of the 20 species we considered had sufficient records for analysis. Hammerhead (Sphyrna spp.), blue (Prionace glauca), mackerel (Isurus oxyrinchus and Lamna nasus), and thresher sharks (Alopias vulpinus) declined between 96 and 99.99% relative to their former abundance. According to World Conservation Union (IUCN) criteria, these species would be considered critically endangered. So far, the lack of quantitative population assessments has impeded shark conservation in the Mediterranean Sea. Our study fills this critical information gap, suggesting that current levels of exploitation put large sharks at risk of extinction in the Mediterranean Sea. Possible ecosystem effects of these losses involve a disruption of top-down control and a release of midlevel consumers.

  9. Aerosol transport of polynuclear aromatic hydrocarbons over the Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Grimalt, J.; Albaiges, J.; Sicre, M.A.; Marty, J.C.; Saliot, A.

    1988-01-01

    A study on the composition of PAH in particle-sized aerosols collected over the open sea (Western Mediterranean) is presented, showing for first time the importance of their atmospheric deposition fluxes. The results are also discussed in terms of air mass trajectories, organic sources, and particle size association. (orig./RB)

  10. Trends in trawl and purse seine catch rates in the north-eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    A. MACHIAS

    2012-12-01

    Full Text Available Data on fishing effort expressed in vessel days at sea and corresponding landing/day for a large number of species have been collected by the Institute of Marine Biological Resources (IMBR since the second half of 1995. Data were collected over a grid of 21 stations throughout the Greek seas. In the present study we analyzed the monthly days at sea as well as catch per day for trawlers and purse seiners from 1996 to 2000, by general linear models and trend analysis. The following vessel size groups per gear were considered: (a trawlers smaller and larger than 20m; (b purse-seiners smaller and larger than 15m. Collected data were also aggregated for five fishing sub-areas: the North Aegean, the Central Aegean, the South Aegean, Cretan waters and the Ionian Sea. Trend analysis of landing/day time series indicated that demersal and pelagic resources are declining in the main fishing grounds. Declining landing/day trends are regarded as indicators of overfishing, especially in the light of the fact that high catch rates are maintained by fishing in ‘hot spots’. The results of the present analysis provide, for the first time, important information on the sustainability of the fisheries in the north-eastern Mediterranean, an area characterized by a complete lack of accurate long-term data on effort and catch per effort

  11. Low Frequency Variability and the Eastern Mediterranean Teleconnection Pattern

    Science.gov (United States)

    Hatzaki, M.; Flocas, H. A.

    2007-12-01

    The long time series analysis of the atmospheric circulation has revealed large scale correlations between the flow at remote locations. These fluctuations belong in the low frequency range of timescale and referred to as teleconnections patterns. They are located in particular places and appear as preferred modes of low-frequency natural variability of the atmospheric circulation with fixed oscillating nodes and antinodes, called poles. These teleconnection patterns describe standing waves oscillating with time scales of a month or longer. It has been recognized that the large scale eddies and their feedback onto the mean flow, the propagation of Rossby waves in the midlatitudes and the stratosphere-troposphere interaction play an important role in understanding low frequency general circulation and variability. In previous studies, the Eastern Mediterranean Teleconnection pattern (EMP) was found with its two poles located in North-eastern Europe and Eastern Mediterranean, and it was predominantly identified at the upper troposphere during winter. An index was defined, based on the exact position of the two poles of the pattern, to represent the strength of the teleconnection pattern and to discriminate its positive and negative phase. The objective of this study is to investigate the large scale dynamics related to the development of EMP. For this purpose, datasets of daily geopotential height, temperature and horizontal wind components at several isobaric levels are employed, as obtained from the NCEP/NCAR and from the ECMWF centres, for the calculation of transient eddy kinetic energy, E-vectors, Rossby wave source and potential vorticity. It was found that the role of the eddy driven mid-latitude jet is important. It is likely that the subtropical jet is passive and that the transient eddies remove much more momentum in the negative phase, when the storm- track comes charging into Europe. Rossby wave propagation seems to determine the differing wave

  12. Plankton in the open Mediterranean Sea: a review

    Science.gov (United States)

    Siokou-Frangou, I.; Christaki, U.; Mazzocchi, M. G.; Montresor, M.; Ribera D'Alcalá, M.; Vaqué, D.; Zingone, A.

    2009-11-01

    We present an overview of the plankton studies conducted during the last 25 years in the epipelagic offshore waters of the Mediterranean Sea. This quasi-enclosed sea is characterized by a rich and complex physical dynamics that includes unique thermohaline features, particular multilayer circulation, topographic gyres, and meso- and sub-mesoscale activity. Recent investigations have basically confirmed the long-recognised oligotrophic character of this sea, which enhances along both the west-east, and the north-south directions. Nutrient availability is low, especially for phosphorous (N:P up to 60), although limitation may be relaxed by inputs from highly populated coasts and from the atmosphere. Phytoplankton biomass as chl-a, generally displays low values (less than 0.2 μg chl-a l-1) over large areas, with a modest late winter increase. A large bloom (up to 3 μg l-1) throughout the late winter and early spring is only observed in the NW area. Relatively high biomass peaks are also recorded in fronts and cyclonic gyres. A deep chlorophyll maximum is a~permanent feature for the whole basin (except during the late winter mixing). It progressively deepens from the Alboran Sea (30 m) to the easternmost Levantine basin (120 m). Primary production reveals a similar west-east decreasing trend and ranges from 59 to 150 g C m-2 y-1 (in situ measurements). Overall the basin is largely dominated by small-sized autotrophs, microheterotrophs and egg-carrying copepod species. The phytoplankton, the microbial (both autotrophic and heterotrophic) and the zooplankton components reveal a considerable diversity and variability over spatial and temporal scales, the latter less explored though. Examples are the wide diversity of dinoflagellates and coccolithophores, the multifarious role of diatoms or picoeukaryotes, and the distinct seasonal or spatial patterns of the species-reach copepod genera or families which dominate in the basin. Major dissimilarities between western and

  13. Particle fluxes in the deep Eastern Mediterranean basins: the role of ocean vertical velocities

    Directory of Open Access Journals (Sweden)

    L. Patara

    2008-08-01

    Full Text Available This paper analyzes the relationship between deep sedimentary fluxes and ocean current vertical velocities in an offshore area of the Ionian Sea, the deepest basin of the Eastern Mediterranean Sea. Sediment trap data are collected at 500 m and 2800 m depth in two successive moorings covering the period September 1999–May 2001. A tight coupling is observed between the upper and deep traps and the estimated particle sinking rates are higher than 200 m day−1. The current vertical velocity field is computed from a high resolution Ocean General Circulation Model simulation and from the wind stress curl. Current vertical velocities are larger and more variable than Ekman vertical velocities, yet the general patterns are alike. Current vertical velocities are generally smaller than 1 m day−1: we therefore exclude a direct effect of downward velocities in determining high sedimentation rates. However, we find that upward velocities in the subsurface layers of the water column are positively correlated with deep particle fluxes. We thus hypothesize that upwelling would produce an increase in upper ocean nutrient levels – thus stimulating primary production and grazing – a few weeks before an enhanced vertical flux is found in the sediment traps. By analyzing the delayed effects of ocean vertical velocities on deep particle fluxes we envisage a spectrum of particle sinking speeds ranging from about 100 m day−1 to more than 200 m day−1. High particle sedimentation rates may be attained by means of rapidly sinking fecal pellets produced by gelatinous macro-zooplankton. Other sedimentation mechanisms, such as dust deposition, are also considered in explaining large pulses of deep particle fluxes. The fast sinking rates estimated in this study might be an evidence of the efficiency of the biological pump in sequestering organic carbon from the surface layers of the deep Eastern Mediterranean basins.

  14. Hindcast oil spill simulations from the existing offshore wells in the Eastern Mediterranean Levantine Basin

    Science.gov (United States)

    Zodiatis, George; Alves, Tiago M.; Kokinou, Eleni; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2017-04-01

    Following the expansion of the exploration and exploitation of the hydrocarbons in the Eastern Mediterranean Levantine Basin during the last 5 years, oil spill simulations for 20 existing offshore platforms/wells were carried out based on new and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The oil spill simulations were carried out using the well known MEDSLIK oil spill model, with the use of high temporal and spatial resolution data for 3D sea currents, winds and waves, provided by the CYCOFOS forecasting system, downscaled from the Copernicus Marine environment monitoring service (CMEMS). The hindcast oil spill simulations from the 20 potential oil spill sources have been prepared for a period of four years, presenting the movement of the spills and the area affected, the fate parameters, the first impact on the coast and the extend of the affected coastline from each location every week. The modeled oil spills took into account the oil spill scenario following the REMPEC MEDEXPOL 2013 experiment. Moreover, a qualitative analysis of the seabed morphology has been applied to examine the direction of the oil slick expansion, shown that the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. The oil spill simulations from the existing offshore wells/platforms, show a clear trend for east and northeast movement of the oil spills in the Eastern Mediterranean Levantine Basin, with the first impact at the coast in a time interval between 1 to 20 days after the first oil spilled at sea, depending on the location of the platforms/wells and of the intensity and direction of the meteo-ocean data.

  15. Particle fluxes in the deep Eastern Mediterranean basins: the role of ocean vertical velocities

    Directory of Open Access Journals (Sweden)

    L. Patara

    2009-03-01

    Full Text Available This paper analyzes the relationship between deep sedimentary fluxes and ocean current vertical velocities in an offshore area of the Ionian Sea, the deepest basin of the Eastern Mediterranean Sea. Sediment trap data are collected at 500 m and 2800 m depth in two successive moorings covering the period September 1999–May 2001. A tight coupling is observed between the upper and deep traps and the estimated particle sinking rates are more than 200 m day−1. The current vertical velocity field is computed from a 1/16°×1/16° Ocean General Circulation Model simulation and from the wind stress curl. Current vertical velocities are larger and more variable than Ekman vertical velocities, yet the general patterns are alike. Current vertical velocities are generally smaller than 1 m day−1: we therefore exclude a direct effect of downward velocities in determining high sedimentation rates. However we find that upward velocities in the subsurface layers of the water column are positively correlated with deep particle fluxes. We thus hypothesize that upwelling would produce an increase in upper ocean nutrient levels – thus stimulating primary production and grazing – a few weeks before an enhanced vertical flux is found in the sediment traps. High particle sedimentation rates may be attained by means of rapidly sinking fecal pellets produced by gelatinous macro-zooplankton. Other sedimentation mechanisms, such as dust deposition, are also considered in explaining large pulses of deep particle fluxes. The fast sinking rates estimated in this study might be an evidence of the efficiency of the biological pump in sequestering organic carbon from the surface layers of the deep Eastern Mediterranean basins.

  16. Non-methane hydrocarbons over the Eastern Mediterranean during summer, measured from northwest Cyprus

    Science.gov (United States)

    Sauvage, Carina; Derstroff, Bettina; Bourtsoukidis, Efstratios; Keßel, Stephan; Thorenz, Ute; Baker, Angela; Williams, Jonathan; Lelieveld, Jos

    2015-04-01

    In summer 2014 the CYprus Photochemistry EXperiment (CYPHEX) field campaign took place at an elevated (600m) measurement site in the north western part of Cyprus close (10 km) to the coast (35,96N, 32,4E) in order to investigate the photochemistry and air mass transport of the eastern Mediterranean. Non-methane hydrocarbons were measured with a commercial GC-FID (AMA instruments GmbH, Ulm, Germany) with a final dataset consisting of two weeks of continuous, hourly measurements for 10 NMHC. NMHCs are a class of volatile organic compounds (VOC) which are emitted by both anthropogenic and natural sources. Their predominant sink in the atmosphere is photochemically driven oxidation by OH radicals. Their atmospheric lifetimes, which range from a few days for more reactive compounds such as pentanes and butanes and up to a month for less reactive ones like ethane, make it possible to deduce photochemical histories and transport regimes from NMHC observations. Furthermore, in the presence of NOx they are important precursors for tropospheric ozone. Backward trajectories show that the airmasses reaching the measurement site had been influenced periodically by emissions from western continental Europe (France, Spain) that crossed the Mediterranean Sea and from eastern continental Europe (Greece and Turkey) more recently influenced by industrial emissions. Varying patterns in NMHC data delineates these two regimes very well, with aged western European air masses being characterized by low level ethane and with toluene and benzene being higher and more variable in plumes from eastern Europe. Additionally, atypical n-butane and i-butane ratios suggest a deviation from the expected predominant oxidation by OH, possibly indicating reaction with chlorine radicals (Cl). The dataset has been evaluated with respect to NMHC sources and oxidative history using different methods of approach.

  17. Observing and simulating the impact of growing urbanization on air quality and climate in the Eastern Mediterranean

    Science.gov (United States)

    Kanakidou, Maria; Myriokefalitakis, Stelios; Mihalopoulos, Nikos; Vrekoussis, Mihalis; Daskalakis, Nikos; Sfakianaki, Maria; Hatziannastassiou, Nikos; Im, Ulas

    2016-07-01

    The Mediterranean, and particularly its east basin, is a crossroad of air masses coming from Europe, Asia and Africa. Over this area, anthropogenic emissions, mainly from Europe, Balkans and the Black Sea, meet with natural emissions from Sahara (Saharan dust), vegetation and the ocean as well as from biomass burning, overall presenting a strong seasonal pattern. As a consequence of its unique location and emissions, the Mediterranean region is climatically very sensitive and often exposed to multiple stresses, such as a simultaneous water shortage and elevated air pollution exposure. During the last decades, the Eastern Mediterranean, following the general trend, has experienced a rapid growth in urbanization, including increased vehicle circulation, and industrialization, all impacting pollutant emissions in the atmosphere. Air pollution is one of the challenging environmental problems for Istanbul and Cairo megacities but also for the whole Eastern Mediterranean region. The recent financial crisis resulted in changes in human habits, energy production and subsequently air pollution. This resulted in changes in tropospheric composition that reflect changes in natural emissions and in human behavior have been detected by satellites and simulated by chemistry transport models. The results are presented and their robustness is discussed.

  18. Genetic structure of Octopus vulgaris (Cephalopoda, Octopodidae) in the central Mediterranean Sea inferred from the mitochondrial COIII gene.

    Science.gov (United States)

    Fadhlaoui-Zid, Karima; Knittweis, Leyla; Aurelle, Didier; Nafkha, Chaala; Ezzeddine, Soufia; Fiorentino, Fabio; Ghmati, Hisham; Ceriola, Luca; Jarboui, Othman; Maltagliati, Ferruccio

    2012-01-01

    The polymorphism of the mitochondrial gene cytochrome oxidase III was studied in the Mediterranean octopus, Octopus vulgaris Cuvier, 1797. A total of 202 specimens from seven sampling sites were analysed with the aim of elucidating patterns of genetic structure in the central Mediterranean Sea and to give an insight into the phylogeny of the Octopus genus. Phylogenetic analyses showed that individuals from the central Mediterranean belong to the O. vulgaris species whose limits should nevertheless be clarified. Concerning genetic structure, two high-frequency haplotypes were present in all locations. The overall genetic divergence (Φ(ST)=0.05, P<0.05) indicated a significant genetic structuring in the study area and an AMOVA highlighted a significant break between western and eastern Mediterranean basins (Φ(CT)=0.094, P<0.05). Possible explanations for the observed patterns of genetic structuring are discussed with reference to their relevance for fisheries management.

  19. Submarine landslides along the eastern Mediterranean Israeli continental slope

    Science.gov (United States)

    Reuven, Einav; Katz, Oded; Aharonov, Einat

    2013-04-01

    Numerous shallow submarine slope failures (scars and deposits) are observed in recent high resolution bathymetric grids of the continental slope off the Israeli eastern Mediterranean coast. The nature of these slope failures is currently not comprehensively understood as well as the question of whether the eastern Mediterranean continental slope is continuously or episodically unstable. We report here first steps towards understanding the present state of this submarine landslide system, which include mapping and analyzing the geology of the landslides and the hosting slopes. The continental slope extends from water depths of about 150 to more than 1000 meters with a slope of less than 5 degrees in general. Bathymetric grids with pixel resolution of 15 m till water depth of 700 m and 50 m till water depth of 1700 m were used. Analyzing the bathymetry revealed three main submarine surface features: (a) numerous shallow landslides, within the upper sequence of the post-Messenian sediments. Landslide widths range between hundreds to thousand of meters at the scar, with scar heights up to hundred meters. The toes of the landslides are not always mapable and lay up to a few kilometers down slope from the scar. Slope angles within the scars are 5 to more than15 degrees. At least two types of landslides were detected: presumably young slides with sharp scars, and presumably old slides with secondary slides and secondary drainage systems developed within the scar area; (b) a few kilometers long, north striking step-like lineaments. Step heights are up to 100 meters and the slopes are up to 20 degrees. The offset between parallel steps is less than a kilometer to a few kilometers. The steps are interpreted as surface expressions of growth faults rooted at the Messinian evaporates up to 1.5 kilometers below surface; (c) a few north striking channels were also detected with steep walls of more than 15 degrees, up to two kilometers width and a few kilometers length. The nature

  20. Improving estimates of riverine fresh water into the Mediterranean sea

    Science.gov (United States)

    Wang, Fuxing; Polcher, Jan

    2017-04-01

    Estimating the freshwater input from the continents into the Mediterranean sea is a difficult endeavor due to the uncertainties from un-gauged rivers, human activities, and measurement of water flow at river outlet. One approach to estimate the freshwater inflow into the Mediterranean sea is based on the observed flux (about 63% available) and a simple annual water balance for rivers without observations (ignoring human usage and other processes). This method is the basis of most water balance studies of the Mediterranean sea and oceanic modelling activities, but it only provides annual mean values with a very strong assumption. Another approach is done by forcing a state of the art land surface model (LSM) with bias corrected atmospheric conditions. This method can estimate total fresh water flowing into the Mediterranean at daily scale but with all the caveats associated to models. We use data assimilation techniques by merging data between the model output (ORCHIDEE LSM developed at Institut Pierre Simon Laplace) and the observed river discharge from Global Runoff Data Center (GRDC) to correct the modelled fluxes with observations over the entire basin. Over each sub watershed, the GRDC data (if available) are applied to correct model simulated river discharge. This will allow to compensate for systematic errors of model or missing processes and provide estimates of the riverine input into the sea at high temporal and spatial resolution. We will analyze the freshwater inflow into the Mediterranean obtained here with different approaches reported in previous paper. The new estimates will serve for ocean modelling and water balance studies of the region.

  1. Particle tracking in the eastern Irish Sea

    Science.gov (United States)

    Wolf, Judith; Amoudry, Karen; Phillips, Hazel; Brown, Jenny

    2017-04-01

    The unstructured grid finite volume community ocean model (FVCOM) has been applied to the west coast of the UK, in order to examine the circulation and transport in the eastern Irish Sea. Tides, freshwater river discharge and meteorological forcing for the year 2008 were used to force the baroclinic hydrodynamic circulation. The hydrodynamics of the Irish Sea are largely governed by the semidiurnal tide, which has a tidal range reaching 10m at Liverpool is the eastern Irish Sea. Tidal currents reach 1 ms-1 over the majority of the area, which means that much of Irish Sea is vertically well-mixed throughout the year period, with a few areas affected by seasonal stratification, such as the cyclonic gyre in the deep channel off Ireland in the western Irish Sea which experiences thermal stratification in summer. In Liverpool Bay, horizontal density gradients, created through freshwater influence from estuaries along the coastline interact with the strong tidal current to produce a phenomenon known as strain-induced periodic stratification (SIPS). There are water quality concerns due to the tendency to eutrophication, as the area is often exposed to industrial pollution and excess nutrients from effluent waters and rivers. There is also concern about the fate of radioactive materials discharged from the Sellafield nuclear reprocessing plant since 1952. In addition to the present discharges from the site, it has been estimated that it is likely that all of the americium and plutonium and around 10% of the caesium entering the Irish Sea were originally assimilated into deposits of silt and mud sediments; this material may be regarded as a considerable potential source of radionuclides. Determining suspended sediment pathways in this region is important in order to identify potential areas vulnerable to deposition of radioactive material, particularly as radionuclide uptake onto sediments takes place in the offshore 'mud patch' before returning to the coast to be deposited

  2. Structural geometry in the eastern Pyrenees and western Gulf of Lion (Western Mediterranean)

    Science.gov (United States)

    Mauffret, Alain; Durand de Grossouvre, Bernard; Tadeu Dos Reis, Antonio; Gorini, Christian; Nercessian, Alex

    2001-11-01

    We present new seismic data from the Gulf of Lion located east of the Pyrenees on the continental shelf of the Mediterranean Sea. The deep penetration LISA (Ligurian-Sardinia Sea) seismic lines, the shots of the LISA cruise recorded on land, and the high definition ELF seismic sections allow us to present a complete picture of the tectonics in this area from the surface to the Moho level, and also to document late Miocene-early Pliocene extensional tectonics in the area. Previous studies show a prominent thinning of the crust observed from the Pyrenees towards the Gulf of Lion. The Moho depth varies from 48 km beneath the Axial Range crust (thickened during the Pyrenean Eocene Orogeny) to 21 km below the Catalan Basin in the Gulf of Lion. This crustal thinning occurred mainly during the early Miocene extension of the Mediterranean Sea. Balanced reconstructed geological sections derived from reflection and refraction seismic data allow us to evaluate the stretching factors at the crustal level. A maximum extension of 25 km is computed for the Catalan Basin area. This extension is related to detachments that penetrate the crust as deep as 11 km to the base of the brittle crust. These intra basement detachments have been confused in the past with the Paleozoic acoustic basement. The detachments show a clear listric shape and the geometry of horst and grabens can be explained by a hanging wall and footwall configuration with isostatic rebound of the footwall. The uplift in the Eastern Pyrenees (Albères and Canigou Massifs), on the other hand, is related to the late Miocene-early Pliocene extension we mapped in the area. These elevated features, probably formed by isostatic rebound, are surrounded by deep basins such as the Roussillon and El Empordà depressions. A 1.7 km uplift during the late Miocene-early Pliocene is computed in the offshore part of the Albères Massif. The cause of this Late Miocene-early Pliocene extension is not well explained although an uplift

  3. Particle size distributions in the Eastern Mediterranean troposphere

    Science.gov (United States)

    Kalivitis, N.; Birmili, W.; Stock, M.; Wehner, B.; Massling, A.; Wiedensohler, A.; Gerasopoulos, E.; Mihalopoulos, N.

    2008-11-01

    Atmospheric particle size distributions were measured on Crete island, Greece in the Eastern Mediterranean during an intensive field campaign between 28 August and 20 October, 2005. Our instrumentation combined a differential mobility particle sizer (DMPS) and an aerodynamic particle sizer (APS) and measured number size distributions in the size range 0.018 μm 10 μm. Four time periods with distinct aerosol characteristics were discriminated, two corresponding to marine and polluted air masses, respectively. In marine air, the sub-μm size distributions showed two particle modes centered at 67 nm and 195 nm having total number concentrations between 900 and 2000 cm-3. In polluted air masses, the size distributions were mainly unimodal with a mode typically centered at 140 nm, with number concentrations varying between 1800 and 2900 cm-3. Super-μm particles showed number concentrations in the range from 0.01 to 2.5 cm-3 without any clear relation to air mass origin. A small number of short-lived particle nucleation events were recorded, where the calculated particle formation rates ranged between 1.1 1.7 cm-3 s-1. However, no particle nucleation and growth events comparable to those typical for the continental boundary layer were observed. Particles concentrations (Diameter population was governed mainly by coagulation and that particle formation was absent during most days.

  4. Relationships among predatory fish, sea urchins and barrens in Mediterranean rocky reefs across a latitudinal gradient.

    Science.gov (United States)

    Guidetti, P; Dulcić, J

    2007-03-01

    Previous studies conducted on a local scale emphasised the potential of trophic cascades in Mediterranean rocky reefs (involving predatory fish, sea urchins and macroalgae) in affecting the transition between benthic communities dominated by erected macroalgae and barrens (i.e., bare rock with partial cover of encrusting algae). Distribution patterns of fish predators of sea urchins (Diplodus sargus sargus, Diplodus vulgaris, Coris julis and Thalassoma pavo), sea urchins (Paracentrotus lividus and Arbacia lixula) and barrens, and fish predation rates upon sea urchins, were assessed in shallow (3-6m depth) sublittoral rocky reefs in the northern, central and southern sectors of the eastern Adriatic Sea, i.e., on a large spatial scale of hundreds of kilometres. No dramatic differences were observed in predatory fish density across latitude, except for a lower density of small D. sargus sargus in the northern Adriatic and an increasing density of T. pavo from north to south. P. lividus did not show any significant difference across latitude, whereas A. lixula was more abundant in the southern than in the central Adriatic. Barrens were more extended in the southern than in the central and northern sectors, and were related with sea urchin density. Fish predation upon adult sea urchins did not change on a large scale, whereas it was slightly higher in the southern sector for juveniles when predation rates of both urchins were pooled. Results show that: (1) assemblages of predatory fish and sea urchins, and barren extent change across latitude in the eastern Adriatic Sea, (2) the weak relations between predatory fish density and predation rates on urchins reveal that factors other than top-down control can be important over large scale (with the caveat that the study was conducted in fished areas) and (3) patterns of interaction among strongly interacting taxa could change on large spatial scales and the number of species involved.

  5. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    Science.gov (United States)

    Grant, K. M.; Grimm, R.; Mikolajewicz, U.; Marino, G.; Ziegler, M.; Rohling, E. J.

    2016-05-01

    The Mediterranean basin is sensitive to global sea-level changes and African monsoon variability on orbital timescales. Both of these processes are thought to be important to the deposition of organic-rich sediment layers or 'sapropels' throughout the eastern Mediterranean, yet their relative influences remain ambiguous. A related issue is that an assumed 3-kyr lag between boreal insolation maxima and sapropel mid-points remains to be tested. Here we present new geochemical and ice-volume-corrected planktonic foraminiferal stable isotope records for sapropels S1 (Holocene), S3, S4, and S5 (Marine Isotope Stage 5) in core LC21 from the southern Aegean Sea. The records have a radiometrically constrained chronology that has already been synchronised with the Red Sea relative sea-level record, and this allows detailed examination of the timing of sapropel deposition relative to insolation, sea-level, and African monsoon changes. We find that sapropel onset was near-synchronous with monsoon run-off into the eastern Mediterranean, but that insolation-sapropel/monsoon phasings were not systematic through the last glacial cycle. These latter phasings instead appear to relate to sea-level changes. We propose that persistent meltwater discharges into the North Atlantic (e.g., at glacial terminations) modified the timing of sapropel deposition by delaying the timing of peak African monsoon run-off. These observations may reconcile apparent model-data offsets with respect to the orbital pacing of the African monsoon. Our observations also imply that the previous assumption of a systematic 3-kyr lag between insolation maxima and sapropel midpoints may lead to overestimated insolation-sapropel phasings. Finally, we surmise that both sea-level rise and monsoon run-off contributed to surface-water buoyancy changes at times of sapropel deposition, and their relative influences differed per sapropel case, depending on their magnitudes. Sea-level rise was clearly important for

  6. Fin whales and microplastics: The Mediterranean Sea and the Sea of Cortez scenarios.

    Science.gov (United States)

    Fossi, Maria Cristina; Marsili, Letizia; Baini, Matteo; Giannetti, Matteo; Coppola, Daniele; Guerranti, Cristiana; Caliani, Ilaria; Minutoli, Roberta; Lauriano, Giancarlo; Finoia, Maria Grazia; Rubegni, Fabrizio; Panigada, Simone; Bérubé, Martine; Urbán Ramírez, Jorge; Panti, Cristina

    2016-02-01

    The impact that microplastics have on baleen whales is a question that remains largely unexplored. This study examined the interaction between free-ranging fin whales (Balaenoptera physalus) and microplastics by comparing populations living in two semi-enclosed basins, the Mediterranean Sea and the Sea of Cortez (Gulf of California, Mexico). The results indicate that a considerable abundance of microplastics and plastic additives exists in the neustonic samples from Pelagos Sanctuary of the Mediterranean Sea, and that pelagic areas containing high densities of microplastics overlap with whale feeding grounds, suggesting that whales are exposed to microplastics during foraging; this was confirmed by the observation of a temporal increase in toxicological stress in whales. Given the abundance of microplastics in the Mediterranean environment, along with the high concentrations of Persistent Bioaccumulative and Toxic (PBT) chemicals, plastic additives and biomarker responses detected in the biopsies of Mediterranean whales as compared to those in whales inhabiting the Sea of Cortez, we believe that exposure to microplastics because of direct ingestion and consumption of contaminated prey poses a major threat to the health of fin whales in the Mediterranean Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. The Mediterranean Sea Mollusks - a school shell collection

    Science.gov (United States)

    Marcu, Delia

    2017-04-01

    School: 1. "Ana Aslan" Technical College, Street Decebal 1, Cluj-Napoca, Romania 2. Orthodox Theological Seminary, Avram Iancu Square No.18, Cluj-Napoca, Romania The aim of the present project is to develop the students awareness of human activities impact on mollusks population in the Mediterranean Sea. Students have studied about the Geography of the Mediterranean Sea and they have the theoretical knowledge related to the its specific flora and fauna. One of the main fears related to the Mediterranean Sea is the loss of marine and coastal biodiversity due to biological disturbance, climate change and human activities. Out of all reasons, the human impact is considered to be the major cause of habitat loss, degradation and extinction. Regarding the Phylum Mollusca a major threat is represented by unregulated fisheries and shell traffic. In order to enable the students possibility to observe the great diversity of the Phylum Mollusca in the Mediterranean Sea, a school shell collection was made. The shells were brought by the students and they had to mention if the shells were bought, received as a souvenir or picked from their environment. Further, the students learned how to prepare the shells for the collection. The next step involved the shell classification and by this activity the students learned how to use the IUCN: International Union for Conservation of Nature database to identify the threatened species, as well as the World Register of Marine Species (WoRMS) for a correct identification of the species. As Romania romania bordering the Black Sea, the students had the opportunity to identify the mollusks species common for both the Mediterranean Sea and the Black Sea. The objectives of this study were to highlight the human-environment relation and the interconnection between environment conditions and life quality, to develop the students research, exploration and investigation skills, to be able to identify the causes of species extinction and methods

  8. Present-day kinematics in the Eastern Mediterranean and Caucasus from dense GPS observations

    Science.gov (United States)

    Ahadov, Bahruz; Jin, Shuanggen

    2017-07-01

    The Eastern Mediterranean and Caucasus are located among the Eurasian, African and Arabian plates, and tectonic activities are very complex. In this paper, the kinematics and strain distribution in these regions are determined and investigated from dense GPS observations with over 1000 stations and longer observations. The elastic block model is used to constrain present-day plate motions and crustal deformation. The relative Euler vectors between the Nubian, Arabian, Caucasus, Anatolian and Central Iranian plates are estimated. The Arabian-Eurasia, Anatolian-Eurasia, Nubian-Eurasia, Caucasus-Eurasia and Central Iranian Euler vectors are 0.584 ± 0.1 Myr-1, 0.825 ± 0.064 Myr-1, 0.35 ± 0.175 Myr-1, 0.85 ± 0.086 Myr-1 and 0.126 ± 0.016 Myr-1. The strain rate in the East Mediterranean and Caucasus has been estimated from the GPS velocity field. The results show that the thrust dominated areas, the eastern Mediterranean-Middle East-Caucasus and Zagros have negative dilatation and the western Anatolia region has positive 2D dilatation rate with significant rotation. The west Anatolian shows the extension in NW-SE with about 150-199 nstrain/yr in the W-E direction. The Central Anatolia shows compression rate below 50 nstrain/yr and extensional strain rate adjacent to East Anatolian Fault and Dead Sea Fault is about 0-100 nstrain/yr. The contraction strain rate is higher in Zagros and Caucasus between 100-150 nstrain/yr and contraction orientation is along the NE-SW direction in Caucasus. The north part of Iran shows less contraction rate below 50 nstrain/yr but North-East Zagros Mountains, Tabriz fault and Chalderan fault show extensional rate between 50-110 nstrain/yr and principal axes rotation in the N-S direction. The maximum contraction observed in the Kopek Dag is about 100-194 nstrain/yr and orientated in the NE-SW direction. East Zagros Mountain and Makran subduction zone have a large clockwise rotation with 70-85 nradian and principal axes remains mostly

  9. New insights into the organic carbon export in the Mediterranean Sea from 3-D modeling

    Directory of Open Access Journals (Sweden)

    A. Guyennon

    2015-04-01

    Full Text Available The Mediterranean Sea is one of the most oligotrophic regions of the oceans, and nutrients have been shown to limit both phytoplankton and bacterial activities. This has direct implications on the stock of dissolved organic carbon (DOC, whose high variability has already been well-documented even if measurements are still sparse and are associated with important uncertainties. We here propose a Mediterranean Basin-scale view of the export of organic carbon, under its dissolved and particulate forms. For this purpose, we have used a coupled model combining a mechanistic biogeochemical model (Eco3M-MED and a high-resolution (eddy-resolving hydrodynamic simulation (NEMO-MED12. This is the first Basin-scale application of the biogeochemical model Eco3M-MED and is shown to reproduce the main spatial and seasonal biogeochemical characteristics of the Mediterranean Sea. Model estimations of carbon export are of the same order of magnitude as estimations from in situ observations, and their respective spatial patterns are consistent with each other. As for surface chlorophyll, nutrient concentrations, and productivity, strong differences between the Western and Eastern Basins are evidenced by the model for organic carbon export, with only 39% of organic carbon (particulate and dissolved export taking place in the Western Basin. The major result is that except for the Alboran Sea, dissolved organic carbon (DOC contribution to organic carbon export is higher than that of particulate (POC in the whole Basin, especially in the Eastern Basin. This paper also investigates the seasonality of DOC and POC exports as well as the differences in the processes involved in DOC and POC exports.

  10. Characterization of a Strain of Fukuyoa paulensis (Dinophyceae) from the Western Mediterranean Sea.

    Science.gov (United States)

    Laza-Martínez, Aitor; David, Helena; Riobó, Pilar; Miguel, Irati; Orive, Emma

    2016-07-01

    A single cell of the dinoflagellate genus Fukuyoa was isolated from the island of Formentera (Balearic Islands, west Mediterranean Sea), cultured, and characterized by morphological and molecular methods and toxin analyses. This is the first report of the Gambierdiscus lineage (genera Fukuyoa and Gambierdiscus) from the western Mediterranean Sea, which is cooler than its eastern basin. Molecular analyses revealed that the Mediterranean strain belongs to F. paulensis and that it bears LSU rDNA sequences identical to New Zealand, Australian, and Brazilian strains. It also shared an identical sequence of the more variable ITS-rDNA with the Brazilian strain. Toxin analyses showed the presence of maitotoxin, 54-deoxyCTX1B, and gambieric acid A. This is the first observation of the two latter compounds in a Fukuyoa strain. Therefore, both Gambierdiscus and Fukuyoa should be considered when as contributing to ciguatera fish poisoning. Different strains of Fukuyoa form a complex of morphologically cryptic lineages where F. paulensis stands as the most distantly related nominal species. The comparison of the ITS2 secondary structures revealed the absence of CBCs among strains. The study of the morphological and molecular traits depicted an unresolved taxonomic scenario impacted by the low strains sampling.

  11. Hydrology and circulation in the North Aegean (eastern Mediterranean throughout 1997 and 1998

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    V. ZERVAKIS

    2012-12-01

    Full Text Available The combination of two research projects offered us the opportunity to perform a comprehensive study of the seasonal evolution of the hydrological structure and the circulation of the North Aegean Sea, at the northern extremes of the eastern Mediterranean. The combination of brackish water inflow from the Dardanelles and the sea-bottom relief dictate the significant differences between the North and South Aegean water columns. The relatively warm and highly saline South Aegean waters enter the North Aegean through the dominant cyclonic circulation of the basin. In the North Aegean, three layers of distinct water masses of very different properties are observed: The 20-50 m thick surface layer is occupied mainly by Black Sea Water, modified on its way through the Bosphorus, the Sea of Marmara and the Dardanelles. Below the surface layer there is warm and highly saline water originating in the South Aegean and the Levantine, extending down to 350-400 m depth. Below this layer, the deeper-than-400 m basins of the North Aegean contain locally formed, very dense water with different θ /S characteristics at each subbasin. The circulation is characterised by a series of permanent, semi-permanent and transient mesoscale features, overlaid on the general slow cyclonic circulation of the Aegean. The mesoscale activity, while not necessarily important in enhancing isopycnal mixing in the region, in combination with the very high stratification of the upper layers, however, increases the residence time of the water of the upper layers in the general area of the North Aegean. As a result, water having out-flowed from the Black Sea in the winter, forms a separate distinct layer in the region in spring (lying between “younger” BSW and the Levantine origin water, and is still traceable in the water column in late summer.

  12. Benefits of the Mediterranean diet beyond the Mediterranean Sea and beyond food patterns.

    Science.gov (United States)

    Martínez-González, Miguel A

    2016-10-14

    Abundant and growing evidence has accrued to demonstrate that the traditional Mediterranean diet is likely to be the ideal dietary pattern for the prevention of cardiovascular disease. A landmark randomized trial (PREDIMED) together with many well-conducted long-term observational prospective cohort studies support this causal effect.A new, large British cohort study by Tong et al. assessing the association between adherence to the Mediterranean diet and cardiovascular disease was recently published in BMC Medicine. Using a superb methodology, they followed-up 23,902 participants for 12.2 years on average and observed several thousand incident cases.The results of this cohort study showed a significant beneficial effect of the Mediterranean diet on cardiovascular events. These findings support the transferability of this dietary pattern beyond the shores of the Mediterranean Sea. The authors provided measures of population impact in cardiovascular prevention and estimated that 19,375 cases of cardiovascular death would be prevented each year in the UK by promoting the Mediterranean Diet.Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0677-4 .

  13. Circulation in the Southeastern Mediterranean Sea (EGITTO-NICOP)

    Science.gov (United States)

    2016-06-07

    variability in the southeastern Mediterranean waters using low- cost satellite-tracked drifters in concert with satellite observations of sea surface...provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB...eddy diffusivities will be estimated. • compare the drifter-inferred currents to SST/pigment structures obtained from satellite data. Images and

  14. Assessing the role of submarine groundwater discharge as a source of Sr to the Mediterranean Sea

    Science.gov (United States)

    Trezzi, Giada; Garcia-Orellana, Jordi; Rodellas, Valentí; Masqué, Pere; Garcia-Solsona, Ester; Andersson, Per S.

    2017-03-01

    Submarine groundwater discharge (SGD) has been identified as an important source of Sr to the ocean and the SGD-driven Sr flux to the global ocean has been recently re-evaluated (Beck et al., 2013). However, the uncertainty of this value is still high because of the uncertainties related to the determination of SGD flow rates and the paucity of 87Sr/86Sr data in SGD end-members. As carbonates have high Sr concentrations and are subjected to intense heightened weathering, they might significantly influence the SGD input of Sr to the ocean. Here we present data on Sr concentrations and 87Sr/86Sr ratios in three carbonate dominated sites of the western area of the Mediterranean Sea, a semi-enclosed basin characterized by abundant coastal carbonates. The 87Sr/86Sr ratios in groundwater were lower compared to modern seawater (∼0.70916), as expected for areas dominated by carbonate lithologies. Concentrations of Sr and 87Sr/86Sr ratios in groundwater showed conservative mixing in the studied subterranean estuaries. By using SGD flow rates reported in the literature for the study areas, a flow-weighted fresh SGD end-member characterized by a Sr concentration of 27-30 μM and a 87Sr/86Sr ratio of 0.707834-0.708020 was calculated for the eastern coast of the Iberian Peninsula. Integrating these Sr data with literature data (i.e. values of Sr concentration and 87Sr/86Sr ratio from other lithologies as well as SGD flow rates), we also calculated the fresh SGD-driven Sr flux to the entire Mediterranean Sea, obtaining a value of (0.34-0.83)·109 mol y-1, with a 87Sr/86Sr of 0.7081-0.7086. Thus, for the entire Mediterranean basin, SGD is globally a source of Sr less radiogenic compared to seawater. The SGD Sr flux to the Mediterranean Sea represents 5-6% of the SGD Sr flux to the global ocean and the Mediterranean SGD end-member has higher Sr concentration (5-12 μM) than the global SGD end-member (2.9 μM). This confirms the significant role of carbonate lithologies on SGD

  15. Isotopic niches of fin whales from the Mediterranean Sea and the Celtic Sea (North Atlantic).

    Science.gov (United States)

    Das, Krishna; Holleville, Ophélie; Ryan, Conor; Berrow, Simon; Gilles, Anita; Ody, Denis; Michel, Loïc N

    2017-06-01

    The fin whale (Balaenoptera physalus) is the most abundant and widespread mysticete species in the Mediterranean Sea, found mostly in deep, offshore waters of the western and central portion of the region. In the Mediterranean, this species is known to feed mainly on krill, in contrast to its Atlantic counterpart, which displays a more diversified diet. The International Whaling Commission recognizes several managements units in the Atlantic and the Mediterranean Sea and the connectivity between these populations is still being debated. Questions remain about inter-individual feeding strategies and trophic ecology. The goal of this study was to compare isotopic niches of fin whales from the Mediterranean Sea and the Celtic Sea (North Atlantic). δ(13)C and δ(15)N values were analysed in 136 skin biopsies from free-ranging Mediterranean fin whales sampled in 2010 and 2011 during campaigns at sea. δ(13)C and δ(15)N values ranged from -20.4 to -17.1‰ and from 5.9 to 8.9‰, respectively. These values are in good agreement with those estimated previously from baleen plates from Mediterranean and North Atlantic fin whales. The narrow isotopic niche width of the Mediterranean fin whale (Standard Ellipses area SEAc) compared to the North Atlantic fin whale raises many concerns in the context of global changes and long-term consequences. One could indeed expect that species displaying narrow niches would be more susceptible to ecosystem fragmentation and other anthropogenic impacts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Common littoral pycnogonids of the Mediterranean Sea

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    Tobias Lehmann

    2014-10-01

    Full Text Available In the present study 21 littoral pycnogonid species from 5 families are analysed: Ammotheidae (9 species, Callipallenidae (5 species, Endeidae (2 species, Phoxichilidiidae (3 species, and Pycnogonidae (2 species. The material was mainly taken from Mediterranean pycnogonid collections housed in the Bavarian State Collection of Zoology. Additional material was collected during field trips. Altogether the material was obtained from six different locations: Banyuls-sur-Mer (France, Tavolara Island (Italy, Elba Island (Italy, Giglio Island (Italy, Sicily Island (Italy, and Istria Peninsula (Croatia. The animals were studied in detail with a scanning electron microscope (SEM. Additionally series of light microscopic pictures were made to generate extended depth of field pictures of whole animals. The observed features are compared with previous literature.

  17. The Cystoseira spp. Communities from the Aegean Sea (NE Mediterranean

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    B. MONTESANTO

    2012-12-01

    Full Text Available A synthetic study of qualitative and quantitative data from some algal communities dominated by different species of the genus Cystoseira has been carried out in three coastal areas of the Aegean Sea. Seasonal samples were taken from 10 stations and a list of 30 species presenting coverage values > 1% was dressed. Ecological indices, such as Shannon Diversity Index, Pielou Eveness and Bray-Curtis Similarity Index were calculate using the PRIMER software. The results from the Aegean Sea were compared with other Mediterranean areas, and the use of Cystoseira communities as ecological quality indicators was discussed.

  18. Per- and polyfluoroalkyl substances in the Western Mediterranean Sea waters.

    Science.gov (United States)

    Brumovský, Miroslav; Karásková, Pavlína; Borghini, Mireno; Nizzetto, Luca

    2016-09-01

    The spatial and temporal distribution of per- and polyfluoroalkyl substances (PFASs) in the open Western Mediterranean Sea waters was investigated in this study for the first time. In addition to surface water samples, a deep water sample (1390 m depth) collected in the center of the western basin was analyzed. Perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were detected in all samples and were the dominant PFASs found. The sum of PFAS concentrations (ΣPFASs) ranged 246-515 pg/L for surface water samples. PFASs in surface water had a relatively homogeneous distribution with levels similar to those previously measured in the Atlantic near the Strait of Gibraltar, in water masses feeding the inflow to the Mediterranean Sea. Higher concentrations of PFHxA, PFHpA and PFHxS were, however, found in the present study. Inflowing Atlantic water and river/coastal discharges are likely the major sources of PFASs to the Western Mediterranean basin. Slightly lower (factor of 2) ΣPFASs was found in the deep water sample (141 pg/L). Such a relatively high contamination of deep water is likely to be linked to recurring deep water renewal fed by downwelling events in the Gulf of Lion and/or Ligurian Sea.

  19. Plankton in the open Mediterranean Sea: a review

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    I. Siokou-Frangou

    2010-05-01

    Full Text Available We present an overview of the plankton studies conducted during the last 25 years in the epipelagic offshore waters of the Mediterranean Sea. This quasi-enclosed sea is characterized by a rich and complex physical dynamics with distinctive traits, especially in regard to the thermohaline circulation. Recent investigations have basically confirmed the long-recognised oligotrophic nature of this sea, which increases along both the west-east and the north-south directions. Nutrient availability is low, especially for phosphorous (N:P up to 60, though this limitation may be buffered by inputs from highly populated coasts and from the atmosphere. Phytoplankton biomass, as chl a, generally displays low values (less than 0.2 μg chl a l−1 over large areas, with a modest late winter increase. A large bloom (up to 3 μg l−1 is observed throughout the late winter and spring exclusively in the NW area. Relatively high biomass values are recorded in fronts and cyclonic gyres. A deep chlorophyll maximum is a permanent feature for the whole basin, except during the late winter mixing. It is found at increasingly greater depths ranging from 30 m in the Alboran Sea to 120 m in the easternmost Levantine basin. Primary production reveals a west-east decreasing trend and ranges between 59 and 150 g C m−2 y−1 (in situ measurements. Overall, the basin is largely dominated by small autotrophs, microheterotrophs and egg-carrying copepod species. The microorganisms (phytoplankton, viruses, bacteria, flagellates and ciliates and zooplankton components reveal a considerable diversity and variability over spatial and temporal scales, although the latter is poorly studied. Examples are the wide diversity of dinoflagellates and coccolithophores, the multifarious role of diatoms or picoeukaryotes, and the distinct seasonal or spatial patterns of the species-rich copepod genera or families which dominate the

  20. Fish geographic distribution range shifts as recorded in the eastern Mediterranean during the last 5 Ma

    Science.gov (United States)

    Agiadi, Konstantina; Karakitsios, Vasileios

    2013-04-01

    Marine fish species geographic distribution is known to reflect the individuals' response to changes in oceanic circulation, temperature, salinity, local geography, other species presence and/or abundance, food availability and other biotic and abiotic factors1. New and published records on the eastern Mediterranean fish, from the end of the Messinian salinity crisis to the present, are here examined, in correlation with palaeoenvironmental data, in order to draw conclusions regarding the abiotic parameters most affecting the fish distribution during the last 5 Ma in this area. This investigation shows that the environmental variables do not affect the fish fauna in a uniform way. Rather, three faunal components may be separated, each occupying a different depth range in the water column. Pelagic fish dwell for the most part on the uppermost 200 m, and their distribution seems to be affected mainly by climatic variability. Mesopelagic fish occupy mostly intermediate depths and their distribution is regulated by the prevailing water circulation patterns. Benthic and benthopelagic fish, which live close or in contact with the sea bottom, are mostly affected by the nature and depth of the substratum. Furthermore, examples from the Ionian2,3 and the Aegean Sea indicate that, during the last 5 Ma, large-scale range shifts, similar to those occurring today, frequently took place in this area. This observation significantly alters previously views on the stability of fish assemblages and the processes occurring today. Acknowledgments. This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: Heracleitus II. Investing in knowledge society through the European Social Fund. References 1 Wooton RJ. 1998. Ecology of teleost fishes,Fish and Fisheries Series,24.Kluwers.392p. 2

  1. Particle size distributions in the Eastern Mediterranean troposphere

    Directory of Open Access Journals (Sweden)

    N. Kalivitis

    2008-04-01

    Full Text Available Atmospheric particle size distributions were measured on Crete island, Greece in the Eastern Mediterranean during an intensive field campaign between 28 August and 20 October 2005. Our instrumentation combined a differential mobility particle sizer (DMPS and an aerodynamic particle sizer (APS and measured number size distributions in the size range 0.018 μm–10 μm. Four time periods with distinct aerosol characteristics were discriminated, two corresponding to marine and polluted air masses, respectively. In marine air, the sub-μm size distributions showed two particle modes centered at 67 nm and 195 nm having total number concentrations between 900 and 2000 cm−3. In polluted air masses, the size distributions were mainly unimodal with a mode typically centered at 140 nm, with number concentrations varying between 1800 and 2900 cm−3. Super-μm particles showed number concentrations in the range from 0.01 to 2.5 cm−3 without any clear relation to air mass origin. A small number of short-lived particle nucleation events were recorded, where the calculated particle formation rates ranged between 1.1–1.7 cm−3 s−1. However, no particle nucleation and growth events comparable to those typical for the continental boundary layer were observed. Particles concentrations (Diameter <50 nm were low compared to continental boundary layer conditions with an average concentration of 300 cm−3. The production of sulfuric acid and its subsequently condensation on preexisting particles was examined with the use of a simplistic box model. These calculations suggested that the day-time evolution of the Aitken particle population was governed mainly by coagulation and that particle formation was absent during most days.

  2. Particle size distributions in the Eastern Mediterranean troposphere

    Directory of Open Access Journals (Sweden)

    N. Kalivitis

    2008-11-01

    Full Text Available Atmospheric particle size distributions were measured on Crete island, Greece in the Eastern Mediterranean during an intensive field campaign between 28 August and 20 October, 2005. Our instrumentation combined a differential mobility particle sizer (DMPS and an aerodynamic particle sizer (APS and measured number size distributions in the size range 0.018 μm–10 μm. Four time periods with distinct aerosol characteristics were discriminated, two corresponding to marine and polluted air masses, respectively. In marine air, the sub-μm size distributions showed two particle modes centered at 67 nm and 195 nm having total number concentrations between 900 and 2000 cm−3. In polluted air masses, the size distributions were mainly unimodal with a mode typically centered at 140 nm, with number concentrations varying between 1800 and 2900 cm−3. Super-μm particles showed number concentrations in the range from 0.01 to 2.5 cm−3 without any clear relation to air mass origin. A small number of short-lived particle nucleation events were recorded, where the calculated particle formation rates ranged between 1.1–1.7 cm−3 s−1. However, no particle nucleation and growth events comparable to those typical for the continental boundary layer were observed. Particles concentrations (Diameter <50 nm were low compared to continental boundary layer conditions with an average concentration of 300 cm−3. The production of sulfuric acid and its subsequently condensation on preexisting particles was examined with the use of a simplistic box model. These calculations suggested that the day-time evolution of the Aitken particle population was governed mainly by coagulation and that particle formation was absent during most days.

  3. Is the distribution of Prochlorococcus and Synechococcus ecotypes in the Mediterranean Sea affected by global warming?

    Directory of Open Access Journals (Sweden)

    M. Ostrowski

    2011-09-01

    Full Text Available Biological communities populating the Mediterranean Sea, which is situated at the northern boundary of the subtropics, are often claimed to be particularly affected by global warming. This is indicated, for instance, by the introduction of (subtropical species of fish or invertebrates that can displace local species. This raises the question of whether microbial communities are similarly affected, especially in the Levantine basin where sea surface temperatures have significantly risen over the last 25 years (0.50 ± 0.11 °C in average per decade, P Prochlorococcus and Synechococcus, was examined during two cruises through both eastern and western Mediterranean Sea basins held in September 1999 (PROSOPE cruise and in June–July 2008 (BOUM cruise. Diversity was studied using dot blot hybridization with clade-specific 16S rRNA oligonucleotide probes and/or clone libraries of the 16S-23S ribosomal DNA Internal Transcribed Spacer (ITS region, with a focus on the abundance of clades that may constitute bioindicators of warm waters. During both cruises, the dominant Prochlorococcus clade in the upper mixed layer at all stations was HLI, a clade typical of temperate waters, whereas the HLII clade, the dominant group in (subtropical waters, was only present at very low concentrations. The Synechococcus community was dominated by clades I, III and IV in the northwestern waters of the Gulf of Lions and by clade III and groups genetically related to clades WPC1 and VI in the rest of the Mediterranean Sea. In contrast, only a few sequences of clade II, a group typical of warm waters, were observed. These data indicate that local cyanobacterial populations have not yet been displaced by their (subtropical counterparts.

  4. Long-period sea-level variations in the Mediterranean

    Science.gov (United States)

    Zerbini, Susanna; Raicich, Fabio; Bruni, Sara; del Conte, Sara; Errico, Maddalena; Prati, Claudio; Santi, Efisio

    2016-04-01

    Since the beginning of its long-lasting lifetime, the Wegener initiative has devoted careful consideration to studying sea-level variations/changes across the Mediterranean Sea. Our study focuses on several long-period sea-level time series (from end of 1800 to 2012) acquired in the Mediterranean by tide gauge stations. In general, the analysis and interpretation of these data sets can provide an important contribution to research on climate change and its impacts. We have analyzed the centennial sea-level time series of six fairly well documented tide gauges. They are: Marseille, in France, Alicante in Spain, Genoa, Trieste, Venice and Marina di Ravenna (formerly Porto Corsini), in Italy. The data of the Italian stations of Marina di Ravenna and Venice clearly indicate that land subsidence is responsible for most of the observed rate of relative sea level rise. It is well known that, in the two areas, subsidence is caused by both natural processes and human activities. For these two stations, using levelling data of benchmarks at, and/or close to, the tide gauges, and for the recent years, also GPS and InSAR height time series, modelling of the long-period non-linear behavior of subsidence was successfully accomplished. After removing the land vertical motions, the estimate of the linear long-period sea-level rise at all six stations yielded remarkably consistent values, between +1,2 and +1,3 mm/yr, with associated errors ranging from ±0,2 to ±0,3 mm/yr (95% confidence interval), which also account for the statistical autocorrelation of the time series. These trends in the Mediterranean area are lower than the global mean rate of 1,7±0,2 mm/yr (1901-2010) presented by the IPCC in its 5th Assessment Report; however, they are in full agreement with a global mean sea-level rise estimate, over the period 1901-1990, recently published by Hay et al. (2015, doi:10.1038/nature14093) and obtained using probabilistic techniques that combine sea-level records with physics

  5. Hydrography in the Mediterranean Sea during a cruise with RV POSEIDON in April 2014

    Directory of Open Access Journals (Sweden)

    D. Hainbucher

    2015-05-01

    Full Text Available We report on data from an oceanographic cruise in the Mediterranean Sea on the German research vessel POSEIDON in April 2014. Data were taken on a west–east section starting at the Strait of Gibraltar and ending south-east of Crete as well on sections in the Ionian and Adriatic Sea. The objectives of the cruise were twofold; long-term variations of the Levantine Intermediate Water (LIW and the deep water masses of the Eastern Mediterranean Sea were investigated. The measurements include salinity, temperature, oxygen and currents and were conducted with a CTD/rosette system, an underway CTD and an ADCP. The sections are on tracks which have been sampled during several other cruises, thus supporting the opportunity to investigate the long term temporal development of the different variables. The use of an underway CTD made it possible to conduct measurements of temperature and salinity with a high resolution of 6 nm and a vertical resolution of 1 dbar for the upper 800 m of the water column.

  6. Seasonal sea level extremes in the Mediterranean Sea and at the Atlantic European coasts

    Directory of Open Access Journals (Sweden)

    M. N. Tsimplis

    2010-07-01

    Full Text Available Hourly sea level data from tide gauges and a barotropic model are used to explore the spatial and temporal variability of sea level extremes in the Mediterranean Sea and the Atlantic coasts of the Iberian peninsula on seasonal time scales. Significant spatial variability is identified in the observations in all seasons. The Atlantic stations show larger extreme values than the Mediterranean Sea primarily due to the tidal signal. When the tidal signal is removed most stations have maximum values of less than 90 cm occurring in winter or autumn. The maxima in spring and summer are less than 60 cm in most stations. The wind and atmospheric forcing contributes about 50 cm in the winter and between 20–40 cm in the other seasons. In the western Mediterranean the observed extreme values are less than 50 cm, except near the Strait of Gibraltar. Direct atmospheric forcing contributes significantly to sea level extremes. Maximum sea level values due to atmospheric forcing reach in some stations 45 cm during the winter. During the summer the contribution of the direct atmospheric forcing is between 10–20 cm. The Adriatic Sea shows a resonant behaviour with maximum extreme observed sea level values around 200 cm found at the northern part. Trends in the 99.9% percentiles are present in several areas, however most of them are removed when the 50% percentile is subtracted indicating that changes in the extremes are in line with mean sea level change. The North Atlantic Oscillation and the Mediterranean Oscillation Index are well correlated with the changes in the 99.9% winter values in the Atlantic, western Mediterranean and the Adriatic stations. The correlation of the NAO and the MOI indices in the Atlantic and western Mediterranean is significant in the autumn too. The correlations between the NAO and MOI index and the changes in the sea level extremes become insignificant when the 50% percentile is removed indicating again that changes in extremes

  7. Excess of {sup 236}U in the northwest Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Chamizo, E., E-mail: echamizo@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía, Thomas Alva Edison 7, 41092 Seville (Spain); López-Lora, M., E-mail: mlopezlora@us.es [Centro Nacional de Aceleradores, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía, Thomas Alva Edison 7, 41092 Seville (Spain); Bressac, M., E-mail: matthieu.bressac@utas.edu.au [IAEA-Environment Laboratories, Monte Carlo 98000 (Monaco); Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS (Australia); Levy, I., E-mail: I.N.Levy@iaea.org [IAEA-Environment Laboratories, Monte Carlo 98000 (Monaco); Pham, M.K., E-mail: M.Pham@iaea.org [IAEA-Environment Laboratories, Monte Carlo 98000 (Monaco)

    2016-09-15

    In this work, we present first {sup 236}U results in the northwestern Mediterranean. {sup 236}U is studied in a seawater column sampled at DYFAMED (Dynamics of Atmospheric Fluxes in the Mediterranean Sea) station (Ligurian Sea, 43°25′N, 07°52′E). The obtained {sup 236}U/{sup 238}U atom ratios in the dissolved phase, ranging from about 2 × 10{sup −9} at 100 m depth to about 1.5 × 10{sup −9} at 2350 m depth, indicate that anthropogenic {sup 236}U dominates the whole seawater column. The corresponding deep-water column inventory (12.6 ng/m{sup 2} or 32.1 × 10{sup 12} atoms/m{sup 2}) exceeds by a factor of 2.5 the expected one for global fallout at similar latitudes (5 ng/m{sup 2} or 13 × 10{sup 12} atoms/m{sup 2}), evidencing the influence of local or regional {sup 236}U sources in the western Mediterranean basin. On the other hand, the input of {sup 236}U associated to Saharan dust outbreaks is evaluated. An additional {sup 236}U annual deposition of about 0.2 pg/m{sup 2} based on the study of atmospheric particles collected in Monaco during different Saharan dust intrusions is estimated. The obtained results in the corresponding suspended solids collected at DYFAMED station indicate that about 64% of that {sup 236}U stays in solution in seawater. Overall, this source accounts for about 0.1% of the {sup 236}U inventory excess observed at DYFAMED station. The influence of the so-called Chernobyl fallout and the radioactive effluents produced by the different nuclear installations allocated to the Mediterranean basin, might explain the inventory gap, however, further studies are necessary to come to a conclusion about its origin. - Highlights: • First {sup 236}U results in the northwest Mediterranean Sea are reported. • Anthropogenic {sup 236}U dominates the whole seawater column at DYFAMED station. • {sup 236}U deep-water column inventory exceeds by a factor of 2.5 the global fallout one. • Saharan dust intrusions are responsible for an annual

  8. Messinian Salinity Crisis - DREAM (Deep-sea Record of Mediterranean Messinian events) drilling projects

    Science.gov (United States)

    Lofi, Johanna; Camerlenghi, Angelo

    2014-05-01

    About 6 My ago the Mediterranean Sea was transformed into a giant saline basin. This event, commonly referred to as the Messinian salinity crisis (MSC), changed the chemistry of the global ocean and had a permanent impact on both the terrestrial and marine ecosystems of a huge area surrounding the Mediterranean area. The first fascinating MSC scenario was proposed following DSDP Leg XIII in 1970 and envisaged an almost desiccated deep Mediterranean basin with a dramatic ~1,500 m drop of sea level, the incision of deep canyons by rivers on the continental margins, and a final catastrophic flooding event when the connections between the Mediterranean Sea and the Atlantic were re-established ~5.33 My ago. In spite of 40 years of multi-disciplinary research conducted on the MSC, modalities, timing, causes, chronology and consequence at local and planetary scale are still not yet fully understood, and the MSC event remains one of the longest-living controversies in Earth Science. Key factor for the controversy is the lack of a complete record of the MSC preserved in the deepest Mediterranean basins. Anywhere else, the MSC mostly generated a sedimentary/time lag corresponding to a widespread erosion surface. Correlations with the offshore depositional units are thus complex, preventing the construction of a coherent scenario linking the outcropping MSC evaporites, the erosion on the margins, and the deposition of clastics and evaporites in the abyssal plains. Recent activity by various research groups in order to identify locations for multiple-site drilling (including riser-drilling) in the Mediterranean Sea that would contribute to solve the open questions still existing about the MSC has culminated in two DREAM Magellan+ Workshops held in 2013 and 2014. A strategy and work plan have been established in order to submit an IODP Multi-phase Drilling Project("Uncovering A Salt Giant")including several site-specific drilling proposals addressing different scientific

  9. The modern and Last Glacial Maximum hydrological cycles of the Eastern Mediterranean and the Levant from a water isotope perspective

    Science.gov (United States)

    Goldsmith, Y.; Polissar, P. J.; Ayalon, A.; Bar-Matthews, M.; deMenocal, P. B.; Broecker, W. S.

    2017-01-01

    The isotopic composition of precipitation (δP) is one of the most widely used and informative terrestrial paleoclimate proxies. δP integrates a series of hydrological processes; therefore, any interpretation of paleohydrology using δP requires a thorough understanding and quantification of the full hydrological cycle. In this paper, we use modern data to analytically model the full isotopic hydrological cycle of the Eastern Mediterranean and the Southern Levant, including oceanic evaporation, distillation during transport and precipitation over land. This model allows us to determine the important factors controlling this system. The model results underscore the significance of the isotopic distillation process driven by the land-sea temperature gradient as a significant factor controlling the long-term average isotopic composition of precipitation across Israel. Based on the understanding of the processes that govern the modern system, we model the isotopic composition of precipitation from the Last Glacial Maximum (LGM) using published data for speleothem oxygen isotopes in calcite, oxygen and hydrogen isotopes in fluid inclusions and clumped isotope values from Soreq Cave and the isotopic composition of East Mediterranean planktonic foraminifera G. ruber. The data and model results indicate two plausible scenarios for the LGM that entail changes in the magnitude of distillation over Israel, in normalized humidity over the Mediterranean and possible shifts of the moisture trajectories over the Mediterranean. The results presented in the paper illustrate the importance of understanding the full local hydrological cycle when reconstructing and interpreting the isotopic composition of precipitation.

  10. Environmental control on Emiliania huxleyi coccolithophore calcification in the Mediterranean Sea

    Science.gov (United States)

    D'Amario, Barbara; Grelaud, Michael; Ziveri, Patrizia

    2016-04-01

    The Mediterranean Sea, a "natural laboratory" characterized by strong environmental gradients, is likely to undergo serious alterations due to climate change and ocean acidification. These processes are expected to affect also phytoplankton distribution. Coccolithophores are the only phytoplankton calcifying group and laboratory studies on E. huxleyi, the most abundant and widely distributed species of coccolithophores worldwide, yield strain-specific results. Culture experiments must be integrated with observations in the natural environment to understand existing interactions between drivers, and to verify population structures in different areas. Two transects spanning the south-western and south-eastern basins have been investigated, combining data from April 2011 (Meteor cruise M84/3) and May 2013 (MedSeA cruise). E. huxleyi coccolith morphometry was analyzed to determine average mass and length. These results were then compared with morphological observations performed on the largely dominant E. huxleyi Type A through scanning electron microscope (SEM). We distinguished four main calcification morphologies within E. huxleyi Type A: low-calcified (A1), medium-calcified (A2), high-calcified with closed central area (A3a), and open central area (A3b). E. huxleyi coccolith mass was strongly and positively correlated with the relative abundance of a particular morphology. Moreover, the calcification morphologies were preferentially distributed in the Mediterranean according to specific combinations of environmental variables, which included the carbonate chemistry system. The distribution of E. huxleyi Type A calcification morphologies in the Mediterranean is likely to be influenced by climate changes. Coccolithophore calcification degree is connected to the carbon cycle through photosynthesis / calcification ratio and sedimentation (particulate inorganic and organic carbon reaching the seafloor). This study aims to provide a basis for future investigations on the

  11. Dinosaurs ''re-write'' the geodynamics of the eastern Mediterranean and the paleogeography of the Apulia Platform

    Science.gov (United States)

    Bosellini, A.

    2002-11-01

    Evidence of a sizeable population of large dinosaurs on the Apulia carbonate platform calls for a revision of the current paleotectonic and paleogeographic scenario of the eastern Mediterranean area. A review of geophysical and geological data of the Ionian Sea and surrounding areas leads to envisage the Late Jurassic-Early Cretaceous Ionian Sea region as a "cul-de-sac"-type basin enclosed by shallow-water carbonate banks, connecting the Apulia carbonate platform to Peloponnesus, northern Cyrenaica, Cyrene Seamount and Medina Ridge. These banks were repeatedly and periodically exposed to subaerial conditions, and offered vast land areas for migration of dinosaurs. As regards the nature of the Mesozoic Ionian basin, interpretations are quite controversial. The "continental" vs. "oceanic" crust debate will likely be solved only when the Ionian basin crust will be reached by drilling. The conclusion of the present review leads to consider Adria as a true African Promontory and the Apulia Platform as a sort of Florida Peninsula, attached to North Africa (Cyrenaica spur), subdividing the oceanic(?) "Mesozoic Mediterranean" into a western Ionian basin and an eastern Levantine basin.

  12. Wave Height Incidence on Mediterranean Short Sea Shipping Routes

    Directory of Open Access Journals (Sweden)

    F. X. Martínez de Osés

    2006-01-01

    Full Text Available According to the recent mid term review of the EU white paper on transport, Short Sea Shipping in EU waters is expected to grow from 2000 to 2020 at a rate of 59% in volume (metric tonnes. If we consider that the overall expected growth in freight exchanges is of 50% (also in volume, sea transport is one of the most feasible ways to reduce traffic congestion on European roads. High speed vessels are a possible way to compete with road transport in certain traffics; however these ships are highly affected by heavy weather. This paper is going to analyse the weather influence on several short sea shipping Mediterranean routes to be served by fast ships.

  13. Neutrino Telescopy in the Mediterranean Sea

    CERN Document Server

    Katz, U F

    2005-01-01

    The observation of high-energy extraterrestrial neutrinos is one of the most promising future options to increase our knowledge on non-thermal processes in the universe. Neutrinos are e.g. unavoidably produced in environments where high-energy hadrons collide; in particular this almost certainly must be true in the astrophysical accelerators of cosmic rays, which thus could be identified unambiguously by sky observations in "neutrino light". On the one hand, neutrinos are ideal messengers for astrophysical observations since they are not deflected by electromagnetic fields and interact so weakly that they are able to escape even from very dense production regions and traverse large distances in the universe without attenuation. On the other hand, their weak interaction poses a significant problem for detecting neutrinos. Huge target masses up to gigatons must be employed, requiring to instrument natural abundances of media such as sea water or antarctic ice. The first generation of such neutrino telescopes is...

  14. Active tectonics of the Eastern Mediterranean region: deduced from GPS, neotectonic and seismicity data

    Directory of Open Access Journals (Sweden)

    R. Reilinger

    1997-06-01

    Full Text Available This paper reviews the main tectonic features of the Eastern Mediterranean region combining the recent information obtained from GPS measurements, seismicity and neotectonic studies. GPS measurements reveal that the Arabian plate moves northward with respect to Eurasia at a rate of 23 ± 1 mm/yr, 10 mm/yr of this rate is taken up by shortening in the Caucasus. The internal deformation in Eastern Anatolia by conjugate strike-slip faulting and E-W trending thrusts, including the Bitlis frontal thrust, accommodates approximately a 15 mm/yr slip rate. The Northeast Anatolian fault, which extends from the Erzincan basin to Caucasus accommodates about 8 ± 5 mm/yr of left-lateral motion. The neotectonic fault pattern in Eastern Anatolia suggests that the NE Anatolian block moves in an E-ENE direction towards the South Caspian Sea. According to the same data, the Anatolian-Aegean block is undergoing a counter-clockwise rotation. However, from the residuals it appears that this solution can only be taken as a preliminary approximation. The Eulerian rotation pole indicates that slip rate along the North Anatolian fault is about 26 ± 3 mm/yr. This value is 10 mm/yr higher than slip rates obtained from geological data and historical earthquake records and it includes westward drift of the Pontides of a few millimetres/year or more. GPS measurements reveal that the East Anatolian fault accommodates an 11 ± 1 mm/yr relative motion. GPS data suggest that Central Anatolia behaves as a rigid block, but from neotectonic studies, it clearly appears that it is sliced by a number of conjugate strike-slip faults. The Isparta Angle area might be considered a major obstacle for the westward motion of the Anatolian block (Central and Eastern Anatolia. The western flank of this geological structure, the Fethiye-Burdur fault zone appears to be a major boundary with a slip rate of 15-20 mm/yr. The Western Anatolian grabens take up a total of 15 mm/yr NE-SW extension

  15. Floating plastic debris in the Central and Western Mediterranean Sea.

    Science.gov (United States)

    Ruiz-Orejón, Luis F; Sardá, Rafael; Ramis-Pujol, Juan

    2016-09-01

    In two sea voyages throughout the Mediterranean (2011 and 2013) that repeated the historical travels of Archduke Ludwig Salvator of Austria (1847-1915), 71 samples of floating plastic debris were obtained with a Manta trawl. Floating plastic was observed in all the sampled sites, with an average weight concentration of 579.3 g dw km(-2) (maximum value of 9298.2 g dw km(-2)) and an average particle concentration of 147,500 items km(-2) (the maximum concentration was 1,164,403 items km(-2)). The plastic size distribution showed microplastics (<5 mm) in all the samples. The most abundant particles had a surface area of approximately 1 mm(2) (the mesh size was 333 μm). The general estimate obtained was a total value of 1455 tons dw of floating plastic in the entire Mediterranean region, with various potential spatial accumulation areas.

  16. Automated inter-station phase velocity measurements across the eastern Mediterranean and Middle East

    Science.gov (United States)

    El-Sharkawy, Amr; Weidle, Christian; Christiano, Luigia; Soomro, Riaz; Lebedev, Sergi; Meier, Thomas

    2016-04-01

    The structure of the lithosphere in northeastern Africa, eastern Mediterranean and the Middle East is highly variable. It ranges from young oceanic lithosphere in the Red Sea to what is considered the oldest oceanic lithosphere on Earth in the Mediterranean Sea north of Libya, and from highly deformed continental lithosphere at the east-Mediterranean margins to more stable continental lithosphere of Phanerozoic origin and to cratonic lithosphere beneath the Arabian Peninsula. Details of the lithospheric structure are, however, poorly known. Surface waves are ideally suited for studies of the lithosphere and the sublithospheric mantle. Our goal is to better define the 3D lithospheric shear-wave velocity structure within this region by surface wave tomography. Using regional to teleseismic Rayleigh and Love waves that traverse the area we can obtain information about its seismic structure by examining phase velocities as a function of frequency. A newly developed algorithm for automated inter-station phase velocity measurements (Soomro et al. 2016) is applied here to obtain both Rayleigh and Love fundamental mode phase velocities. We utilize a database consisting of more than 3800 regional and teleseismic earthquakes recorded by more than 1850 broadband seismic stations within the area, provided by the European Integrated Data Archive (WebDc/EIDA) and IRIS. Moreover, for the first time, data from the Egyptian National Seismological Network (ENSN), recorded by up to 25 broad band seismic stations, is also included in the analysis. For each station pair approximately located on the same great circle path, the recorded waveforms are cross correlated and the dispersion curves of fundamental modes are calculated from the phase of the weighted cross correlation functions. Path average dispersion curves are obtained by averaging the smooth parts of single-event dispersion curves. Parameters tests and preliminary results of automatically measured phase velocities are

  17. Deep silicon maxima in the stratified oligotrophic Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Y. Crombet

    2011-02-01

    Full Text Available The silicon biogeochemical cycle has been studied in the Mediterranean Sea during late summer/early autumn 1999 and summer 2008. The distribution of nutrients, particulate carbon and silicon, fucoxanthin (Fuco, and total chlorophyll-a (TChl-a were investigated along an eastward gradient of oligotrophy during two cruises (PROSOPE and BOUM encompassing the entire Mediterranean Sea during the stratified period. At both seasons, surface waters were depleted in nutrients and the nutriclines gradually deepened towards the East, the phosphacline being the deepest in the easternmost Levantine basin. Following the nutriclines, parallel deep maxima of biogenic silica (DSM, fucoxanthin (DFM and TChl-a (DCM were evidenced during both seasons with maximal concentrations of 0.45 μmol L−1 for BSi, 0.26 μg L−1 for Fuco, and 1.70 μg L−1 for TChl-a, all measured during summer. Contrary to the DCM which was a persistent feature in the Mediterranean Sea, the DSM and DFMs were observed in discrete areas of the Alboran Sea, the Algero-Provencal basin, the Ionian sea and the Levantine basin, indicating that diatoms were able to grow at depth and dominate the DCM under specific conditions. Diatom assemblages were dominated by Chaetoceros spp., Leptocylindrus spp., Pseudonitzschia spp. and the association between large centric diatoms (Hemiaulus hauckii and Rhizosolenia styliformis and the cyanobacterium Richelia intracellularis was observed at nearly all sites. The diatom's ability to grow at depth is commonly observed in other oligotrophic regions and could play a major role in ecosystem productivity and carbon export to depth. Contrary to the common view that Si and siliceous phytoplankton are not major components of the Mediterranean biogeochemistry, we suggest here that diatoms, by persisting at depth during the stratified period, could contribute to a

  18. Excess of (236)U in the northwest Mediterranean Sea.

    Science.gov (United States)

    Chamizo, E; López-Lora, M; Bressac, M; Levy, I; Pham, M K

    2016-09-15

    In this work, we present first (236)U results in the northwestern Mediterranean. (236)U is studied in a seawater column sampled at DYFAMED (Dynamics of Atmospheric Fluxes in the Mediterranean Sea) station (Ligurian Sea, 43°25'N, 07°52'E). The obtained (236)U/(238)U atom ratios in the dissolved phase, ranging from about 2×10(-9) at 100m depth to about 1.5×10(-9) at 2350m depth, indicate that anthropogenic (236)U dominates the whole seawater column. The corresponding deep-water column inventory (12.6ng/m(2) or 32.1×10(12) atoms/m(2)) exceeds by a factor of 2.5 the expected one for global fallout at similar latitudes (5ng/m(2) or 13×10(12) atoms/m(2)), evidencing the influence of local or regional (236)U sources in the western Mediterranean basin. On the other hand, the input of (236)U associated to Saharan dust outbreaks is evaluated. An additional (236)U annual deposition of about 0.2pg/m(2) based on the study of atmospheric particles collected in Monaco during different Saharan dust intrusions is estimated. The obtained results in the corresponding suspended solids collected at DYFAMED station indicate that about 64% of that (236)U stays in solution in seawater. Overall, this source accounts for about 0.1% of the (236)U inventory excess observed at DYFAMED station. The influence of the so-called Chernobyl fallout and the radioactive effluents produced by the different nuclear installations allocated to the Mediterranean basin, might explain the inventory gap, however, further studies are necessary to come to a conclusion about its origin.

  19. An evaluation of surface micro- and mesoplastic pollution in pelagic ecosystems of the Western Mediterranean Sea.

    Science.gov (United States)

    Faure, Florian; Saini, Camille; Potter, Gaël; Galgani, François; de Alencastro, Luiz Felippe; Hagmann, Pascal

    2015-08-01

    This study examines the distribution, abundance and characteristics of surface micro- and mesoplastic debris in the Western Mediterranean Sea. 41 samples were collected in 2011 (summer) and 2012 (summer). Results, firstly, revealed that micro- (Sea.

  20. Breaking biogeographic barriers: Molecular and morphological evidences for the Lessepsian invasion of soritid foraminifers to the Mediterranean Sea

    Science.gov (United States)

    Merkado, G.; Abramovich, S.; Abdu, U.; Almogi-Labin, A.; Pawlowski, J.; Holzmann, M.

    2012-04-01

    In recent years we have been witnessing a large-scale invasion (tropicalization) into the Eastern Mediterranean of many alien tropical species. The main factors that promote this process includes: 1. The ongoing warming of sea surface temperatures in the last decades. 2. The opening of the Suez Canal in 1869 that created an artificial connection between the Mediterranean and the Indo-Pacific realm of the Red Sea. This connection resulted in an ongoing unidirectional migration (termed the Lessepsian migration) of hundreds of species from Red Sea to the Mediterranean Sea. 3. The closure of the Nile River by the High Aswan Dam that blocked its nutrient discharge and created hyper-oligotrophic conditions in the Eastern Mediterranean. Larger symbiont-bearing benthic foraminifera were chosen in this study as an ideal target group for documenting this process. Their main advantage is that some of these species are clearly Indo-Pacific migrants while others represent re-encountering of allopatric populations that were isolated for at least 5.5 m.y. The first stage of this study involved the genetic characterization of soritids. Living specimens of Sorites and Amphisorus morphospecies were collected from the Red Sea and the Mediterranean and their ribosomal DNA (rDNA) sequences were determined in order to see the genetic relation between these two "recently connected" locations. The morphological characteristics of each specimen were documented by Scanning Electron Microscope micrographs and digital imaging. In the Red Sea, the specimens were collected from two shallow stations (5-6 m water depth) in the Gulf of Elat, representing different habitats: 1. Tur-Yam, characterizes by abundant Halophila sea grass. 2. The Inter University Institution in Elat, characterizes by pebbles with no sea grass. In the Mediterranean, specimens were collected along the shore of Northern Israel at Shikmona, Haifa, one of the few locations along the Israeli Mediterranean coast where living

  1. Primary health care in the Eastern Mediterranean Region: from Alma-Ata to Doha.

    Science.gov (United States)

    Shawky, S

    2012-12-04

    The celebration in Doha of the 30th anniversary of the Alma-Ata Declaration at the International Conference on Primary Health Care renewed the commitment of the Eastern Mediterranean Region to primary health care as the tool for better health. The principles agreed at Alma-Ata in 1978 apply as much now as they did before. The event provided an opportunity for the Eastern Mediterranean countries to define future directions to steer the health systems to integrate primary health care and harness the intersectoral approach.

  2. Eastern Equatorial Pacific Sea Level Pressure (1949-present)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is one of the CPC?s Monthly Atmospheric and SST Indices. It contains standardized sea level pressure anomalies over the equatorial eastern Pacific region...

  3. Is the distribution of Prochlorococcus and Synechococcus ecotypes in the Mediterranean Sea affected by global warming?

    Directory of Open Access Journals (Sweden)

    M. Ostrowski

    2011-05-01

    Full Text Available Biological communities populating the Mediterranean Sea, which is situated at the northern boundary of the subtropics, are often claimed to be particularly affected by global warming. This is indicated, for instance, by the introduction of (subtropical species of fish or invertebrates that can displace local species. This raises the question of whether microbial communities are similarly affected, especially in the Levantine basin where sea surface temperatures have risen in recent years. In this paper, the genetic diversity of the two most abundant members of the phytoplankton community, the picocyanobacteria Prochlorococcus and Synechococcus, was examined on a transect from the South coast of France to Cyprus in the summer of 2008 (BOUM cruise. Diversity was studied using dot blot hybridization with clade-specific 16S rRNA oligonucleotide probes and clone libraries of the 16S–23S ribosomal DNA Internal Transcribed Spacer (ITS region. Data were compared with those obtained during the PROSOPE cruise held almost a decade earlier, with a focus on the abundance of clades that may constitute bioindicators of warm waters. During both cruises, the dominant Prochlorococcus clade in the upper mixed layer at all stations was HLI, a clade typical of temperate waters, whereas the HLII clade, the dominant group in (subtropical waters, was only present at very low concentrations. The Synechococcus community was dominated by clades I, III and IV in the northwestern waters of the Gulf of Lions and by clade III and groups genetically related to clades WPC1 and VI in the rest of the Mediterranean Sea. In contrast, only a few sequences of clade II, a group typical of warm waters, were observed. These data indicate that local cyanobacterial populations have not yet been displaced by their (subtropical counterparts. This is discussed in the context of the low phosphorus concentrations found in surface waters in the eastern Mediterranean basin, as this may

  4. Occurrence of organochlorine contaminants (PCBs, PCDDs and PCDFs) and pathologic findings in loggerhead sea turtles, Caretta caretta, from the Adriatic Sea (Mediterranean Sea).

    Science.gov (United States)

    Storelli, Maria M; Zizzo, Nicola

    2014-02-15

    Livers of 12 loggerhead sea turtles, Caretta caretta from the Eastern Mediterranean Sea (Adriatic Sea) were analyzed for the presence of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Pathological and microbiological studies were also carried out in order to provide a contribution to the knowledge of causes of Mediterranean turtle death. Boat-strike injuries, entanglement in derelict fishing nets and ingestion of hooks and monofilament lines are the causes of death most frequently observed. PCBs (average: 1,399 ng g(-1) fat basis) were the dominant chemicals, followed by PCDFs (average: 61 pg g(-1) fat basic) and PCDDs (average: 16 pg g(-1) fat basis). Hexachlorobiphenyl 153 accounted for the greatest proportion of the total PCBs, followed in order by PCB 138 and PCB 180 (14.1%). Mid-chlorinated, penta-through hepta-PCBs were among the top contributors to the sum of total PCBs, while the homolog pattern of PCCD/Fs was dominated by the tetra- to hexa-substituted congeners. In general the contamination level observed here was comparable with that reported in literature for specimens from different marine areas. Average TEQPCDD/Fs+Dl-PCBs concentration was 27.02 pg g(-1) wet weight (305.1 pg g(-1) lipid weight), with dioxin like-PCBs (93.4%) contributing much more to the total than PCDFs (3.9%) and PCDDs (2.7%). The appreciable concentration of TEQ would at first suggest that there are signs of potential threats to the health of these marine reptiles. Apart from PCBs, this is the first study documenting concentrations of PCDD/Fs in marine turtles from the Mediterranean Sea. Further investigations are urgently needed to characterize their contamination level for a better future protection and conservation of this endangered animal.

  5. Metabarcoding analysis of European hake diet in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Giulia Riccioni

    2015-10-01

    Full Text Available European hake (EH, Merluccius merluccius, is a demersal fish distributed from the North Sea and Atlantic to the Levantine Sea in the Mediterranean. EH is an important predator of deep Mediterranean upper shelf slope communities and it is currently characterised by growth overexploitation. EH adults feed mainly on fish and squids whereas the young (<16 cm feed on crustaceans. All current EH diet studies relied on the morphological identification of prey remains in stomach content, however this method is labour intensive and it precludes the identification of strongly digested food. The development of High-Throughput Sequencing (HTS approaches provide more accurate methods for dietary studies revealing many consumed species simultaneously (DNA metabarcoding. The aim of this study is to use a HTS approach based on COI amplification, contextually to classic microscopic morphological identification, to analyse EH stomach content and to evaluate the efficiency of the molecular method. HTS sequencing has been carried out on the amplicons obtained by PCR amplification (Leray et al. 2013 of stomach remains and all the Miseq Illumina paired-end reads have been analysed by using bioinformatic tools (Boyer et al. 2015 for taxonomic assignment. The selected sequences clustered in OCTUs (Operational Clustered Taxonomic Units and taxonomically assigned, will be used in diversity analyses to compute distance matrices among samples, to compare taxa summaries from different samples, to create networks and perform PCA and PcoA analysis. Classic microscopic morphological analyses on stomach content remains have been carried out contextually to compare the results of the two methods. The molecular approach has proven a promising method to study marine fish dietary habits. All the data will be summarized to reconstruct EH trophic dynamics in the Mediterranean Sea.

  6. Fine-resolution simulation of surface current and sea ice in the Arctic Mediterranean Seas

    Institute of Scientific and Technical Information of China (English)

    LIU Xiying; ZHANG Xuehong; YU Rucong; LIU Hailong; LI Wei

    2007-01-01

    A fine-resolution model is developed for ocean circulation simulation in the National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG),Chinese Academy of Sciences, and is applied to simulate surface current and sea ice variations in the Arctic Mediterranean Seas. A dynamic sea ice model in elastic-viscous-plastic rheology and a thermodynamic sea ice model are employed. A 200-year simulation is performed and a dimatological average of a 10-year period (141 st-150 th) is presented with focus on sea ice concentration and surface current variations in the Arctic Mediterranean Seas. The model is able to simulate well the East Greenland Current, Beaufort Gyre and the Transpolar Drift, but the simulated West Spitsbergen Current is small and weak. In the March climatology, the sea ice coverage can be simulated well except for a bit more ice in east of Spitsbergen Island. The result is also good for the September scenario except for less ice concentration east of Greenland and greater ice concentration near the ice margin. The extra ice east of Spitsbergen Island is caused by sea ice current convergence forced by atmospheric wind stress.

  7. Mediterranean and Atlantic deep-sea fish assemblages: differences in biomass composition and size-related structure

    Directory of Open Access Journals (Sweden)

    Enric Massutí

    2004-12-01

    Full Text Available Data obtained over a period of twenty years from 214 bottom trawls, towed on a single warp at depths between 402 and 1993 m in the western Mediterranean (Algerian and Balearic basins and eastern North Atlantic (Rockall Trough and Porcupine Seabight, allowed a standardised comparison of density, biomass composition and size-related structure for both the whole fish fauna and for the most common species found within the deep-sea fish assemblages. All four areas are characterised by distinctly different and well-documented oceanographic conditions, biogeographical affinities and fishing exploitation. The results showed clear differences between the Atlantic and the Mediterranean deep-sea fish fauna, not only in density, species richness and composition, but also in the structure of the biomass that constitutes these assemblages. These differences are discussed in relation to environmental conditions and fishing pattern, which have determined the adaptive responses of both individual species and the whole ecosystem.

  8. Potential Use of HF Radar for Tsunami Detection in the Central and Eastern Mediterranean

    Science.gov (United States)

    Cokacar, Tulay; Necmioglu, Ocal; Ozer, Ceren

    2016-04-01

    Today, HF radar is recognized as internationally cost-effective and efficient solution to provide near-real time measurements that cover a large area continuously over time for ocean hazards warning and long term ocean monitoring studies such as, seasonal forecasts of climate, hurricanes, s torm surges and large-scale ocean circulation changes. These radar systems recently became an operational tool in coastal monitoring worldwide. They are used for many operational applications that include ship detection, tracking, guidance, distribution of pollutants, fishery and oceanography. HF radar data used for the tsunami warnings, can also be used for the other purposes and be of potential interest to wide application area users and stakeholders. Moreover multi user applications will ensure the system is maintained operationally over the long term. Hence the system is cost effective also with regards to maintenance. New algorithms allow useful detection and verification for tsunami detection. While technical monitoring capacity and the algorithms for tsunami detection is improved significantly, further studies are required to obtain complete wave height determination. We analysed the available technology and algorithms for the purpose of tsunami detection in the central-eastern Mediterranean and its connected Seas (Aegean and Black Sea). Since the study area is characterized by narrow continental shelf area, the HF radar observation for the purpose of tsunami detection is possible in restricted areas. While extensive continental shelves in the northeastern Black Sea and along the coast of Tunisia in the central Mediterranean let tsunami detection 2.5 hours before tsunami waves hit the coast, the detection is possible around 1 hr or less in advance for the remaining basins with wide continental shelf areas. The bathymetric structure is important for deciding the applicability of HF radar systems for the tsunami detection in continental shelf areas, which can be covered by

  9. Recent sea surface temperature trends and future scenarios for the Mediterranean Sea:

    OpenAIRE

    2014-01-01

    We analyse recent Mediterranean Sea surface temperatures (SSTs) and their response to global change using 1/4-degree gridded advanced very-high-resolution radiometer (AVHRR) daily SST data, 1982-2012. These data indicate significant annual warming (from 0.24°C decade-1 west of the Strait of Gibraltar to 0.51°C decade-1 over the Black Sea) and significant spatial variation in annual average SST (from 15ºC over the Black Sea to 21°C over the Levantine sub-basin). Ensemble mean scenarios indicat...

  10. Bryozoan diversity in the Mediterranean Sea: an update

    Directory of Open Access Journals (Sweden)

    A. ROSSO

    2016-07-01

    Full Text Available This paper provides a current view of the bryozoan biodiversity of the Mediterranean Sea updating the checklist by Rosso (2003. Bryozoans presently living in the Mediterranean increase to 556 species, 212 genera and 93 families. Cheilostomes largely prevail (424 species, 159 genera and 64 families followed by cyclostomes (75 species, 26 genera and 11 families and ctenostomes (57 species, 27 genera and 18 families. Few families and genera make the bulk of this biodiversity whereas one third of families are monospecific. The number of species-rank taxa has increased by 81 in the last dozen years but most of these additions relate to the revision of material from old collections and to the introduction of non-indigenous species. Most of the bryozoan diversity is distributed in the coralligenous and dark and semi-dark cave biocoenoses followed by detritic bottoms. Diversity lowers in shallow-water vegetated bottoms and in bathyal habitats. Further increase in diversity is expected from investigation of still poorly known areas and habitats and the need for rapid assessment is remarked on in view of the management of Mediterranean habitats through the EU Marine Strategy Directive.

  11. Food web structure and vulnerability of a deep-sea ecosystem in the NW Mediterranean Sea

    Science.gov (United States)

    Tecchio, Samuele; Coll, Marta; Christensen, Villy; Company, Joan B.; Ramírez-Llodra, Eva; Sardà, Francisco

    2013-05-01

    There is increasing fishing pressure on the continental margins of the oceans, and this raises concerns about the vulnerability of the ecosystems thriving there. The current knowledge of the biology of deep-water fish species identifies potential reduced resilience to anthropogenic disturbance. However, there are extreme difficulties in sampling the deep sea, resulting in poorly resolved and indirectly obtained food-web relationships. Here, we modelled the flows and biomasses of a Mediterranean deep-sea ecosystem, the Catalan Sea continental slope at depths of 1000-1400 m. This is the first model of a deep-water ecosystem in the Mediterranean Sea. The objectives were to (a) quantitatively describe the food web structure of the ecosystem, (b) examine the role of key species in the ecosystem, and (c) explore the vulnerability of this deep-sea ecosystem to potential future fishing exploitation. We used the Ecopath with Ecosim (EwE) modelling approach and software to model the ecosystem. The trophic model included 18 consumers, a marine snow group, and a sediment detritus group. Trophic network analysis identified low levels of consumer biomass cycling and low system omnivory index when compared with expected values of marine ecosystems, and higher cycling and omnivory when compared with available EwE models of shallower areas of the Mediterranean Sea. The majority of flows in the ecosystem were concentrated at the trophic level of first-order consumers (TL 2). Benthic invertebrates and demersal sharks were identified to have key ecological roles in the ecosystem. We used the dynamic temporal model Ecosim to simulate expansion of the red-shrimp benthic trawl fishery that currently operates at shallower depths, down to 800 m depth. The simulations showed reductions in fish biomass and that the state of the deep continental slope ecosystem in the western Mediterranean seems to be the result of a long-term succession process, which has reached ecological stability, and is

  12. Megaturbidite triggered by the ad 365 Cretan earthquake in the Mediterranean Sea

    Science.gov (United States)

    Polonia, Alina; Bonatti, Enrico; Camerlenghi, Angelo; Gasperini, Luca; Lucchi, Renata; Panieri, Giuliana

    2013-04-01

    Ionian Sea about 15.000 years B.P., implying a large recurrence time of such extreme sedimentary events in the Mediterranean Sea. References: Kastens, K. A., and M. B. Cita (1981), Tsunami induced sediment transport in the abyssal Mediterranean Sea, Geol. Soc. Am. Bull., 89, 591-604. Hieke, W. (1984), A thick holocene homogenite from the Ionian abyssal plain (Eastern Mediterranean), Mar. Geol., 55, 63-78. Pareschi, M. T., E. Boschi, and M. Favalli (2006b), Lost tsunami, Geophys. Res. Lett., 33. Polonia, A., G. Panieri, L. Gasperini, G. Gasparotto, L. G. Bellucci, and L. Torelli. Turbidite paleoseismology in the Calabrian Arc Subduction Complex (Ionian Sea). Geochem. Geophys. Geosyst., doi:10.1029/2012GC004402, in press. Vigliotti, L. (2008), Comment on ''Lost tsunami'' by Maria Teresa Pareschi et al., Geophys. Res. Lett., 35.

  13. Acidification of the Mediterranean Sea during the 21st century

    Science.gov (United States)

    Le Vu, Briac; Palmieri, Julien; Orr, James C.; Dutay, Jean Claude; Sevault, Florence

    2014-05-01

    We modeled the carbon cycle in the Mediterranean Sea to study how its changes due to climate change and rising levels of atmospheric CO2 may differ from those typical of the global ocean. More specifically, we coupled offline an ocean biogeochemical model (PISCES) to a regional eddy-permitting model of the Mediterranean Sea (NEMO-MED8, 1/8° nominal horizonal resolution) using forcing from coupled regional climate model simulations of which the ocean circulation component was identical. Here we describe the simulated changes in pH and the associated carbonate system during the 21st century. Separate simulations were made with climate forcing for a hindcast (1965-2008) and for the future (2000-2100). For the former, climate and CO2 forcings were based on observations; for the latter, both climate and CO2 were driven by the IPCC SRES-A2 scenario. Our hindcast simulation over the period 1965-2008 allowed us to evaluate the model and assess recent variability of the carbonate system. In our future simulation, we used separate tracers to distinguish (1) the change due to climate change and the increase in atmospheric CO2 (from 370 to 800 ppm) and (2) the change due only to climate change (holding atmospheric CO2 to the year-2000 level of 370 ppm). By difference, we isolated the geochemical effect (anthropogenic CO2 perturbation). The hindcast simulation demonstrates that the model captures the amplitude and phase of the annual cycle of temperature, pCO2 and pH, in agreement with data from the DYFAMED station. That seasonal variability of surface pCO2 is everywhere driven by variations in temperature. These results lends support that the model is able to quantify the acidification of the Mediterranean Sea during the industrial period and for the future. However, they do not constrain the model's simulated effects of future climate change on ocean circulation and ocean biology, both of which in turn influence the carbon cycle. Similar to estimates for the global ocean

  14. Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19 by multiple Soviet Union institutes (NODC Accession 0077413)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19...

  15. Interannual variability of chlrophyll concentration in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karanje, S.

    The monthly mean chlorophyll pigment concentrations and diffuse attenuation were derived for the eastern Arabian Sea [5-16oN; 70-80oE] from SeaWiFS global 9-km resolution data product for the period January 1998 to December 2007. These data were...

  16. Sampling of an STT event over the Eastern Mediterranean region by lidar and electrochemical sonde

    Directory of Open Access Journals (Sweden)

    A. Papayannis

    2005-09-01

    Full Text Available A two-wavelength ultraviolet (289–316nm ozone Differential Absorption Lidar (DIAL system is used to perform ozone measurements in the free troposphere in the Eastern Mediterranean (Northern Greece. The ozone DIAL profiles obtained during a Stratosphere-to-Troposphere Transport (STT event are compared to that acquired by an electrochemical ozonesonde, in the altitude range between 2 and 10 km. The measurement accuracy of these two instruments is also discussed. The mean difference between the ozone profiles obtained by the two techniques is of the order of 1.11 ppbv (1.86%, while the corresponding standard deviation is 4.69 ppbv (8.16%. A case study of an STT event which occurred on 29 November 2000 is presented and analyzed, using ozone lidar, satellite and meteorological data, as well as air mass back-trajectory analysis. During this STT event ozone mixing ratios of 55–65 ppbv were observed between 5 and 7 km height above sea level (a.s.l.. Stratospheric air was mixed with tropospheric air masses, leading to potential vorticity (PV losses due to diabatic processes. The ozone DIAL system can be used for following STT events and small-scale mixing phenomena in the free troposphere, and for providing sequences of vertical ozone profiles in the free troposphere.

    Keywords. Atmospheric composition and structure (Evolution of the atmosphere; Instruments and techniques – Meteorology and atmospheric dynamics (Middle atmosphere dynamics; Turbulence

  17. Temporal variations and sources of Eastern Mediterranean aerosols based on a 9-year observation

    Science.gov (United States)

    Öztürk, F.; Zararsız, A.; Dutkiewicz, V. A.; Husain, L.; Hopke, P. K.; Tuncel, G.

    2012-12-01

    Concentrations of 48 elements, NO3-, SO42-, Cl-, NH4+, and black carbon (BC) were determined in PM10 aerosols collected daily at a rural Eastern Mediterranean (EM) site (Antalya, 30.34°E, 36.47°N) from 1993 to 2001. Temporal variations (daily, seasonal and long term), sources and source regions of EM aerosols were delineated. Concentrations of elements with marine and crustal origin were more episodic as compared to anthropogenic ones. Most of the variables showed well defined seasonal cycles. Concentrations of crustal elements increased in summer while winter concentrations of marine elements were considerably higher than in summer. Trends in concentrations were analyzed using the Kendall test. Essentially, all elements showed decreasing trends. Sen's slope was applied to find the magnitude of the trends. The annual rate of decrease was found to change from 0.001 to 209 ng m-3. A receptor-based model, Positive Matrix Factorization (PMF), resolved five factors influencing the chemical composition of EM aerosols as airborne dust, oil combustion, coal combustion, motor vehicle emissions and sea salt. Potential Source Contribution Function (PSCF) analysis was performed to identify the likely areas influencing the chemical composition of aerosol samples. Local and remote sources were detected for the factors resolved by PMF. PSCF maps including backward trajectories at starting height of 900 hPa have indicated that North Africa is the major source contributing to the concentrations of variables associated with dust factor.

  18. The popular resort port of cruise tourism in the Eastern Mediterranean Basin: Turkey

    Directory of Open Access Journals (Sweden)

    Okan Yaşar

    2012-02-01

    Full Text Available Cruise tourism is in most demand in Europe and North America. The Eastern Mediterranean, and consequently Turkey rank among the destinations that cruise ship tour companies prefer to travel. Part of the demand for cruise tourism, which has been displaying a constantly raising momentum in tourism movements in the world, is now being directed towards Turkey. Nonetheless, the cruise tourism trend is spreading and prompting domestic demand in Turkey as well. A significant boom in the domestic demand has led to the commencement of cruise tours to the Black Sea, the Greek Islands, the Dalmatian shores and Italy leaving from Istanbul, Izmir and Kusadasi harbors. Turkey’s active foreign demand for cruise tourism mostly focuses on ports and its surrounding supply of services. Cruise tourism is now one of the predominant agendas within policies for diversifying and spreading tourism. Within one year Turkey managed to be ranked among the first ten countries in regard to the number of tourists and tourism revenues in the world.

  19. The popular resort port of cruise tourism in the Eastern Mediterranean Basin: Turkey

    Directory of Open Access Journals (Sweden)

    Okan Yasar

    2012-02-01

    Full Text Available Cruise tourism is in most demand in Europe and North America. The Eastern Mediterranean, and consequently Turkey rank among the destinations that cruise ship tour companies prefer to travel. Part of the demand for cruise tourism, which has been displaying a constantly raising momentum in tourism movements in the world, is now being directed towards Turkey. Nonetheless, the cruise tourism trend is spreading and prompting domestic demand in Turkey as well. A significant boom in the domestic demand has led to the commencement of cruise tours to the Black Sea, the Greek Islands, the Dalmatian shores and Italy leaving from Istanbul, Izmir and Kusadasi harbors. Turkey’s active foreign demand for cruise tourism mostly focuses on ports and its surrounding supply of services. Cruise tourism is now one of the predominant agendas within policies for diversifying and spreading tourism. Within one year Turkey managed to be ranked among the first ten countries in regard to the number of tourists and tourism revenues in the world.       

  20. Is coccolithophore distribution in the Mediterranean Sea related to seawater carbonate chemistry?

    Science.gov (United States)

    Oviedo, A.; Ziveri, P.; Álvarez, M.; Tanhua, T.

    2015-01-01

    The Mediterranean Sea is considered a "hot spot" for climate change, being characterized by oligotrophic to ultra-oligotrophic waters and rapidly increasing seasurface temperature and changing carbonate chemistry. Coccolithophores are considered a dominant phytoplankton group in these waters. As marine calcifying organisms they are expected to respond to the ongoing changes in seawater carbonate chemistry. We provide here a description of the springtime coccolithophore distribution in the Mediterranean Sea and relate this to a broad set of in situ-measured environmental variables. Samples were taken during the R/V Meteor (M84/3) oceanographic cruise in April 2011, between 0 and 100 m water depth from 28 stations. Total diatom and silicoflagellate cell concentrations are also presented. Our results highlight the importance of seawater carbonate chemistry, especially [CO32-] but also [PO43-] in unraveling the distribution of heterococcolithophores, the most abundant coccolithophore life phase. Holo- and heterococcolithophores respond differently to environmental factors. For instance, changes in heterococcolithophore assemblages were best linked to the combination of [CO32-], pH, and salinity (ρ = 0.57), although salinity might be not functionally related to coccolithophore assemblage distribution. Holococcolithophores, on the other hand, showed higher abundances and species diversity in oligotrophic areas (best fit, ρ = 0.32 for nutrients), thriving in nutrient-depleted waters. Clustering of heterococcolithophores revealed three groups of species sharing more than 65% similarities. These clusters could be assigned to the eastern and western basins and deeper layers (below 50 m), respectively. In addition, the species Gephyrocapsa oceanica, G. muellerae, and Emiliania huxleyi morphotype B/C are spatially distributed together and trace the influx of Atlantic waters into the Mediterranean Sea. The results of the present work emphasize the importance of considering

  1. Dynamic processes associated with the eastern Mediterranean 'bomb' of 2004

    Science.gov (United States)

    Karacostas, T. S.; Brikas, D.; Pytharoulis, I.

    2010-09-01

    The meteorological "bomb" of the 21st and 22nd of January 2004, that affected the eastern Aegean Sea with very strong winds reaching 80 kts, excessive rain and even snow, with accumulations of at least one (1) meter on Limnos island and mean sea-level pressure at the record level of 972 hPa on Ikaria island, is studied from the synoptic and mostly dynamic concept. Lagouvardos and co-authors have already proved that the upper tropospheric PV anomaly was a necessary ingredient of the explosive cyclogenesis and the latter was attributed to the merger of troughs coming from North Africa and Europe. The present study is mainly concerned with the dynamic processes that led to the explosive cyclogenesis of 21 - 22 January 2004. Relying upon the use of the original ECMWF data information, a serious attempt is made to investigate, verify and justify the space and time of the "bomb explosion", the accompanied characteristics and the reasons causing the cyclolysis. Upper and lower tropospheric level forcing mechanisms are identified and monitored and a quantitative dynamical picture is provided for the explosively (pre) cyclogenetic period. The explosive cyclogenesis begins in Gabes Sea, just off the Libyan coast, the low forming on a frontogenetically active occlusion of a Saharan depression, when a tropopause fold/upper level front system crosses aloft. The occlusion is traced back to the Sahara desert, as a low level convergence/frontal zone, along which Qs vectors indicate an anticyclonic rotation of the warm part of the front. Dynamic tropopause maps show significant cold air advection just upstream the area of surface cyclogenesis on the 21st of January 2004. Consequently, an upper level vortex forms, which perturbs the thermal field, maximizing Q vector convergence above the bomb. Gradually the role of the tropopause decreases, as the upper level front system weakens. During these initial stages, when the low level vortex of the bomb is not yet well defined, the

  2. Trophic structure of pelagic species in the northwestern Mediterranean Sea

    Science.gov (United States)

    Albo-Puigserver, Marta; Navarro, Joan; Coll, Marta; Layman, Craig A.; Palomera, Isabel

    2016-11-01

    Ecological knowledge of food web interactions within pelagic marine communities is often limited, impairing our capabilities to manage these ecologically and economically important marine fish species. Here we used stable isotope analyses to investigate trophic interactions in the pelagic ecosystem of the northwestern Mediterranean Sea during 2012 and 2013. Our results suggest that European sardine, Sardina pilchardus, and anchovy, Engraulis encrasicolus, are consumers located at relatively low levels of the pelagic food web. Unexpectedly, the round sardinella, Sardinella aurita, appeared to be located at a higher trophic level than the other small pelagic fish species, although previous studies found similarity in their diets. Isotope data suggested that trophic niches of species within the genera Trachurus spp. and Scomber spp., were distinct. Atlantic bonito Sarda sarda, European hake Merluccius merluccius and European squid Loligo vulgaris, appeared to feed at higher trophic levels than other species. Despite some intraspecific seasonal variability for some species, community trophic structure appeared relatively stable through the year. These data provide an important step for developing models of food web dynamics in the northwestern Mediterranean Sea.

  3. Seasonal variability in the Central Mediterranean Sea circulation

    Directory of Open Access Journals (Sweden)

    R. Sorgente

    Full Text Available A high resolution eddy-resolving primitive equation numerical model, based on the Princeton Ocean Model (POM, is used to study the seasonal variability of the general circulation in the Central Mediterranean Sea. The model is run on a seasonal cycle, perpetual year simulation for five years, with nesting to the coarser resolution Ocean General Circulation Model (OGCM, covering the whole Mediterranean Sea. The model results are compared to the current knowledge on the hydrography and dynamics of the area, with a special focus on the annual cycle of the Modified Atlantic Water (MAW, on the circulation in the Sardinia Channel, the water exchange across the Strait of Sicily, and on the transition and fate of the Levantine Intermediate Water (LIW. The results show that the adopted coupling techniques between the two models give a proficient downscaling of the large-scale OGCM flow field into the regional scale model. The numerical solution is also used to highlight the seasonal characteristics of important dynamical features in the area, as well as to shed light on the scarcely known circulation regimes along the north African shelf and slope.

    Key words. Oceanography: general (numerical modelling; Oceanography: physical (currents; general circulation

  4. A model study of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001)

    NARCIS (Netherlands)

    Roelofs, GJ; Scheeren, HA; Heland, J; Ziereis, H; Lelieveld, J

    2003-01-01

    A coupled tropospheric chemistry-climate model is used to analyze tropospheric ozone distributions observed during the MINOS campaign in the eastern Mediterranean region ( August, 2001). Modeled ozone profiles are generally in good agreement with the observations. Our analysis shows that the atmosph

  5. A model study of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001)

    NARCIS (Netherlands)

    Roelofs, GJ; Scheeren, HA; Heland, J; Ziereis, H; Lelieveld, J

    2003-01-01

    A coupled tropospheric chemistry-climate model is used to analyze tropospheric ozone distributions observed during the MINOS campaign in the eastern Mediterranean region ( August, 2001). Modeled ozone profiles are generally in good agreement with the observations. Our analysis shows that the

  6. Communication Barriers: A Study of Eastern Mediterranean University Students' and Teachers' of Online Program and Courses

    Science.gov (United States)

    Isman, Aytekin; Altinay, Fahriye

    2005-01-01

    This research study defines communication barriers in online programs and courses by determining the perceptions of students and teachers at Eastern Mediterranean University. It aims to get the answers to the questions of what sorts of problems students and teachers face while being involved in online courses and online programs. Distance…

  7. The eastern Mediterranean climate at times of sapropel formation: a review

    NARCIS (Netherlands)

    Rohling, E.J.; Hilgen, F.J.

    2007-01-01

    Sapropel formation in the eastern Mediterranean coincided closely with minima in the precession index. Such minima occur approximately every 21000 years. At such times perihelion falls within Northern Hemisphere summer. Minima in the precession index are characterized by intensified Indian Ocean

  8. Sulphur geochemistry and sapropel formation : syngenetic and diagenetic signals in eastern Mediterranean sediments

    NARCIS (Netherlands)

    Passier, Hilde Françoise

    1998-01-01

    In this thesis the sulphur geochemistry of eastern Mediterranean sediments is studied. The sediments discussed were recovered during the 1987 ABC cruise with R/V Tyro (core ABC27), the 1988 BAMO-3 expedition of R/V Bannock (cores GC17 and GC21), the 1991 Marflux cruise with R/V Marion Dufresne

  9. Molecular palaeontology of eastern Mediterranean sapropels: Evidence for photic zone euxinia

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Bosch, Hendrik-Johannes (paleontoloog); Leeuw, J.W. de

    1997-01-01

    Organic geochemical data are presented for two Pliocene sapropels recovered during Ocean Drilling Program (ODP) Leg 160 in the Eastern Mediterranean Basin. One sapropel from Site 969 is exceptionally rich in organic carbon (TOC up to 30%) and the other one, from Site 967, has a more typical organic

  10. Molecular palaeontology of eastern Mediterranean sapropels: Evidence for photic zone euxinia

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Bosch, Hendrik-Johannes (paleontoloog); Leeuw, J.W. de

    1997-01-01

    Organic geochemical data are presented for two Pliocene sapropels recovered during Ocean Drilling Program (ODP) Leg 160 in the Eastern Mediterranean Basin. One sapropel from Site 969 is exceptionally rich in organic carbon (TOC up to 30%) and the other one, from Site 967, has a more typical organic

  11. Isotopic values of plants in relation to water availability in the Eastern Mediterranean region.

    Science.gov (United States)

    Hartman, Gideon; Danin, Avinoam

    2010-04-01

    Plant C and N isotope values often correlate with rainfall on global and regional scales. This study examines the relationship between plant isotopic values and rainfall in the Eastern Mediterranean region. The results indicate significant correlations between both C and N isotope values and rainfall in C(3) plant communities. This significant relationship is maintained when plant communities are divided by plant life forms. Furthermore, a seasonal increase in C isotope values is observed during the dry season while N isotope values remain stable across the wet and dry seasons. Finally, the isotopic pattern in plants originating from desert environments differs from those from Mediterranean environments because some desert plants obtain most of their water from secondary sources, namely water channeled by local topographic features rather than direct rainfall. From these results it can be concluded that water availability is the primary factor controlling C and N isotope variability in plant communities in the Eastern Mediterranean.

  12. Atmospheric Electricity Effects of Eastern Mediterranean Dust Storms

    Science.gov (United States)

    Katz, Shai; Yair, Yoav; Yaniv, Roy; Price, Colin

    2016-04-01

    We present atmospheric electrical measurements conducted at the Wise Observatory (WO) in Mizpe-Ramon (30035'N, 34045'E) and Mt. Hermon (30024'N, 35051'E), Israel, during two massive and unique dust storms that occurred over the Eastern Mediterranean region on February 10-11 and September 08-12, 2015. The first event transported Saharan dust from Egypt and the Sinai Peninsula in advance of a warm front of a Cyprus low pressure system. In the second event, dust particles were transported from the Syrian desert, which dominates the north-east border with Iraq, through flow associated with a shallow Persian trough system. In both events the concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 2200 μg m-3. Aerosol Optical Thickness (AOT) obtained from the AERONET station in Sde-Boker reached values up to 4.0. The gradual intensification of the first event reached peak values on the February 11th > 1200 μg m-3 and an AOT ~ 1.8, while the second dust storm commenced on September 8th with a sharp increase reaching peak values of 2225 μg m-3 and AOT of 4.0. Measurements of the fair weather vertical electric field (Ez) and of the vertical current density (Jz) were conducted continuously with a 1 minute temporal resolution. During the February event, very large fluctuations in the electrical parameters were measured at the WO. The Ez values changed between +1000 and +8000 V m-1 while the Jz fluctuated between -10 and +20 pA m-2 (this is an order of magnitude larger compared to the fair weather current density of ~2 pA m-2. In contrast, during the September event, Ez values registered at WO were between -430 and +10 V m-1 while the Jz fluctuated between -6 and +3 pA m2. For the September event the Hermon site showed Ez and Jz values fluctuating between -460 and +570 V m-1 and -14.5 and +18 pA m-2 respectively. The electric field and current variability, amplitude and the

  13. Prehistoric (Chalcolithic) Eastern Mediterranean tsunami deposit identified offshore central Israel

    Science.gov (United States)

    Tyuleneva, Natalia; Braun, Yael; Suchkov, Igor; Goodman-Tchernov, Beverly

    2017-04-01

    The shallow shelf area ( 15-30 m water depth) offshore Israel, bears great potential for paleo-tsunami studies. It was shown in the course of previous research that in these offshore marine deposits, tsunami generated sedimentary layers can be well preserved and readily identified; unlike in onshore sedimentary sequences, which experience continuous exogenous natural and anthropogenic influence. A sediment core, 219 cm long, was obtained from 15.3 m water depth, in about 4 km north of Caesarea. Grain size at 1 cm interval as well as XRD and XRF analyses at coarser resolution were performed. Previously carried out research allowed correlation of two anomalous layers in this core with well described sediment sequences offshore Caesarea. These two events correspond best with the proposed events of 749 AD and 1500 BC. Identified unusual layers in this core bear certain set of proxies that are characteristic for tsunami generated deposits and easily distinguished from the local normal marine setting. The latter is characterized by three dominating mineralogical components, such as carbonaceous sand derived either from biogenic material, namely shell fragments or from eroded limestones and dolomites that outcrop the mountains to the east; siliciclastic quartz for the sand fraction and mineral smectite for the clays. The supply of the two latter terrigenous sedimentary components comes from the Nile River, which has been a stable and predominant source of sediments for the past 8 ka. The aim of this study is to characterize the earliest unusual sedimentary layer found down core between 191 and 211 cm. This layer was attributed to a tsunami-generated sedimentary sequence in the studied core. Absolute age determination based on 14C gave the time frame from 5.6 to 6 ka BP, making this event the oldest identified in the Eastern Mediterranean to date. This tsunami corresponds to the Chalcolithic ('Copper Age') cultural period of the region. Prehistoric age of these sediments

  14. Invasion pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea.

    Science.gov (United States)

    Ghabooli, Sara; Shiganova, Tamara A; Briski, Elizabeta; Piraino, Stefano; Fuentes, Veronica; Thibault-Botha, Delphine; Angel, Dror L; Cristescu, Melania E; Macisaac, Hugh J

    2013-01-01

    Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I) and nuclear (Internal Transcribed Spacer) markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, N a = 10) preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise F ST = 0.001-0.028). However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise F ST = 0.010-0.032), raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native region sources

  15. Invasion pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Sara Ghabooli

    Full Text Available Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I and nuclear (Internal Transcribed Spacer markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, N a = 10 preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise F ST = 0.001-0.028. However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise F ST = 0.010-0.032, raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native

  16. Invasion Pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea

    Science.gov (United States)

    Ghabooli, Sara; Shiganova, Tamara A.; Briski, Elizabeta; Piraino, Stefano; Fuentes, Veronica; Thibault-Botha, Delphine; Angel, Dror L.; Cristescu, Melania E.; MacIsaac, Hugh J.

    2013-01-01

    Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I) and nuclear (Internal Transcribed Spacer) markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, Na = 10) preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise FST = 0.001–0.028). However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise FST = 0.010–0.032), raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native region sources

  17. Mediterranean sea eddy kinetic energy variability from 11 years of altimetric data

    Science.gov (United States)

    Pujol, M.-I.; Larnicol, G.

    2005-12-01

    specific variability pattern is observed in each sub-basin of the Mediterranean Sea (Western, Ionian and Levantine). The observed permanent/recurrent structures, as well as the transient ones, are subject to annual variations that occurred with different phases: permanent/recurrent structures (such as the Alboran Gyres and the Ierapetra Eddy — IE) are at maximum intensity in late summer (October to January) whereas areas of mesoscale activity (southwest of Sardinia, central Ionian and Mersa-Matruh areas) display maximum intensity in winter (January to April). Both annual and interannual variations are more pronounced in the eastern part of the basin. On the western side, mesoscale activity is relatively stable. The appearance of sporadic energetic structures leads to a positive trend in the Alboran Sea and north of the Tyrrhenian, while a negative trend is observed south of Majorca. The seasonal EKE variations are mainly concentrated southwest of Sardinia. They are found to be modulated by interannual variability, with a weakening of both the mean EKE and the amplitude of the seasonal cycle between 1997 and 2000 and between 2001 and 2003. In the Ionian Sea, the EKE variability is affected by the reversal of the circulation in 1997. This phenomenon suggests that the decadal scale of variability should not be overlooked in this basin. A strong positive EKE trend, coupled with an increase in the seasonal cycle amplitude, is observed in 1997 in the central Ionian. The high correlation of wind stress variations and high-frequency EKE in the Ionian Sea, suggests that the seasonal variations are partly due to wind-induced mesoscale activity. In the Levantine Sea, an even stronger positive EKE trend is observed, partly influenced by strong activity around the IE and in the Mersa-Matruh and Shikmona areas. Seasonal variations are present all over the studied period and are either largely influenced by the IE activity at the beginning and end of the period, or are concentrated at

  18. Distribution of bioluminescent organisms in the Mediterranean Sea and predicted effects on a deep-sea neutrino telescope

    Science.gov (United States)

    Craig, Jessica; Jamieson, Alan J.; Heger, Amandine; Priede, Imants G.

    2009-04-01

    The density of bioluminescent organisms was measured using an ISIT camera profiler in the eastern and western Mediterranean, from the subsurface layer to the seafloor; in the Ligurian, Tyrrhenian, Ionian, Adriatic Seas and the Strait of Sicily, including neutrino telescope sites at ANTARES and NESTOR. A west-east gradient in the density of bioluminescent animals in deep water (1500-2500 m) was observed, with the average density in the Ligurian (ANTARES) Sea (0.65±0.13 m-3) an order of magnitude greater than the E Ionian (NESTOR) Sea (0.06±0.04 m-3). Additionally, an exponential relationship was found between the density of near-bed bioluminescence (0-400 mab) and depth, with greatest divergence from the trend at the extreme west and easterly sites. For small scale effects we applied flash kinetics of bioluminescent organisms to map the bioluminescent field around a sphere; we predict most light emission downstream of an optical module.

  19. The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth.

    Directory of Open Access Journals (Sweden)

    Stephen M Techtmann

    Full Text Available The waters of the Eastern Mediterranean are characterized by unique physical and chemical properties within separate water masses occupying different depths. Distinct water masses are present throughout the oceans, which drive thermohaline circulation. These water masses may contain specific microbial assemblages. The goal of this study was to examine the effect of physical and geological phenomena on the microbial community of the Eastern Mediterranean water column. Chemical measurements were combined with phospholipid fatty acid (PLFA analysis and high-throughput 16S rRNA sequencing to characterize the microbial community in the water column at five sites. We demonstrate that the chemistry and microbial community of the water column were stratified into three distinct water masses. The salinity and nutrient concentrations vary between these water masses. Nutrient concentrations increased with depth, and salinity was highest in the intermediate water mass. Our PLFA analysis indicated different lipid classes were abundant in each water mass, suggesting that distinct groups of microbes inhabit these water masses. 16S rRNA gene sequencing confirmed the presence of distinct microbial communities in each water mass. Taxa involved in autotrophic nitrogen cycling were enriched in the intermediate water mass suggesting that microbes in this water mass may be important to the nitrogen cycle of the Eastern Mediterranean. The Eastern Mediterranean also contains numerous active hydrocarbon seeps. We sampled above the North Alex Mud Volcano, in order to test the effect of these geological features on the microbial community in the adjacent water column. The community in the waters overlaying the mud volcano was distinct from other communities collected at similar depths and was enriched in known hydrocarbon degrading taxa. Our results demonstrate that physical phenomena such stratification as well as geological phenomena such as mud volcanoes strongly

  20. Particle Size Distribution of Airborne Microorganisms and Pathogens during an Intense African Dust Event in the Eastern Mediterranean

    Science.gov (United States)

    Polymenakou, Paraskevi N.; Mandalakis, Manolis; Stephanou, Euripides G.; Tselepides, Anastasios

    2008-01-01

    Background The distribution of microorganisms, and especially pathogens, over airborne particles of different sizes has been ignored to a large extent, but it could have significant implications regarding the dispersion of these microorganisms across the planet, thus affecting human health. Objectives We examined the microbial quality of the aerosols over the eastern Mediterranean region during an African storm to determine the size distribution of microorganisms in the air. Methods We used a five-stage cascade impactor for bioaerosol collection in a coastal city on the eastern Mediterranean Sea during a north African dust storm. Bacterial communities associated with aerosol particles of six different size ranges were characterized following molecular culture–independent methods, regardless of the cell culturability (analysis of 16S rRNA genes). Results All 16S rDNA clone libraries were diverse, including sequences commonly found in soil and marine ecosystems. Spore-forming bacteria such as Firmicutes dominated large particle sizes (> 3.3 μm), whereas clones affiliated with Actinobacteria (found commonly in soil) and Bacteroidetes (widely distributed in the environment) gradually increased their abundance in aerosol particles of reduced size (< 3.3 μm). A large portion of the clones detected at respiratory particle sizes (< 3.3 μm) were phylogenetic neighbors to human pathogens that have been linked to several diseases. Conclusions The presence of aerosolized bacteria in small size particles may have significant implications to human health via intercontinental transportation of pathogens. PMID:18335093

  1. Establishing the identity and assessing the dynamics of invasion in the Mediterranean Sea by the dusky sweeper, Pempheris rhomboidea Kossmann & Räuber, 1877 (Pempheridae, Perciformes)

    KAUST Repository

    Azzurro, Ernesto

    2014-12-30

    © 2014, Springer International Publishing Switzerland. We investigate the genetic diversity of the sweeper Pempheris, a biological invader that entered the Mediterranean Sea via the Suez Canal. Two mitochondrial regions and one nuclear region were sequenced and topological reconstructions investigated from samples collected from the eastern Mediterranean Sea, Red Sea and three Indo-Pacific localities. Morphological and molecular analyses assigned samples from this study to three distinct species of Pempheris in the Red Sea (P. flavicyla, P. rhomboidea, and P. tominagai) and confirmed a misidentification of the Mediterranean sweepers, previously identified as P. vanicolensis and now recognized as P.rhomboidea. Pempheris rhomboidea clustered in a single clade including specimens from Madagascar and South Africa. Similarly to most other studied Lessepsian bioinvaders, no evidence of a genetic bottleneck in its invasive Mediterranean population was found. Yet, lowered gene flow levels were observed between Red Sea and Mediterranean populations in this species. These findings highlight the importance of molecular tools to the proper identification of morphologically challenging alien organisms and contribute to the understanding of the dynamics of Lessepsian invasions.

  2. Age and growth determination by skeletochronology in loggerhead sea turtles (Caretta caretta from the Mediterranean Sea

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    Paolo Casale

    2011-03-01

    Full Text Available Skeletochronology was applied to humerus bones to assess the age and growth rates of loggerhead sea turtles (Caretta caretta in the Mediterranean Sea. Fifty-five dead turtles with curved carapace lengths (CCL ranging from 24 to 86.5 cm were collected from the central Mediterranean. Sections of humeri were histologically processed to analyze annual growth marks. Two approaches were used to estimate the somatic growth in the form of a von Bertalanffy growth function. The first approach was based on calculating the total number of growth marks, which corresponds to the age of turtles at death. The second approach estimates the carapace length at old growth marks in order to provide the growth rate of each turtle. The observed individual growth rates ranged from 1.4 to 6.2 cm yr–1, and showed both elevated inter- and intra-individual variability possibly related to the environmental variability experienced by turtles during their lifetime. Both approaches gave similar results and suggest that Mediterranean loggerhead turtles take 14.9 to 28.5 years to reach a CCL of 66.5 to 84.7 cm. This size corresponds to the average size of nesting females found in the most important Mediterranean nesting sites and can be considered the approximate size at maturity.

  3. Biodiversity patterns of crustacean suprabenthic assemblages along an oligotrophic gradient in the bathyal Mediterranean Sea

    Science.gov (United States)

    Almeida, Mariana; Frutos, Inmaculada; Tecchio, Samuele; Lampadariou, Nikolaos; Company, Joan B.; Ramirez-Llodra, Eva; Cunha, Marina R.

    2017-03-01

    Crustacean suprabenthic abundance, community structure, α-diversity (both taxonomic and trophic) and β-diversity were studied along a West-East gradient of oligotrophy in the deep Mediterranean Sea. The assemblages were sampled with a suprabenthic sledge in three regions (western, central and eastern basins) at three water depths (1200, 2000 and 3000 m) in May-June 2009. Environmental data were obtained at each sampling location including sediment properties, oceanographic variables near the seafloor and in the water column, and proxies of epipelagic productivity at the surface. Our results, concerning the crustacean component of the suprabenthos, showed complex trends in community structure and biodiversity across different spatial scales (longitudinal, bathymetric, and near-bottom distribution). A decrease in the number of species and abundance, accompanied by changes in the trophic structure of the assemblages were observed from West to East. In the eastern region the assemblages were impoverished in number of trophic guilds and trophic diversity. The West-East oligotrophic gradient was identified as the main driver in community structure as shown by the significant correlation with trophic environmental variables. Differences in community structure across regions were more marked at greater depths, while at the shallower sites assemblages were more similar. Within each basin, abundance, number of species and number of trophic groups decreased with depth, showing high turnover rates between 1200 and 2000 m depths. The small-scale (0-150 cm) vertical distribution of the suprabenthos was interpreted in relation to the species' functional traits (e.g. swimming activity, migratory behaviour, bottom dependence, feeding habits). Bottom-dependent and more mobile components of the suprabenthos were apparently responding differently to the various environmental challenges imposed by the large-scale longitudinal and bathymetric gradients. We propose that the bathyal

  4. Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea

    Science.gov (United States)

    Jeanthon, C.; Boeuf, D.; Dahan, O.; Le Gall, F.; Garczarek, L.; Bendif, E. M.; Lehours, A.-C.

    2011-07-01

    Aerobic anoxygenic phototrophic (AAP) bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a (BChl-a), the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 54 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority (~94 %) was affiliated to the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies between culture-based and molecular methods, this study highlights the existing gaps in the understanding

  5. Fingerprint of the atmospheric deposition on the biogeochemical functioning in the Mediterranean Sea - Evolution since the preindustrial era and projections

    Science.gov (United States)

    Christodoulaki, Sylvia; Petihakis, George; Mihalopoulos, Nikolaos; Tsiaras, Kostas; Triantafyllou, George; Kanakidou, Maria

    2017-04-01

    The atmospheric deposition of trace elements in the marine environment plays a major role in low-nutrient low-chlorophyll (LNLC) regions, such as the Mediterranean Sea. Particularly the deposition of nitrogen (mainly nitrate and ammonium) and phosphorous (phosphate) represents an important source of essential nutrients for the growth of phytoplankton and bacteria, enhancing the marine productivity in these oligotrophic areas. In this study we investigate how the increase in atmospheric deposition of N over the past 1.5 century, together with a smaller increase in atmospheric P deposition onto the surface seawater, affected the nutrient stoichiometry and the marine ecosystem in the Eastern Mediterranean Sea and how this impact will change in the near future. To this end, and in order to understand the atmospheric and marine processes that regulate the effects of atmospheric deposition in the marine ecosystem and the N/P ratio as well as its temporal evolution in the Eastern Mediterranean, a 1-D coupled physical- biogeochemical model is used. The model is forced by observations of atmospheric deposition fluxes at Crete, while for the hindcast (1860) and forecast (2030) simulations, the changes in atmospheric deposition calculated by global chemistry- transport models are applied to the present-day observed fluxes. Then, a coupled 3-D hydrodynamic/biogeochemical model that is currently operational within the POSEIDON forecast system, forced by the TM4-ECPL global atmospheric chemistry transport model, is implemented at Mediterranean basin scale. Both the 1D and the 3D models show that the atmospheric deposition of N and P is capable of explaining the observed west-to-east gradient of N/P ratio in the sea. Impacts of atmospheric deposition of N and P on the marine carbon and nutrients cycles are investigated and discussed. This work has been supported by Thales - ADAMANT project (ESF - NSRF 2007- 2013).

  6. The Mediterranean Sea Regime Shift at the End of the 1980s, and Intriguing Parallelisms with Other European Basins

    Science.gov (United States)

    Conversi, Alessandra; Fonda Umani, Serena; Peluso, Tiziana; Molinero, Juan Carlos; Santojanni, Alberto; Edwards, Martin

    2010-01-01

    Background Regime shifts are abrupt changes encompassing a multitude of physical properties and ecosystem variables, which lead to new regime conditions. Recent investigations focus on the changes in ecosystem diversity and functioning associated to such shifts. Of particular interest, because of the implication on climate drivers, are shifts that occur synchronously in separated basins. Principal Findings In this work we analyze and review long-term records of Mediterranean ecological and hydro-climate variables and find that all point to a synchronous change in the late 1980s. A quantitative synthesis of the literature (including observed oceanic data, models and satellite analyses) shows that these years mark a major change in Mediterranean hydrographic properties, surface circulation, and deep water convection (the Eastern Mediterranean Transient). We provide novel analyses that link local, regional and basin scale hydrological properties with two major indicators of large scale climate, the North Atlantic Oscillation index and the Northern Hemisphere Temperature index, suggesting that the Mediterranean shift is part of a large scale change in the Northern Hemisphere. We provide a simplified scheme of the different effects of climate vs. temperature on pelagic ecosystems. Conclusions Our results show that the Mediterranean Sea underwent a major change at the end of the 1980s that encompassed atmospheric, hydrological, and ecological systems, for which it can be considered a regime shift. We further provide evidence that the local hydrography is linked to the larger scale, northern hemisphere climate. These results suggest that the shifts that affected the North, Baltic, Black and Mediterranean (this work) Seas at the end of the 1980s, that have been so far only partly associated, are likely linked as part a northern hemisphere change. These findings bear wide implications for the development of climate change scenarios, as synchronous shifts may provide the key

  7. The Mediterranean Sea regime shift at the end of the 1980s, and intriguing parallelisms with other European basins.

    Directory of Open Access Journals (Sweden)

    Alessandra Conversi

    Full Text Available BACKGROUND: Regime shifts are abrupt changes encompassing a multitude of physical properties and ecosystem variables, which lead to new regime conditions. Recent investigations focus on the changes in ecosystem diversity and functioning associated to such shifts. Of particular interest, because of the implication on climate drivers, are shifts that occur synchronously in separated basins. PRINCIPAL FINDINGS: In this work we analyze and review long-term records of Mediterranean ecological and hydro-climate variables and find that all point to a synchronous change in the late 1980s. A quantitative synthesis of the literature (including observed oceanic data, models and satellite analyses shows that these years mark a major change in Mediterranean hydrographic properties, surface circulation, and deep water convection (the Eastern Mediterranean Transient. We provide novel analyses that link local, regional and basin scale hydrological properties with two major indicators of large scale climate, the North Atlantic Oscillation index and the Northern Hemisphere Temperature index, suggesting that the Mediterranean shift is part of a large scale change in the Northern Hemisphere. We provide a simplified scheme of the different effects of climate vs. temperature on pelagic ecosystems. CONCLUSIONS: Our results show that the Mediterranean Sea underwent a major change at the end of the 1980s that encompassed atmospheric, hydrological, and ecological systems, for which it can be considered a regime shift. We further provide evidence that the local hydrography is linked to the larger scale, northern hemisphere climate. These results suggest that the shifts that affected the North, Baltic, Black and Mediterranean (this work Seas at the end of the 1980s, that have been so far only partly associated, are likely linked as part a northern hemisphere change. These findings bear wide implications for the development of climate change scenarios, as synchronous shifts

  8. Interannual differences for sea turtles bycatch in Spanish longliners from Western Mediterranean Sea.

    Science.gov (United States)

    Báez, José C; Macías, David; García-Barcelona, Salvador; Real, Raimundo

    2014-01-01

    Recent studies showed that regional abundance of loggerhead and leatherback turtles could oscillate interannually according to oceanographic and climatic conditions. The Western Mediterranean is an important fishing area for the Spanish drifting longline fleet, which mainly targets swordfish, bluefin tuna, and albacore. Due to the spatial overlapping in fishing activity and turtle distribution, there is an increasing sea turtle conservation concern. The main goal of this study is to analyse the interannual bycatch of loggerhead and leatherback turtles by the Spanish Mediterranean longline fishery and to test the relationship between the total turtle by-catch of this fishery and the North Atlantic Oscillation (NAO). During the 14 years covered in this study, the number of sea turtle bycatches was 3,940 loggerhead turtles and 8 leatherback turtles, 0.499 loggerhead turtles/1000 hooks and 0.001014 leatherback turtles/1000 hooks. In the case of the loggerhead turtle the positive phase of the NAO favours an increase of loggerhead turtles in the Western Mediterranean Sea. However, in the case of leatherback turtle the negative phase of the NAO favours the presence of leatherback turtle. This contraposition could be related to the different ecophysiological response of both species during their migration cycle.

  9. Interannual Differences for Sea Turtles Bycatch in Spanish Longliners from Western Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    José C. Báez

    2014-01-01

    Full Text Available Recent studies showed that regional abundance of loggerhead and leatherback turtles could oscillate interannually according to oceanographic and climatic conditions. The Western Mediterranean is an important fishing area for the Spanish drifting longline fleet, which mainly targets swordfish, bluefin tuna, and albacore. Due to the spatial overlapping in fishing activity and turtle distribution, there is an increasing sea turtle conservation concern. The main goal of this study is to analyse the interannual bycatch of loggerhead and leatherback turtles by the Spanish Mediterranean longline fishery and to test the relationship between the total turtle by-catch of this fishery and the North Atlantic Oscillation (NAO. During the 14 years covered in this study, the number of sea turtle bycatches was 3,940 loggerhead turtles and 8 leatherback turtles, 0.499 loggerhead turtles/1000 hooks and 0.001014 leatherback turtles/1000 hooks. In the case of the loggerhead turtle the positive phase of the NAO favours an increase of loggerhead turtles in the Western Mediterranean Sea. However, in the case of leatherback turtle the negative phase of the NAO favours the presence of leatherback turtle. This contraposition could be related to the different ecophysiological response of both species during their migration cycle.

  10. Vertical ozone measurements in the troposphere over the Eastern Mediterranean and comparison with Central Europe

    Directory of Open Access Journals (Sweden)

    P. D. Kalabokas

    2007-02-01

    Full Text Available Vertical ozone profiles measured in the period 1996–2002 in the framework of the MOZAIC project (Measurement of Ozone and Water Vapor by Airbus in Service Aircraft for flights connecting Central Europe to the Eastern Mediterranean basin (Heraklion, Rhodes; Antalya were analysed in order to evaluate the high rural ozone levels recorded in the Mediterranean area during summertime. The 77 flights during summer (JJAS showed significantly (10–12 ppb, 20–40% enhanced ozone mixing ratios in the lower troposphere over the Eastern Mediterranean frequently exceeding the 60 ppb, 8-h EU air quality standard, whereas ozone between 700 hPa and 400 hPa was only slightly (3–5 ppb, 5–10% higher than over central Europe. Analysis of composite weather maps for the high and low ozone cases, as well as back-trajectories and vertical profiles of carbon monoxide, suggest that the main factor leading to high tropospheric ozone values in the area is anticyclonic influence, in combination with a persistent northerly flow in the lower troposphere during summertime over the Aegean. On the other hand the lowest ozone levels are associated with low-pressure systems, especially the extension of the Middle East low over the Eastern Mediterranean area.

  11. Vertical ozone measurements in the troposphere over the Eastern Mediterranean and comparison with Central Europe

    Directory of Open Access Journals (Sweden)

    P. D. Kalabokas

    2007-07-01

    Full Text Available Vertical ozone profiles measured in the period 1996–2002 in the framework of the MOZAIC project (Measurement of Ozone and Water Vapor by Airbus in Service Aircraft for flights connecting Central Europe to the Eastern Mediterranean basin (Heraklion, Rhodes, Antalya were analysed in order to evaluate the high rural ozone levels recorded in the Mediterranean area during summertime. The 77 flights during summer (JJAS showed substantially (10–12 ppb, 20–40% enhanced ozone mixing ratios in the lower troposphere over the Eastern Mediterranean frequently exceeding the 60 ppb, 8-h EU air quality standard, whereas ozone between 700 hPa and 400 hPa was only slightly (3–5 ppb, 5–10% higher than over Central Europe. Analysis of composite weather maps for the high and low ozone cases, as well as back-trajectories and vertical profiles of carbon monoxide, suggest that the main factor leading to high tropospheric ozone values in the area is anticyclonic influence, in combination with a persistent northerly flow in the lower troposphere during summertime over the Aegean. On the other hand the lowest ozone levels are associated with low-pressure systems, especially the extension of the Middle East low over the Eastern Mediterranean area.

  12. Volatile organic compounds (VOCs) in photochemically aged air from the eastern and western Mediterranean

    Science.gov (United States)

    Derstroff, Bettina; Hüser, Imke; Bourtsoukidis, Efstratios; Crowley, John N.; Fischer, Horst; Gromov, Sergey; Harder, Hartwig; Janssen, Ruud H. H.; Kesselmeier, Jürgen; Lelieveld, Jos; Mallik, Chinmay; Martinez, Monica; Novelli, Anna; Parchatka, Uwe; Phillips, Gavin J.; Sander, Rolf; Sauvage, Carina; Schuladen, Jan; Stönner, Christof; Tomsche, Laura; Williams, Jonathan

    2017-08-01

    During the summertime CYPHEX campaign (CYprus PHotochemical EXperiment 2014) in the eastern Mediterranean, multiple volatile organic compounds (VOCs) were measured from a 650 m hilltop site in western Cyprus (34° 57' N/32° 23' E). Periodic shifts in the northerly Etesian winds resulted in the site being alternately impacted by photochemically processed emissions from western (Spain, France, Italy) and eastern (Turkey, Greece) Europe. Furthermore, the site was situated within the residual layer/free troposphere during some nights which were characterized by high ozone and low relative humidity levels. In this study we examine the temporal variation of VOCs at the site. The sparse Mediterranean scrub vegetation generated diel cycles in the reactive biogenic hydrocarbon isoprene, from very low values at night to a diurnal median level of 80-100 pptv. In contrast, the oxygenated volatile organic compounds (OVOCs) methanol and acetone exhibited weak diel cycles and were approximately an order of magnitude higher in mixing ratio (ca. 2.5-3 ppbv median level by day, range: ca. 1-8 ppbv) than the locally emitted isoprene and aromatic compounds such as benzene and toluene. Acetic acid was present at mixing ratios between 0.05 and 4 ppbv with a median level of ca. 1.2 ppbv during the daytime. When data points directly affected by the residual layer/free troposphere were excluded, the acid followed a pronounced diel cycle, which was influenced by various local effects including photochemical production and loss, direct emission, dry deposition and scavenging from advecting air in fog banks. The Lagrangian model FLEXPART was used to determine transport patterns and photochemical processing times (between 12 h and several days) of air masses originating from eastern and western Europe. Ozone and many OVOC levels were ˜ 20 and ˜ 30-60 % higher, respectively, in air arriving from the east. Using the FLEXPART calculated transport time, the contribution of photochemical

  13. Volatile organic compounds (VOCs in photochemically aged air from the eastern and western Mediterranean

    Directory of Open Access Journals (Sweden)

    B. Derstroff

    2017-08-01

    Full Text Available During the summertime CYPHEX campaign (CYprus PHotochemical EXperiment 2014 in the eastern Mediterranean, multiple volatile organic compounds (VOCs were measured from a 650 m hilltop site in western Cyprus (34° 57′ N/32° 23′ E. Periodic shifts in the northerly Etesian winds resulted in the site being alternately impacted by photochemically processed emissions from western (Spain, France, Italy and eastern (Turkey, Greece Europe. Furthermore, the site was situated within the residual layer/free troposphere during some nights which were characterized by high ozone and low relative humidity levels. In this study we examine the temporal variation of VOCs at the site. The sparse Mediterranean scrub vegetation generated diel cycles in the reactive biogenic hydrocarbon isoprene, from very low values at night to a diurnal median level of 80–100 pptv. In contrast, the oxygenated volatile organic compounds (OVOCs methanol and acetone exhibited weak diel cycles and were approximately an order of magnitude higher in mixing ratio (ca. 2.5–3 ppbv median level by day, range: ca. 1–8 ppbv than the locally emitted isoprene and aromatic compounds such as benzene and toluene. Acetic acid was present at mixing ratios between 0.05 and 4 ppbv with a median level of ca. 1.2 ppbv during the daytime. When data points directly affected by the residual layer/free troposphere were excluded, the acid followed a pronounced diel cycle, which was influenced by various local effects including photochemical production and loss, direct emission, dry deposition and scavenging from advecting air in fog banks. The Lagrangian model FLEXPART was used to determine transport patterns and photochemical processing times (between 12 h and several days of air masses originating from eastern and western Europe. Ozone and many OVOC levels were  ∼  20 and  ∼  30–60 % higher, respectively, in air arriving from the east. Using the FLEXPART

  14. Eastern Mediterranean Natural Gas: Analyzing Turkey’s Stance

    Directory of Open Access Journals (Sweden)

    Abdullah Tanrıverdi

    2013-10-01

    Full Text Available Recent large-scale natural gas discoveries in East Mediterranean have drawn attention to the region. The discoveries caused both hope and tension in the region. As stated, the new resources may serve as a new hope for all relevant parties as well as the region if managed in a collaborative and conciliatory way. Energy may be a remedy to Cyprus’ financial predicament, initiate a process for resolving differences between Turkey and Cyprus, normalize Israel-Turkey relations and so on. On the contrary, adopting unilateral and uncooperative approach may aggravate the tension and undermine regional stability and security. In this sense, the role of energy in generating hope or tension is dependent on the approaches of related parties. The article will analyze Turkey’s attitude in East Mediterranean case in terms of possible negative and positive implications for Turkey in the energy field. The article examines Turkey’s position and the reasons behind its stance in the East Mediterranean case. Considering Turkey’s energy profile and energy policy goals, the article argues that the newly found hydrocarbons may bring in more stakes for Turkey if Turkey adopts a cooperative approach in this case.

  15. Levantilides A and B, 20-Membered Macrolides from a Micromonospora Strain Isolated from the Mediterranean Deep Sea Sediment

    Directory of Open Access Journals (Sweden)

    Jutta Wiese

    2011-01-01

    Full Text Available Two new 20-membered macrolides, levantilide A and B, were isolated from the Micromonospora strain M71-A77. Strain M71-A77 was recovered from an Eastern Mediterranean deep-sea sediment sample and revealed to produce the levantilides under in situ salinity of 38.6‰. The chemical structures of the levantilides were elucidated on the basis of different one- and two- dimensional NMR experiments. Levantilide A exhibits a moderate antiproliferative activity against several tumor cell lines.

  16. Temporal nutrient dynamics in the Mediterranean Sea in response to anthropogenic inputs

    Science.gov (United States)

    Moon, Ji-Young; Lee, Kitack; Tanhua, Toste; Kress, Nurit; Kim, Il-Nam

    2016-05-01

    The temporal dynamics of the concentrations of nitrate (N), phosphate (P), and the N:P ratio in the upper water column (200-600 m) of the Mediterranean (MED) Sea were investigated using observational data (~123,100 data points) collected between 1985 and 2014. The studied variables were found to evolve similarly in the western and eastern MED Sea. In both basins, the N concentration increased during the first part of the observational period (1985-1998), and the temporal trend of N was broadly consistent with the history of riverine and atmospheric nitrogen input from populated areas in Europe, with a lag period of 20 years. In subsequent years, the N concentration was high and relatively constant between 1998 and 2005, after which N decreased gradually, although the decreasing trend was indistinct in the western basin. In particular, the trend of constant then declining N after 1998 is consistent with the history of pollutant nitrogen emissions from the European continent, allowing a 20 year lag following the introduction of regulation of pollutant nitrogen in the 1970s. The three-phase temporal transition in P in both basins was more consistent with the riverine phosphorus input, with a lag period of 20 years. Our analysis indicates that the recent dynamics of N and P in the upper MED Sea has been sensitive to the dynamics of anthropogenic nitrogen and phosphorus input from atmospheric deposition and rivers.

  17. Diversity of Micromonospora strains from the deep Mediterranean Sea and their potential to produce bioactive compounds

    Directory of Open Access Journals (Sweden)

    Andrea Gärtner

    2016-06-01

    Full Text Available During studies on bacteria from the Eastern Mediterranean deep-sea, incubation under in situ conditions (salinity, temperature and pressure and heat treatment were used to selectively enrich representatives of Micromonospora. From sediments of the Ierapetra Basin (4400 m depth and the Herodotos Plain (2800 m depth, 21 isolates were identified as members of the genus Micromonospora. According to phylogenetic analysis of 16S rRNA gene sequences, the Micromonospora isolates could be assigned to 14 different phylotypes with an exclusion limit of ≥ 99.5% sequence similarity. They formed 7 phylogenetic clusters. Two of these clusters, which contain isolates obtained after enrichment under pressure incubation and phylogenetically are distinct from representative reference organism, could represent bacteria specifically adapted to the conditions in situ and to life in these deep-sea sediments. The majority of the Micromonospora isolates (90% contained at least one gene cluster for biosynthesis of secondary metabolites for non-ribosomal polypeptides and polyketides (polyketide synthases type I and type II. The determination of biological activities of culture extracts revealed that almost half of the strains produced substances inhibitory to the growth of Gram-positive bacteria. Chemical analyses of culture extracts demonstrated the presence of different metabolite profiles also in closely related strains. Therefore, deep-sea Micromonospora isolates are considered to have a large potential for the production of new antibiotic compounds.

  18. Biodiversity data requirements for systematic conservation planning in the Mediterranean Sea

    DEFF Research Database (Denmark)

    Levin, Noam; Coll, Marta; Fraschetti, Simonetta

    2014-01-01

    that the availability and spatial resolution of information required for setting conservation goals largely varies among and within the countries surrounding the Mediterranean Sea, with more and better quality data often available for the European countries located in the western Mediterranean Sea. Additionally...... in the Mediterranean Sea, data on the spatial distribution of ecological features (abiotic variables, species, communities, habitats and ecosystems) is required to inform conservation scientists and planners. However, the spatial data required is often lacking. In this review, we aim to address the status of our...

  19. Observations on the distribution, population structure and biology of Bathypterois mediterraneus Bauchot, 1962 in three areas of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Gianfranco d'Onghia

    2004-12-01

    Full Text Available During the DESEAS cruise Bathypterois mediterraneus specimens were sampled in the Balearic Sea between 1000 and 2800 m as well as in the western and eastern Ionian Sea from 800 to 3300 m and from 800 to 2600 m respectively. The species was found to be more abundant at depths of 1500-2000 m. The size-range was 26-190 mm and the most abundant size class was around 100-120 mm standard length. No significant size-depth trends were shown for either length or weight. Negative allometry was shown in the growth of fishes and otoliths and in the relationship between fish length and otolith size in the samples from the western and eastern Ionian Sea. In these two areas the absolute growth was estimated by adopting the Von Bertalanffy function (western Ionian: SL∞ = 194.3 ± 38.51 mm, k = 0.146 ± 0.061/year, t0 = - 0.921 ± 0.699, ø' = 3.74; eastern Ionian: SL∞ = 180.23 ± 63.36 mm, k = 0.150 ± 0.112/year, t0 = - 0.968 ± 0.868, ø' = 3.70. Although most of the specimens were immature, some ripe gonads were recorded in individuals greater than 104 mm in standard length, confirming the simultaneous hermaphroditism in this fish. The results are discussed in relation to previous observations on the life strategy of B.mediterraneus in the Mediterranean Sea.

  20. A Mössbauer spectroscopic study of the iron redox transition in eastern Mediterranean sediments

    NARCIS (Netherlands)

    Zee, C. van der; Slomp, C.P.; Rancourt, D.G.; Lange, G.J. de; Raaphorst, W. van

    2005-01-01

    Fe cycling at two sites in the Mediterranean Sea (southwest of Rhodes and in the North Aegean) has been studied, combining the pore water determination of nutrients, manganese, and iron, citrate-bicarbonate-dithionite (CDB) and total sediment extractions, X-ray diffraction, and 57Fe Mössbauer

  1. Exploiting coastal altimetry to improve the surface circulation scheme over the central Mediterranean Sea

    Science.gov (United States)

    Jebri, Fatma; Birol, Florence; Zakardjian, Bruno; Bouffard, Jérome; Sammari, Cherif

    2016-07-01

    This work is the first study exploiting along track altimetry data to observe and monitor coastal ocean features over the transition area between the western and eastern Mediterranean Basins. The relative performances of both the AVISO and the X-TRACK research regional altimetric data sets are compared using in situ observations. Both products are cross validated with tide gauge records. The altimeter-derived geostrophic velocities are also compared with observations from a moored Acoustic Doppler Current Profiler. Results indicate the good potential of satellite altimetry to retrieve dynamic features over the area. However, X-TRACK shows a more homogenous data coverage than AVISO, with longer time series in the 50 km coastal band. The seasonal evolution of the surface circulation is therefore analyzed by conjointly using X-TRACK data and remotely sensed sea surface temperature observations. This combined data set clearly depicts different current regimes and bifurcations, which allows us to propose a new seasonal circulation scheme for the central Mediterranean. The analysis shows variations of the path and temporal behavior of the main circulation features: the Atlantic Tunisian Current, the Atlantic Ionian Stream, the Atlantic Libyan Current, and the Sidra Gyre. The resulting bifurcating veins of these currents are also discussed, and a new current branch is observed for the first time.

  2. Geographical gradients of dissolved Vitamin B12 in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Sophie eBonnet

    2013-06-01

    Full Text Available Most eukaryotic phytoplankton require vitamin B12 to grow. However, the cycling of this organic growth factor has received substantially less attention than other bioactive substances such as trace metals in the marine environment. This is especially true in the Mediterranean Sea, where direct measurements of dissolved vitamins have never been reported. We report here the first direct measurements of dissolved vitamin B12 across longitudinal gradients in Mediterranean waters. The range of vitamin B12 concentrations measured over the whole transect was 0.5 to 6.2 pM, which is slightly higher than the range (undetectable – 4 pM of ambient concentrations measured in other open ocean basins in the Pacific and Atlantic oceans. The concentrations measured in the western basin were significantly higher (p<0.05 than those of the eastern basin. They were positively correlated with chlorophyll concentrations in the most western part of the basin, and did not show any significant correlation with any other biological variables in other regions of the sampling transect.

  3. Geographical gradients of dissolved Vitamin B12 in the Mediterranean Sea

    Science.gov (United States)

    Bonnet, S.; Tovar-Sánchez, A.; Panzeca, C.; Duarte, C. M.; Ortega-Retuerta, E.; Sañudo-Wilhelmy, S. A.

    2013-01-01

    Most eukaryotic phytoplankton require vitamin B12 to grow. However, the cycling of this organic growth factor has received substantially less attention than other bioactive substances such as trace metals in the marine environment. This is especially true in the Mediterranean Sea, where direct measurements of dissolved vitamins have never been reported. We report here the first direct measurements of dissolved vitamin B12 across longitudinal gradients in Mediterranean waters. The range of vitamin B12 concentrations measured over the whole transect was 0.5–6.2 pM, which is slightly higher than the range (undetectable—4 pM) of ambient concentrations measured in other open ocean basins in the Pacific and Atlantic oceans. The concentrations measured in the western basin were significantly higher (p < 0.05) than those of the eastern basin. They were positively correlated with chlorophyll concentrations in the most western part of the basin, and did not show any significant correlation with any other biological variables in other regions of the sampling transect. PMID:23772225

  4. On the occurrence of Zenopsis conchifer (Lowe, 1852 (Osteichthyes, Zeidae in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Fernández, A. M.

    2013-03-01

    Full Text Available The capture of four specimens of Silvery John Dory (Zenopsis conchifer,a species recorded in the Mediterranean Sea for the first time in 2006, is reported from the Iberian coast (western Mediterranean. One of the specimens was caught near the Strait of Gibraltar and is probably a vagrant. Despite these catches, there is no evidence of a self–sustaining population, so this species should be considered as alien in the Mediterranean.

  5. Taxonomic research on Squalus megalops (Macleay, 1881 and Squalus blainvillei (Risso, 1827 (Chondrichthyes: Squalidae in Tunisian waters (central Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Sondes Marouani

    2011-11-01

    Full Text Available Two species of spurdog of the genus Squalus occur in the Gulf of Gabès (southern Tunisia, central Mediterranean: the longnose spurdog Squalus blainvillei (Risso, 1827 and a short-snout spurdog of the Squalus megalops-cubensis group. Morphometric and meristic data as well as a genetic analyses (DNA inter-simple sequence repeat markers and molecular barcoding methods support the assignation of this short-snout spurdog to Squalus megalops (Macleay, 1881. Squalus megalops occurs commonly in temperate and tropical Australian waters, and is also thought to occur in the eastern Atlantic, southern Indian Ocean and western North Pacific although these records need to be confirmed. Our study confirms that it occurs in the Mediterranean Sea. Populations of both S. blainvillei and S. megalops are described based on Tunisian material.

  6. Constraints on the neodymium (Nd) oceanic cycle in the Mediterranean Sea using a high resolution coupled model

    Science.gov (United States)

    Ayache, Mohamed; Jeandel, Catherine; Dutay, Jean-claude; Arsouze, Thomas

    2015-04-01

    Exchange" hypothesis as the main source/sink term of Nd to the oceanic reservoir. Coupling the circulation with a detailed biogeochemical model is currently ongoing. The Boundary Exchange is parameterized using a first order relaxation equation towards the Nd Isotopic composition of the margins. We also investigated the impact of the inter annual variability of the circulation of the Mediterranean Sea on the distribution of the Nd oceanic isotopic composition, focusing on observed events such the Eastern Mediterranean Transient (EMT) or the Western Mediterranean transition (WMT).

  7. A seasonal model of the Mediterranean Sea general circulation

    Science.gov (United States)

    Roussenov, Vassil; Stanev, Emil; Artale, Vincenzo; Pinardi, Nadia

    1995-07-01

    This paper describes the seasonal characteristics of the Mediterranean Sea general circulation as simulated by a primitive equation general circulation model. The forcing is composed of climatological monthly mean atmospheric parameters, which are used to compute the heat and momentum budgets at the air-sea interface of the model. This allows heat fluxes to be determined by a realistic air-sea interaction physics. The Strait of Gibraltar is open, and the model resolution is ? in the horizontal and 19 levels in the vertical. The results show the large seasonal cycle of the circulation and its transient characteristics. The heat budget at the surface is characterized by lateral boundary intensifications occurring in downwelling and up welling areas of the basin. The general circulation is composed of subbasin gyres, and cyclonic motion dominates the northern and anticyclonic motion the southern part of the basin. The Atlantic stream which enters from Gibraltar and assumes the form of different boundary current subsystems is a coherent structure at the surface. At depth it appears as current segments and jets around a vigorous gyre system. The seasonal variability is manifested not only by a change in amplitude and location of the gyres but also by the appearance of seasonally recurrent gyres in different parts of the basin. Distinct westward propagation of these gyres occurs, together with amplitude changes. For the first time a Mersa-Matruh Gyre is successfully simulated due to the introduction of our heat fluxes at the air-sea interface. The seasonal thermocline is formed each summer, and a deep winter mixed layer is produced in the region of Levantine intermediate water formation. Deep water renewal does not occur, probably due to the climatological forcing used.

  8. The use of fish metabolic, pathological and parasitological indices in pollution monitoring . II. The Red Sea and Mediterranean

    Science.gov (United States)

    Diamant, A.; Banet, A.; Paperna, I.; Westernhagen, H. v.; Broeg, K.; Kruener, G.; Koerting, W.; Zander, S.

    1999-12-01

    The complex interactions between parasites, hosts and the environment are influenced by the stability of the ecosystem. Heteroxenous parasites, with complex, multiple-host life cycles, can persist only in habitats where the full range of their required hosts are present. Conversely, in impoverished environments such as those impacted by environmental stress, monoxenous species that have simple, single-host life cycles are likely to predominate. In the present study, we analyzed the ratio between heteroxenous and monoxenous (H/M) parasites as well as parasite species richness (SH/SM) and species diversity in rabbitfish (Siganus rivulatus) collected from several sites in the Red Sea. The rabbitfish is a Suez Canal immigrant, well established in the eastern Mediterranean, and fish were also collected from a site on the Mediterranean coast of Israel. Separate treatment of the micro- and macroparasite components of the rabbitfish parasite communities in the Red Sea suggested that macroparasites only - monogenea and gut parasites - were better indicators than the parasite community as a whole. Quantification of macroparasites is accurate, saves time and effort, produces more accurate data and better differentiates between sites. Higher H/M ratios and SH/SM ratios were found in the rabbitfish collected at the ecologically stable habitat of the coral reef compared to rabbitfish from sandy habitat or mariculture-impacted sandy habitat. The results of the study emphasized the negative impacts of cage mariculture on the environment. The rabbitfish collected near the mariculture farms supported the poorest and least diverse parasite communities of all sampled sites, with virtual depletion of heteroxenous species, and even reduction of gill monogenean infections on the hosts. When results from the Mediterranean sites were compared with those of the Red Sea, the data showed full representation of monoxenous parasites (all but one of Red Sea origin), while heteroxenous species

  9. Long-range transport of Saharan dust and chemical transformations over the Eastern Mediterranean

    Science.gov (United States)

    Athanasopoulou, E.; Protonotariou, A.; Papangelis, G.; Tombrou, M.; Mihalopoulos, N.; Gerasopoulos, E.

    2016-09-01

    Three recent Saharan dust outbreaks during different seasons (4-6 days in winter of 2009, late autumn of 2010 and summer of 2011) are selected in order to study the chemical footprint and aging processes of dust intrusions over the Eastern Mediterranean (EM). The applied model system (PMCAMx, WRF and GEOS-CHEM) and methodology are found competent to reproduce dust production, long-range transport and chemical transformations over the EM, with the synergistic use of synoptic patterns analysis, optical depth retrievals, back-trajectories, surface and satellite aerosol measurements. The dust loads were high during the cold period events and much lighter during summertime, when transport was mainly in the free troposphere. In all cases, dust originated from the northwest and/or west Saharan desert and reached the EM from the west/southwest. Sensitivity runs underlie the effect of dust transport on the chemical constituents of aerosols over the EM and show a large impact on calcium (70-90% of maximum daily values 2-5 μg m-3), with its gradient at surface level being around -10% per 100 km along the dust pathway. For the cold period cases, this value can also be considered analogous to the dust dissipation ratio, because the plume is vertically extended down to the surface layers. Interestingly, the surface particulate nitrate concentrations over the EM are reversely affected by the approaching dust loads, exhibiting the highest values (up to 6 μg m-3) and the largest dust fraction (ca. 70%) during summertime. This is attributed to the enhanced nitric acid formation under high atmospheric temperature and insolation, its uptake onto the carbonate dust particles, and their effective accumulation, due to low deposition rates over the sea and scarce precipitation. Sulfate formation onto dust particles is found insignificant (rapid reaction with ammonia and/or sea-salt), while the influence of dust and sea-salt on sodium, when spatio-temporal averages are calculated, is

  10. The impact of monsoon outflow from India and Southeast Asia in the upper troposphere over the eastern Mediterranean

    NARCIS (Netherlands)

    Scheeren, HA; Lelieveld, J; Roelofs, GJ; Williams, J; Fischer, H; de Reus, M; de Gouw, JA; Warneke, C; Holzinger, R; Schlager, H; Klupfel, T; Bolder, M; van der Veen, C; Lawrence, M

    2003-01-01

    A major objective of the Mediterranean INtensive Oxidant Study (MINOS) was to investigate long-range transport of pollutants ( notably ozone precursor species). Here we present trace gas measurements from the DLR ( German Aerospace Organization) Falcon aircraft in the eastern Mediterranean troposphe

  11. Precession driven changes in terrestrial organic matter input to the Eastern Mediterranean leading up to the Messinian Salinity Crisis

    NARCIS (Netherlands)

    Mayser, Jan Peter; Flecker, Rachel; Marzocchi, Alice; Kouwenhoven, Tanja J.; Lunt, Dan J.; Pancost, Rich D.

    2017-01-01

    Eastern Mediterranean sediments over the past 12 Myr commonly show strongly developed precessional cyclicity, thought to be a biogeochemical response to insolation-driven freshwater input from run-off. The Mediterranean's dominant freshwater source today and in the past, is the Nile, which is fed by

  12. The impact of monsoon outflow from India and Southeast Asia in the upper troposphere over the eastern Mediterranean

    NARCIS (Netherlands)

    Scheeren, HA; Lelieveld, J; Roelofs, GJ; Williams, J; Fischer, H; de Reus, M; de Gouw, JA; Warneke, C; Holzinger, R; Schlager, H; Klupfel, T; Bolder, M; van der Veen, C; Lawrence, M

    2003-01-01

    A major objective of the Mediterranean INtensive Oxidant Study (MINOS) was to investigate long-range transport of pollutants ( notably ozone precursor species). Here we present trace gas measurements from the DLR ( German Aerospace Organization) Falcon aircraft in the eastern Mediterranean troposphe

  13. Problems of the active tectonics of the Eastern Black Sea

    Science.gov (United States)

    Javakhishvili, Z.; Godoladze, T.; Dreger, D. S.; Mikava, D.; Tvaliashvili, A.

    2016-12-01

    The Black Sea Basin is the part of the Arabian Eurasian Collision zone and important unit for understanding the tectonic process of the region. This complex basin comprises two deep basins, separated by the mid-Black Sea Ridge. The basement of the Black Sea includes areas with oceanic and continental crust. It was formed as a "back-arc" basin over the subduction zone during the closing of the Tethys Ocean. In the past decades the Black Sea has been the subject of intense geological and geophysical studies. Several papers were published about the geological history, tectonics, basement relief and crustal and upper mantle structure of the basin. New tectonic schemes were suggested (e. g. Nikishin et al 2014, Shillington et al. 2008, Starostenko et al. 2004 etc.). Nevertheless, seismicity of the Black Sea is poorly studied due to the lack of seismic network in the coastal area. It is considered, that the eastern basin currently lies in a compressional setting associated with the uplift of the Caucasus and structural development of the Caucasus was closely related to the evolution of the Eastern Black Sea Basin. Analyses of recent sequence of earthquakes in 2012 can provide useful information to understand complex tectonic structure of the Eastern Black Sea region. Right after the earthquake of 2012/12/23, National Seismic monitoring center of Georgia deployed additional 4 stations in the coastal area of the country, close to the epicenter area, to monitor aftershock sequence. Seismic activity in the epicentral area is continuing until now. We have relocated approximately 1200 aftershocks to delineate fault scarf using data from Georgian, Turkish and Russian datacenters. Waveforms of the major events and the aftershocks were inverted for the fault plane solutions of the events. For the inversion were used green's functions, computed using new 1D velocity model of the region. Strike-slip mechanism of the major events of the earthquake sequence indicates extensional

  14. First record of the polychaetous annelid Diopatra micrura Pires et al., 2010 in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    A. ARIAS

    2013-07-01

    Full Text Available Until now the only recognised species of the onuphid genus Diopatra in the Mediterranean Sea was D. neapolitana. This paper reports the presence of another species, D. micrura, in the western Mediterranean, occurring in shallow waters along the coasts of southeastern Spain.

  15. First record of the polychaetous annelid Diopatra micrura Pires et al., 2010 in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    A. ARIAS

    2013-12-01

    Full Text Available Until now the only recognised species of the onuphid genus Diopatra in the Mediterranean Sea was D. neapolitana. This paper reports the presence of another species, D. micrura, in the western Mediterranean, occurring in shallow waters along the coasts of southeastern Spain. 

  16. A new alien gastropod Pseudorhaphitoma iodolabiata (Hornung & Mermod, 1928 (Mangeliidae, Mollusca in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    B. OZTURK

    2012-12-01

    Full Text Available The study documents the occurrence of a new alien gastropod Pseudorhaphitoma iodolabiata in the Mediterranean Sea, collected inIskenderun Bay, Turkey, on September 2011. This record increases to 213 the number of alien molluscs in the Mediterranean.

  17. Octopus vulgaris (Cuvier, 1797) in the Mediterranean Sea: Genetic Diversity and Population Structure: e0149496

    National Research Council Canada - National Science Library

    Daniele De Luca; Gaetano Catanese; Gabriele Procaccini; Graziano Fiorito

    2016-01-01

      The common octopus, Octopus vulgaris Cuvier 1797, is a largely exploited cephalopod species in the Mediterranean Sea and the Atlantic Ocean, as well as along the coasts of Africa, Brazil and Japan...

  18. Phylogeographic patterns of Merodon hoverflies in the Eastern Mediterranean region: revealing connections and barriers.

    Science.gov (United States)

    Ståhls, Gunilla; Vujić, Ante; Petanidou, Theodora; Cardoso, Pedro; Radenković, Snezana; Ačanski, Jelena; Pérez Bañón, Celeste; Rojo, Santos

    2016-04-01

    We investigated the phylogeographic patterns of Merodon species (Diptera, Syrphidae) in the Eastern Mediterranean. Ten species were sampled on five different islands and mainland sites as a minimum. All samples were screened for their mtDNA COI barcode haplotype diversity, and for some samples, we additionally generated genomic fingerprints. The recently established zoogeographic distribution categories classify these species as having (1) Balkan distribution; (2) Anatolian distribution; (3) continental areas and large islands distribution; and (4) with wide distribution. The ancestral haplotypes and their geographical localities were estimated with statistical parsimony (TCS). TCS networks identified as the ancestral haplotype samples that originated from localities situated within the distributional category of the species in question. Strong geographical haplotype structuring was detected for many Merodon species. We were particularly interested to test the relative importance of current (Aegean Sea) and past Mid-Aegean Trench) barriers to dispersal for Merodon flies in the Aegean. We employed phylogenetic β-diversity (Pβ total) and its partition in replacement (Pβ repl) and richness difference (Pβ rich) to test the importance of each explanatory variable (interisland distance, MAT, and island area) in interisland differences using partial Mantel tests and hierarchical partitioning of variation. β-Analyses confirmed the importance of both current and past barriers to dispersal on the evolution of group. Current interisland distance was particularly important to explain the replacement of haplotypes, while the MAT was driving differences in richness of haplotypes, revealing the MAT as a strong past barrier whose effects are still visible today in the phylogenetic history of the clade in the Aegean. These results support the hypothesis of a highly restricted dispersal and gene flow among Merodon populations between islands since late Pleistocene. Additionally

  19. Recent sea surface temperature trends and future scenarios for the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Mohamed Shaltout

    2014-06-01

    Full Text Available We analyse recent Mediterranean Sea surface temperatures (SSTs and their response to global change using 1/4-degree gridded advanced very-high-resolution radiometer (AVHRR daily SST data, 1982–2012. These data indicate significant annual warming (from 0.24 °C decade−1 west of the Strait of Gibraltar to 0.51 °C decade−1 over the Black Sea and significant spatial variation in annual average SST (from 15 °C over the Black Sea to 21 °C over the Levantine sub-basin. Ensemble mean scenarios indicate that the study area SST may experience significant warming, peaking at 2.6 °C century−1 in the Representative Concentration Pathways 85 (RCP85 scenario.

  20. Recent sea surface temperature trends and future scenarios for the Mediterranean Sea:

    Directory of Open Access Journals (Sweden)

    Mohamed Shaltout

    2014-06-01

    Full Text Available We analyse recent Mediterranean Sea surface temperatures (SSTs and their response to global change using 1/4-degree gridded advanced very-high-resolution radiometer (AVHRR daily SST data, 1982-2012. These data indicate significant annual warming (from 0.24°C decade-1 west of the Strait of Gibraltar to 0.51°C decade-1 over the Black Sea and significant spatial variation in annual average SST (from 15ºC over the Black Sea to 21°C over the Levantine sub-basin. Ensemble mean scenarios indicate that the study area SST may experience significant warming, peaking at 2.6°C century-1 in the Representative Concentration Pathways 85 (RCP85 scenario.

  1. Calculating the water and heat balances of the Eastern Mediterranean Basin using ocean modelling and available meteorological, hydrological and ocean data

    Directory of Open Access Journals (Sweden)

    Anders Omstedt

    2012-04-01

    Full Text Available Eastern Mediterranean water and heat balances wereanalysed over 52 years. The modelling uses a process-orientedapproach resolving the one-dimensional equations of momentum,heat and salt conservation; turbulence is modelled using a two-equation model. The results indicate that calculated temperature and salinity follow the reanalysed data well. The water balance in the Eastern Mediterranean basin was controlled by the difference between inflows and outflows through the Sicily Channel and by net precipitation. The freshwater component displayed a negative trend over the study period, indicating increasing salinity in the basin.The heat balance was controlled by heat loss from the water surface, solar radiation into the sea and heat flow through the Sicily Channel. Both solar radiation and net heat loss displayed increasing trends, probably due to decreased total cloud cover. In addition, the heat balance indicated a net import of approximately 9 W m-2 of heat to the Eastern Mediterranean Basin from the Western Basin.

  2. Shallow water wave spectral characteristics along the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Shanas, P.R.; Dubhashi, K.K.

    The spectral characteristics of shallow water waves were studied at two locations along the eastern Arabian Sea during 2011. Wave spectra were single-peaked from June to October and predominantly double-peaked during the rest of the year. Even...

  3. Multivariate Empirical Orthogonal Function analysis of the upper thermocline structure of the Mediterranean Sea from observations and model simulations

    Directory of Open Access Journals (Sweden)

    S. Sparnocchia

    Full Text Available Multivariate vertical Empirical Orthogonal Functions (EOF are calculated for the entire Mediterranean Sea both from observations and model simulations, in order to find the optimal number of vertical modes to represent the upper thermocline vertical structure. For the first time, we show that the large-scale Mediterranean thermohaline vertical structure can be represented by a limited number of vertical multivariate EOFs, and that the "optimal set" can be selected on the basis of general principles. In particular, the EOFs are calculated for the combined temperature and salinity statistics, dividing the Mediterranean Sea into 9 regions and grouping the data seasonally. The criterion used to establish whether a reduced set of EOFs is optimal is based on the analysis of the root mean square residual error between the original data and the profiles reconstructed by the reduced set of EOFs. It was found that the number of EOFs needed to capture the variability contained in the original data changes with geographical region and seasons. In particular, winter data require a smaller number of modes (4–8, depending on the region than the other seasons (8–9 in summer. Moreover, western Mediterranean regions require more modes than the eastern Mediterranean ones, but this result may depend on the data scarcity in the latter regions. The EOFs computed from the in situ data set are compared to those calculated using data obtained from a model simulation. The main results of this exercise are that the two groups of modes are not strictly comparable but their ability to reproduce observations is the same. Thus, they may be thought of as equivalent sets of basis functions, upon which to project the thermohaline variability of the basin.

    Key words. Oceanography: general (water masses – Oceanography: physical (hydrography; instruments and techniques

  4. Near-field tsunami early warning and emergency planning in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Gerassimos A. Papadopoulos

    2013-04-01

    Full Text Available The new European project Near-field Tsunami Early Warning and Emergency Planning in the Mediterranean Sea (NEARTOWARN faces the need to develop operational tsunami early warning systems in near-field (local conditions where the travel time of the first tsunami wave is very short, that is less than 30 min, which is a typical case in the North East Atlantic and the Mediterranean Sea region but also elsewhere around the globe. The operational condition that should be fulfilled is that the time of tsunami detection, plus the time of warning transmitting, plus the time of evacuation should not exceed the travel time of the first tsunami wave from its source to the closest evacuation zone. To this goal the time to detect of the causative earthquake should be compressed at the very minimum. In this context the core of the proposed system is a network of seismic early warning devices, which activate and send alert in a few seconds after the generation of a near-field earthquake, when a seismic ground motion exceeding a prescribed threshold is detected. Then civil protection mobilizes to manage the earthquake crisis but also to detect and manage a possible tsunami through a geographical risk management system. For the tsunami detection the system is supported by tide-gauges of radar type, a database of presimulated tsunami scenarios, and a local tsunami decision matrix. The island of Rhodes in the eastern termination of the Hellenic Arc and Trench has been selected for a pilot and operational development of the local tsunami warning system given that the island is a highly popular tourist destination, historically it was hit by large tsunamigenic earthquakes and was recently the master test-site for the pan-European FP6 tsunami research project Tsunami Risk ANd Strategies For the European Region (TRANSFER.

  5. Zooplankton incidence in abnormally high sea surface temperature in the Eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Zooplankton in an abnormally high sea surface temperature (33.1 to 33.8 degrees C) and alternate bands of slick formation were studied in the Eastern Arabian Sea during 26 and 29 April 1981. The phenomenon which may be due to intense diurnal heating...

  6. Extant Rhabdosphaeraceae (coccolithophorids, class Prymnesiophyceae) from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean

    NARCIS (Netherlands)

    Kleijne, A.

    1992-01-01

    Rhabdosphaerids were consistently present as a minor constituent of the 1985 summer coccolithophorid flora in surface waters of the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic. Sixteen taxa are identified, belonging to seven genera, including the two new combinations Cyrtosphaera acu

  7. The Genus Lepidochitona Gray, 1821 (Mollusca: Polyplacophora) in the Northeastern Atlantic Ocean, The Mediterranean Sea and the Black Sea

    NARCIS (Netherlands)

    Kaas, P.; Belle, van R.A.

    1981-01-01

    Nine species of Lepidochitona from the NE Atlantic and adjacent seas are described, two of which are new to science: L. monterosatoi from the Mediterranean Sea, and L. iberica from Ria de Arosa, NW Spain. The taxa Middendorffia Dall, 1882, and Mopaliella Thiele, 1909, are rejected and synonymized

  8. Productivity changes in the Mediterranean Sea for the 21st century in response to changes in the regional atmospheric forcing

    Directory of Open Access Journals (Sweden)

    Diego M Macias

    2015-10-01

    Full Text Available The Mediterranean Sea is considered as a hotspot for climate change because of its location in the temperate region and because it is a semi-enclosed basin surrounded by highly populated and developed countries. Some expected changes include an increase in air temperature and changes in the periodicity and spatial distribution of rainfall. Alongside, demographic and politics changes will alter freshwater quantity and quality. All these changes will have an impact on the ecological status of marine ecosystems in the basin. We use a 3D hydrodynamic-biogeochemical coupled model of the entire Mediterranean Sea to explore potential changes in primary productivity (mean values and spatial distribution under two emission scenarios (rcp4.5 and rcp8.5.To isolate the effects of changes in atmospheric conditions alone, in this ensemble of simulations rivers conditions (water flow and nutrient concentrations are kept unchanged and equal to its climatological values for the last 10 years. Despite the significant warming trend, the mean integrated primary production rate in the entire basin remains almost unchanged. However characteristic spatial differences are consistently found in the different simulations. The western basin becomes more oligotrophic associated to a surface density decrease (increase stratification because of the influence of the Atlantic waters which prevents surface salinity to increase. In the eastern basin, on the contrary, all model runs simulates an increase in surface production linked to a density increase (less stratification because of the increasing evaporation rate. The simulations presented here demonstrate the basic response patterns of the Mediterranean Sea ecosystem to changing climatological conditions. Although unlikely, they could be considered as a ‘baseline’ of expected consequences of climatic changes on marine conditions in the Mediterranean.

  9. Biogeochemical and physical controls on concentrations of polycyclic aromatic hydrocarbons in water and plankton of the Mediterranean and Black Seas

    Science.gov (United States)

    Berrojalbiz, Naiara; Dachs, Jordi; Ojeda, MaríA. José; Valle, MaríA. Carmen; Castro-JiméNez, Javier; Wollgast, Jan; Ghiani, Michela; Hanke, Georg; Zaldivar, José Manuel

    2011-12-01

    The Mediterranean and Black Seas are unique marine environments subject to important anthropogenic pressures due to atmospheric and riverine inputs of organic pollutants. They include regions of different physical and trophic characteristics, which allow the studying of the controls on pollutant occurrence and fate under different conditions in terms of particles, plankton biomass, interactions with the atmosphere, biodegradation, and their dependence on the pollutant physical chemical properties. Polycyclic Aromatic Hydrocarbons (PAHs) have been measured in samples of seawater (dissolved and particulate phases) and plankton during two east-west sampling cruises in June 2006 and May 2007. The concentrations of dissolved PAHs were higher in the south-western Black Sea and Eastern Mediterranean than in the Western Mediterranean, reflecting different pollutant loads, trophic conditions and cycling. Particle and plankton phase PAH concentrations were higher when lower concentrations of suspended particles and biomass occurred, with apparent differences due to the PAH physical chemical properties. The surface PAH particle phase concentrations decreased when the total suspended particles (TSP) increased for the higher molecular weight (MW) compounds, consistent with controls due to particle settling depletion of water column compounds and dilution. Conversely, PAH concentrations in plankton decreased at higher biomass only for the low MW PAHs, suggesting that biodegradative processes in the water column are a major driver of their occurrence in the photic zone. The results presented here are the most extensive data set available for the Mediterranean Sea and provide clear evidence of the important physical and biological controls on PAH occurrence and cycling in oceanic regions.

  10. Reanalysis of biogeochemical properties in the Mediterranean Sea

    Science.gov (United States)

    Cossarini, Gianpiero; Teruzzi, Anna; Salon, Stefano; Solidoro, Cosimo

    2014-05-01

    In the 3D variational (3DVAR) assimilation approach the error covariance matrix can be decomposed in a series of operators. The decomposition makes the 3DVAR particularly suitable for marine biogeochemistry data assimilation, because of the reduced computational costs of the method and its modularity, which allows to define the covariance among the biogeochemical variables in a specific operator. In the present work, the results of 3DVAR assimilation of surface chlorophyll concentration in a multi-annual simulation of the Mediterranean Sea biogeochemistry are presented. The assimilated chlorophyll concentrations are obtained from satellite observations (Volpe et al. 2012). The multi-annual simulation is carried out using the OPATM-BFM model (Lazzari et al. 2012), which describes the low trophic web dynamics and is offline coupled with the MFS physical model (Oddo et al. 2009). In the OPATM-BFM four types of phytoplankton are simulated in terms of their content in carbon, nitrogen, phosphorous, silicon and chlorophyll. In the 3DVAR the error covariance matrix has been decomposed in three different operators, which account for the vertical, the horizontal and the biogeochemical covariance (Teruzzi et al. 2014). The biogeochemical operator propagates the result of the assimilation to the OPATM-BFM variables, providing innovation for the components of the four phytoplankton types. The biogeochemical covariance has been designed supposing that the assimilation preserves the physiological status and the relative abundances of phytoplankton types. Practically, the assimilation preserves the internal quotas of the components for each phytoplankton as long as the optimal growth rate condition are maintained. The quotas preservation is not applied when the phytoplankton is in severe declining growth phase, and the correction provided by the assimilation is set equal to zero. Moreover, the relative abundances among the phytoplankton functional types are preserved. The 3DVAR

  11. Sea truth validation of sea WiFS ocean colour sensor in the coastal waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Suresh, T.; Matondkar, S.G.P.; Desa, E.

    In this paper we report bio-optical measurements made during an ocean colour validation cruise SK 149C in November 1999 of the research vessel Sagar Kanya in the coastal waters of the Eastern Arabian Sea. The chlorophyll concentration...

  12. Quaternary active tectonic structures in the offshore Bajo Segura basin (SE Iberian Peninsula - Mediterranean Sea)

    Science.gov (United States)

    Perea, H.; Gràcia, E.; Alfaro, P.; Bartolomé, R.; Lo Iacono, C.; Moreno, X.; Masana, E.; Event-Shelf Team

    2012-10-01

    The Bajo Segura fault zone (BSFZ) is the northern terminal splay of the Eastern Betic shear zone (EBSZ), a large left-lateral strike-slip fault system of sigmoid geometry stretching more than 450 km from Alicante to Almería. The BSFZ extends from the onshore Bajo Segura basin further into the Mediterranean Sea and shows a moderate instrumental seismic activity characterized by small earthquakes. Nevertheless, the zone was affected by large historical earthquakes of which the largest was the 1829 Torrevieja earthquake (IEMS98 X). The onshore area of the BSFZ is marked by active transpressive structures (faults and folds), whereas the offshore area has been scarcely explored from the tectonic point of view. During the EVENT-SHELF cruise, a total of 10 high-resolution single-channel seismic sparker profiles were obtained along and across the offshore Bajo Segura basin. Analysis of these profiles resulted in (a) the identification of 6 Quaternary seismo-stratigraphic units bounded by five horizons corresponding to regional erosional surfaces related to global sea level lowstands; and (b) the mapping of the active sub-seafloor structures and their correlation with those described onshore. Moreover, the results suggest that the Bajo Segura blind thrust fault or the Torrevieja left-lateral strike-slip fault, with prolongation offshore, could be considered as the source of the 1829 Torrevieja earthquake. These data improve our understanding of present deformation along the BSFZ and provide new insights into the seismic hazard in the area.

  13. Calculating the water and heat balances of the Eastern Mediterranean basin using ocean modelling and available meteorological, hydrological, and ocean data

    Directory of Open Access Journals (Sweden)

    M. Shaltout

    2011-06-01

    Full Text Available This paper analyses the Eastern Mediterranean water and heat balances over a 52-yr period. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat, and salt conservation, with turbulence modelled using a two-equation model. The exchange through the Sicily Channel connecting the Eastern and Western basins is calculated from satellite altimeter data. The results illustrates that calculated surface temperature and salinity follow the reanalysed data well and with biases of −0.4 °C and −0.004, respectively. Monthly and yearly temperature and salinity cycles are also satisfactory simulated. Reanalysed data and calculated water mass structure and heat balance components are in good agreement, indicating that the air-sea interaction and the turbulent mixing are realistically simulated. The study illustrates that the water balance in the Eastern Mediterranean basin is controlled by the difference between inflows/outflows through the Sicily Channel and by the net precipitation rates. The heat balance is controlled by the heat loss from the water surface, sun radiation into the sea, and heat flow through the Sicily Channel, the first two displaying both climate trends. An annual net heat loss of approximately 9 W m−2 was balanced by net heat in flow through the Sicily Channel.

  14. Calculating the water and heat balances of the Eastern Mediterranean basin using ocean modelling and available meteorological, hydrological, and ocean data

    Science.gov (United States)

    Shaltout, M.; Omstedt, A.

    2011-06-01

    This paper analyses the Eastern Mediterranean water and heat balances over a 52-yr period. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat, and salt conservation, with turbulence modelled using a two-equation model. The exchange through the Sicily Channel connecting the Eastern and Western basins is calculated from satellite altimeter data. The results illustrates that calculated surface temperature and salinity follow the reanalysed data well and with biases of -0.4 °C and -0.004, respectively. Monthly and yearly temperature and salinity cycles are also satisfactory simulated. Reanalysed data and calculated water mass structure and heat balance components are in good agreement, indicating that the air-sea interaction and the turbulent mixing are realistically simulated. The study illustrates that the water balance in the Eastern Mediterranean basin is controlled by the difference between inflows/outflows through the Sicily Channel and by the net precipitation rates. The heat balance is controlled by the heat loss from the water surface, sun radiation into the sea, and heat flow through the Sicily Channel, the first two displaying both climate trends. An annual net heat loss of approximately 9 W m-2 was balanced by net heat in flow through the Sicily Channel.

  15. Systematic reviews addressing identified health policy priorities in Eastern Mediterranean countries: a situational analysis.

    Science.gov (United States)

    El-Jardali, Fadi; Akl, Elie A; Karroum, Lama Bou; Kdouh, Ola; Akik, Chaza; Fadlallah, Racha; Hammoud, Rawan

    2014-08-20

    Systematic reviews can offer policymakers and stakeholders concise, transparent, and relevant evidence pertaining to pressing policy priorities to help inform the decision-making process. The production and the use of systematic reviews are specifically limited in the Eastern Mediterranean region. The extent to which published systematic reviews address policy priorities in the region is still unknown. This situational analysis exercise aims at assessing the extent to which published systematic reviews address policy priorities identified by policymakers and stakeholders in Eastern Mediterranean region countries. It also provides an overview about the state of systematic review production in the region and identifies knowledge gaps. We conducted a systematic search of the Health System Evidence database to identify published systematic reviews on policy-relevant priorities pertaining to the following themes: human resources for health, health financing, the role of the non-state sector, and access to medicine. Priorities were identified from two priority-setting exercises conducted in the region. We described the distribution of these systematic reviews across themes, sub-themes, authors' affiliations, and countries where included primary studies were conducted. Out of the 1,045 systematic reviews identified in Health System Evidence on selected themes, a total of 200 systematic reviews (19.1%) addressed the priorities from the Eastern Mediterranean region. The theme with the largest number of systematic reviews included was human resources for health (115) followed by health financing (33), access to medicine (27), and role of the non-state sector (25). Authors based in the region produced only three systematic reviews addressing regional priorities (1.5%). Furthermore, no systematic review focused on the Eastern Mediterranean region. Primary studies from the region had limited contribution to systematic reviews; 17 systematic reviews (8.5%) included primary

  16. High resolution surface solar radiation patterns over Eastern Mediterranean: Satellite, ground-based, reanalysis data and radiative transfer simulations

    Science.gov (United States)

    Alexandri, G.; Georgoulias, A.; Meleti, C.; Balis, D.

    2013-12-01

    Surface solar radiation (SSR) and its long and short term variations play a critical role in the modification of climate and by extent of the social and financial life of humans. Thus, SSR measurements are of primary importance. SSR is measured for decades from ground-based stations for specific spots around the planet. During the last decades, satellite observations allowed for the assessment of the spatial variability of SSR at a global as well as regional scale. In this study, a detailed spatiotemporal view of the SSR over Eastern Mediterranean is presented at a high spatial resolution. Eastern Mediterranean is affected by various aerosol types (continental, sea, dust and biomass burning particles) and encloses countries with significant socioeconomical changes during the last decades. For the aims of this study, SSR data from satellites (Climate Monitoring Satellite Application Facility - CM SAF) and our ground station in Thessaloniki, a coastal city of ~1 million inhabitants in northern Greece, situated in the heart of Eastern Mediterranean (Eppley Precision pyranometer and Kipp & Zonen CM-11 pyranometer) are used in conjunction with radiative transfer simulations (Santa Barbara DISORT Atmospheric Radiative Transfer - SBDART). The CM SAF dataset used here includes monthly mean SSR observations at a high spatial resolution of 0.03x0.03 degrees for the period 1983-2005. Our ground-based SSR observations span from 1983 until today. SBDART radiative transfer simulations were implemented for a number of spots in the area of study in order to calculate the SSR. High resolution (level-2) aerosol and cloud data from MODIS TERRA and AQUA satellite sensors were used as input, as well as ground-based data from the AERONET. Data from other satellites (Earth Probe TOMS, OMI, etc) and reanalysis projects (ECMWF) were used where needed. The satellite observations, the ground-based measurements and the model estimates are validated against each other. The good agreement

  17. Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe

    Science.gov (United States)

    Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A.; Tilinina, Natalia; Gulev, Sergey K.; Latif, Mojib

    2016-08-01

    The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970-1999 and 2000-2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000-2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970-1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes.

  18. Atmospheric Deposition And MediterraneAN sea water productiviTy (Thales - ADAMANT) An overview

    Science.gov (United States)

    Christodoulaki, Sylvia; Petihakis, George; Triantafyllou, George; Pitta, Paraskevi; Papadimitriou, Vassileios; Tsiaras, Konstantinos; Mihalopoulos, Nikolaos; Kanakidou, Maria

    2015-04-01

    In the marine environment the salinity and biological pumps sequester atmospheric carbon dioxide. The biological pump is directly related to marine primary production which is controlled by nutrient availability mainly of iron, nitrogen and phosphorus. The Mediterranean Sea, especially the eastern basin is one of the most oligotrophic seas. The nitrogen (N) to phosphorus (P) ratio is unusually high, especially in the eastern basin (28:1) and primary production is limited by phosphorus availability. ADAMANT project contributes to new knowledge into how nutrients enter the marine environment through atmospheric deposition, how they are assimilated by organisms and how this influences carbon and nutrient fluxes. Experimental work has been combined with atmospheric and marine models. Important knowledge is obtained on nutrients deposition through mesocosm experiments on their uptake by the marine systems and their effects on the marine carbon cycle and food chain. Kinetic parameters of adsorption of acidic and organic volatile compounds in atmospheric samples of dust and marine salts are estimated in conjunction with solubility of N and P in mixtures contained in dust. Atmospheric and oceanographic models are coupled to create a system that is able to holistically simulate the effects of atmospheric deposition on the marine environment over time, beginning from the pre-industrial era until the future years (hind cast, present and forecast simulations). This research has been co-financed by the European Union (European Social Fund) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework - Research Funding Program: THALES, Investing in knowledge society through European Social Fund.

  19. Spatiotemporal variability and contribution of different aerosol types to the aerosol optical depth over the Eastern Mediterranean

    Science.gov (United States)

    Georgoulias, Aristeidis K.; Alexandri, Georgia; Kourtidis, Konstantinos A.; Lelieveld, Jos; Zanis, Prodromos; Pöschl, Ulrich; Levy, Robert; Amiridis, Vassilis; Marinou, Eleni; Tsikerdekis, Athanasios

    2016-11-01

    This study characterizes the spatiotemporal variability and relative contribution of different types of aerosols to the aerosol optical depth (AOD) over the Eastern Mediterranean as derived from MODIS (Moderate Resolution Imaging Spectroradiometer) Terra (March 2000-December 2012) and Aqua (July 2002-December 2012) satellite instruments. For this purpose, a 0.1° × 0.1° gridded MODIS dataset was compiled and validated against sun photometric observations from the AErosol RObotic NETwork (AERONET). The high spatial resolution and long temporal coverage of the dataset allows for the determination of local hot spots like megacities, medium-sized cities, industrial zones and power plant complexes, seasonal variabilities and decadal averages. The average AOD at 550 nm (AOD550) for the entire region is ˜ 0.22 ± 0.19, with maximum values in summer and seasonal variabilities that can be attributed to precipitation, photochemical production of secondary organic aerosols, transport of pollution and smoke from biomass burning in central and eastern Europe and transport of dust from the Sahara and the Middle East. The MODIS data were analyzed together with data from other satellite sensors, reanalysis projects and a chemistry-aerosol-transport model using an optimized algorithm tailored for the region and capable of estimating the contribution of different aerosol types to the total AOD550. The spatial and temporal variability of anthropogenic, dust and fine-mode natural aerosols over land and anthropogenic, dust and marine aerosols over the sea is examined. The relative contribution of the different aerosol types to the total AOD550 exhibits a low/high seasonal variability over land/sea areas, respectively. Overall, anthropogenic aerosols, dust and fine-mode natural aerosols account for ˜ 51, ˜ 34 and ˜ 15 % of the total AOD550 over land, while, anthropogenic aerosols, dust and marine aerosols account ˜ 40, ˜ 34 and ˜ 26 % of the total AOD550 over the sea, based on

  20. Physiography and structure of Bacino Bannock (eastern mediterranean)

    Science.gov (United States)

    Camerlenghi, Angelo; McCoy, Floyd W.

    1990-03-01

    Detailed analysis of the morphology of Bacino Bannock, a deep-sea basin filled by a hypersaline brine, shows with unusual detail the effect on the ocean floor topography of the deformation and dissolution of a salt body under tectonic stress. Although salt diapirism occurs in the central part of the investigated area, the major cause of basin formation is dissolution of subsurface evaporites which creates negative relief that exceeds by about one order of magnitude the positive relief. The true shape of the deformed salt deposit is preserved as a result of the absence of a thick post-evaporites sedimentary cover.

  1. The role of the Miocene-to-Pliocene transition in the Eastern Mediterranean extrusion tectonics: Constraints from numerical modelling

    Science.gov (United States)

    Capitanio, Fabio A.

    2016-08-01

    In the Eastern Mediterranean, extension in the Aegean Sea and lateral Anatolian extrusion are contrasting and seemingly unrelated examples of continental tectonics developed during Tethys closure. We use numerical modelling to investigate the relation of the tectonic regimes to the underlying subduction dynamics, during subduction land-locking and slab break-off. We find that the tectonics has a two-phase evolution: 1) an incipient phase, with back arc spreading and transcurrent shear zone formation and lateral escape of a block in the upper plate interiors, and 2) a reorganisation phase, during which the transcurrent shear zone propagates and the extruding block internally stretches, progressively separating from the opening back arc domain, while the collisional margin reactivates into a transform plate boundary. The regimes are explained by two concurring plate margin processes: 1) mantle tractions following the subduction and retreat of a land-locked oceanic slab, and 2) stresses propagated through rigid indentation upon slab break-off. These have different spatial and temporal fingerprints: long-term trench retreat and convergence slow-down follow continental subduction, while stresses localise atop the newly formed slab edge upon slab break-off, fastening up margin reorganisation, driving faulting and extrusion, yet fading rapidly, forcing local tectonics rearrangement. A comparison with the Eastern Mediterranean allows an explanation for the time evolution of the tectonics here, and emphasises the role of the Miocene-to-Pliocene tectonics transition, previously not considered. This offers a novel key to the dynamics of the enigmatic evolution of this area.

  2. Results on SSH neural network forecasting in the Mediterranean Sea

    Science.gov (United States)

    Rixen, Michel; Beckers, Jean-Marie; Alvarez, Alberto; Tintore, Joaquim

    2002-01-01

    Nowadays, satellites are the only monitoring systems that cover almost continuously all possible ocean areas and are now an essential part of operational oceanography. A novel approach based on artificial intelligence (AI) concepts, exploits pasts time series of satellite images to infer near future ocean conditions at the surface by neural networks and genetic algorithms. The size of the AI problem is drastically reduced by splitting the spatio-temporal variability contained in the remote sensing data by using empirical orthogonal function (EOF) decomposition. The problem of forecasting the dynamics of a 2D surface field can thus be reduced by selecting the most relevant empirical modes, and non-linear time series predictors are then applied on the amplitudes only. In the present case study, we use altimetric maps of the Mediterranean Sea, combining TOPEX-POSEIDON and ERS-1/2 data for the period 1992 to 1997. The learning procedure is applied to each mode individually. The final forecast is then reconstructed form the EOFs and the forecasted amplitudes and compared to the real observed field for validation of the method.

  3. The diet and feeding ecology of Conger conger (L. 1758 in the deep waters of the Eastern Ionian Sea

    Directory of Open Access Journals (Sweden)

    A. ANASTASOPOULOU

    2013-07-01

    Full Text Available The diet of the European conger eel Conger conger was investigated for the first time in the Eastern Mediterranean. Fish dominated the European conger eel diet in the deep waters of E. Ionian Sea. All other prey taxa were identified as accidental preys. However, intestine analysis showed that Natantia, Brachyura and Cephalopoda might have a more important contribution in the diet of the species. C. conger exhibited a benthopelagic feeding behavior as it preyed upon both demersal and mesopelagic taxa. The high vacuity index and the low stomach and intestine fullness indicated that the feeding intensity of the species in the deep waters of Eastern Ionian Sea was quite low. C. conger feeding strategy was characterised by specialisation in various resource items. A between-phenotype contribution to niche width was observed for some prey categories. European Conger eel feeding specialisation seemed to be an adaptation to a food-scarce environment, as typified in deep-water habitats

  4. The Mediterranean Sea system: a review and an introduction to the special issue

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    T. Tanhua

    2013-09-01

    Full Text Available The Mediterranean Sea is a semi-enclosed sea characterized by high salinities, temperatures and densities. The net evaporation exceeds the precipitation, driving an anti-estuarine circulation through the Strait of Gibraltar, contributing to very low nutrient concentrations. The Mediterranean Sea has an active overturning circulation, one shallow cell that communicates directly with the Atlantic Ocean, and two deep overturning cells, one in each of the two main basins. It is surrounded by populated areas and is thus sensitive to anthropogenic forcing. Several dramatic changes in the oceanographic and biogeochemical conditions have been observed during the past several decades, emphasizing the need to better monitor and understand the changing conditions and their drivers. During 2011 three oceanographic cruises were conducted in a coordinated fashion in order to produce baseline data of important physical and biogeochemical parameters that can be compared to historic data and be used as reference for future observational campaigns. In this article we provide information on the Mediterranean Sea oceanographic situation, and present a short review that will serve as background information for the special issue in Ocean Science on "Physical, chemical and biological oceanography of the Mediterranean Sea". An important contribution of this article is the set of figures showing the large-scale distributions of physical and chemical properties along the full length of the Mediterranean Sea.

  5. Population genetic structure in Sabatieria (Nematoda) reveals intermediary gene flow and admixture between distant cold seeps from the Mediterranean Sea.

    Science.gov (United States)

    De Groote, Annelies; Hauquier, Freija; Vanreusel, Ann; Derycke, Sofie

    2017-07-01

    There is a general lack of information on the dispersal and genetic structuring for populations of small-sized deep-water taxa, including free-living nematodes which inhabit and dominate the seafloor sediments. This is also true for unique and scattered deep-sea habitats such as cold seeps. Given the limited dispersal capacity of marine nematodes, genetic differentiation between such geographically isolated habitat patches is expected to be high. Against this background, we examined genetic variation in both mitochondrial (COI) and nuclear (18S and 28S ribosomal) DNA markers of 333 individuals of the genus Sabatieria, abundantly present in reduced cold-seep sediments. Samples originated from four Eastern Mediterranean cold seeps, separated by hundreds of kilometers, and one seep in the Southeast Atlantic. Individuals from the Mediterranean and Atlantic were divided into two separate but closely-related species clades. Within the Eastern Mediterranean, all specimens belonged to a single species, but with a strong population genetic structure (ΦST = 0.149). The haplotype network of COI contained 19 haplotypes with the most abundant haplotype (52% of the specimens) shared between all four seeps. The number of private haplotypes was high (15), but the number of mutations between haplotypes was low (1-8). These results indicate intermediary gene flow among the Mediterranean Sabatieria populations with no evidence of long-term barriers to gene flow. The presence of shared haplotypes and multiple admixture events indicate that Sabatieria populations from disjunct cold seeps are not completely isolated, with gene flow most likely facilitated through water current transportation of individuals and/or eggs. Genetic structure and molecular diversity indices are comparable to those of epiphytic shallow-water marine nematodes, while no evidence of sympatric cryptic species was found for the cold-seep Sabatieria.

  6. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

    Directory of Open Access Journals (Sweden)

    K. Sevastou

    2012-12-01

    Full Text Available The long held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and bacteria, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine spanning over 4 km in depth revealed a high diversity in terms of both metazoan meiofauna and microbial communities. The higher meiofaunal abundance and richness observed in the northern Aegean Sea highlights the effect of productivity on benthic patterns. Non parametric analyses detected no differences for meiobenthic standing stocks and major taxa diversity (α, β, γ and δ components between the two habitats (basin vs. slope for the whole investigated area and within each region, but revealed significant bathymetric trends: abundance and richness follow the well-known gradient of decreasing values with increasing depth, whereas differentiation diversity (β- and δ-diversity increases with depth. In spite of a similar bathymetric trend observed for nematode genera richness, no clear pattern was detected with regard to habitat type; the observed number of nematode genera suggests higher diversity in slopes, whereas richness estimator Jack1 found no differences between habitats. On the other hand, δ-diversity was higher at the basin habitat, but no differences were found among depth ranges, though turnover values were high in all pairwise comparisons of the different depth categories. Results of multivariate analysis are in line with the above findings, indicating high

  7. Re-description of Timarete punctata (Polychaeta: Cirratulidae and its occurrence in the Mediterranean Sea

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    Melih Ertan Çinar

    2007-12-01

    Full Text Available Timarete punctata (Grube, 1859 is re-described based on type material. In addition, a lectotype and paralectotype are designated for this species. Specimens of T. punctata collected from the western Atlantic, Indian Ocean and Mediterranean Sea were examined and their morphological characters compared using correlation and regression analysis. A number of characters were found to be size- dependent. The presence of T. punctata in the Levantine Sea (but not in the rest of the Mediterranean suggests that it could be a Lessepsian species. This species might have previously been reported in the Levantine Sea as Cirriformia semicincta (Ehlers, 1905.

  8. Low planktic foraminiferal diversity and abundance observed in a spring 2013 west-east Mediterranean Sea plankton tow transect

    Science.gov (United States)

    Mallo, Miguel; Ziveri, Patrizia; Mortyn, P. Graham; Schiebel, Ralf; Grelaud, Michael

    2017-05-01

    Planktic foraminifera were collected with 150 µm BONGO nets from the upper 200 m water depth at 20 stations across the Mediterranean Sea between 2 May and 2 June 2013. The main aim is to characterize the species distribution and test the covariance between foraminiferal area density (ρA) and seawater carbonate chemistry in a biogeochemical gradient including ultraoligotrophic conditions. Average foraminifera abundances are 1.42 ± 1.43 ind. 10 m-3 (ranging from 0.11 to 5.20 ind. 10 m-3), including 12 morphospecies. Large differences in species assemblages and total abundances are observed between the different Mediterranean sub-basins, with an overall dominance of spinose, symbiont-bearing species indicating oligotrophic conditions. The highest values in absolute abundance are found in the Strait of Gibraltar and the Alboran Sea. The western basin is dominated by Globorotalia inflata and Globigerina bulloides at slightly lower standing stocks than in the eastern basin. In contrast, the planktic foraminiferal assemblage in the warmer, saltier, and more nutrient-limited eastern basin is dominated by Globigerinoides ruber (white). These new results, when combined with previous findings, suggest that temperature-induced surface water stratification and food availability are the main factors controlling foraminiferal distribution. In the oligotrophic and highly alkaline and supersaturated with respect to calcite and aragonite Mediterranean surface water, standing stocks and ρA of G. ruber (white) and G. bulloides are affected by both food availability and seawater carbonate chemistry. Rapid warming increased surface ocean stratification impacting food availability and changes in trophic conditions could be the causes of reduced foraminiferal abundance, diversity, and species-specific changes in planktic foraminiferal calcification.

  9. Toward tracing routes of bottom waters in the Eastern Mediterranean basin using a multidisciplinary approach

    Science.gov (United States)

    Rubino, Angelo; Zanchettin, Davide; Bensi, Manuel; Cardin, Vanessa; Hainbucher, Dagmar; Baldi, Franco; Marchetto, Davide; Mapelli, Francesca; Borin, Sara

    2013-04-01

    We use near-bottom measurements of total mercury, biopolymeric carbon and its constituents, microbial activities, and bacterial diversity to attempt tracing routes of convectively generated bottom waters toward the abyss of the Eastern Mediterranean basin. The advantage of employing these parameters -which are often linked to persistent biological activities rather than to episodic flow phenomena- to complement the traditionally used ones (temperature, salinity, and dissolved oxygen) is twofold: they can yield valuable information even when the values of temperature and salinity in competing sources are virtually indistinguishable and they can allow also for a spatial and temporal integration of the export of newly formed deep waters. In our case study -the Eastern Mediterranean basin, which can be considered as a miniature global ocean - the proposed method seems to be able to capture two different exporting routes from the northern convective source and one exporting route from the eastern convective source, thus elucidating further aspects of the structure and variability of the local deep stratification.

  10. Millennial to orbital-scale variations of drought intensity in the Eastern Mediterranean

    Science.gov (United States)

    Stockhecke, Mona; Timmermann, Axel; Kipfer, Rolf; Haug, Gerald H.; Kwiecien, Ola; Friedrich, Tobias; Menviel, Laurie; Litt, Thomas; Pickarski, Nadine; Anselmetti, Flavio S.

    2016-02-01

    Millennial to orbital-scale rainfall changes in the Mediterranean region and corresponding variations in vegetation patterns were the result of large-scale atmospheric reorganizations. In spite of recent efforts to reconstruct this variability using a range of proxy archives, the underlying physical mechanisms have remained elusive. Through the analysis of a new high-resolution sedimentary section from Lake Van (Turkey) along with climate modeling experiments, we identify massive droughts in the Eastern Mediterranean for the past four glacial cycles, which have a pervasive link with known intervals of enhanced North Atlantic glacial iceberg calving, weaker Atlantic Meridional Overturning Circulation and Dansgaard-Oeschger cold conditions. On orbital timescales, the topographic effect of large Northern Hemisphere ice sheets and periods with minimum insolation seasonality further exacerbated drought intensities by suppressing both summer and winter precipitation.

  11. A pollen-based environmental reconstruction in Lake Hazar (Eastern Turkey) during the Late Pleistocene-Holocene: Example for the Eastern Mediterranean Realm

    Science.gov (United States)

    Biltekin, Demet; Kadir Eris, Kürsad; Namik Cagatay, Memet; Nagihan Arslan, Tugce; Akcer On, Sena; Acar, Dursun

    2016-04-01

    Eastern Mediterranean realm historically is a melting area for ancient civilisations. This region has been therefore anthropogenically influenced since the Late Pleistocene. The understanding the processes between vegetation and climate, pollen analysis is a significant proxy in the investigation of past climate, vegetation records and the human influence on the environment. In this research, we carried out the environmental changes during the Late Pleistocene-Holocene using multi-proxy analysis (palynology, XRF core scanner, magnetic susceptibility and TOC) in the sediment core obtained from 54.39 m depth on the northern shelf of Lake Hazar using a percussion piston corer. Lake Hazar (38° 31' N-39° 25' E) is located at ca. 1255 m above sea level, 22 km south-east of Elazıǧ city in eastern Turkey in the south-east Taurus Mountains. It is an oligotrophic, alkaline soda and a tectonic lake being situated on East Anatolian Fault Zone (EAFZ). The chronology of the sediment core has been determined using AMS radiocarbon method. We present the first pollen record from the core sediments in Lake Hazar, providing insight into multi-millennial scale climatic changes over the last ~15 14C ka BP. In the piston core, the Bølling/Allerød period is associated by the presence of Pistacia reflecting milder winter conditions with high biological productivity. Onset of the Younger Dryas (YD) period is marked by increase in herbaceous plants and lake level lowering that can also be documented by high magnetic susceptibility and Ca/Ti ratio. The spread of deciduous Quercus at the beginning of Holocene can be attributed to significant forestation due to a high humidity that was presumably sufficient for the establishment of oak forest. An increase in Quercus continued in most of the early and middle Holocene. The 3rd millenium crisis is strongly characterized by an increase in herbal elements, and a decline in Quercus, pointing to dry climatic conditions. The most striking

  12. Thessaloniki Mud Volcano, the Shallowest Gas Hydrate-Bearing Mud Volcano in the Anaximander Mountains, Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    C. Perissoratis

    2011-01-01

    Full Text Available A detailed multibeam survey and the subsequent gravity coring carried out in the Anaximander Mountains, Eastern Mediterranean, detected a new active gas hydrate-bearing mud volcano (MV that was named Thessaloniki. It is outlined by the 1315 m bathymetric contour, is 1.67 km2 in area, and has a summit depth of 1260 m. The sea bottom water temperature is 13.7∘C. The gas hydrate crystals generally have the form of flakes or rice, some larger aggregates of them are up to 2 cm across. A pressure core taken at the site contained 3.1 lt. of hydrocarbon gases composed of methane, nearly devoid of propane and butane. The sediment had a gas hydrate occupancy of 0.7% of the core volume. These characteristics place the gas hydrate field at Thessaloniki MV at the upper boundary of the gas hydrate stability zone, prone to dissociation with the slightest increase in sea water temperature, decrease in hydrostatic pressure, or change in the temperature of the advecting fluids.

  13. The dissolved yellow substance and the shades of blue in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    B. Gentili

    2009-11-01

    Full Text Available When the nominal algorithms commonly in use in Space Agencies are applied to satellite Ocean Color data, the retrieved chlorophyll concentrations in the Mediterranean Sea are recurrently notable overestimates of the field values. Accordingly, several regionally tuned algorithms have been proposed in the past to correct for this deviation. Actually, the blueness of the Mediterranean waters is not as deep as expected from the actual (low chlorophyll content, and the modified algorithms account for this peculiarity. Among the possible causes for such a deviation, an excessive amount of yellow substance (or of chromophoric dissolved organic matter, CDOM has been frequently cited. This conjecture is presently tested, by using a new technique simply based on the simultaneous consideration of marine reflectance determined at four spectral bands, namely at 412, 443, 490, and 555 nm, available on the NASA-SeaWiFS sensor (Sea–viewing Wide Field-of-view Sensor. It results from this test that the concentration in yellow colored material (quantified as ay, the absorption coefficient of this material at 443 nm is about twice that one observed in the nearby Atlantic Ocean at the same latitude. There is a strong seasonal signal, with maximal ay values in late fall and winter, an abrupt decrease beginning in spring, and then a flat minimum during the summer months, which plausibly results from the intense photo-bleaching process favored by the high level of sunshine in these areas. Systematically, the ay values, reproducible from year to year, are higher in the western basin compared with those in the eastern basin (by about 50%. The relative importance of the river discharges into this semi-enclosed sea, as well as the winter deep vertical mixing occurring in the northern parts of the basins may explain the high yellow substance background. The regionally tuned [Chl] algorithms, actually reflect the

  14. Modelling and forecasting monthly swordfish catches in the Eastern Mediterranean

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    Konstantinos I. Stergiou

    2003-04-01

    Full Text Available In this study, we used the X-11 census technique for modelling and forecasting the monthly swordfish (Xiphias gladius catches in the Greek Seas during 1982-1996 and 1997 respectively, using catches reported by the National Statistical Service of Greece (NSSG. Forecasts built with X-11 were also compared with those derived from ARIMA andWinter’s exponential smoothing (WES models. The X-11 method captured the features of the study series and outperformed the other two methods, in terms of both fitting and forecasting performance, for all the accuracy measures used. Thus, with the exception of October, November and December 1997, when the corresponding absolute percentage error(APE values were very high (as high as 178.6% because of the low level of the catches, monthly catches during the remaining months of 1997 were predicted accurately, with a mean APE of 12.5%. In contrast, the mean APE values of the other two methods for the same months were higher (ARIMA: 14.6%; WES: 16.6%. The overall good performance of X-11 andthe fact that it provides an insight into the various components (i.e. the seasonal, trend-cycle and irregular components of the time series of interest justify its use in fisheries research. The basic features of the swordfish catches revealed by the application of the X-11 method, the effect of the length of the forecasting horizon on forecasting accuracy and the accuracy of the catches reported by NSSG are also discussed.

  15. Spatial Model Assessment of P Transport from Soils to Waterways in an Eastern Mediterranean Watershed

    Directory of Open Access Journals (Sweden)

    Oren Reichmann

    2013-03-01

    Full Text Available P index is a management tool commonly used to identify critical source areas (CSAs in agro-catchments. We tested the applicability of several P-index models adjusted to Eastern Mediterranean conditions. On the basis of model structure and data requirements, we selected the Arkansas model and two models with the RUSLE equation and runoff curve number (RCN. Concurrently, we developed a GIS-based Hermon-P model which was designed to simulate rainfall–runoff events representing the major nutrient-transport mechanism in Eastern Mediterranean. The P index values computed by the Arkansas and RUSLE models exhibited low correlation (r2 < 0.32 with the measured soluble reactive (SRP and total P (TP, while the RCN model result correlations were somewhat higher (r2 = 0.53 for SRP and 0.45 for TP. High correlations between the calculated and measured P during rainfall–runoff events were only achieved with the Hermon model (r2 = 0.77 to 0.9. These high coefficients resulted from avoiding subjective categorization of the continuous variables and using the measured site-specific erosional predictors instead. On one occasion, during the first significant runoff event of the year, the Hermon model failed to predict total P in the stream water (r2 = 0.14 because of considerable resuspension of stream sediments. Most of the P-index models are based on the perceptual transfer-continuum framework that was developed for temperate agro-catchments; this framework does not consider P resuspension along streams during rainfall–runoff events. Hence, a new set of equations should be added to the P index to account for potential resuspension in Eastern Mediterranean streams at the beginning of the hydrological year.

  16. Hierarchy of source-to-sink systems - Example from the Nile distribution across the eastern Mediterranean

    Science.gov (United States)

    Schattner, Uri; Lazar, Michael

    2016-08-01

    A standard source-to-sink approach examines sediment transport along an imaginary axis (regarded here as primary) extending between land, the continental margin and a nearby basin. This approach oversimplifies the development of depositional environments located off the axis (regarded here as secondary). Similarly, it imposes that factors affecting the primary source (e.g. climate) will directly be reflected in the secondary sink. The current study examines this suggested hierarchy in a confined basin, where the sedimentary budget remains closed. It evaluates the mechanism connecting between the primary and secondary axes. The study focuses on the Nile sedimentary system, across northeastern Africa and the eastern Mediterranean basin (primary axis) and the Levant depositional system (secondary sink). We hypothesize that since secondary river input into the Levant basin is negligible, the main secondary source is seafloor currents. The Levant Jet System (LJS) transported sediments from the Nile cone along the Levant margin at depths between 0 and 350 m, during the Holocene and until today. Once the LJS reaches its capacity to transport sediments, the surplus falls downslope to the deep basin. By integrating seismic and bathymetric data, this paper suggests a unifying mechanism integrating deposition, erosion and transport of sediments across the Levant margin and basin throughout the Quaternary. Results show that during both highstand and lowstand conditions the primary source-to-sink axis delivers sediments to the deep basin via south to north meandering channels. The LJS transports sediments that build the shelf, while unconfined overspills slide downslope to accumulate across the continental rise. However, when sea levels drop, the capacity of the LJS weakens. This results in a drastic decrease in sedimentation across the shelf and rise, accompanied by confined downslope turbidity flows into the deep basin. We conclude that seafloor currents serve as an immediate

  17. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

    Directory of Open Access Journals (Sweden)

    K. Sevastou

    2013-07-01

    Full Text Available The long-held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and microbes, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean Basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine spanning over 4 km in depth revealed a high diversity, irrespective of the benthic group or level of taxonomic analysis. A common decreasing bathymetric trend was detected for meiobenthic abundance, major taxa diversity and nematode genera richness, but no differences were found between the two habitats (basin vs slope. In contrast, microbial richness is significantly higher at the basin ecosystem and tends to increase with depth. Multivariate analyses (β- and δ-diversity and ordination analysis complemented these results and underlined the high within-habitat variability of benthic communities. Meiofaunal communities in particular were found to change gradually and vary more towards the abyss. On the other hand, microbial communities were highly variable, even among samples of the same area, habitat and bathymetry. A significant proportion of the variation of benthic communities and their descriptors was explained by depth and proxies of food availability (sedimentary pigments and organic content, but the combination of predictor variables and the strength of the relationship varied depending on the data set used (based on type of habitat, benthic component, taxonomic level. This, along with the observed high within-habitat variability suggests that other factors, which tend to vary at local scale (hydrodynamics, substrate

  18. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

    Science.gov (United States)

    Sevastou, K.; Lampadariou, N.; Polymenakou, P. N.; Tselepides, A.

    2013-07-01

    The long-held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and microbes, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean Basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine) spanning over 4 km in depth revealed a high diversity, irrespective of the benthic group or level of taxonomic analysis. A common decreasing bathymetric trend was detected for meiobenthic abundance, major taxa diversity and nematode genera richness, but no differences were found between the two habitats (basin vs slope). In contrast, microbial richness is significantly higher at the basin ecosystem and tends to increase with depth. Multivariate analyses (β- and δ-diversity and ordination analysis) complemented these results and underlined the high within-habitat variability of benthic communities. Meiofaunal communities in particular were found to change gradually and vary more towards the abyss. On the other hand, microbial communities were highly variable, even among samples of the same area, habitat and bathymetry. A significant proportion of the variation of benthic communities and their descriptors was explained by depth and proxies of food availability (sedimentary pigments and organic content), but the combination of predictor variables and the strength of the relationship varied depending on the data set used (based on type of habitat, benthic component, taxonomic level). This, along with the observed high within-habitat variability suggests that other factors, which tend to vary at local scale (hydrodynamics, substrate structure

  19. Water Soluble Organic Compounds over the Eastern Mediterranean: Study of their occurrence and sources

    Science.gov (United States)

    Tziaras, T.; Spyros, A.; Mandalakis, M.; Apostolaki, M.; Stephanou, E. G.

    2010-05-01

    Fine marine aerosols influence the climate system by acting as cloud condensation nuclei (CCN) in the atmosphere. The organic chemical composition and origin of the marine fine particulate matter are still largely unknown, because of the insufficient reports on in situ studies, the large variability in the emission from the sea, from the complex transfer of gases and particles at the air-sea interface, and the transport of aerosol particles from very distant sources. As important processes of formation of marine organic aerosol production we consider: transport of terrestrial particles, secondary organic aerosol (SOA) formation from the oxidation of biogenic dimethyl-sulfide (DMS), and biogenic particle emissions through sea spray. Specific compounds related to the above-mentioned processes have been proposed as molecular markers: e.g. n-alkanoic acids and n-alkanes (terrestrial particles), levoglucosan (biomass burning aerosol), aminoacids (biological terrestrial or marine particles), methanesulphonate (MSA) (DMS oxidation), C8 and C9 dicarboxylic acids and oxo-carboxylic acids (marine SOA) and other short-chain dicarboxylic acids (marine or terrestrial SOA), and humic-like compounds (emission of marine organic carbon). In our study, we made an effort to characterize the water-soluble organic fraction of marine aerosols collected at a background sampling site of Eastern Mediterranean (Finokalia, N35o20', E25o40', Island of Crete, Greece). The sampling period was 2007-2008. In order to identify and quantify the water-soluble organic compounds of marine aerosols determined in the present study we have used gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and nuclear magnetic resonance spectroscopy (NMR) and ion chromatography (IC). The origin of air masses arriving in the study area was studied by using backward trajectories calculation (NOAA HYSPLIT Model). In addition, we have used the "MODIS fire products" for fire

  20. Nd isotopes in deep-sea corals in the North-eastern Atlantic

    Science.gov (United States)

    Copard, Kevin; Colin, Christophe; Douville, Eric; Freiwald, Andre; Gudmundsson, Gudmundur; De Mol, Ben; Frank, Norbert

    2010-09-01

    Neodymium (Nd) concentrations and isotopic signatures of living and fossil deep-sea coral species Lophelia pertusa, Desmophyllum dianthus and Madrepora oculata from the northeast Atlantic Ocean have been investigated in order to test the ability of deep-sea corals to reconstruct the seawater Nd isotopic signature and past changes of ocean circulation in the eastern North Atlantic. Small quantities of Nd—less than 45 ng/g—are incorporated into the aragonite skeleton of living deep-sea corals that dwell at upper intermediate depths throughout the Northeast Atlantic. Rigorous cleaning techniques are needed in order to avoid Nd contamination from manganese-oxide and iron hydroxide coatings. Moreover, Nd isotopic compositions have been measured using thermal ionization mass spectrometry (TIMS) by Nd-oxide method. Our data indicate that the isotopic signatures of modern corals are similar to those of adjacent water masses, implying that deep-sea corals can serve as an archive of the seawater Nd isotopic compositions in the past. The first results from few fully-cleaned fossils corals collected within the Porcupine Seabight and the southwest Rockall Bank reveal significantly higher ɛNd for corals dated between 150 ± 40 and 3060 ± 90 yrs than those of the living corals located in similar areas. This suggests rapid hydrological variations along the eastern margin of the North Atlantic Ocean at intermediate water depth with higher contribution of the Mediterranean Overflow Waters (MOW) or other temperate Atlantic mid-depth water masses (ENACW or NAC) in the past.

  1. First evidence of European eels exiting the Mediterranean Sea during their spawning migration

    DEFF Research Database (Denmark)

    Amilhat, Elsa; Aarestrup, Kim; Faliex, Elisabeth

    2016-01-01

    The migration route and the spawning site of the European eel Anguilla anguilla are still uncertain. It has been suggested that the Mediterranean eel stock does not contribute to spawning because there is no evidence of eels leaving the Mediterranean Sea. To test this hypothesis, we equipped eight...... female silver eels from the south of France with pop-up satellite tags during escapement from coastal waters. Once in deeper water, the eels quickly established diel vertical migration (DVM) between the upper and lower mesopelagic zone. Five tagged eels were taken by predators within the Mediterranean...... to show that eels from Mediterranean can cross the Strait of Gibraltar and continue their migration into the Atlantic Ocean. This finding suggests that Mediterranean countries, as for other EU states, have an important role to play in contributing to conservation efforts for the recovery of the European...

  2. Failure Mechanisms of Ana Slide, Eivissa Channel, Western Mediterranean Sea

    Science.gov (United States)

    Lafuerza, S.; Sultan, N.; Canals, M.; Lastras, G.; Cattaneo, A.; Frigola, J.; Costa, S.; Berndt, C.

    2011-12-01

    Fluid seepage has been considered as the most plausible explanation to account for slope instabilities in the Eivissa Channel in between the Iberian Peninsula and the Balearic Islands, Western Mediterranean Sea. In situ geotechnical tests and sediment cores obtained in the Ana Slide area, on the Balearic slope of the Eivissa Channel, suggest that the development of the basal failure surface (BFS) was favoured by contrasting hydro-mechanical properties between a coarse unit (U7) charged with methane and a fine-grained unit above (U6). The presence of past methane seepage has been inferred from high magnetic susceptibility values found in sediments from the headwall area and is supported by seismic reflection data. Geotechnical data from piezocone tests, laboratory analyses and numerical calculations indicate degradation of the undrained shear strength generated by methane exsolution and expansion as the only plausible mechanism to explain the origin of Ana Slide. The probability of failure for different critical failure surfaces has been investigated by using the SAMU-3D slope stability model taking into account the role of free gas in the development of the landslide. According to SAMU-3D, the most probable failure surface is related to a minimum degradation of the undrained shear strength of units U6 and U7 of 95% and a basal failure surface developed at the base of U6, which acted as a weak layer. Wheeler's theory suggests that 9% of free-gas saturation in U7 is enough to reduce the undrained shear strength by 95%. However, using the theory of the undrained equilibrium behaviour of gassy sediments we conclude that the excess fluid pressure generated by gas exsolution and expansion is not relevant to bring the slope to fail.

  3. WHO EMRO's approach for supporting e-health in the Eastern Mediterranean Region.

    Science.gov (United States)

    N, Al-Shorbaji

    2006-01-01

    "E-health" is a generic term covering the use of computer and communication applications and technologies in health and medical care. This paper outlines WHO's dynamic and diversified approach for supporting e-health by the Regional Office of the Eastern Mediterranean. This includes: policy-setting; human resources development; planning, monitoring and evaluation; networking and communication; infrastructure development; consulting services; electronic publishing; systems development; e-learning; telemedicine; and online library services and support to HINARI It also reviews some of the impediments towards development of e-health in the Region.

  4. The fate of Cystoseira crinita, a forest-forming Fucale (Phaeophyceae, Stramenopiles), in France (North Western Mediterranean Sea)

    Science.gov (United States)

    Blanfuné, A.; Boudouresque, C. F.; Verlaque, M.; Thibaut, T.

    2016-11-01

    In the Mediterranean Sea, Fucales, and in particular the species of the genus Cystoseira C. Agardh, are habitat-forming species dominating several benthic assemblages from the littoral fringe down to 70-80 m depth in the clearest waters. They generate high primary production involved in the maintenance of diversified trophic levels, they provide shelter, food, habitat and nursery areas to many species, and they are long-lived species that constitute a good model for studying human impact on species diversity. Cystoseira crinita Duby is a Mediterranean endemic cespitose species, living in shallow waters (0-5 m depth), in places with little wave action and high solar irradiance. To reconstruct the long-term patterns of change in its distribution along the French Mediterranean coast (French Catalonia, Languedoc, Provence, French Riviera and Corsica), all the historical data (published articles, unpublished reports and herbarium vouchers) collected since the 18th century were searched and analysed. To assess the current status of the species, several field surveys were conducted between 2010 and 2016 by snorkelling and SCUBA diving. Cystoseira crinita is currently extinct in French Catalonia, near-extinct in Languedoc and western Provence, and functionally extinct on the French Riviera coast, while the eastern Provence and Corsican populations have remained stable. The main probable causes of decline are habitat destruction and overgrazing by herbivores.

  5. Role of the Alboran Sea volcanic arc choking the Mediterranean to the Messinian salinity crisis and foundering biota diversification in North Africa and Southeast Iberia

    Science.gov (United States)

    Booth-Rea, Guillermo; Ranero, Cesar R.; Grevemer, Ingo

    2016-04-01

    The Mediterranean Sea desiccated ~5.96 million years ago when it became isolated from the world oceans during the Messinian salinity crisis. This event permitted the exchange of terrestrial biota between Africa and Iberia contributing to the present rich biodiversity of the Mediterranean region. The cause chocking the Mediterranean has been proposed to be tectonic uplift and dynamic topography but the driving mechanism still remains debated. We present a new wide-angle seismic profile that provides a detailed image of the thickness and seismic velocity distribution of the crust in the eastern Alboran basin. The velocity model shows a characteristic structure of a subduction-related volcanic arc with a high-velocity lower crust and a 16-18 km total-thickness igneous crust that magmatic accreted mostly between ~10-6 Ma across the eastern Alboran basin. Estimation of the isostatically corrected depth of the arc crust taking into account the original thermal structure and sediment-loading subsidence since 6 Ma places a large area of the eastern Alboran basin above sea level at the time. This estimation is supported by geophysical data showing subaereal erosional unconformities for that time. This model may explain several up-to-now-disputed features of the Messinian salinity crisis, including: the progressive isolation of the Mediterranean since 7.1 Ma with the disappearance of open marine taxa, the existence of evaporites mostly to the east of the volcanic arc, the evidence that the Gibraltar straits were not a land bridge offered by continuous Messinian open marine sediments at ODP site 976 in the western Alboran basin, the importance of southeastern Iberia and North Africa as centres of biota diversification since before the salinity crisis, and patterns of speciation irradiating from SE Iberia and the eastern Rif in some taxons.

  6. Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    C. Jeanthon

    2011-07-01

    Full Text Available Aerobic anoxygenic phototrophic (AAP bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a (BChl-a, the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 54 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority (~94 % was affiliated to the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies

  7. Thermohaline properties in the Eastern Mediterranean in the last three decades: is the basin returning to the pre-EMT situation?

    Science.gov (United States)

    Cardin, V.; Civitarese, G.; Hainbucher, D.; Bensi, M.; Rubino, A.

    2015-01-01

    Temperature, salinity and oxygen data collected during April and June 2011 (M84/3 and P414 cruises respectively) are analysed to derive the oceanographic characteristics of the Eastern Mediterranean (EM) basin. These observed characteristics are compared with those from previous cruises over the period 1987-2011. As a result, the interannual and decadal variability of the EM thermohaline properties are discussed in the context of the evolution of the Eastern Mediterranean Transient (EMT) and of the general circulation of the basin. We found that the state of the EM is still far from the pre-EMT conditions, though the 2011 results possibly indicate a slow return to this status. In particular, a comparison between thermohaline property evolution deriving from interannual variability of the preconditioning and air-sea interaction (heat fluxes) in the South Adriatic and the Cretan Seas reveals aspects of the alternation of the two dense water sources (Adriatic and Aegean) during the last three decades, which have strong implications for the hydrographic characteristics of the intermediate and deep layers of the Ionian and Levantine basins.

  8. Hydrography of the eastern Arabian Sea during summer monsoon 2002

    Indian Academy of Sciences (India)

    D Shankar; S S C Shenoi; R K Nayak; P N Vinayachandran; G Nampoothiri; A M Almeida; G S Michael; M R Ramesh Kumar; D Sundar; O P Sreejith

    2005-10-01

    Hydrographic observations in the eastern Arabian Sea (EAS)during summer monsoon 2002 (during the first phase of the Arabian Sea Monsoon Experiment (ARMEX))include two approximately fortnight-long CTD time series.A barrier layer was observed occasionally during the two time series. These ephemeral barrier layers were caused by in situ rainfall,and by advection of low-salinity (high-salinity)waters at the surface (below the surface mixed layer).These barrier layers were advected away from the source region by the West India Coastal Current and had no discernible effect on the sea surface temperature.The three high-salinity water masses,the Arabian Sea High Salinity Water (ASHSW),Persian Gulf Water (PGW),and Red Sea Water (RSW),and the Arabian Sea Salinity Minimum also exhibited intermittency:they appeared and disappeared during the time series.The concentration of the ASHSW,PGW,and RSWdecreased equatorward,and that of the RSW also decreased offshore.The observations suggest that the RSW is advected equatorward along the continental slope off the Indian west coast.

  9. Climatic features of the Mediterranean Sea detected by the analysis of the longwave radiative bulk formulae

    Directory of Open Access Journals (Sweden)

    M. E. Schiano

    Full Text Available Some important climatic features of the Mediterranean Sea stand out from an analysis of the systematic discrepancies between direct measurements of longwave radiation budget and predictions obtained by the most widely used bulk formulae. In particular, under clear-sky conditions the results show that the surface values of both air temperature and humidity over the Mediterranean Sea are larger than those expected over an open ocean with the same amount of net longwave radiation. Furthermore, the twofold climatic regime of the Mediterranean region strongly affects the downwelling clear-sky radiation. This study suggests that a single bulk formula with constant numerical coefficients is unable to reproduce the fluxes at the surface for all the seasons.

    Key words: Meteorology and Atmospheric dynamics (radiative processes – Oceanography: general (marginal and semienclosed seas; marine meteorology

  10. Three Anisakis spp. isolated from toothed whales stranded along the eastern Adriatic Sea coast.

    Science.gov (United States)

    Blažeković, Kristina; Pleić, Ivana Lepen; Đuras, Martina; Gomerčić, Tomislav; Mladineo, Ivona

    2015-01-01

    Knowledge concerning cetacean ecology in the Mediterranean is limited but important for sustainable planning and enforcement of appropriate conservation measures. Any information that might help to elucidate their ecology is essential. We explored the population and genetic structures of Anisakis spp. nematodes isolated from four toothed whale species - bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), Risso's dolphins (Grampus griseus) and Cuvier's beaked whales (Ziphius cavirostris) - stranded along the eastern Adriatic Sea coast (1990-2012) to reveal more information on host ecological patterns. Lower parasite prevalence was observed in resident dolphin species compared with occasionally occurring species, as well as in young compared with adult dolphins, indicating different feeding habits related to age. No unequivocal relationship between the biological traits of a host (age, body length, body mass and blubber depth) and Anisakis population parameters was observed. Phylogenetic analysis revealed a new geographical record of Anisakis simplex sensu stricto (1.96%) and Anisakis physeteris (1.31%) in the Adriatic Sea in addition to resident Anisakis pegreffii (96.73%). In an assessment of the Adriatic Sea and oceans worldwide, the genetic structure of Anisakis revealed that A. pegreffii populations do not differ among various final host species but do differ with respect to geographical location in contrast to previously accepted Anisakis panmixia. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  11. Trace elements in striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean: A 10-years perspective.

    Science.gov (United States)

    Shoham-Frider, Efrat; Goffman, Oz; Harlavan, Yehudit; Kress, Nurit; Morick, Danny; Roditi-Elasar, Mia; Shefer, Edna; Kerem, Dan

    2016-08-15

    Concentrations of Hg, Se, Cd, Cu, Zn, Fe, Mn and As, in kidney, liver, muscle and blubber from 7 specimens of Stenella coeruleoalba, stranded along the Israeli Mediterranean coast (IMC) from 2006 to 2011 (2011-series) were determined and compared to previous data on S. coeruleoalba from the IMC (2001-series). No differences were observed in essential and toxic elements concentrations, between the two series, except for hepatic Mn which was higher in the latter. Hg/Se molar ratios in blubber, kidney and liver increased linearly with log Hg concentrations, while muscle was more heterogenic in this respect. Means (±SD) of hepatic Hg concentrations (134±89 and 181±200mgkg(-1), from the 2011 and 2001 series, respectively) were similar to that found in 2007-2009 specimens from Spain, possibly reflecting the relatively high natural background levels of mercury in the Mediterranean Sea.

  12. Alien species in the Mediterranean Sea by 2010. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD. Part I. Spatial distribution

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2012-12-01

    Full Text Available The state-of-art on alien species in the Mediterranean Sea is presented, making distinctions among the four subregions defined in the EU Marine Strategy Framework Directive: (i the Western Mediterranean Sea (WMED; (ii the Central Mediterranean Sea (CMED; (iii the Adriatic Sea (ADRIA; and (iv the Eastern Mediterranean Sea (EMED. The updated checklist (December 2010 of marine alien species within each subregion, along with their acclimatization status and origin, is provided. A total of 955 alien species is known in the Mediterranean, the vast majority of them having being introduced in the EMED (718, less in the WMED (328 and CMED (267 and least in the Adriatic (171. Of these, 535 species (56% are established in at least one area.Despite the collective effort of experts who attempted in this work, the number of introduced species remains probably underestimated. Excluding microalgae, for which knowledge is still insufficient, aliens have increased the total species richness of the Mediterranean Sea by 5.9%. This figure should not be directly read as an indication of higher biodiversity, as spreading of so many aliens within the basin is possibly causing biotic homogenization. Thermophilic species, i.e. Indo-Pacific, Indian Ocean, Red Sea, Tropical Atlantic, Tropical Pacific, and circum(subtropical, account for 88.4% of the introduced species in the EMED, 72.8% in the CMED, 59.3% in the WMED and 56.1% in the Adriatic. Cold water species, i.e. circumboreal, N Atlantic, and N Pacific, make up a small percentage of the introduced species, ranging between 4.2% and 21.6% and being more numerous in the Adriatic and less so in the EMED.Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.

  13. {sup 137}Cs baseline levels in the Mediterranean and Black Sea: A cross-basin survey of the CIESM Mediterranean Mussel Watch programme

    Energy Technology Data Exchange (ETDEWEB)

    Thebault, Herve [IRSN, LERCM, Centre Ifremer, BP 330, F-83507 La Seyne sur Mer (France); Rodriguez y Baena, Alessia M. [International Commission for the Scientific Exploration of the Mediterranean Sea (CIESM), 16 Blvd de Suisse, MC-98000 Principality of Monaco (Monaco); Andral, Bruno [Ifremer, BP 330, F-83507 La Seyne sur Mer (France); Barisic, Delko [Center for Marine and Environmental Research, Lab. for Trace Physical Chemistry, Ruder Boskovic Inst., P.O. Box 1016, Bijenicka 54, 10002 Zagreb (Croatia); Albaladejo, Jose Benedicto [Inst. Espanol de Oceanografi' a (IEO), Centro Oceanografico de Murcia - Calle Varadero No. 1, 30740 San Pedro del Pinatar (Spain); Bologa, Alexandru S. [National Institute for Marine Research and Development ' Grigore Antipa' , RO-900581, Constantza (Romania); Boudjenoun, Redouane [Commissariat a l' Energie Atomique (COMENA), Centre de Radioprotection Recherche Nucleaire d' Algeret de Surete, Lab. d' Etudes d' Impact Radiologique, 2 Blvd F. Fanon - BP 399 Alger-Gare, 16000 Alger (Algeria); Delfanti, Roberta [Ente per le Nuove Tecnologie, l' Energia, e l' Ambiente (ENEA), Marine Environment Research Centre, La Spezia (Italy); Egorov, Victor N. [Inst. of Biology of the Southern Seas (IBSS), National Academy of Sciences of the Ukraine, 2 Porspekt Nakhimova, 99 011 Sevastopol, Crimea (Ukraine); El Khoukhi, Tahar [Centre d' Etudes Nucleaires de la Maamora (CNESTEN), BP 1382 RP Rabat 10001 (Morocco); Florou, Heleni [National Centre for Scientific Research ' Demokritos' , Aghia Paraskevi 153 10, P.O. Box 60228, Athens (Greece); Kniewald, Goran [Center for Marine and Environmental Research, Lab. for Trace Physical Chemistry, Ruder Boskovic Inst., P.O. Box 1016, Bijenicka 54, 10002 Zagreb (Croatia); Noureddine, Abdelkader [Commissariat a l' Energie Atomique (COMENA), Centre de Radioprotection Recherche Nucleaire d' Algeret de Surete, Lab. d' Etudes d' Impact Radiologique, 2 Blvd F. Fanon - BP 399 Alger-Gare, 16000 Alger (Algeria)] (and others)

    2008-07-01

    The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify {sup 137}Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured {sup 137}Cs levels were found to be very low (usually <1 Bq kg{sup -1} wet wt) {sup 137}Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.

  14. Heat and salt redistribution within the Mediterranean Sea in the Med-CORDEX model ensemble

    Science.gov (United States)

    Llasses, J.; Jordà, G.; Gomis, D.; Adloff, F.; Macías, D.; Harzallah, A.; Arsouze, T.; Akthar, N.; Li, L.; Elizalde, A.; Sannino, G.

    2016-06-01

    Characterizing and understanding the basic functioning of the Mediterranean Sea in terms of heat and salt redistribution within the basin is a crucial issue to predict its evolution. Here we quantify and analyze the heat and salt transfers using a simple box model consisting of four layers in the vertical for each of the two (western and eastern) basins. Namely, we box-average 14 regional simulations of the Med-CORDEX ensemble plus a regional and a global reanalysis, computing for each of them the heat and salt exchanges between layers. First, we analyze in detail the mechanisms behind heat and salt redistribution at different time scales from the outputs of a single simulation (NEMOMED8). We show that in the western basin the transfer between layer 1 (0-150 m) and layer 2 (150-600 m) is upwards for most models both for heat and salt, while in the eastern basin both transfers are downwards. A feature common to both basins is that the transports are smaller in summer than in winter due to the enhanced stratification, which dampen the mixing between layers. From the comparison of the 16 simulations we observe that the spread between models is much larger than the ensemble average for the salt transfer and for the heat transfer between layer 1 and layer 2. At lower layers (below 600 m) there is a set of models showing a good agreement between them, while others are not correlated with any other. The mechanisms behind the ensemble spread are not straightforward. First, to have a coarse resolution prevents the model to correctly represent the heat and salt redistribution in the basin. Second, those models with a very different initial stratification also show a very different redistribution, especially at intermediate and deep layers. Finally, the assimilation of data seems to perturb the heat and salt redistribution. Besides this, the differences among regional models that share similar spatial resolution and initial conditions are induced by more subtle mechanisms

  15. Simulated anthropogenic CO2 storage and acidification of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    J. Palmiéri

    2015-02-01

    Full Text Available Constraints on the Mediterranean Sea's storage of anthropogenic CO2 are limited, coming only from data-based approaches that disagree by more than a factor of two. Here we simulate this marginal sea's anthropogenic carbon storage by applying a perturbation approach in a high-resolution regional model. Our model simulates that, between 1800 and 2001, basin-wide CO2 storage by the Mediterranean Sea has increased by 1.0 Pg C, a lower limit based on the model's weak deep-water ventilation, as revealed by evaluation with CFC-12. Furthermore, by testing a data-based approach (transit time distribution in our model, comparing simulated anthropogenic CO2 to values computed from simulated CFC-12 and physical variables, we conclude that the associated basin-wide storage of 1.7 Pg, published previously, must be an upper bound. Out of the total simulated storage of 1.0 Pg C, 75% comes from the air–sea flux into the Mediterranean Sea and 25% comes from net transport from the Atlantic across the Strait of Gibraltar. Sensitivity tests indicate that the Mediterranean Sea's higher total alkalinity, relative to the global-ocean mean, enhances the Mediterranean's total inventory of anthropogenic carbon by 10%. Yet the corresponding average anthropogenic change in surface pH does not differ significantly from the global-ocean average, despite higher total alkalinity. In Mediterranean deep waters, the pH change is estimated to be between −0.005 and −0.06 pH units.

  16. Consumers of sea urchins, Paracentrotus lividus and Arbacia lixula, in shallow Mediterranean rocky reefs

    Science.gov (United States)

    Guidetti, Paolo

    2004-04-01

    Underwater observations on fish and asteroid consumers (i.e. predators and scavengers) of sea urchins, Paracentrotus lividus and Arbacia lixula, were carried out at several locations in shallow Mediterranean rocky reefs. Observations conducted in the marine reserve of Torre Guaceto (Adriatic Sea) revealed that sparid fishes, Diplodus sargus and D. vulgaris, are the main fish predators of small (sargus were able to prey upon small and medium, and occasionally large (>4 cm) sea urchins, whereas medium and small Diplodus preyed mainly upon small sea urchins. The number of sea urchins preyed upon by fishes was negatively related to sea urchin size for both species. P. lividus appeared to be subject to higher predation levels than A. lixula. The scavenger guild comprised 11 fish species, with D. sargus, D. vulgaris, Coris julis and Chromis chromis accounting for about 80% of scavenger fishes. Observations performed at several locations in the Mediterranean on the predatory asteroid Marthasterias glacialis revealed that only 3% of the detected individuals were preying upon sea urchins. Due to the importance of sea urchins for assemblage structure and functioning of Mediterranean rocky reef ecosystems, these results may have also important implications for management of fishing activities.

  17. Dolphin morbillivirus infection in different parts of the Mediterranean Sea

    NARCIS (Netherlands)

    M.F. van Bressem; I.K.G. Visser (Ilona); R.L. de Swart (Rik); C. Örvell; L. Stanzani; E. Androukaki (Eugenia); K. Siakavara; A.D.M.E. Osterhaus (Albert)

    1993-01-01

    textabstractMorbillivirus were isolated from Mediterranean striped dolphins (Stenella coeruleoalba) dying along the coasts of Italy and Greece in 1991. They were antigenically identical to the morbilliviruses isolated from striped dolphins in Spain in 1990.

  18. The Impact of a Warmer Mediterranean Sea on Central European Summer Flooding

    Science.gov (United States)

    Volosciuk, Claudia; Semenov, Vladimir; Maraun, Douglas; Latif, Mojib; Tilinina, Natalia

    2014-05-01

    Central European climate is influenced by the Mediterranean Sea, which experienced a strong increase in sea surface temperature (SST) during the last four decades. One example of extreme weather events are cyclones following the "Vb" pathway. These cyclones are generated over the Mediterranean Sea and travel northeastwards around the Alps and then hit countries like Poland and Germany. The cyclones carry large amounts of moisture and cause extreme precipitation, and subsequently flooding, particularly in summer. These floods, such as the Elbe flood in 2002, have devastating societal impacts and also influence ecosystems. To analyse the potential impact of increased Mediterranean SST on extreme precipitation in Europe, a series of simulations with the atmospheric general circulation model (AGCM) ECHAM5 has been carried out. ECHAM5 was run at high horizontal resolution (T159) and integrated for 40 years in each experiment. The control run is forced by SST and sea ice concentration (SIC) climatology derived from 1970-1999. A warmer climate is simulated by using global climatological SST and SIC from 2000-2012. To disentangle the impact of the Mediterranean Sea, an additional simulation was performed with the same global SST and SIC as in the control run, but with the warmer 2000-2012 SST climatology restricted to the Mediterranean and Black Seas. 20-season return levels were derived as a measure of extreme precipitation for daily as well as five day precipitation in JJA (June, July, August). These return levels are estimated as quantiles of a stationary generalised extreme value (GEV) distribution. Although the increase in the number of Vb cyclones is only modest, precipitation return levels in JJA show an increase along the Vb cyclone track, for daily (up to approximately 63 %) as well as for five day (up to approximately 76 %) precipitation extremes. This increase can be attributed to the warmer Mediterranean Sea, as it is observed in both the globally warmer and

  19. Propagation regimes and populations of internal waves in the Mediterranean Sea basin

    Science.gov (United States)

    Kurkina, Oxana; Rouvinskaya, Ekaterina; Talipova, Tatiana; Soomere, Tarmo

    2017-02-01

    The geographical and seasonal distributions of kinematic and nonlinear parameters of long internal waves are derived from the Generalized Digital Environmental Model (GDEM) climatology for the Mediterranean Sea region, including the Black Sea. The considered parameters are phase speed of long internal waves and the coefficients at the dispersion, quadratic and cubic terms of the weakly-nonlinear Korteweg-de Vries-type models (in particular, the Gardner model). These parameters govern the possible polarities and shapes of solitary internal waves, their limiting amplitudes and propagation speeds. The key outcome is an express estimate of the expected parameters of internal waves for different regions of the Mediterranean basin.

  20. Simulation of tsunami generation, propagation and coastal inundation in the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    A. G. Samaras

    2015-05-01

    Full Text Available In the present work, an advanced tsunami generation, propagation and coastal inundation 2-DH model (i.e. 2-D Horizontal model based on the higher-order Boussinesq equations – developed by the authors – is applied to simulate representative earthquake-induced tsunami scenarios in the Eastern Mediterranean. Two areas of interest were selected after evaluating tsunamigenic zones and possible sources in the region: one at the Southwest of the island of Crete in Greece and one at the East of the island of Sicily in Italy. Model results are presented in the form of extreme water elevation maps, sequences of snapshots of water elevation during the propagation of the tsunamis, and inundation maps of the studied low-lying coastal areas. This work marks one of the first successful applications of a fully nonlinear model for the 2-DH simulation of tsunami-induced coastal inundation; acquired results are indicative of the model's capabilities, as well of how areas in the Eastern Mediterranean would be affected by eventual larger events.

  1. Mesoscale modeling of combined aerosol and photo-oxidant processes in the eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    M. Lazaridis

    2004-09-01

    Full Text Available Particulate matter and photo-oxidant processes in the Eastern Mediterranean have been studied using the UAM-AERO mesoscale air quality model in conjunction with the NILU-CTM regional model. Meteorological data were obtained from the RAMS prognostic meteorological model. The modeling domain includes the eastern Mediterranean area between the Greek mainland and the island of Crete. The modeling system is applied to study the atmospheric processes in three periods, i.e. 13–16 July 2000, 26–30 July 2000 and 7–14 January 2001. The spatial and temporal distributions of both gaseous and particulate matter pollutants have been extensively studied together with the identification of major emission sources in the area. The modeling results were compared with field data obtained in the same period. Comparison of the modeling results with measured data was performed for a number of gaseous and aerosol species. The UAM-AERO model underestimates the PM10 measured concentrations during summer but better comparison has been obtained for the winter data.

  2. High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region

    Science.gov (United States)

    Douaihy, Bouchra; Vendramin, Giovanni G.; Boratyński, Adam; Machon, Nathalie; Bou Dagher-Kharrat, Magda

    2011-01-01

    Background and aims Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation. Methodology Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine. Principal results Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were Na=8.78 and He=0.76, respectively. The fixation index showed a significant deviation from Hardy–Weinberg equilibrium and an excess of homozygotes (FIS=0.27–0.56). A moderate level of genetic differentiation was observed among the populations (FST=0.075, P2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters. Conclusions High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish–southeastern European populations. PMID:22476474

  3. Situational analysis of tuberculosis control programs in the Eastern Mediterranean Region: Gaps and solutions.

    Science.gov (United States)

    Baghdadi, Samiha

    2016-12-01

    The objectives of this study were to highlight the key challenges and the strategic directions to scale-up tuberculosis (TB) care in the Eastern Mediterranean Region (EMR); to review TB burden in EMR, and evaluate the progress toward Millennium Development Goals (MDGs) targets by 2015; to identify the main obstacles for optimal TB care toward TB elimination; and to provide strategic directions to address the key challenges. The Eastern Mediterranean Region is composed of 22 countries with 648 million populations. The region has estimated TB incidence of 116 per 100,000. The estimated number of incident TB cases in 2015 was 749000 TB case. The paper is based on the Annual World Health Organization Global TB report on implementation of TB control strategy. The EMR is a middle TB- and MDR-TB-burden region with 22 countries. As for MDGs, the region was able to meet the mortality target and revert TB incidence but could not achieve the prevalence target. The main challenges are limited infrastructure, human capacity, funds, use of new diagnostics tools and new medicines, and involvement of all stakeholders and community in TB care and control in addition to complex emergencies. The year 2015 marks a transition from the MDGs to the Sustainable Development Goals and from the Stop TB Strategy to the End TB Strategy. The region will move into three main directions: complete pending tasks, mitigate the impact of the complex emergencies on TB control, and move toward TB elimination. Copyright © 2016.

  4. High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region.

    Science.gov (United States)

    Douaihy, Bouchra; Vendramin, Giovanni G; Boratyński, Adam; Machon, Nathalie; Bou Dagher-Kharrat, Magda

    2011-01-01

    Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation. Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine. Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were N(a)=8.78 and H(e)=0.76, respectively. The fixation index showed a significant deviation from Hardy-Weinberg equilibrium and an excess of homozygotes (F(IS)=0.27-0.56). A moderate level of genetic differentiation was observed among the populations (F(ST)=0.075, P2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters. High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish-southeastern European populations.

  5. First record of Kemp’s ridley sea turtle, Lepidochelys kempii (Garman, 1880 (Cheloniidae, from the Italian waters (Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Gianni Insacco

    2010-07-01

    Full Text Available In this work the authors describe the first case of Lepidochelys kempii stranding (Garman, 1880 happened in Italian waters (Sicily, Messina and considered to be the fifth in the entire Mediterranean Sea. A young individual was recovered with a longline hook in its oesophageal.

  6. The impact of temperature changes on summer time ozone and its' precursors in the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    U. Im

    2011-02-01

    Full Text Available Changes in temperature due to variability in meteorology and climate change are expected to significantly impact atmospheric composition. The Mediterranean is a climate sensitive region and includes megacities like Istanbul and large urban agglomerations such as Athens. The effect of temperature changes on gaseous air pollutant levels and the atmospheric processes that are controlling them in the Eastern Mediterranean are here investigated. The WRF/CMAQ mesoscale modeling system is used, coupled with the MEGAN model for the processing of biogenic volatile organic compound emissions. A set of temperature perturbations (spanning from 1 to 5 K is applied on a base case simulation corresponding to July 2004. The results indicate that the Eastern Mediterranean basin acts as a reservoir of pollutants and their precursor emissions from large urban agglomerations. During summer, chemistry is a major sink at these urban areas near the surface, and a minor contributor at downwind areas. On average, the atmospheric processes are more effective within the first 1000 m. The response rate of biogenic emissions to temperature changes is calculated to be 9±3% K−1. Ozone concentrations respond almost linearly to the changes in the ambient temperature with rates of 1±0.1 ppb O3 K−1 for all studied urban and receptor stations except for Istanbul, where a 0.4±0.1 ppb O3 K−1 change rate is calculated, which is almost half of the domain-averaged increase of 0.9±0.1 ppb O3 K−1. The computed changes in atmospheric processes are also linearly related with temperature changes.

  7. The impact of temperature changes on summer time ozone and its precursors in the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    U. Im

    2011-04-01

    Full Text Available Changes in temperature due to variability in meteorology and climate change are expected to significantly impact atmospheric composition. The Mediterranean is a climate sensitive region and includes megacities like Istanbul and large urban agglomerations such as Athens. The effect of temperature changes on gaseous air pollutant levels and the atmospheric processes that are controlling them in the Eastern Mediterranean are here investigated. The WRF/CMAQ mesoscale modeling system is used, coupled with the MEGAN model for the processing of biogenic volatile organic compound emissions. A set of temperature perturbations (spanning from 1 to 5 K is applied on a base case simulation corresponding to July 2004. The results indicate that the Eastern Mediterranean basin acts as a reservoir of pollutants and their precursor emissions from large urban agglomerations. During summer, chemistry is a major sink at these urban areas near the surface, and a minor contributor at downwind areas. On average, the atmospheric processes are more effective within the first 1000 m above ground. Temperature increases lead to increases in biogenic emissions by 9±3% K−1. Ozone mixing ratios increase almost linearly with the increases in ambient temperatures by 1±0.1 ppb O3 K−1 for all studied urban and receptor stations except for Istanbul, where a 0.4±0.1 ppb O3 K−1 increase is calculated, which is about half of the domain-averaged increase of 0.9±0.1 ppb O3 K−1. The computed changes in atmospheric processes are also linearly related with temperature changes.

  8. Stable carbon isotope gradients in benthic foraminifera as proxy for organic carbon fluxes in the Mediterranean Sea

    Science.gov (United States)

    Theodor, Marc; Schmiedl, Gerhard; Jorissen, Frans; Mackensen, Andreas

    2016-11-01

    We have determined stable carbon isotope ratios of epifaunal and shallow infaunal benthic foraminifera in the Mediterranean Sea to relate the inferred gradient of pore water δ13CDIC to varying trophic conditions. This is a prerequisite for developing this difference into a potential transfer function for organic matter flux rates. The data set is based on samples retrieved from a well-defined bathymetric range (400-1500 m water depth) of sub-basins in the western, central, and eastern Mediterranean Sea. Regional contrasts in organic matter fluxes and associated δ13CDIC of pore water are recorded by the δ13C difference (Δδ13CUmed-Epi) between the shallow infaunal Uvigerina mediterranea and epifaunal species (Planulina ariminensis, Cibicidoides pachydermus, Cibicides lobatulus). Within epifaunal taxa, the highest δ13C values are recorded for P. ariminensis, providing the best indicator for bottom water δ13CDIC. In contrast, C. pachydermus reveals minor pore water effects at the more eutrophic sites. Because of ontogenetic trends in the δ13C signal of U. mediterranea of up to 1.04 ‰, only tests larger than 600 µm were used for the development of the transfer function. The recorded differences in the δ13C values of U. mediterranea and epifaunal taxa (Δδ13CUmed-Epi) range from -0.46 to -2.13 ‰, with generally higher offsets at more eutrophic sites. The measured δ13C differences are related to site-specific differences in microhabitat, depth of the principal sedimentary redox boundary, and TOC content of the ambient sediment. The Δδ13CUmed-Epi values reveal a consistent relation to Corg fluxes estimated from satellite-derived surface water primary production in open-marine settings of the Alboran Sea, Mallorca Channel, Strait of Sicily, and southern Aegean Sea. In contrast, Δδ13CUmed-Epi values in areas affected by intense resuspension and riverine organic matter sources of the northern to central Aegean Sea and the canyon systems of the Gulf of Lion

  9. Interannual sea level variability in the Eastern Indian Ocean and Southern South China Sea

    Science.gov (United States)

    Mohan, S. S.; Vethamony, P.

    2016-12-01

    Sea level anomalies (SLAs) derived from satellite observations (over a period of 21 years) and tide gauge data compiled from 24 stations from the Eastern Indian Ocean (EIO) and southern South China Sea (SCS) have been analysed to study the inter-annual variability of SLAs in the EIO and southern SCS. To examine the seasonality in interannual variability, 3 months to 7 years band pass filtered non-seasonal SLAs were considered. A large fraction of interannual SLA variability in the south eastern SCS is linked to ENSO and rest of the region is characterized by small scale interannual variations. Analysis of both tide gauge and altimetry data confirms that interannual sea level anomalies in the SCS shows seasonality with pronounced variation occurring during winter and fall seasons. Both tide gauge and altimetry data show that 40% of interannual SLAs at Malacca Strait and southeastern SCS and 50% at Java Sea could be explained by both ENSO and IOD. Malacca Strait and Java Sea SLAs at interannual scale show coherent variability with that of eastern equatorial Indian Ocean. Regional correlation pattern and Wavelet power spectrum of SLAs at Java Sea shows similar dominant periodicities as in the Malacca Strait. Strong oscillations associated with climate modes are centered at 2-5 year period. Interannual SLAs at southeastern SCS show the importance of western Pacific on sea level modulation through the Luzon and Mindoro Straits. Wind variations largely explain the interannual SLA variation in the EIO and southern SCS. Interannual zonal wind variations in the equatorial Indian Ocean induce SLA variations in the Malacca Strait and Java Sea. Remote and local winds that drive interannual variability of SLAs in the EIO and southeastern SCS are associated with both ENSO and IOD events.

  10. Cenozoic evolution of the eastern Danish North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Huuse, M.; Lykke-Andersen, H.; Michelsen, O.

    2003-12-01

    This paper provides a review of recent high-resolution and conventional seismic investigations in the eastern Danish North Sea and destribes their implications for the development of the eastern North Sea Basin. The results tomprise detailed timestructure maps of four major unconformities in the eastern Danish North Sea: the Top Chalk surface (mid-Paleogene), near top Oligocene, the mid-Miocene unconformity, and base Quatemary. The maps show that the eastem Danish North Sea has been affected by fauldng and salt diapirism throughout the Cenozoic. Carbonate mounds, erosional valleys and pockmark- or karstlike struttures were identitied at the top of the Upper Cretaceous-Danian Chalk Group. Strike-parallel erosional features and depositional geometries observed at near top Oligocene and at the mid-Miocene unconformity indicate that these major sequence boundarics tan be attributed to large-scale lateral changes in sediment supply directions. Increases in sediment flux to the southeastern North Sea at the Eocene/Oligocene transition and in the post-Middle Miocene appear to correlate with similar events world wide and with long term {delta} {sup 18} O increases, indicating forting by global factors, i.e. eustasy and climate. Stratal geometries observed on the seismic data indicate that the socalled `Neogene uplift' of the Bastern Danish North Sea may have been hundreds of metres less than previously suggested. lt is argued that late Cenozoic uplift of the basin margin and of mountain peaks in southern Norway may have been caused entirely by isostatic uplift of the trust in response to accelerated late Cenozoic denudation and dissection of topography created in the Paleogene. The late Cenozoic periods of accelerated denudation and incision rates were most likely driven by climatic deterioration and long term eustatic lowering rather than active late Cenozoic tectonics, the cause of which is conjectural. A series of shallow thrust struttures and an associated system

  11. Global warming and mass mortalities of benthic invertebrates in the Mediterranean Sea.

    Science.gov (United States)

    Rivetti, Irene; Fraschetti, Simonetta; Lionello, Piero; Zambianchi, Enrico; Boero, Ferdinando

    2014-01-01

    Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface) of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945-2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas.

  12. Global warming and mass mortalities of benthic invertebrates in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Irene Rivetti

    Full Text Available Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945-2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas.

  13. Phylogenetics, biogeography and population genetics of the ascidian Botryllus schlosseri in the Mediterranean Sea and beyond.

    Science.gov (United States)

    Reem, Eitan; Douek, Jacob; Paz, Guy; Katzir, Gadi; Rinkevich, Baruch

    2017-02-01

    The wide distribution of the ascidian Botryllus schlosseri along the Mediterranean coasts has been documented since the eighteenth century. However, despite copious documentation, analyses of dispersal modes and genetic profiles were limited to local populations or restricted regions. In order to get a pan-Mediterranean overview, 288 specimens from 11 populations of B. schlosseri from the western and eastern Mediterranean basins were sampled and analyzed using five microsatellite loci and COI sequences. Both molecular markers revealed high polymorphisms, with 182 microsatellites alleles and 54 COI haplotypes. Overall, Fst, Dest, and COI Фpt values were 0.146, 0.635 and 0.322, respectively, reflecting a high genetic diversity and a significant genetic structure as compared to other B. schlosseri populations worldwide, reflected by substantially higher values for effective number of alleles (Ne) in the Mediterranean. A phylogenetic analysis of the COI sequences resulted in four distinct clades and two molecular operational taxonomic units (OTUs). We recorded a stronger genetic structure among the populations of the eastern basin compared to the western basin (microsatellites Fst=0.217 versus 0.082; COI Фpt=0.416 versus 0.171), suggesting either a restricted connectivity between the basins or a stronger genetic drift in each basin. The occurrence of two OTUs and different ecological conditions may also contribute to this finding. Mean Nei's genetic distance in the eastern Mediterranean populations was more than three times higher compared to the western basin. No correlation was observed between geographic and genetic distances (Mantel test), suggesting that maritime transport is the main dispersal vector of B. schlosseri colonies. The possibility that the Mediterranean is a center of diversity for B. schlosseri, and probably its site of origin, is further discussed.

  14. Population genetic history of Aristeus antennatus (Crustacea: Decapoda in the Western and Central Mediterranean Sea.

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    Annamaria Marra

    Full Text Available Aristeus antennatus is an ecologically and economically important deep-water species in the Mediterranean Sea. In this study we investigated the genetic variability of A. antennatus sampled from 10 sampling stations in the Western and Central Mediterranean. By comparing our new samples with available data from the Western area, we aim to identify potential genetic stocks of A. antennatus and to reconstruct its historical demography in the Mediterranean. We analyzed two regions of mitochondrial DNA in 319 individuals, namely COI and 16S. We found two main results: i the genetic diversity values consistent with previous data within the Mediterranean and the absence of barriers to gene flow within the Mediterranean Sea; ii a constant long-term effective population size in almost all demes but a strong signature of population expansion in the pooled sample about 50,000 years B.P./ago. We propose two explanation for our results. The first is based on the ecology of A. antennatus. We suggest the existence of a complex meta-population structured into two layers: a deeper-dwelling stock, not affected by fishing, which preserves the pattern of historical demography; and genetically homogeneous demes inhabiting the fishing grounds. The larval dispersal, adult migration and continuous movements of individuals from "virgin" deeper grounds not affected by fishing to upper fishing areas support an effective 'rescue effect' contributing to the recovery of the exploited stocks and explain their genetic homogeneity throughout the Mediterranean Sea. The second is based on the reproduction model of this shrimp: the high variance in offspring production calls for a careful interpretation of the data observed under classical population genetics and Kingman's coalescent. In both cases, management policies for A. antennatus will therefore require careful evaluation of the meta-population dynamics of all stocks in the Mediterranean. In the future, it will be

  15. North-eastern Atlantic and Mediterranean species of Cornulariidae Dana, 1846 (Anthozoa: Stolonifera) with the description of a new genus

    NARCIS (Netherlands)

    López-González, P.J.; Ocaña, O.; García-Gómez, J.C.; Núñez, J.

    1995-01-01

    The North-eastern Atlantic and Mediterranean species of the family Cornulariidae are re-examined and taxonomically revised. This family is mainly characterized by the absence of sclerites. Up to now, only one genus, Cornularia Lamarck, 1816, has been assigned to the family. Studies of the internal

  16. Sea-level change and projected future flooding along the Egyptian Mediterranean coast

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    Mohamed Shaltout

    2015-10-01

    The results indicate that DT can be used to study coastal and deep-water sea-level changes in the study area. The southern Levantine sub-basin sea level has recently risen by an average of 3.1 cm decade−1 and exhibits significant annual sea-level variation of −17 cm to 8 cm. The sea-level variation is significantly affected by several factors: sea-level variation west of the Gibraltar Strait, steric sea level, and sea-surface temperature. The GFDL simulations best describing the recent sea level over the study area, i.e., GFDL-CM3 and GFDL-ESM2M, are used to calculate the two-model ensemble mean (GFDL-2ENM, which indicates that Egypt's Mediterranean coast will experience substantial sea-level rise (SLR this century. The estimated uncertainty over the study area was 4–22 cm by 2100, with the emission assumptions dominating the three sources of uncertainty sources. Comparing the projected SLRs with digital elevation data indicates that Egypt's Mediterranean coast will only be safe from flooding by 2100 if effective adaptation methods are applied.

  17. Metazoan parasite infection in the swordfish, Xiphias gladius, from the Mediterranean Sea and comparison with Atlantic populations: implications for its stock characterization

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    Mattiucci Simonetta

    2014-01-01

    Full Text Available Thirteen parasite taxa were identified in the Mediterranean swordfish by morphological and genetic/molecular methods. The comparison of the identified parasite taxa and parasitic infection values observed in the Mediterranean swordfish showed statistically significant differences with respect to those reported for its Atlantic populations. A stepwise Linear Discriminant Analysis of the individual fish examined showed a separation among three groups: one including fish from the Mediterranean Sea (CTS, STS, and IOS; one consisting of fish from the Central South (CS, Eastern Tropical (ET, and Equatorial (TEQ Atlantic; and a third comprising the fish sampled from the North-West Atlantic (NW; the CN Atlantic sample was more similar to the first group rather than to the other Atlantic ones. The nematodes Hysterothylacium petteri and Anisakis pegreffii were the species that contributed most to the characterization of the Mediterranean swordfish samples with respect to these Atlantic ones. Anisakis brevispiculata, A. physeteris, A. paggiae, Anisakis sp. 2, Hysterothylacium incurvum, Hepatoxylon trichiuri, Sphyriocephalus viridis, and their high infection levels were associated with the swordfish from the Central and the Southern Atlantic areas. Finally, H. corrugatum, A. simplex (s.s., Rhadinorhynchus pristis, and Bolbosoma vasculosum were related to the fish from the North-West (NW Atlantic area. These results indicate that some parasites, particularly Anisakis spp. larvae identified by genetic markers, could be used as “biological tags” and support the existence of a Mediterranean swordfish stock.

  18. First occurrence of a Hymenosomatid crab Elamena mathoei (Desmarest, 1823 (Crustacea: Decapoda: Brachyura in the Mediterranean Sea

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    J. ZAOUALI

    2013-07-01

    Full Text Available Mediterranean fauna is undergoing drastic modifications as a result of anthropogenic activities and global warming. The most important of these is the colonization of the Mediterranean Sea by alien species, many of them entering through the Suez Canal. While many of them are still confined to the Levant Basin, several have extended their distribution westwards to Tunisian waters. The presence of the Indo-west Pacific hymenosomatid crab Elamena mathoei on a rocky shore at Sidi Daoud, Cape Bon Peninsula, Tunisia, is the first Mediterranean record of this species. It is a testimony to the changes in the patterns of invasion in the Mediterranean Sea.

  19. Effect of ocean warming and acidification on a plankton community in the NW Mediterranean Sea

    NARCIS (Netherlands)

    Maugendre, L.; Gattuso, J.-P.; Louis, J.; de Kluijver, A.; Marro, S.; Soetaert, K.; Gazeau, F.

    2015-01-01

    The effect of ocean warming and acidification was investigated on a natural plankton assemblage from an oligotrophic area, the bay of Villefranche (NW Mediterranean Sea). The assemblage was sampled in March 2012 and exposed to the following four treatments for 12 days: control (~360 µatm, 14°C),

  20. Eight years of wind measurements from scatterometer for wind resource mapping in the Mediterranean Sea

    DEFF Research Database (Denmark)

    Furevik, Birgitte R.; Sempreviva, Anna Maria; Cavaleri, Luigi;

    2011-01-01

    Eight years of wind observations from the SeaWinds scatterometer instrument on the National Aeronautics and Space Administration QuikScat satellite and in situ data from 11 locations in the Mediterranean have been considered. The data have been co-located in time and space, and it is shown...