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Sample records for eastern ionian sea

  1. The diet and feeding ecology of Conger conger (L. 1758 in the deep waters of the Eastern Ionian Sea

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    A. ANASTASOPOULOU

    2013-06-01

    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

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

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    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.    

  3. Random Forest population modelling of striped and common-bottlenose dolphins in the Gulf of Taranto (Northern Ionian Sea, Central-eastern Mediterranean Sea)

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    Carlucci, Roberto; Cipriano, Giulia; Paoli, Chiara; Ricci, Pasquale; Fanizza, Carmelo; Capezzuto, Francesca; Vassallo, Paolo

    2018-05-01

    This study provides the first estimates of density and abundance of the striped dolphin Stenella coeruleoalba and common bottlenose dolphin Tursiops truncatus in the Gulf of Taranto (Northern Ionian Sea, Central Mediterranean Sea) and identifies the predictive variables mainly influencing their occurrence and concentration in the study area. Conventional Distance Sampling (CDS) and the Delta approach on Random Forest (DaRF) methods have been applied to sightings data collected between 2009 and 2016 during standardized vessel-based surveys, providing similar outcomes. The mean value of density over the entire study area was 0.72 ± 0.26 specimens/km2 for the striped dolphin and 0.47 ± 0.09 specimens/km2 for the common bottlenose dolphin. The abundance estimated by DaRF in the Gulf of Taranto was 10080 ± 3584 specimens of S. coeruleoalba and 6580 ± 1270 specimens of T. truncatus, respectively. Eight predictive variables were selected, considering both the local physiographic features and human activities existing in the investigated area. The explanatory variables depth, distance from the coast, distance from industrial areas and distance from areas exploited by fishery seem to play a key role in influencing the spatial distribution of both species, whereas the geomorphological variables proved to be the most significant factors shaping the concentration of both dolphins. The establishment of a Specially Protected Area of Mediterranean Importance (SPAMI) according the SPA/BD Protocol in the Gulf of Taranto is indicated as an effective management tool for the conservation of both dolphin populations in the Central-eastern Mediterranean Sea.

  4. 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.

  5. Effects of water depth, seasonal exposure, and substrate orientation on microbial bioerosion in the Ionian Sea (Eastern Mediterranean.

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    Claudia Färber

    highlight the relevance of bioerosion and accretion for the carbonate budget of the Ionian Sea.

  6. On the impact of the Bimodal Oscillating System (BiOS on the biogeochemistry and biology of the Adriatic and Ionian Seas (Eastern Mediterranean

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    G. Civitarese

    2010-12-01

    Full Text Available Analysis of 20-year time-series of the vertically averaged salinity and nutrient data in the Southern Adriatic shows that the two parameters are subject to strong decadal variability. In addition, it is documented that nutrient and salinity variations are out of phase. Nutrients in the Ionian and in the Adriatic vary in parallel except that generally the nutrient content in the Adriatic is lower than in the Ionian, a fact that has been attributed to primary producer consumption following the winter convective mixing. As shown earlier, North Ionian Gyre (NIG changes its circulation sense on a decadal scale due to the Bimodal Oscillating System, i.e. the feedback mechanism between the Adriatic and Ionian. Cyclonic circulation causes a downwelling of the nitracline along the borders of the NIG and a decrease in the nutrient content of the water flowing into the Adriatic across the Otranto Strait, and vice versa. In addition, the highly oligotrophic central area of the Ionian shows annual blooms only during cyclonic NIG circulation. Inversion of the sense of the NIG results in the advection of Modified Atlantic Water or of the Levantine/Eastern Mediterranean waters in the Adriatic. Here, we show that the presence of allochtonous organisms from Atlantic/Western Mediterranean and Eastern Mediterranean/temperate zone in the Adriatic are concurrent with the anticyclonic and cyclonic circulations of the NIG, respectively. On the basis of the results presented, a revision of the theory of Adriatic ingressions formulated in the early 1950s is proposed.

  7. Seasonal variation of deep-sea bioluminescence in the Ionian Sea

    International Nuclear Information System (INIS)

    Craig, Jessica; Jamieson, Alan J.; Bagley, Philip M.; Priede, Imants G.

    2011-01-01

    The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p<0.001), where a deep autumnal peak in BL density occurred between 500 and 2400 m. No significant seasonal variation in BL density was found in the east Ionian Sea (p=0.07). In both spring and autumn, significant differences in BL density were found through the water column between the east and west Ionian Sea (p<0.001).

  8. Seasonal variation of deep-sea bioluminescence in the Ionian Sea

    Energy Technology Data Exchange (ETDEWEB)

    Craig, Jessica, E-mail: j.craig@abdn.ac.u [University of Aberdeen, Oceanlab, Main Street, Newburgh, Aberdeenshire, AB41 6AA (United Kingdom); Jamieson, Alan J.; Bagley, Philip M.; Priede, Imants G. [University of Aberdeen, Oceanlab, Main Street, Newburgh, Aberdeenshire, AB41 6AA (United Kingdom)

    2011-01-21

    The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p<0.001), where a deep autumnal peak in BL density occurred between 500 and 2400 m. No significant seasonal variation in BL density was found in the east Ionian Sea (p=0.07). In both spring and autumn, significant differences in BL density were found through the water column between the east and west Ionian Sea (p<0.001).

  9. 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.

  10. Water transparency measurements in the deep Ionian Sea

    CERN Document Server

    Anassontzis, E G; Belias, A; Fotiou, A; Grammatikakis, G; Kontogiannis, H; Koske, P; Koutsoukos, S; Lykoussis, V; Markopoulos, E; Psallidas, A; Resvanis, L K; Siotis, I; Stavrakakis, S; Stavropoulos, G; Zhukov, V A

    2010-01-01

    A long optical base line spectrophotometer designed to measure light transmission in deep sea waters is described. The variable optical path length allows measurements without the need for absolute or external calibration. The spectrophotometer uses eight groups of uncollimated light sources emitting in the range 370–530 nm and was deployed at various depths at two locations in the Ionian Sea that are candidate sites for a future underwater neutrino telescope. Light transmission spectra at the two locations are presented and compared.

  11. Crustal Structure of the Ionian Basin and Eastern Sicily Margin: Results From a Wide-Angle Seismic Survey

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    Dellong, David; Klingelhoefer, Frauke; Kopp, Heidrun; Graindorge, David; Margheriti, Lucia; Moretti, Milena; Murphy, Shane; Gutscher, Marc-Andre

    2018-03-01

    In the Ionian Sea (central Mediterranean) the slow convergence between Africa and Eurasia results in the formation of a narrow subduction zone. The nature of the crust of the subducting plate remains debated and could represent the last remnants of the Neo-Tethys ocean. The origin of the Ionian basin is also under discussion, especially concerning the rifting mechanisms as the Malta Escarpment could represent a remnant of this opening. This subduction retreats toward the south-east (motion occurring since the last 35 Ma) but is confined to the narrow Ionian basin. A major lateral slab tear fault is required to accommodate the slab roll-back. This fault is thought to propagate along the eastern Sicily margin but its precise location remains controversial. This study focuses on the deep crustal structure of the eastern Sicily margin and the Malta Escarpment. We present two two-dimensional P wave velocity models obtained from forward modeling of wide-angle seismic data acquired onboard the R/V Meteor during the DIONYSUS cruise in 2014. The results image an oceanic crust within the Ionian basin as well as the deep structure of the Malta Escarpment, which presents characteristics of a transform margin. A deep and asymmetrical sedimentary basin is imaged south of the Messina strait and seems to have opened between the Calabrian and Peloritan continental terranes. The interpretation of the velocity models suggests that the tear fault is located east of the Malta Escarpment, along the Alfeo fault system.

  12. Dinoflagellate cysts from surface sediments of Syracuse Bay (Western Ionian Sea, Mediterranean)

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    Rubino, Fernando; Belmonte, Manuela; Caroppo, Carmela; Giacobbe, Mariagrazia

    2010-02-01

    The occurrence and abundance of dinoflagellate cysts were investigated for the first time at an Ionian locality along the south-eastern coast of Sicily, subject to spring-summer harmful algal events. Thirty-four cyst morphotypes were recognized belonging to 24 taxa identified at least at the genus level. Cyst abundance in surface sediments ranged from 43 to 828 cysts g -1 dry weight, with the highest numbers recorded at the most restricted station. Germination experiments allowed confirmation of species identification determined by cyst analysis and provided clonal cultures of Alexandrium minutum and Gymnodinium nolleri, two of the bloom-forming species in the area. This represents the first record of G. nolleri for the Mediterranean Sea.

  13. Active faults and historical earthquakes in the Messina Straits area (Ionian Sea

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    A. Polonia

    2012-07-01

    Full Text Available The Calabrian Arc (CA subduction complex is located at the toe of the Eurasian Plate in the Ionian Sea, where sediments resting on the lower plate have been scraped off and piled up in the accretionary wedge due to the African/Eurasian plate convergence and back arc extension. The CA has been struck repeatedly by destructive historical earthquakes, but knowledge of active faults and source parameters is relatively poor, particularly for seismogenic structures extending offshore. We analysed the fine structure of major tectonic features likely to have been sources of past earthquakes: (i the NNW–SSE trending Malta STEP (Slab Transfer Edge Propagator fault system, representing a lateral tear of the subduction system; (ii the out-of-sequence thrusts (splay faults at the rear of the salt-bearing Messinian accretionary wedge; and (iii the Messina Straits fault system, part of the wide deformation zone separating the western and eastern lobes of the accretionary wedge.

    Our findings have implications for seismic hazard in southern Italy, as we compile an inventory of first order active faults that may have produced past seismic events such as the 1908, 1693 and 1169 earthquakes. These faults are likely to be source regions for future large magnitude events as they are long, deep and bound sectors of the margin characterized by different deformation and coupling rates on the plate interface.

  14. Late Holocene tectonic implications deduced from tidal notches in Leukas and Meganisi islands (Ionian Sea)

    International Nuclear Information System (INIS)

    Evelpidou, N.; Karkani, A.; Pirazzoli, P.

    2017-01-01

    In this paper the tectonic behavior of Leukas and Meganisi islands (Ionian Sea) is examined through underwater research carried out in both islands. A possible Late Holocene correlation between coseismic subsidences is attempted and evidenced by submerged tidal notches in both islands. These subsidence events probably occurred after the uplift that affected the northernmost part of Leukas around 4 to 5ka BP. In conclusion, although the whole area was affected by a similar tectonic strain, certain coseismic events were only recorded in one of the two islands and in some cases they affected only part of the study area.

  15. Late Holocene tectonic implications deduced from tidal notches in Leukas and Meganisi islands (Ionian Sea)

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    Evelpidou, N.; Karkani, A.; Pirazzoli, P.

    2017-11-01

    In this paper the tectonic behavior of Leukas and Meganisi islands (Ionian Sea) is examined through underwater research carried out in both islands. A possible Late Holocene correlation between coseismic subsidences is attempted and evidenced by submerged tidal notches in both islands. These subsidence events probably occurred after the uplift that affected the northernmost part of Leukas around 4 to 5ka BP. In conclusion, although the whole area was affected by a similar tectonic strain, certain coseismic events were only recorded in one of the two islands and in some cases they affected only part of the study area.

  16. Trace metal distributions in Posidonia oceanica and sediments from Taranto Gulf (Ionian Sea, Southern Italy

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    A. DI LEO

    2013-03-01

    Full Text Available Distribution of metals (Hg, Pb, Sn, Cu, Cd and Zn was determined in sediments and in different tissues of Posidonia oceanica collected from San Pietro Island, Taranto Gulf (Ionian Sea, Southern Italy. In seagrass, results, compared with metal concentrations in sediments, showed that the highest concentrations of Hg, Pb, Sn and Cu were found in the roots, while in the green leaves were found the highest levels of Cd and Zn. Instead the lowest metal concentrations were found in the basal part of the leaf. Levels of  metals in the leaves were similar to those found by other authors in uncontaminated areas of the Mediterranean Sea. Mercury levels in roots were correlated to levels in sediments. This could demonstrate the plant memorizes sediments contamination . This study reinforces the usefulness and the relevance of Posidonia oceanica as an indicator of spatial metal contamination and an interesting tool for environmental quality evaluation.

  17. Yearlong moored bioluminescence and current data at KM3NeT neutrino telescope sites in the deep Ionian Sea

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    van Haren, H.; de Jong, M.; Kooijman, P.

    2015-01-01

    Yearlong observations are presented using stand-alone small optical sensors and current meters in the deep Ionian Sea, E-Mediterranean. At two future neutrino telescope sites, off Sicily (I) and off Peloponessos (Gr), we deployed 2500–3000 m long mooring lines with oceanographic instrumentation. At

  18. Sequence of eruptive events in the Vesuvio area recorded in shallow-water Ionian Sea sediments

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    C. Taricco

    2008-01-01

    Full Text Available The dating of the cores we drilled from the Gallipoli terrace in the Gulf of Taranto (Ionian Sea, previously obtained by tephroanalysis, is checked by applying a method to objectively recognize volcanic events. This automatic statistical procedure allows identifying pulse-like features in a series and evaluating quantitatively the confidence level at which the significant peaks are detected. We applied it to the 2000-years-long pyroxenes series of the GT89-3 core, on which the dating is based. The method confirms the dating previously performed by detecting at a high confidence level the peaks originally used and indicates a few possible undocumented eruptions. Moreover, a spectral analysis, focussed on the long-term variability of the pyroxenes series and performed by several advanced methods, reveals that the volcanic pulses are superimposed to a millennial trend and a 400 years oscillation.

  19. Sequence of eruptive events in the Vesuvio area recorded in shallow-water Ionian Sea sediments

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    Taricco, C.; Alessio, S.; Vivaldo, G.

    2008-01-01

    The dating of the cores we drilled from the Gallipoli terrace in the Gulf of Taranto (Ionian Sea), previously obtained by tephroanalysis, is checked by applying a method to objectively recognize volcanic events. This automatic statistical procedure allows identifying pulse-like features in a series and evaluating quantitatively the confidence level at which the significant peaks are detected. We applied it to the 2000-years-long pyroxenes series of the GT89-3 core, on which the dating is based. The method confirms the dating previously performed by detecting at a high confidence level the peaks originally used and indicates a few possible undocumented eruptions. Moreover, a spectral analysis, focussed on the long-term variability of the pyroxenes series and performed by several advanced methods, reveals that the volcanic pulses are superimposed to a millennial trend and a 400 years oscillation.

  20. Assessment of offshore wind power potential in the Aegean and Ionian Seas based on high-resolution hindcast model results

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    Takvor Soukissian

    2017-03-01

    Full Text Available In this study long-term wind data obtained from high-resolution hindcast simulations is used to analytically assess offshore wind power potential in the Aegean and Ionian Seas and provide wind climate and wind power potential characteristics at selected locations, where offshore wind farms are at the concept/planning phase. After ensuring the good model performance through detailed validation against buoy measurements, offshore wind speed and wind direction at 10 m above sea level are statistically analyzed on the annual and seasonal time scale. The spatial distribution of the mean wind speed and wind direction are provided in the appropriate time scales, along with the mean annual and the inter-annual variability; these statistical quantities are useful in the offshore wind energy sector as regards the preliminary identification of favorable sites for exploitation of offshore wind energy. Moreover, the offshore wind power potential and its variability are also estimated at 80 m height above sea level. The obtained results reveal that there are specific areas in the central and the eastern Aegean Sea that combine intense annual winds with low variability; the annual offshore wind power potential in these areas reach values close to 900 W/m2, suggesting that a detailed assessment of offshore wind energy would be worth noticing and could lead in attractive investments. Furthermore, as a rough estimate of the availability factor, the equiprobable contours of the event [4 m/s ≤ wind speed ≤ 25 m/s] are also estimated and presented. The selected lower and upper bounds of wind speed correspond to typical cut-in and cut-out wind speed thresholds, respectively, for commercial offshore wind turbines. Finally, for seven offshore wind farms that are at the concept/planning phase the main wind climate and wind power density characteristics are also provided.

  1. Crustal structure of the Ionian basin and eastern Sicily margin : results from a wide angle seismic survey and implication for the crustal nature and origin of the basin, and the recent tear fault location

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    Gutscher, M. A.; Dellong, D.; Klingelhoefer, F.; Kopp, H.; Graindorge, D.; Margheriti, L.; Moretti, M.

    2017-12-01

    In the Ionian Sea (Central Mediterranean) the slow convergence between Africa and Eurasia results in the formation of a narrow subduction zone. The nature of the crust and lithosphere of the subducting plate remain debated and could represent the last remnants of the Neo-Tethys ocean. The rifting mechanism that produced the Ionian basin are also still under discussion with the Malta escarpment representing a possible remnant of this opening. At present, this subduction is still retreating to the south-east (motion occurring since the last 35 Ma) but is confined to the narrow Ionian Basin. In order to accommodate slab roll-back, a major lateral slab tear fault is required. This fault is thought to propagate along the eastern Sicily margin but its precise location remains controversial. This study focuses on the deep crustal structure of the Eastern-Sicily margin and the Malta Escarpment by presenting two wide-angle velocity profiles crossing these structures roughly orthogonally. The data used for the forward velocity modeling were acquired onboard the R/V Meteor during the DIONYSUS cruise in 2014. The results image an oceanic crust within the Ionian basin as well as the deep structure of the Malta Escarpment which presents characteristics of a transform margin. A deep and asymmetrical sedimentary basin is imaged south of the Messina strait and seems to have opened in between the Calabrian and Peloritan continental terranes. The interpretation of the velocity models suggests that the tear fault is located east of the Malta Escarpment, along the Alfeo fault system.

  2. Gravity-Driven Deposits in an Active Margin (Ionian Sea) Over the Last 330,000 Years

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    Köng, Eléonore; Zaragosi, Sébastien; Schneider, Jean-Luc; Garlan, Thierry; Bachèlery, Patrick; Sabine, Marjolaine; San Pedro, Laurine

    2017-11-01

    In the Ionian Sea, the subduction of the Nubia plate underneath the Eurasia plate leads to an important sediment remobilization on the Calabrian Arc and the Mediterranean Ridge. These events are often associated with earthquakes and tsunamis. In this study, we analyze gravity-driven deposits in order to establish their recurrence time on the Calabrian Arc and the western Mediterranean Ridge. Four gravity cores collected on ridges and slope basins of accretionary prisms record turbidites, megaturbidites, slumping and micro-faults over the last 330,000 years. These turbidites were dated by correlation with a hemipelagic core with a multi-proxy approach: radiometric dating, δ18O, b* colour curve, sapropels and tephrochronology. The origin of the gravity-driven deposits was studied with a sedimentary approach: grain-size, lithology, thin section, geochemistry of volcanic glass. The results suggest three periods of presence/absence of gravity-driven deposits: a first on the western lobe of the Calabrian Arc between 330,000 and 250,000 years, a second between 120,000 years and present day on the eastern lobe of the Calabrian Arc and over the last 60,000 years on the western lobe, and a third on the Mediterranean Ridge over the last 37,000 years. Return times for gravity-driven deposits are around 1,000 years during the most important record periods. The turbidite activity also highlights the presence of volcaniclastic turbidites that seems to be link to the Etna changing morphology over the last 320,000 years.

  3. Potential tsunamigenic hazard associated to submarine mass movement along the Ionian continental margin (Mediterranean Sea).

    Science.gov (United States)

    Ceramicola, S.; Tinti, S.; Praeg, D.; Zaniboni, F.; Planinsek, P.

    2012-04-01

    Submarine mass movements are natural geomorphic processes that transport marine sediment down continental slopes into deep-marine environments. Type of mass wasting include creep, slides, slump, debris flows, each with its own features and taking place over timescale from seconds to years. Submarine landslides can be triggered by a number of different causes, either internal (such as changes in physical chemical sediment properties) or external (e.g. earthquakes, volcanic activity, salt movements, sea level changes etc.). Landslides may mobilize sediments in such a way as to form an impulsive vertical displacement of a body of water, originating a wave or series of waves with long wavelengths and long periods called tsunamis ('harbor waves'). Over 600 km of continental margin has been investigated by OGS in the Ionian sea using geophysical data - morpho-bathymetry (Reson 8111, 8150) and sub-bottom profiles (7-10 KHz) - collected aboard the research vessel OGS Explora in the framework of the MAGIC Project (Marine Geohazard along the Italian Coasts), funded by the Italian Civil Protection. The objective of this project is the definition of elements that may constitute geological risk for coastal areas. Geophysical data allowed the recognition of four main types of mass wasting phenomena along the slopes of the ICM: 1) mass transport complexes (MTCs) within intra-slope basins. Seabed imagery show the slopes of all the seabed ridges to be marked by headwall scarps recording widespread failure, multiple debris flows in several basins indicate one or more past episodes of failure that may be linked to activity on the faults bounding the structural highs. 2) submarine landslide - a multiple failure event have been identified (Assi landslide) at about 6 km away from the coastline nearby Riace Marina. Headwall scars up to 50 m high across water depths of 700 to 1400 m, while sub-bottom profiles indicate stacked slide deposits at and near seabed. 4) canyon headwalls - in the

  4. Optimization of water resources management using SWOT analysis: the case of Zakynthos Island, Ionian Sea, Greece

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    Diamantopoulou, P.; Voudouris, K.

    2008-03-01

    Zakynthos, an island of 408 km2 in the Ionian Sea, is completely dependent on its groundwater resources for fulfilling the demands of the water supplies. The use of groundwater resources has become particularly intensive during the last decades because of the intense urbanization, the tourist development and the irrigated land expansion that took place. The main aquifers are developed in limestones (karstic), sandstones of neogene deposits (confined) and alluvial deposits (phreatic). This paper focuses on the assessment of their hydrogeological characteristics and the groundwater quality. For this investigation, groundwater level measurements, drilling data, pumping tests and chemical analyses of groundwater samples were used. The average annual consumption that is abstracted from the aquifer systems, is 4.9 × 106 m3 year-1. The exploitable groundwater reserves were estimated to be 3.3 × 106 m3 year-1. In the last decades, the total abstractions exceed the natural recharge, due to the tourist development; therefore the aquifer systems are not used safely. The results of chemical analyses showed a deterioration of the groundwater quality. According to the analyses the shallow alluvial aquifer and the confined aquifer are polluted by nitrates at concentrations in excess of 25 mg L-1. High sulphate concentrations might be related to the dissolution of gypsum. Seawater intrusion phenomena are recorded in coastal parts of aquifer systems. The increased Cl- concentrations in karstic aquifer indicate signs of overexploitation. Strengths, weaknesses, opportunities and threats (SWOT) analysis was applied in order to evaluate the SWOT of the groundwater resources. Moreover, some recommendations are made to assist the rational management that aim at improving the sustainability of the groundwater resources of Zakynthos Island.

  5. Evidence of mud diapirism and coral colonies in the ionian sea (central mediterranean from high resolution chirp sonar survey

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    C. Corselli

    2006-06-01

    Full Text Available A chirp sonar survey in the Ionian Sea investigated the Calabrian margin, the Calabrian accretionary wedge, the Taranto Trench and the Apulian foreland. Shallow tectonics structures have been related to deeper ones, recognised on CROP seismic profiles. The identified echo characters have been compared with those described in the modern literature and have been related to different kinds of sediments, on the basis of core samples. Based on echo character and morphology we have recognised: 1 A widespread presence of mounds, up to 50 m high, occurring on the Apulian plateau as isolated mounds in the deepest zones (1600-800 m and in groups in the shallower ones (800-600 m; they have been interpreted as coral mounds, according to a recent discovery of living deep water coral colonies in this zone. 2 Some mud diapirs, isolated or in groups of two or three elements, widespread in the whole study area. In analogy of what has been observed on the Mediterranean Ridge, their presence suggests the activity of deep tectonic structures (thrusts and faults and a reduced thickness (or absence of Messinian evaporites in this part of the Ionian Sea.

  6. PALEOBATHYMETRIC INTERPRETATION OF THE FISH OTOLITHS FROM THE LOWER - MIDDLE QUATERNARY DEPOSITS OF KEPHALLONIA AND ZAKYNTHOS ISLANDS (IONIAN SEA, WESTERN GREECE

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    KONSTANTINA AGIADI

    2010-03-01

    Full Text Available Fish otoliths are herein used to estimate the depositional depth of the Early - Middle Pleistocene deposits at SE Zakynthos and SW Kephallonia Islands (Ionian Sea, Western Greece, through comparison with the modern bathymetric distributions of the identified fish taxa. These estimates provide a more detailed picture of the depth variations for the Gelasian - Ionian stage interval in the study areas. The Lower Pleistocene marine deposits of the Gerakas Formation (SE Zakynthos Island, Ionian Sea were deposited at average depths of 400-450 meters, with eustacy playing an important role in the depth variability, between 1.95-1.73 Ma. An uplifting episode, followed by subsidence takes place between 1.73-1.66 Ma, taking the area to 200-300 meters of depth, and then back to 400-500 meters. However, the area seems uplifted again to 200-400 meters later on in the Calabrian stage (1.25-0.97 Ma. Sedimentation of the Akrotiri deposits (NW Kephallonia Island, Ionian Sea, during the same chronostratigraphic interval, took place in a similar setting. At the Early Pleistocene (1.95-1.73 Ma this basin reached depths of 400-450 meters, with uplift and following subsidence taking place between 1.73-1.66 Ma. Overall, the application of fish otolith paleobathymetry in the study areas provide a detailed picture of the depth variations for the Early Quaternary interval and refine the currently hypothesized pattern of tectonic movements. 

  7. Population genomics meet Lagrangian simulations: Oceanographic patterns and long larval duration ensure connectivity among Paracentrotus lividus populations in the Adriatic and Ionian seas.

    Science.gov (United States)

    Paterno, Marta; Schiavina, Marcello; Aglieri, Giorgio; Ben Souissi, Jamila; Boscari, Elisa; Casagrandi, Renato; Chassanite, Aurore; Chiantore, Mariachiara; Congiu, Leonardo; Guarnieri, Giuseppe; Kruschel, Claudia; Macic, Vesna; Marino, Ilaria A M; Papetti, Chiara; Patarnello, Tomaso; Zane, Lorenzo; Melià, Paco

    2017-04-01

    Connectivity between populations influences both their dynamics and the genetic structuring of species. In this study, we explored connectivity patterns of a marine species with long-distance dispersal, the edible common sea urchin Paracentrotus lividus , focusing mainly on the Adriatic-Ionian basins (Central Mediterranean). We applied a multidisciplinary approach integrating population genomics, based on 1,122 single nucleotide polymorphisms (SNPs) obtained from 2b-RAD in 275 samples, with Lagrangian simulations performed with a biophysical model of larval dispersal. We detected genetic homogeneity among eight population samples collected in the focal Adriatic-Ionian area, whereas weak but significant differentiation was found with respect to two samples from the Western Mediterranean (France and Tunisia). This result was not affected by the few putative outlier loci identified in our dataset. Lagrangian simulations found a significant potential for larval exchange among the eight Adriatic-Ionian locations, supporting the hypothesis of connectivity of P. lividus populations in this area. A peculiar pattern emerged from the comparison of our results with those obtained from published P. lividus cytochrome b (cytb) sequences, the latter revealing genetic differentiation in the same geographic area despite a smaller sample size and a lower power to detect differences. The comparison with studies conducted using nuclear markers on other species with similar pelagic larval durations in the same Adriatic-Ionian locations indicates species-specific differences in genetic connectivity patterns and warns against generalizing single-species results to the entire community of rocky shore habitats.

  8. Spatio-temporal changes of Munida Rutllanti Zariquiey-Alvarez, 1952 (Decapoda: Galatheidae in the North-Western Ionian Sea (Central Mediterranean

    Directory of Open Access Journals (Sweden)

    P. MAIORANO

    2013-09-01

    Full Text Available The spatio-temporal pattern of Munida rutllanti distribution in the north-western Ionian Sea has been studied. Data were collected during 14 experimental trawl surveys conducted from 1997 to 2010 as part of the international MEDITS project. The hauls were carried out during day-light hours between depths of 10 and 800 m in the spring season. A progressive increase in the abundance index (N/km2 of M. rutllanti was observed from 2000 to 2008, then a sharp decrease was shown in the last two years. The greatest and lowest abundance indices were observed in the Apulian and central Calabrian sub-areas, respectively. The species was collected between 107 and 795 m in depth, with a significant increase and decrease over time in the maximum and minimum depth of finding, respectively. A highly significant increase over time in the mean carapace length was also observed in the whole study area. The widespread occurrence and increasing abundance of this species in the Ionian Sea could be related to the increase in temperature and the variation in hydrographic conditions which occurred in the Ionian basin during the EMT-BiOS phenomenon.

  9. Continuous monitoring of noise levels in the Gulf of Catania (Ionian Sea). Study of correlation with ship traffic.

    Science.gov (United States)

    Viola, S; Grammauta, R; Sciacca, V; Bellia, G; Beranzoli, L; Buscaino, G; Caruso, F; Chierici, F; Cuttone, G; D'Amico, A; De Luca, V; Embriaco, D; Favali, P; Giovanetti, G; Marinaro, G; Mazzola, S; Filiciotto, F; Pavan, G; Pellegrino, C; Pulvirenti, S; Simeone, F; Speziale, F; Riccobene, G

    2017-08-15

    Acoustic noise levels were measured in the Gulf of Catania (Ionian Sea) from July 2012 to May 2013 by a low frequency (<1000Hz) hydrophone, installed on board the NEMO-SN1 multidisciplinary observatory. NEMO-SN1 is a cabled node of EMSO-ERIC, which was deployed at a water depth of 2100m, 25km off Catania. The study area is characterized by the proximity of mid-size harbors and shipping lanes. Measured noise levels were correlated with the passage of ships tracked with a dedicated AIS antenna. Noise power was measured in the frequency range between 10Hz and 1000Hz. Experimental data were compared with the results of a fast numerical model based on AIS data to evaluate the contribution of shipping noise in six consecutive 1/3 octave frequency bands, including the 1/3 octave frequency bands centered at 63Hz and 125Hz, indicated by the Marine Strategy Framework Directive (2008/56/EC). Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. A Holistic Approach to Fishery Management: Evidence and Insights from a Central Mediterranean Case Study (Western Ionian Sea

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    Tommaso Russo

    2017-06-01

    Full Text Available The new Common Fisheries Policy (CFP is designed to represent an appropriate response to the uncertainties and challenges facing the fisheries sector. It also adopts a holistic approach to fisheries management, considering all factors driving fishers' behavior, and ultimately, the long-term maintenance of living resources. The most reliable way to pursue these aims could be represented by a change in the exploitation pattern, in order to guarantee the sustainability of fisheries without compromising their socioeconomic viability. In this paper, the demersal fisheries of the Ionian Sea [Geographic Sub-area (GSA 19] were analyzed with respect to their spatial, temporal, economic, and biological characteristics in terms of four key species for fisheries, namely European hake, red mullet, giant red shrimp, and deep-water rose shrimp. Specifically, (1 a quantitative procedure was applied to break down the whole system (including small-scale fleet components into a series of fishing grounds using input data about fishing efforts; (2 the different fleet segments were defined as a combination of main gear and fishing grounds; (3 the effort and production by fleet segment were derived according to biological samplings of commercial data (Data Collection Framework for the collection and management of fisheries data, DCF, information on localization of nursery and spawning grounds, and expert knowledge; and (4 all this information was used to feed a bioeconomic modeling tool (BEMTOOL, and to explore alternative exploitation patterns. A series of scenarios including the status quo were defined, starting from the actual management approach based on temporal fishing closure. The results showed that significant improvements in the exploitation pattern could be achieved by setting up spatial and/or temporal gear-specific bans of the fishing activity. More specifically, scenarios based on a 3-month fishing ban for trawlers are expected to provide high rebuilding

  11. Dinoflagellate cysts and benthic foraminifera in surface sediments from the Mar Piccolo in Taranto (Ionian Sea, Southern Italy)

    Science.gov (United States)

    Ferraro, L.; Rubino, F.; Frontalini, F.; Belmonte, M.; Di Leo, A.; Giandomenico, S.; Greco, M.; Lirer, F.; Spada, L.; Vallefuoco, M.

    2012-12-01

    characteristic, cysts constitute a reservoir of potential biodiversity but can also be useful indicators of productivity, eutrophication and pollution in recent marine environments. In this way, the sampling sediments of a coastal marine area, allows to monitor the responses of both microplankton and microbenthos to possible disturbance events of the ecosystem. A preliminary study, preparatory to a more detailed sampling survey during winter 2013, was carried out in December 2011 in the Mar Piccolo of Taranto (Ionian Sea), on surface sediment samples which were analyzed to identify living benthic foraminiferal assemblages and dormant stages of plankton in order to establish the potentiality of these organisms as bio-indicators of environmental stress conditions.

  12. Searching for a stock structure in Sardina pilchardus from the Adriatic and Ionian seas using a microsatellite DNA-based approach

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    Paolo Ruggeri

    2013-10-01

    Full Text Available In the present study the genetic variability of European sardine from Adriatic and Ionian seas was investigated in order to detect the occurrence of genetic structure within and between these basins. In several samples the analysis of genetic variability at eight microsatellite loci showed a number of homozygote individuals higher than expected at Hardy-Weinberg equilibrium. The inter-population differentiation level estimated by AMOVA, qST and rRST and Bayesian descriptors detected no signs of population differentiation between the samples analysed. These results are consistent with previous studies based on allozymes and several mitochondrial DNA markers and add further evidence contradicting the early identification, based on morphological and reproductive data, of two sub-populations in the Adriatic Sea.

  13. 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

  14. On the thermoluminescence profile of an Ionian Sea sediment: evidence of 137, 118, 12.1 and 10.8y cycles in the last two millennia

    International Nuclear Information System (INIS)

    Cini Castagnoli, G.; Bonino, G.; Provenzale, A.

    1988-01-01

    The thermoluminescence profile of an Ionian Sea recent sedimentary core, constructed with 467 equispaced data points and spanning 18 centuries from 170 to 1974 A.D. is studied. Several time series analysis methods reveal two evident periodicities on the centennial time scale, at 137 years and 118 years, both with their second harmonics. Together with these slow cyclic variations two sharp periodicities appear on the decennial time scale, at 12.1 years and 10.8 years. In the present study the amplitude and phase of these waves have been determined and it is shown that their summation accounts for more than 50% of the standard deviation of the whole time series and that they correctly reproduce the basic characteristics of the data

  15. 137 Caesium distribution in the eastern Mediterranean Sea. Recent changes and future trends

    International Nuclear Information System (INIS)

    Papucci, C.; Delfanti, R.

    1999-01-01

    A series of sampling campaigns were carried out in the eastern Mediterranean in the period 1995-1997, to examine the relationship between the distribution of 137Cs in the water column and water mass circulation. 137Cs concentration in the surface water ranges between 3.3 and 4.0 mBq/l all over the area, indicating that the input due to the Chernobyl accident has been transferred to deep water layers by convection processes. In fact, in the vertical profiles, relative maxima are observed in the intermediate (4 mBq/l) and deep waters (∼2.5 mBq/l) formed after the Chernobyl accident. A clear Chernobyl signal also traces the new deep waters formed in the Aegean Sea that, exiting from the Cretan Arc Straits, since 1991 are spreading in the bottom layer of the eastern Mediterranean. The changes in 137Cs vertical profiles related to the new thermohaline circulation of the intermediate and deep waters of the eastern Mediterranean are being monitored at a deep station in the western Ionian Sea. The 1997 profile shows a decrease in 137Cs concentration both in the Levantine intermediate water and in the eastern Mediterranean deep water with respect to 1996. The decrease in Levantine intermediate water is likely due to seasonal/interannual variability, while the changes in the deep layer are related to the spreading westward into the Ionian of the new Aegean dense water. Along the path towards the western Mediterranean, 137Cs content in the Levantine intermediate water decreases from ∼4 mBq/l in the W-Ionian Sea to ∼2 mBq/l at the western sill of the Sicily Straits, due to mixing with underlying water, with lower caesium content, near the Malta Sill. Time-series measurements at the western sill of the Sicily Straits show that, while 137Cs concentration in the surface water entering the eastern Mediterranean remained constant (∼3.5 mBq/l) in the period 1993-1997, its level in the Levantine intermediate water leaving the basin decreased from 3.5 to 2.0 mBq/l

  16. Development from the seafloor to the sea surface of the cabled NEMO-SN1 observatory in the Western Ionian Sea

    Science.gov (United States)

    Sparnocchia, Stefania; Beranzoli, Laura; Borghini, Mireno; Durante, Sara; Favali, Paolo; Giovanetti, Gabriele; Italiano, Francesco; Marinaro, Giuditta; Meccia, Virna; Papaleo, Riccardo; Riccobene, Giorgio; Schroeder, Katrin

    2015-04-01

    A prototype of cabled deep-sea observatory has been operating in real-time since 2005 in Southern Italy (East Sicily, 37°30' N - 15°06'E), at 2100 m water depth, 25 km from the harbor of the city of Catania. It is the first-established real-time node of the "European Multidisciplinary Seafloor and water column Observatory" (EMSO, http://www.emso-eu.org) a research infrastructure of the Sector Environment of ESFRI. In the present configuration it consists of two components: the multi-parametric station NEMO-SN1 (TSN branch) equipped with geophysical and environmental sensors for measurements at the seafloor, and the NEMO-OνDE station (TSS branch) equipped with 4 wideband hydrophones. A 28 km long electro-optical cable connects the observatory to a shore laboratory in the Catania harbor, hosting the data acquisition system and supplying power and data transmission to the underwater instrumentation. The NEMO-SN1 observatory is located in an area particularly suited to multidisciplinary studies. The site is one of the most seismically active areas of the Mediterranean (some of the strongest earthquakes occurred in 1169, 1693 and 1908, also causing very intense tsunami waves) and is close to Mount Etna, one of the largest and most active volcanoes in Europe. The deployment area is also a key site for monitoring deep-water dynamics in the Ionian Sea, connecting the Levantine basin to the southern Adriatic basin where intermediate and deep waters are formed, and finally to the western Mediterranean Sea via the Strait of Sicily. The observatory is being further developed under EMSO MedIT (http://www.emso-medit.it/en/), a structural enhancement project contributing to the consolidation and enhancement of the European research infrastructure EMSO in Italian Convergence Regions. In this framework, a new Junction Box will be connected to the TSN branch and will provide wired and wireless (acoustic connections) for seafloor platforms and moorings. This will allow the

  17. Seasonal fluctuations of some biological traits of the invader Caprella scaura (Crustacea: Amphipoda: Caprellidae in the Mar Piccolo of Taranto (Ionian Sea, southern Italy

    Directory of Open Access Journals (Sweden)

    Ermelinda Prato

    2013-03-01

    Full Text Available Caprella scaura is an epifaunal amphipod crustacean that originates in the western Indian Ocean and has spread throughout the world, but very little is known about fundamental aspects of its biology. This paper is the first presentation of its life history traits in an invaded region. The study was conducted in the Mar Piccolo basin (southern Italy, Ionian Sea, over a one-year period. All biological parameters showed a strong seasonal pattern, breeding peaked twice during the year and the number of eggs in the ventral brood pouch ranged from 5 to 72. The sex ratio was generally close to 1:1. A strong correlation between total length of ovigerous females and number of eggs was observed. The mean length of both mature males and mature females was 10.63 and 7.70 mm, respectively. The results of this study showed that the population dynamics of this species was not dissimilar to that of other caprellids or marine epifaunal Crustacea. This caprellid has given rise to a stable population in the Mar Piccolo; it was present all year round in the study area but its density suggests that it is not yet a strong invader.

  18. The impact of hangingcleaning husbandry practices on Mediterranean mussels, Mytilus galloprovincialis Lmk, cultivated in the Mar Piccolo (Taranto, Ionian Sea, Italy

    Directory of Open Access Journals (Sweden)

    Gerardo Centoducati

    2010-01-01

    Full Text Available The impact of the stressful hanging-cleaning husbandry practices on the growth conditions of the cultured Mediterranean mussels, Mytilus galloprovincialis Lmk, cultivated in the Mar Piccolo (Ionian Sea was investigated from November 2005 to June 2006. The experimental strings were randomly organized in four groups, with five replications, exposed to different time periods of hanging: Group A, none; Group B, once every 15 days; Group C, once every 30 days; Group D, once every 60 days. The study, carried out on a total of 2000 mussels, showed that the cleaning of the mussel strings using the hanging-cleaning practice exerted an adverse effect on mussel growth (SGR%=46.62 in Group A; 44.85 in Group D; 43.72 in Group C; 42.12 in Group B. In particular, the highest percentage of meat yield occurred in the mussels more frequently exposed to air (Group B, 4.2±0.43 g in spite of their lower morphometric variable values. In order to evaluate mussel condition, three different indexes were calculated. The hanging practice in mussel cultivation, commonly used in the basin of Taranto and in many mussel farms all over the world, would provide an economic benefit to the mussel farmers allowing the greatest production and the highest specific growth rate (SGR% of mussels, together with a more appreciable aesthetic for the consumer. Our findings suggest that the hanging practice every 60 days would provide an economic benefit allowing an increase of about 30% of total string weight compared to the 30-day hanging practice commonly in use.

  19. Mapping cold-water coral habitats at different scales within the Northern Ionian Sea (Central Mediterranean: an assessment of coral coverage and associated vulnerability.

    Directory of Open Access Journals (Sweden)

    Alessandra Savini

    Full Text Available In this study, we mapped the distribution of Cold-Water Coral (CWC habitats on the northern Ionian Margin (Mediterranean Sea, with an emphasis on assessing coral coverage at various spatial scales over an area of 2,000 km(2 between 120 and 1,400 m of water depth. Our work made use of a set of data obtained from ship-based research surveys. Multi-scale seafloor mapping data, video inspections, and previous results from sediment samples were integrated and analyzed using Geographic Information System (GIS-based tools. Results obtained from the application of spatial and textural analytical techniques to acoustic meso-scale maps (i.e. a Digital Terrain Model (DTM of the seafloor at a 40 m grid cell size and associated terrain parameters and large-scale maps (i.e. Side-Scan Sonar (SSS mosaics of 1 m in resolution ground-truthed using underwater video observations were integrated and revealed that, at the meso-scale level, the main morphological pattern (i.e. the aggregation of mound-like features associated with CWC habitat occurrences was widespread over a total area of 600 km(2. Single coral mounds were isolated from the DTM and represented the geomorphic proxies used to model coral distributions within the investigated area. Coral mounds spanned a total area of 68 km(2 where different coral facies (characterized using video analyses and mapped on SSS mosaics represent the dominant macro-habitat. We also mapped and classified anthropogenic threats that were identifiable within the examined videos, and, here, discuss their relationship to the mapped distribution of coral habitats and mounds. The combined results (from multi-scale habitat mapping and observations of the distribution of anthropogenic threats provide the first quantitative assessment of CWC coverage for a Mediterranean province and document the relevant role of seafloor geomorphology in influencing habitat vulnerability to different types of human pressures.

  20. Mapping cold-water coral habitats at different scales within the Northern Ionian Sea (Central Mediterranean): an assessment of coral coverage and associated vulnerability.

    Science.gov (United States)

    Savini, Alessandra; Vertino, Agostina; Marchese, Fabio; Beuck, Lydia; Freiwald, André

    2014-01-01

    In this study, we mapped the distribution of Cold-Water Coral (CWC) habitats on the northern Ionian Margin (Mediterranean Sea), with an emphasis on assessing coral coverage at various spatial scales over an area of 2,000 km(2) between 120 and 1,400 m of water depth. Our work made use of a set of data obtained from ship-based research surveys. Multi-scale seafloor mapping data, video inspections, and previous results from sediment samples were integrated and analyzed using Geographic Information System (GIS)-based tools. Results obtained from the application of spatial and textural analytical techniques to acoustic meso-scale maps (i.e. a Digital Terrain Model (DTM) of the seafloor at a 40 m grid cell size and associated terrain parameters) and large-scale maps (i.e. Side-Scan Sonar (SSS) mosaics of 1 m in resolution ground-truthed using underwater video observations) were integrated and revealed that, at the meso-scale level, the main morphological pattern (i.e. the aggregation of mound-like features) associated with CWC habitat occurrences was widespread over a total area of 600 km(2). Single coral mounds were isolated from the DTM and represented the geomorphic proxies used to model coral distributions within the investigated area. Coral mounds spanned a total area of 68 km(2) where different coral facies (characterized using video analyses and mapped on SSS mosaics) represent the dominant macro-habitat. We also mapped and classified anthropogenic threats that were identifiable within the examined videos, and, here, discuss their relationship to the mapped distribution of coral habitats and mounds. The combined results (from multi-scale habitat mapping and observations of the distribution of anthropogenic threats) provide the first quantitative assessment of CWC coverage for a Mediterranean province and document the relevant role of seafloor geomorphology in influencing habitat vulnerability to different types of human pressures.

  1. New Fisheries-related data from the Mediterranean Sea (November, 2016

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    A. ANASTASOPOULOU

    2016-11-01

    Full Text Available In this fourth Collective Article, with fisheries-related data from the Mediterranean, we present weight-length relationships for eight deep-sea fish species (Brama brama, Conger conger, Etmopterus spinax, Molva macrophthalma, Mora moro, Pagellus bogaraveo, Phycis blennoides from the Eastern Ionian Sea; Scyliorhinus canicula from various locations in the Mediterranean Sea and weight-length relationships and condition factor of five Mugilidae species (Liza aurata, Liza saliens, Liza ramada, Mugil cephalus, Chelon labrosus from a Mediterranean lagoon in the Ionian Sea. Moreover, we present otolith weight, fish length and otolith length relationships of the red mullet (Mullus barbatus in the Aegean and Ionian Sea and otolith weight relationships in European hake (Merluccius merluccius from the Greek Seas.

  2. Geodetic and seismological investigation in the Ionian area

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    F. Riguzzi

    1997-06-01

    Full Text Available Geodetic and seismic evidence of crustal deformations in the Ionian area are shown in this paper. The Ionian GPS network, composed of nine sites crossing the Ionian Sea from Calabria, Southern Italy, to Northwestern Greece, was established and surveyed in 1991, 1994, 1995 within the framework of the TYRGEONET project (Anzidei et al., 1996. In 1996 a return campaign was carried out after the occurrence of seismic activity in 1995. The displacement pattern obtained for the Greek side of the network agrees well with those previously displayed, both in magnitude and direction, confirming a mean displacement rate of about 1-2 cm1/yr. The same agreement is not found for the Italian side of the network, where no significant deformations were detected between 1994 and 1996. Seismic deformation was also studied for the same area, starting from the moment tensors of events which occurred in the last 20 years with magnitude greater than 5.0; evident similarity with the displacement field exhibited by the Greek side of the Ionian Sea by geodetic surveys was inferred. On the contrary, the motion detected for the Italian area cannot be simply related to seismic activity.

  3. Summer Distribution, Relative Abundance and Encounter Rates of Cetaceans in the Mediterranean Waters off Southern Italy (Western Ionian Sea and Southern Tyrrhenian Sea

    Directory of Open Access Journals (Sweden)

    R. SANTORO

    2015-07-01

    Full Text Available In summer 2010 and summer 2011, weekly cetacean surveys were undertaken in “passing mode”, using ferries as platform of opportunity, along the “fixed line transect” between Catania and Civitavecchia (Southern Italy. Of the 20 species of cetaceans confirmed for the Mediterranean sea, 8 were sighted within the survey period: 7 species represented by Mediterranean subpopulations (Balaenoptera physalus, Physeter macrocephalus, Stenella coeruleoalba, Delphinus delphis, Grampus griseus, Tursiops truncatus and Ziphius cavirostris and one considered visitor (Steno bredanensis. We had a total of 220 sightings during the 2010 and a total of 240 sightings in the 2011. The most frequent species was S. coeruleoalba. By the comparison of the data from the two sampling seasons, a significant increase of D. delphis sightings and a decrease of sightings of B. physalus and P. macrocephalus was observed from 2010 to 2011. While all the other species were observed in both sampling seasons, Z. cavirostris and Steno bredanensis were observed only during 2011. The presence of mixed groups of odontocetes was documented too: we sighted groups composed by S. coeruleoalba and D. delphis, by S. coeruleoalba and T. truncatus, and by S. coeruleoalba and G. griseus. The results of this research add useful information on cetacean species in a very poorly known area and highlight the need to standardize large scale and long term monitoring programs in order to detect variation in presence, abundance and distribution of cetaceans populations and understand the effect of anthropogenic factors.

  4. Investigating the chlorophyll-a variability in the Gulf of Taranto (North-western Ionian Sea) by a multi-temporal analysis of MODIS-Aqua Level 3/Level 2 data

    Science.gov (United States)

    Ciancia, Emanuele; Coviello, Irina; Di Polito, Carmine; Lacava, Teodosio; Pergola, Nicola; Satriano, Valeria; Tramutoli, Valerio

    2018-03-01

    The analysis of chlorophyll-a (chl-a) variability on a long-term basis could allow detecting possible issues in the whole marine ecosystem functioning. The Gulf of Taranto (Southern Italy), in the North-western Ionian Sea (Mediterranean Sea), has been affected by several environmental threats in the last decade, thus deserving the implementation of an adequate monitoring system able to provide accurate indications about the variability of the most relevant bio-optical parameters. In this context, the main objectives of this study are to investigate the long-term chl-a variability in the Gulf of Taranto and identify the occurrence of any past spatiotemporal anomalies by implementing the multi-temporal Robust Satellite Technique (RST) on a 12-year (2003-2015) period of MODIS/AQUA Level 3/Level 2 chlorophyll-a data. The achieved results show well-clustered near-surface positive chl-a anomalies during the January-February 2011 period. This detected offshore phytoplankton bloom may be related to sub-basin processes, such as the inflow of the Western Adriatic Coastal Current (WACC), probably fostered by the cyclonic reversal of the Bimodal Oscillating System (BiOS) mechanism. Therefore, the RST approach proved successful in detecting chl-a anomalous variations with a high level of confidence regardless of the absolute value measured, thus suggesting its exportability in other areas with different site-setting conditions.

  5. Modelling travel and residence times in the eastern Irish Sea

    International Nuclear Information System (INIS)

    Dabrowski, T.; Hartnett, M.

    2008-01-01

    The Irish Sea, which lies between 51 deg. N-56 deg. N and 2 deg. 50'W-7 deg. W, provides a sheltered environment to exploit valuable fisheries resource. Anthropogenic activity is a real threat to its water quality. The majority of freshwater input down rivers flows into the eastern Irish Sea. The structure of the water circulation was not well understood during the planning of Sellafield nuclear plant outfall site in the eastern Irish Sea. A three-dimensional primitive equation numerical model was applied to the Irish Sea to simulate both barotropic and baroclinic circulation within the region. High accuracy was achieved with regard to the prediction of both tidal circulation and surface and nearbed water temperatures across the region. The model properly represented the Western Irish Sea Gyre, induced by thermal stratification and not known during planning Sellafield. Passive tracer simulations based on the developed hydrodynamic model were used to deliver residence times of the eastern Irish Sea region for various times of the year as well as travel times from the Sellafield outfall site to various locations within the Irish Sea. The results indicate a strong seasonal variability of travel times from Sellafield to the examined locations. Travel time to the Clyde Sea is the shortest for the autumnal tracer release (90 days); it takes almost a year for the tracer to arrive at the same location if it is released in January. Travel times from Sellafield to Dublin Bay fall within the range of 180-360 days. The average residence time of the entire eastern Irish Sea is around 7 months. The areas surrounding the Isle of Man are initially flushed due to a predominant northward flow; a backwater is formed in Liverpool Bay. Thus, elevated tracer concentrations are predicted in Liverpool Bay in the case of accidental spills at the Sellafield outfall site

  6. 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

  7. 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...

  8. 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...

  9. 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.

  10. Currents in the Eastern Irish Sea

    International Nuclear Information System (INIS)

    Howarth, M.J.

    1983-01-01

    Low level radioactive waste is discharged from the nuclear re-processing plant at Sellafield, Cumbria. Its movement away from the discharge point is determined by the Irish Sea's dynamics, both for the soluble compounds and for those compounds which become attached to the sediment. Near Sellafield the tidal currents are weak and parallel to the shore, becoming stronger east/west to the north and south of the Isle of Man. Wind driven currents near Sellafield are predominantly north-westward, strongest near the coast, and oppose the other low frequency currents. Hence, the soluble effluent will initially be dispersed parallel to the shore by the weak tidal currents, moving episodically, southeastward during weak winds and northwestward during storms. Eventually it will leave the Irish Sea, flowing northward through the North Channel. (author)

  11. Biodiversity of deep-sea demersal megafauna in western and central Mediterranean basins

    Directory of Open Access Journals (Sweden)

    Samuele Tecchio

    2011-06-01

    Full Text Available Abundance, biomass and diversity patterns of bathyal and abyssal Mediterranean megafauna (fishes and invertebrates were analyzed in the western Balearic Sea, the western Ionian Sea and the eastern Ionian Sea. Sampling was conducted with a Otter-trawl Maireta System (OTMS at depths ranging from 600 to 4000 m. A series of ecological indicators were computed: total abundance and biomass, Margalef species richness, Shannon-Wiener diversity and Pielou’s index of evenness. A multidimensional scaling was applied, indicating that the megafauna communities were grouped by depth, while geographic area had a less defined influence. Margalef richness declined with depth in all three areas, but more steeply in the western Ionian Sea. Pielou’s evenness behaved differently in the three zones, showing a V-shaped curve in the eastern Ionian while showing a decreasing pattern in the other two areas. At lower slope depths, massive presence of the fishes Alepocephalus rostratus in the western basin and Bathypterois mediterraneus in the central basin caused a sharp reduction in evenness.

  12. Salinity in the Sicily Channel corroborates the role of the Adriatic–Ionian Bimodal Oscillating System (BiOS in shaping the decadal variability of the Mediterranean overturning circulation

    Directory of Open Access Journals (Sweden)

    M. Gačić

    2013-01-01

    Full Text Available Previous studies have demonstrated that the salinity in the Levantine basin depends on the intensity of the Atlantic water (AW inflow. Moreover, its spreading eastward (to the Levantine basin or northward (to the Ionian Sea is determined by the Ionian circulation pattern, i.e. by the Adriatic–Ionian Bimodal Oscillating System (BiOS mechanism. The aim of this paper is to relate salinity variations in the Levantine basin to the salt content variability in the core of the Levantine Intermediate Water (LIW passing through the Sicily Channel (SC and its possible impact on the Western Mediterranean Transition – WMT (i.e. the sudden salinity and temperature increase in the deep layer of the Algero-Provençal subbasin occurring since 2004. From the historical data set MEDAR/MEDATLAS in the Levantine and northern Ionian, we present evidence of decadal occurrences of extreme salinities associated with the varying influx of AW over the last 60 yr. Furthermore, we show that the salinity variations in the two subbasins are out of phase. High-salinity episodes in the Levantine are a pre-conditioning for the potential occurrence of the events like the Eastern Mediterranean Transient (EMT. Cross-correlation between the salinity time series in the Levantine basin and in the SC suggests that the travel time of the LIW is between 10 and 13 yr. Comparing the timing of the salinity increase associated with the WMT and the salinity in the LIW core in the SC, we estimate that the total time interval needed for the signal propagating from the Levantine to reach the deep mixed layers of the Algero-Provençal subbasin is about 25 yr. We also showed that the extra salt input from the eastern Mediterranean contribute up to about 60% to the salt content increase in the bottom layer of the western Mediterranean.

  13. 77 FR 23209 - Endangered and Threatened Species; Proposed Delisting of Eastern DPS of Steller Sea Lions

    Science.gov (United States)

    2012-04-18

    ... of these fisheries are not likely to cause the eastern DPS to become in danger of extinction in the... coastal habitats is likely to cause the eastern DPS of Steller sea lion to become in danger of extinction... likely to cause the eastern DPS of Steller sea lions to become in danger of extinction in the foreseeable...

  14. Indian Ocean dipole modulated wave climate of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Anoop, T.R.; SanilKumar, V.; Shanas, P.R.; Glejin, J.; Amrutha, M.M.

    –378, 2016 www.ocean-sci.net/12/369/2016/ doi:10.5194/os-12-369-2016 © Author(s) 2016. CC Attribution 3.0 License. Indian Ocean Dipole modulated wave climate of eastern Arabian Sea T. R. Anoop1, V. Sanil Kumar1, P. R. Shanas1,2, J. Glejin1, and M. M. Amrutha1... are available on the website of the Japanese Agency of Marine–Earth Science and Technology (www.jamstec.go.jp). The tropical IO displays strong inter-annual climate vari- ability associated with the El Niño–Southern Oscillation (ENSO) and the IOD (Murtugudde et...

  15. Neogene dinocyst zonation for the eastern North Sea Basin, Denmark

    DEFF Research Database (Denmark)

    Dybkjær, Karen; Piasecki, Stefan

    2010-01-01

    A dinocyst zonation for the Neogene succession in the eastern part of the North Sea Basin (Denmark) is presented. The zonation is based on an extensive database comprising data from more than fifty onshore and offshore boreholes and about twenty five outcrops. Most of the nineteen dinocyst zones......, of the Lower Miocene, and of the Upper Miocene and Pliocene successions. The previous zonation of the onshore Danish Middle Miocene is reconsidered and partly redefined. The zonation is correlated with other biostratigraphic subdivisions of the Neogene succession in the Danish region in addition to litho...

  16. Bacterial community composition in different sediments from the Eastern Mediterranean Sea: a comparison of four 16S ribosomal DNA clone libraries.

    Science.gov (United States)

    Polymenakou, Paraskevi N; Bertilsson, Stefan; Tselepides, Anastasios; Stephanou, Euripides G

    2005-10-01

    The regional variability of sediment bacterial community composition and diversity was studied by comparative analysis of four large 16S ribosomal DNA (rDNA) clone libraries from sediments in different regions of the Eastern Mediterranean Sea (Thermaikos Gulf, Cretan Sea, and South lonian Sea). Amplified rDNA restriction analysis of 664 clones from the libraries indicate that the rDNA richness and evenness was high: for example, a near-1:1 relationship among screened clones and number of unique restriction patterns when up to 190 clones were screened for each library. Phylogenetic analysis of 207 bacterial 16S rDNA sequences from the sediment libraries demonstrated that Gamma-, Delta-, and Alphaproteobacteria, Holophaga/Acidobacteria, Planctomycetales, Actinobacteria, Bacteroidetes, and Verrucomicrobia were represented in all four libraries. A few clones also grouped with the Betaproteobacteria, Nitrospirae, Spirochaetales, Chlamydiae, Firmicutes, and candidate division OPl 1. The abundance of sequences affiliated with Gammaproteobacteria was higher in libraries from shallow sediments in the Thermaikos Gulf (30 m) and the Cretan Sea (100 m) compared to the deeper South Ionian station (2790 m). Most sequences in the four sediment libraries clustered with uncultured 16S rDNA phylotypes from marine habitats, and many of the closest matches were clones from hydrocarbon seeps, benzene-mineralizing consortia, sulfate reducers, sulk oxidizers, and ammonia oxidizers. LIBSHUFF statistics of 16S rDNA gene sequences from the four libraries revealed major differences, indicating either a very high richness in the sediment bacterial communities or considerable variability in bacterial community composition among regions, or both.

  17. The Myth of the Ionian Agora

    DEFF Research Database (Denmark)

    Dickenson, Christopher Paul

    2018-01-01

    Pausanias famously compared the loose arrangement of stoas on the agora of Elis to the more formalized plan that he associated with Ionia. Modern scholars have assumed that the “Ionian Agora” was therefore a specific type of public square. Classifying agoras by type has supported the interpretati...

  18. Vertical distribution of mesozooplankton in the central and eastern Arabian Sea during the winter monsoons

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Haridas, P.; Nair, K.K.C.; Gopalakrishnan, T.C.; Shiney, P.; Madhupratap, M.

    The vertical distribution of mesozooplankton in the central and eastern Arabian Sea was investigated during the winter monsoon in 1995. Samples were analysed from discrete depth zones defined according to oxygen and temperature profiles of the water...

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

    KAUST Repository

    Tsiola, A.; Pitta, P.; Fodelianakis, Stylianos; Pete, R.; Magiopoulos, I.; Mara, P.; Psarra, S.; Tanaka, T.; Mostajir, B.

    2015-01-01

    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

  20. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (Oceanography data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  1. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (TSG-thermosalinigraph data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  2. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  3. AFSC/ABL: Eastern Bering Sea (EMA-BASIS) Zooplankton data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  4. Ecology and distribution of recent planktonic foraminifera in eastern part of Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, K.K.; Jayalakshmy, K.V.; Kutty, M.K.

    Thirty species of living planktonic foraminifera have been studied from 97 plankton tows collected from the eastern Arabian Sea with an accent on their ecological and distributional aspects. Species density is higher with less dominance in the deep...

  5. AFSC/RACE/EcoFOCI: 2010 Eastern Bering Sea Juvenile Survey - 1MF10

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data collected on this cruise included the following: We conducted a juvenile fish and benthic fish prey survery in the eastern Bering Sea (61 3-meter beam trawls,...

  6. Studies on the microzooplankton from the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Gauns, M; Mohanraju, R.; Madhupratap, M

    Numerical abundance and composition of microzooplankton in the upper 200 m were studied from the central and eastern Arabian Sea during three seasons. Protozoans, comprising of ciliates (loricates and aloricates), flagellates and sarcodines were...

  7. Obsolete - AFSC/RACE/Eco-FOCI: 2010 Eastern Bering Sea Juvenile Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data collected on this cruise included the following: We conducted a juvenile fish and benthic fish prey survery in the eastern Bering Sea (61 3-meter beam trawls,...

  8. Characteristics of long-period swells measured in the near shore regions of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Johnson, G.; SanilKumar, V.; Amrutha, M.M.; Singh, J.

    Measured wave data covering two years simultaneously at 3 locations along the eastern Arabian Sea reveals the presence of long-period (peak wave period > 18 s) low-amplitude waves (significant wave height < 1 m) and the characteristics...

  9. Dissolved aluminium in the surface microlayer of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Narvekar, P.V.; Singbal, S.Y.S.

    Measurements of dissolved aluminium (Al) in surface microlayer (SML) samples from the eastern Arabian Sea during the southwest (summer) and northwast (winter) monsoon periods have revealed much higher concentrations (23-657 nmol kg sup(-1)) than...

  10. Skate Bathyraja spp. egg predation in the eastern Bering Sea.

    Science.gov (United States)

    Hoff, G R

    2009-01-01

    Predation on skate eggs by snails was examined for three skate species at seven nursery sites in three regions (north, middle and south) of the eastern Bering Sea. Mean predation levels were 6.46% for the Alaska skate Bathyraja parmifera, 2.65% for the Aleutian skate Bathyraja aleutica and 22.25% for the Bering skate Bathyraja interrupta. Predation levels were significantly higher at the middle and north sites than the south sites for all species combined. Predation levels decreased with increasing egg-case densities at all nursery sites, and the highest predation levels occurred where egg-case densities were very low. Predated egg-case density increased with increasing snail densities across all nursery sites examined. The Oregon triton Fusitriton oregonensis was the most abundant snail species at all nursery sites and displayed ability to drill holes in the egg case of B. parmifera. Holes left by predatory snails in egg cases of B. parmifera were significantly larger, and of different shape at the middle site compared to the south site. Holes in B. parmifera were also significantly larger than those in egg cases of B. interrupta across all sites examined. Egg cases of B. aleutica possess surface spines that cover the egg case and may inhibit predation by snails at a greater rate than that of the B. parmifera and B. interrupta, which have a smoother egg-case surface.

  11. The exclusive economic zone debates in the Eastern Mediterranean Sea and fisheries

    OpenAIRE

    Başeren, Bayram Öztürk and Sertaç Hami; Öztürk, Bayram

    2015-01-01

    Abstract Delimitation and proclamations of the Exclusive Economic Zone in the Eastern Mediterranean Sea is important issue for several reasons for the bordering nations. The Mediterranean Sea is unique case due to geographical characteristics and some conflicts already existed on maritime delimitations among some nations. It’s a matter of fact that; all States will have to reach agreement, regarding proclamations of the delimitation of the Exclusive Economic Zone in the Eastern Mediterranean ...

  12. The exclusive economic zone debates in the Eastern Mediterranean Sea and fisheries

    OpenAIRE

    Başeren, Bayram Öztürk and Sertaç Hami

    2008-01-01

    Abstract Delimitation and proclamations of the Exclusive Economic Zone in the Eastern Mediterranean Sea is important issue for several reasons for the bordering nations. The Mediterranean Sea is unique case due to geographical characteristics and some conflicts already existed on maritime delimitations among some nations. It’s a matter of fact that; all States will have to reach agreement, regarding proclamations of the delimitation of the Exclusive Economic Zone in the Eastern Mediterranean ...

  13. The physiological adaptations and toxin profiles of the toxic Alexandrium fundyense on the eastern Bering Sea and Chukchi Sea shelves.

    Science.gov (United States)

    Natsuike, Masafumi; Oikawa, Hiroshi; Matsuno, Kohei; Yamaguchi, Atsushi; Imai, Ichiro

    2017-03-01

    Abundant cyst distributions of the toxic dinoflagellate Alexandrium fundyense (previous A. tamarense north American clade) were recently observed on the north Chukchi Sea shelf and on the eastern Bering Sea shelf, suggesting that A. fundyense is both highly adapted to the local environments in the high latitude areas and might cause toxin contamination of plankton feeders. However, little is known about the physiological characteristics and toxin profiles of A. fundyense in these areas, which are characterized by low water temperatures, weak sunlight, and more or less permanent ice cover during winter. To clarify the physiological characteristics of A. fundyense, the effects of water temperature and light intensity on the vegetative growth and toxin profiles of this species were examined using A. fundyense strains isolated from one sediment sample collected from each area. Using the same sediments samples, seasonal changes of the cyst germination in different water temperatures were investigated. Vegetative cells grew at temperatures as low as 5°C and survived at 1°C under relatively low light intensity. They also grew at moderate water temperatures (10-15°C). Their cysts could germinate at low temperatures (1°C) and have an endogenous dormancy period from late summer to early spring, and warmer water temperatures (5-15°C) increased germination success. These physiological characteristics suggest that A. fundyense in the Chukchi Sea and eastern Bering Sea is adapted to the environments of high latitude areas. In addition, the results suggest that in the study areas A. fundyense has the potential to germinate and grow when water temperatures increase. Cellular toxin amounts of A. fundyense strains from the eastern Bering Sea and Chukchi Sea were ranged from 7.2 to 38.2 fmol cell -1 . These toxin amounts are comparable with A. fundyense strains isolated from other areas where PSP toxin contamination of bivalves occurs. The dominant toxin of the strains isolated

  14. Corals, Canyons, and Conservation: Science Based Fisheries Management Decisions in the Eastern Bering Sea

    Directory of Open Access Journals (Sweden)

    Steve A. MacLean

    2017-05-01

    Full Text Available When making science matter for conservation, marine conservation practitioners, and managers must be prepared to make the appropriate decision based on the results of the best available science used to inform it. For nearly a decade, many stakeholders encouraged the North Pacific Fishery Management Council to enact protections for deep-sea corals in several canyons in the Eastern Bering Sea slope. In 2014, at the request of the Council, the National Marine Fisheries Service, Alaska Fisheries Science Center conducted a strip-transect survey along the Eastern Bering Sea slope to validate the results of a model predicting the occurrence of deep-sea coral habitat. More than 250,000 photos were analyzed to estimate coral, sponge, and sea whip abundance, distribution, height, and vulnerability to anthropogenic damage. The results of the survey confirmed that coral habitat and occurrence was concentrated around Pribilof Canyon and the adjacent slope. The results also confirmed that the densities of corals in the Eastern Bering Sea were low, even where they occurred. After reviewing the best available scientific information, the Council concluded that there is no scientific evidence to suggest that deep-sea corals in the Eastern Bering Sea slope or canyons are at risk from commercial fisheries under the current management structure, and that special protections for deep-sea corals were not warranted.

  15. Eddy Mediated Nutrient Pattern in the North Eastern Arabian Sea

    Science.gov (United States)

    Thachaparambil, M.; Moolakkal Antony, R.; B R, S.; V N, S.; N, C.; M, S.

    2016-02-01

    A Cold Core Eddy (CCE) mediated nutrient pattern in the North Eastern Arabian Sea (NEAS) is explained based on in situ measurments during March 2013 onboard FORV Sagar Sampada which was not reported earlier in the area. Samples for physical, chemical and biological parameters were collected in 5 stations along the diameter of the eddy and following standard protocols. The core of the CCE is identified at 21°20.38'N; 66°30.68'E with a diameter of 120Km. Earlier studies explaining the process and the forcing mechanism of the particular eddy records that, the eddy is short term (1-3 months) and is regular during the season. Surface waters were well oxygenated (>4.8 ml L-1) in the core. Surface value of nutrients viz., Nitrate, Nitrite, Silicate and phosphate in the core regions was 0.9µM, 0.01 µM, 0.5 µM and 0.7 µM respectively indicating upwelling in the core. Spring intermonsoon (SIM) is generally termed as a transition period between the active winter and summer seasons and as per earlier studies, high biological production and the regularly occurring Noctilica bloom is supported by the nutrient loading due to convective mixing during winter as well as regenerated production. However, present observations shows that, nutrient pumping due to the upwelling associated with the CCE also contributes for sustaining high biological production and are evident in the Chl a and mesozooplankton biovolume which records values of 4.35mg/m3 and 1.09ml/m3 respectively in the core. An intense Noctiluca blooms observed in the western flank of the eddy (Chl a 13.25 mg/m3; cell density 5.8×106 cells/litre), where Nitrate concentration records 1.04µM explains the role of such mesoscale processes in the sustenance of the HAB events. While eastern flank of the CCE showed typical open ocean condition of the season showing Nitrate 0.08µM; Chl a 0.23mg/m3; and phytoplankton cell density as 421 cells/litre. Keywords: Cold core eddy, nutrients, NEAS, SIM, biological production

  16. Submarine sand ridges and sand waves in the eastern part of the China Sea

    Science.gov (United States)

    Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

    2016-04-01

    Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

  17. Nitrogen fixation rates in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ahmed, A.; Gauns, M.; Kurian, S.; Bardhan, P.; Pratihary, A.K.; Naik, H.; Shenoy, D.M.; Naqvi, S.W.A.

    The Arabian Sea experiences bloom of the diazotroph Trichodesmium during certain times of the year when optimal sea surface temperature and oligotrophic condition favour their growth. We measured nitrogen fixation rates in the euphotic zone during...

  18. Distribution of meiobenthos at bathyal depths in the Mediterranean Sea. A comparison between sites of contrasting productivity

    Directory of Open Access Journals (Sweden)

    Anastasios Tselepides

    2004-12-01

    Full Text Available In order to study the distribution of meiobenthos (Metazoa and Foraminifera at bathyal depths along a west-east productivity gradient in the Mediterranean Sea, stations along the continental slopes of the Balearic Sea, west Ionian and east Ionian Seas were sampled during the DESEAS Trans-Mediterranean Cruise in June-July 2001. Standing stock of total meiobenthos differed considerably among the sampling stations, with marked differences occurring between sampling depths and sites. At 600 m depth, meiobenthic abundances were slightly higher over the Balearic continental slope, whereas at the deeper stations (800 m and 1500-1700 m, abundances were significantly higher in the west Ionian Sea. Significant relationships were found between the abundances of major groups and the chloroplastic pigments, indicating that food availability is a major factor controlling the distribution of meiobenthos. Apart from the overall differences in productivity between the western and eastern Mediterranean Sea, local hydrographic features and topographic differences greatly influence the spatial variability of the environmental parameters within each sub-basin and thus the distribution of meiobenthos in the bathyal zone.

  19. Assessment of metal element concentrations in mussel (M. Galloprovincialis) in Eastern Black Sea, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, U. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey)], E-mail: berrenazli@yahoo.com; Damla, N.; Kobya, A.I. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey); Bulut, V.N. [Giresun University, Department of Chemistry, 28049 Giresun (Turkey); Duran, C. [Karadeniz Technical University, Department of Chemistry, 61080 Trabzon (Turkey); Dalgic, G. [Rize University, Faculty of Fisheries, 53100 Rize (Turkey); Bozaci, R. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey)

    2008-12-30

    The main goal of this work is to determine the effects of pollution of copper, lead and zinc mines on the Eastern Black Sea. Metal and heavy metal concentrations in the Eastern Black Sea mussels were measured using Energy Dispersive X-ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectroscopy (FAAS). The analytical results showed that the tissue of mussel in Eastern Black Sea contains K, Ca, Fe, Cu, Zn, and Sr elements, and the shell of mussel contains Ca, Cu, Sr, and Ba elements. Due to the detection limit of EDXRF, the mussels were analyzed with FAAS for Cr, Mn, Ni, Cd and Pb elements. An ANOVA and Pearson correlation analyses were performed. The results showed although that the mean concentrations of Cu and Zn for the tissue of the mussels were markedly above the permissible levels of the Turkish regulations, Zn concentration is in the limits of the Food and Agriculture Organization (FAO)

  20. Ongoing decline of shark populations in the Eastern Red Sea

    KAUST Repository

    Spaet, Julia L.Y.

    2016-06-30

    Information on the abundance and diversity of Red Sea elasmobranchs is notoriously scarce, even though sharks are among the most profitable fisheries of the region. Effective conservation would ideally entail baselines on pristine conditions, yet no such data is available for the Red Sea. To collect distribution and abundance data on Red Sea elasmobranchs, we conducted a dedicated longline and Baited Remote Underwater Video system (BRUVs) sampling program along the entire Red Sea coast of Saudi Arabia over the course of two years. Both survey techniques were opportunistically employed at central and southern Saudi Arabian (SA) Red Sea reef systems. In addition, BRUVs were employed in the northern SA Red Sea and at selected reef systems in Sudan. Shark catch per unit effort (CPUE) data for BRUVs and longline surveys were compared to published data from non-Red Sea reef systems. This comparison revealed CPUE estimates several orders of magnitude lower for both survey methods in the SA Red Sea compared to other reef systems around the world. Catch per unit effort values of BRUVs on Sudanese reefs on the contrary were within the range of estimates from various locations where sharks are considered common. We argue that decades of heavy fishing pressure on Red Sea marine resources has significantly altered the community structure of SA Red Sea reefs. There is an urgent need to establish effective management strategies for species of highest conservation concern. Our results have the potential to be used as a baseline, if such management strategies were to be established. © 2016 Elsevier Ltd

  1. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from METEOR in the Adriatic Sea, Aegean Sea and others from 2011-04-05 to 2011-04-28 (NODC Accession 0108079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108079 includes discrete sample and profile data collected from METEOR in the Adriatic Sea, Aegean Sea, Alboran Sea, Ionian Sea, Mediterranean Sea,...

  2. The south-eastern North Sea : losses of vertebrate fauna during the past 2000 years

    NARCIS (Netherlands)

    Wolff, W.J.

    At least 31 species of marine mammals, marine and coastal birds, and marine and anadromous fish have disappeared temporarily or permanently from the coasts of The Netherlands and in most cases also from the south-eastern North Sea (south of 54 degrees N) during the past 2000 years-In 18-22 cases,

  3. Biogeochemical relationships between ultrafiltered dissolved organic matter and picoplankton activity in the Eastern Mediterranean Sea

    NARCIS (Netherlands)

    Meador, Travis B.; Gogou, Alexandra; Spyres, Georgina; Herndl, Gerhard J.; Krasakopoulou, Evangelia; Psarra, Stella; Yokokawa, Taichi; De Corte, Daniele; Zervakis, Vassilis; Repeta, Daniel J.

    2010-01-01

    We targeted the warm, subsurface waters of the Eastern Mediterranean Sea (EMS) to investigate processes that are linked to the chemical composition and cycling of dissolved organic carbon (DOC) in seawater. The apparent respiration of semi-labile DOC accounted for 27 +/- 18% of oxygen consumption in

  4. Differential growth of larval sprat Sprattus sprattus across a tidal front in the eastern North Sea

    DEFF Research Database (Denmark)

    Munk, Peter

    1993-01-01

    Spatial variations in abundance and growth of larval sprat Sprattus sprattus L. were examined across a tidal front in the eastern North Sea, off the west coast of Denmark. The aim of the study was to evaluate the potential advantage for sprat larvae of residing in the vicinity of a tidal front...

  5. Swath bathymetric investigation of the seamounts located in the Laxmi Basin, eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.; Murty, G.P.S.; Srinivas, K.; Chaubey, A.K.; Sudhakar, T.; Nair, R.R.

    Multibeam (hydrosweep) swath bathymetric investigations revealed the presence of a NNW trending linear seamount chain along the axial part of the Laxmi Basin in the eastern Arabian Sea, between 15~'N, 70~'15'E and 17~'20'N, 69~'E. This chain...

  6. Controls on organic carbon distribution in sediments from the eastern Arabian Sea margin

    Digital Repository Service at National Institute of Oceanography (India)

    Thamban, M.; Rao, V.P.; Raju, S.V.

    Sediment cores from the upper continental slope of the eastern Arabian Sea have high organic carbon (OC), CaCO sub(3), and sand content at the top. The values decrease with increasing depth in the Holocene and Upper Pleistocene. Topographic highs...

  7. Variations in swells along Eastern Arabian Sea during the summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Johnson, G.; SanilKumar, V.; Sanjiv, P.C.; Singh, J.; Pednekar, P.S.; AshokKumar, K.; Dora, G.U.; Gowthaman, R.

    A study was carried out to find the variation in wave characteristics along the eastern Arabian Sea and the influence of swells in the nearshore waves at 3 locations during summer monsoon in 2010. Percentage of swells in the measured waves was 75...

  8. Spatial and temporal variation of surface waves in shallow waters along the eastern Arabian Sea.

    Digital Repository Service at National Institute of Oceanography (India)

    Anoop, T.R.; SanilKumar, V.; Shanas, P.R.

    We studied the spatial and temporal variation of surface waves along the eastern Arabian Sea during 2011 and 2012. Measured directional wave data at two shallow water locations and re-analysis datasets (ERA-Interim) at 0.751 intervals at four...

  9. Circumstantial Evidence of Possible Hot Spot Activity Outside Rhodes, Eastern Mediterranean Sea

    OpenAIRE

    Miliaresis, George

    2014-01-01

    Zouzias Dimitrios, St Seymour Karen, Miliaresis George, Vamvoukakis Costas (2008). Circumstantial Evidence of Possible Hot Spot Activity Outside Rhodes, Eastern Mediterranean Sea. 3rd International Conference on the Geology of the Tethys (8-11 January, 2008, South Valley University - Aswan). [Abstract in Program

  10. Shipboard measurements of nitrogen dioxide, nitrous acid, nitric acid and ozone in the Eastern Mediterranean Sea

    Czech Academy of Sciences Publication Activity Database

    Večeřa, Zbyněk; Mikuška, Pavel; Smolík, Jiří; Eleftheriadis, K.; Bryant, C.; Colbeck, I.; Lazaridis, M.

    2008-01-01

    Roč. 8, č. 1 (2008), s. 117-125 ISSN 1567-7230 Grant - others:5th FP Commission of the EC(XE) EVK2-CT-1999-0052 SUB-AERO Institutional research plan: CEZ:AV0Z40310501; CEZ:AV0Z40720504 Keywords : reactive nitrogen species * ozone * Eastern Mediterranean Sea Subject RIV: CB - Analytical Chemistry, Separation

  11. DDT residues in fishes from the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shailaja, M.S.; SenGupta, R.

    degrees E) were obtained from the commercial jetty within 2 h of landing while those from the open sea (16 degrees 30'N 69 degrees E-19 degrees 30'N 67 degrees E) such as Tylosurus sp. (longtom), Coryphaena hippurus (dolphin fish), Loligo sp. (squid...

  12. ORGANOCHLORINE CONTAMINANTS IN SEA TURTLES FROM THE EASTERN PACIFIC

    Science.gov (United States)

    We measured organochlorine residues in three species of sea turtles from the Baja California peninsula, Mexico. Seventeen of 21 organochlorine pesticides analyzed were detected, with heptachlor epoxide and y-hexachlorocyclohexane the most prevalent in 14 (40%) and 11 (31%) of th...

  13. Distribution of aerobic anoxygenic phototrophs in the Eastern Adriatic Sea

    Czech Academy of Sciences Publication Activity Database

    Šantić, D.; Šestanović, S.; Vrdoljak, A.; Šolić, M.; Kušpilić, G.; Ninčević Gladan, Ž.; Koblížek, Michal

    2017-01-01

    Roč. 130, SEP 2017 (2017), s. 134-141 ISSN 0141-1136 R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Aerobic anoxygenic phototrophs * Adriatic sea * Picoplankton Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.101, year: 2016

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Growth Rate Potential of Juvenile Sockeye Salmon in Warmer and Cooler Years on the Eastern Bering Sea Shelf

    Directory of Open Access Journals (Sweden)

    Edward V. Farley

    2009-01-01

    Full Text Available A spatially explicit bioenergetics model was used to predict juvenile sockeye salmon Oncorhynchus nerka growth rate potential (GRP on the eastern Bering Sea shelf during years with cooler and warmer spring sea surface temperatures (SSTs. Annual averages of juvenile sockeye salmon GRP were generally lower among years with cooler SSTs and generally higher in offshore than nearshore regions of the eastern Bering Sea shelf during years with warmer SSTs. Juvenile sockeye salmon distribution was significantly (P<.05 related to GRP and their prey densities were positively related to spring SST (P<.05. Juvenile sockeye salmon GRP was more sensitive to changes in prey density and observed SSTs during years when spring SSTs were warmer (2002, 2003, and 2005. Our results suggest that the pelagic productivity on the eastern Bering Sea shelf was higher during years with warmer spring SSTs and highlight the importance of bottom-up control on the eastern Bering Sea ecosystem.

  17. Orbital-scale denitrification changes in the Eastern Arabian Sea during the last 800 kyrs.

    Science.gov (United States)

    Kim, Ji-Eun; Khim, Boo-Keun; Ikehara, Minoru; Lee, Jongmin

    2018-05-04

    Denitrification in the Arabian Sea is closely related to the monsoon-induced upwelling and subsequent phytoplankton production in the surface water. The δ 15 N values of bulk sediments collected at Site U1456 of the International Ocean Discovery Program (IODP) Expedition 355 reveal the orbital-scale denitrification history in response to the Indian Monsoon. Age reconstruction based on the correlation of planktonic foraminifera (Globigerinoides ruber) δ 18 O values with the LR04 stack together with the shipboard biostratigraphic and paleomagnetic data assigns the study interval to be 1.2 Ma. Comparison of δ 15 N values during the last 800 kyrs between Site U1456 (Eastern Arabian Sea) and Site 722B (Western Arabian Sea) showed that δ 15 N values were high during interglacial periods, indicating intensified denitrification, while the opposite was observed during glacial periods. Taking 6‰ as the empirical threshold of denitrification, the Eastern Arabian Sea has experienced a persistent oxygen minimum zone (OMZ) to maintain strong denitrification whereas the Western Arabian Sea has undergone OMZ breakdown during some glacial periods. The results of this study also suggests that five principal oceanographic conditions were changed in response to the Indian Monsoon following the interglacial and glacial cycles, which controls the degree of denitrification in the Arabian Sea.

  18. Biogeochemical significance of eddies of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; DineshKumar, P.K.; Nair, M.

    upon the gradients in nutrients and phytoplankton initially present and on the intrinsic biological reaction rates. Thus, phytoplankton with a rapid growth rate will benefit from arriving within a patch of nutrient-rich water, possibly at the cost... carbon removal in the sea: The continental connection, – In: Upwelling systems: Evolution Since the early Miocene, C. P. Summerhayes et al. eds., Geological Society of London Special Publication 64: 167-176. [17] Joseph, T., Shaiju, P., Laluraj, C...

  19. Flow Patterns in the Eastern Chukchi Sea: 2010-2015

    Science.gov (United States)

    Stabeno, Phyllis; Kachel, Nancy; Ladd, Carol; Woodgate, Rebecca

    2018-02-01

    From 2010 to 2015, moorings were deployed on the northern Chukchi Sea at nine sites. Deployment duration varied from 5 years at a site off Icy Cape to 1 year at a site north of Hanna Shoal. In addition, 39 satellite-tracked drifters (drogue depth 25-30 m) were deployed in the region during 2012-2015. The goals of this manuscript are to describe currents in the Chukchi Sea and their relationship to ice and winds. The north-south pressure gradient results in, on average, a northward flow over the Chukchi shelf, which is modified by local winds. The volume transport near Icy Cape (˜0.4 Sv) was ˜40% of flow through Bering Strait and varied seasonally, accounting for >50% of summer and ˜20% of winter transport in Bering Strait. Current direction was strongly influenced by bathymetry, with northward flow through the Central Channel and eastward flow south of Hanna Shoal. The latter joined the coastal flow exiting the shelf via Barrow Canyon. Drifter trajectories indicated the transit from Bering Strait to the mouth of Barrow Canyon took ˜90 days during the ice-free season. Most (˜70%) of the drifters turned westward at the mouth of Barrow Canyon and continued westward in the Chukchi Slope Current. This slope flow was largely confined to the upper 300 m, and although it existed year-round, it was strongest in spring and summer. Drifter trajectories indicated that the Chukchi Slope Current extends as far west as the mouth of Herald Canyon. The remaining ˜30% of the drifters turned eastward or were intercepted by sea ice.

  20. Glaciotectonic deformations in the Jammerbugt and glaciodynamic development in the eastern North Sea

    DEFF Research Database (Denmark)

    Pedersen, Stig A. Schack; Boldreel, Lars Ole

    2017-01-01

    –Early Weichselian Skærumhede Group, indicating a Saalian age of the glaciotectonic deformation. The balancing of the thrust fault structures shows that the thrust sheets in the tailing end of the complex had their source in the Skagerrak sea. The hole caused by displacement contributed to formation of the Skagerrak......The Quaternary geology in the eastern part of the North Sea is characterized by large-scale glaciotectonic complexes. The northernmost complex is the Jammerbugt Glaciotectonic Complex here addressed, which occupies an area of more than 300km2. It was recently recognized during an investigation...... of conventional seismic profiles located about 10km offshore the west coast of northern Denmark. The deformed bedrock includes the main part of the Cretaceous Chalk Group in the North Sea. In the northern part of the complex the detachment surface is situated in Lower Cretaceous greensand about 400m below sea...

  1. Nutrient biogeochemistry of the eastern Arabian Sea during the southwest monsoon retreat

    Digital Repository Service at National Institute of Oceanography (India)

    George, R; Muraleedharan, K.R; Martin, G.D.; Sabu, P.; Gerson, V.J.; Dineshkumar, P.K.; Nair, S.M.; Chandramohanakumar, N.; Nair, K.K.C.

    and adjoining southeastern Arabian Sea. Curr Sci 96:364–375 Jyothibabu R, Madhu NV, Jayalakshmi KV, Balachandran KK, Shiyas CA, Martin GD, Nair KKC (2006) Impact of freshwater influx on microzooplankton mediated food web in a tropical estuary (Cochin backwaters... ARTICLE Nutrient biogeochemistry of the eastern Arabian Sea during the southwest monsoon retreat Rejomon George • K. R. Muraleedharan • G. D. Martin • P. Sabu • Vijay John Gerson • P. K. Dineshkumar • S. M. Nair • N. Chandramohanakumar • K. K. C. Nair...

  2. Cenozoic structures and the tectonic evolution of the eastern North Sea

    DEFF Research Database (Denmark)

    Clausen, O.R.; Nielsen, S.B.; Egholm, D.L.

    2011-01-01

    Abundant seismic sections and well data from the Cenozoic succession in the eastern North Sea area generally reveal normal faulting, salt tectonics and localized tectonic inversion. However, inferences on the Cenozoic dynamic evolution of the region require thorough analysis of interactions between...... or cover tectonism took place. Our objectives are thus 1) to analyze the interaction between basement and cover structures, and if possible 2) to relate the structures to the regional tectonic evolution. The Zechstein evaporites pinch out onto the Ringkøbing-Fyn High, which in the eastern North Sea...... influencede.g. Miocene deposition and controlled the generation of second order faults. The latter detached along the top Chalk Group due to the topography generated during faulting, i.e. they are second order detachment surfaces. We conclude that the regional tectonic significance of the Cenozoic structures...

  3. AFSC/NMML: Cetacean line-transect survey in the eastern Bering Sea shelf; 1999, 2000, 2002, and 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visual surveys for cetaceans were conducted on the eastern Bering Sea shelf along transect lines, in association with the AFSC.s echo integration trawl surveys for...

  4. Offshore limit of coastal ocean variability identified from hydrography and altimeter data in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Swamy, G.N.; Somayajulu, Y.K.

    In this communication, we describe a hitherto-unknown offshore limit to the coastal ocean variability signatures away from the continental shelf in the eastern Arabian Sea, based on hydrographic observations and satellite altimeter (TOPEX...

  5. Temperature, salinity, and dissolved oxygen profile data from MULTIPLE SHIPS in the Eastern Mediterranean Sea: (NODC Accession 9400176)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Conductivity, Temperature and Depth (CTD) and other data were collected in Mediterranean Sea, Eastern Basin as part of Mediterranean Ocean Circulation project. Data...

  6. Acoustic-Trawl Survey of Walleye Pollock on the Eastern Bering Sea Shelf (DY1407, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey on the eastern Bering Sea...

  7. Variation of paleo-productivity and terrigenous input in the eastern Arabian Sea during the past 100 ka

    Digital Repository Service at National Institute of Oceanography (India)

    Ishfaq, A.M.; Pattan, J.N.; Matta, V.M.; Banakar, V.K.

    A 4.1m long sediment core from the eastern Arabian Sea is studied using multiple geochemical proxies to understand the variation of productivity and terrigenous matter supply during the past 100 ka. The temporal variation in element concentration...

  8. Census of biodiversity in marine caves of the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    V. GEROVASILEIOU

    2015-03-01

    Full Text Available Scientific information on the biodiversity of marine caves in the eastern Mediterranean is limited, especially when considering the extensively studied caves of the north-western and central Mediterranean. Aiming to enhance current knowledge regarding cave communities, this study represents a first assessment of the marine cave biota of the eastern Mediterranean, as this has been defined by the European Union’s Marine Strategy Framework Directive (MSFD. Information retrieved from an extensive overview of relevant scientific documents was combined with original data recorded from 23 marine caves of the north-eastern Mediterranean. Our results report a total of 520 taxa recorded in eastern Mediterranean marine caves to date, the majority of which are sponges, polychaetes, rhodophytes, bivalves, fishes, and gastropods. These include several protected, endemic, and alien species. However, not all taxonomic groups have been equally studied among different areas and future studies are expected to raise the number of endemic and alien species. The overall observed trend is that the reported species number is generally related to sampling effort and scientific expertise. The most well-studied marine cave communities of the eastern Mediterranean are those of the Aegean Sea (especially its northern sector, which presented the highest number of species, followed by those of the Levantine. Furthermore, our research in Aegean caves revealed numerous new records for the marine cave fauna of the eastern basin, while several species are reported for the first time in the marine cave habitat. The critical need for further scientific research, monitoring, and conservation of this unique ecosystem was highlighted by (i the presence of certain species endemic to the eastern Mediterranean coupled with a high proportion of alien species, especially in the Levantine, and (ii the marine cave habitat availability in isolated insular areas of the eastern Mediterranean.

  9. Radionuclides and trace metals in eastern Mediterranean Sea algae

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Mamish, S.; Budier, Y.

    2003-01-01

    Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that 137 Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg -1 dry weight) while the levels of naturally occurring radionuclides, such as 210 Po and 210 Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg -1 dry weight) for 210 Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate 210 Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br

  10. Modeling of the branches of the Tsushima Warm Current in the eastern Japan sea

    International Nuclear Information System (INIS)

    Kawamura, Hideyuki; Ito, Toshimichi; Hirose, Naoki; Yoon, Jong-Hwan; Takikawa, Tetsutaro

    2009-01-01

    The branches of the Tsushima Warm Current (TWC) are realistically reproduced using a three-dimensional ocean general circulation model (OGCM). Simulated structures of the First Branch and the Second Branch of the TWC (FBTWC and SBTWC) in the eastern Japan Sea are mainly addressed in this study, being compared with measurement in the period September-October 2000. This is the first numerical experiment so far in which the OGCM is laterally exerted by real volume transports measured by acoustic Doppler current profiler (ADCP) through the Tsushima Straits and the Tsugaru Strait. In addition, sea level variation measured by tide-stations along the Japanese coast as well as satellite altimeters is assimilated into the OGCM through a sequential data assimilation method. It is demonstrated that the assimilation of sea level variation at the coastal tide-stations is useful in reproducing oceanic conditions in the nearshore region. We also examine the seasonal variation of the branches of the TWC in the eastern Japan Sea in 2000. It is suggested as a consequence that the FBTWC is continuous along northwestern Honshu Island in summertime, while it degenerates along the coast between the Sado Strait and the Oga Peninsula in other seasons. On the other hand, a mainstream of the SBTWC exists with meanders and eddies in the offshore region deeper than 1000 m to the north of the Sado Island throughout the year. (author)

  11. Radium isotopes in the Orinoco estuary and Eastern Caribbean Sea

    International Nuclear Information System (INIS)

    Moore, W.S.; Todd, J.F.

    1993-01-01

    Radium isotopes provide a means of identifying the source of freshened waters in the ocean and determining the time elapsed since these waters were in the estuary. The authors present evidence that during April, waters from the Amazon mixing zone pass within 50 km of the mouth of the Orinoco River. These Amazon waters are characterized by a lower 228 Ra/ 226 Ra activity ratio (AR) than are waters from the Orinoco at similar salinities. During autumn, the increased discharge of the Orinoco displaces the freshened Amazon waters seaward, yet the two can be distinguished clearly. Within the Caribbean Sea, waters of Orinoco origin carry a characteristic radium signature including excess activities of 224 Ra. This isotope may be used to estimate the time elapsed since the waters were removed from contact with sediments. Current speeds based on 224 Ra dating ranged from 15 to 33 cm/s during April. The radium isotopes also provide an assessment of sediment mixing in the estuary. During low discharge (April), considerable mixing of older sediment by physical or biological processes or dredging maintained high activities of 228 Ra in the estuary and produced the highest 228 Ra/ 226 Ra AR's yet measured in any estuary. During high discharge (September), a large fraction of the 228 Ra was derived from desorption from fresh sediment rather than mixing of older sediments. Activities of 224 Ra were high in the estuary during both high and low discharge, indicating that considerable mixing of recently introduced sediment must occur during each period. During April, 224 Ra and 228 Ra activities in the water were about equal, indicating that most of the sediment being resuspended had been stored in the estuary long enough to reestablish radioactive equilibrium in the 232 Th decay series (i.e., 20 years). 19 refs., 11 figs., 3 tabs

  12. Formation of Barents Sea Branch Water in the north-eastern Barents Sea

    Directory of Open Access Journals (Sweden)

    Vidar S. Lien

    2013-09-01

    Full Text Available The Barents Sea throughflow accounts for approximately half of the Atlantic Water advection to the Arctic Ocean, while the other half flows through Fram Strait. Within the Barents Sea, the Atlantic Water undergoes considerable modifications before entering the Arctic Ocean through the St. Anna Trough. While the inflow area in the south-western Barents Sea is regularly monitored, oceanographic data from the outflow area to the north-east are very scarce. Here, we use conductivity, temperature and depth data from August/September 2008 to describe in detail the water masses present in the downstream area of the Barents Sea, their spatial distribution and transformations. Both Cold Deep Water, formed locally through winter convection and ice-freezing processes, and Atlantic Water, modified mainly through atmospheric cooling, contribute directly to the Barents Sea Branch Water. As a consequence, it consists of a dense core characterized by a temperature and salinity maximum associated with the Atlantic Water, in addition to the colder, less saline and less dense core commonly referred to as the Barents Sea Branch Water core. The denser core likely constitutes a substantial part of the total flow, and it is more saline and considerably denser than the Fram Strait branch as observed within the St. Anna Trough. Despite the recent warming of the Barents Sea, the Barents Sea Branch Water is denser than observed in the 1990s, and the bottom water observed in the St. Anna Trough matches the potential density at 2000 m depth in the Arctic Ocean.

  13. Geothermal structure of the eastern Black Sea basin and the eastern Pontides orogenic belt: Implications for subduction polarity of Tethys oceanic lithosphere

    Directory of Open Access Journals (Sweden)

    Nafiz Maden

    2013-07-01

    Full Text Available The numerical results of thermal modeling studies indicate that the lithosphere is cold and strong beneath the Black Sea basin. The thermal lithospheric thickness increases southward from the eastern Pontides orogenic belt (49.4 km to Black Sea basin (152.2 km. The Moho temperature increases from 367 °C in the trench to 978 °C in the arc region. The heat flow values for the Moho surface change between 16.4 mW m−2 in the Black Sea basin and 56.9 mW m−2 in the eastern Pontides orogenic belt. Along the southern Black Sea coast, the trench region has a relatively low geothermal potential with respect to the arc and back-arc region. The numerical studies support the existence of southward subduction beneath the Pontides during the late Mesozoic–Cenozoic.

  14. Earthquake Scenario-Based Tsunami Wave Heights in the Eastern Mediterranean and Connected Seas

    Science.gov (United States)

    Necmioglu, Ocal; Özel, Nurcan Meral

    2015-12-01

    We identified a set of tsunami scenario input parameters in a 0.5° × 0.5° uniformly gridded area in the Eastern Mediterranean, Aegean (both for shallow- and intermediate-depth earthquakes) and Black Seas (only shallow earthquakes) and calculated tsunami scenarios using the SWAN-Joint Research Centre (SWAN-JRC) code ( Mader 2004; Annunziato 2007) with 2-arcmin resolution bathymetry data for the range of 6.5—Mwmax with an Mw increment of 0.1 at each grid in order to realize a comprehensive analysis of tsunami wave heights from earthquakes originating in the region. We defined characteristic earthquake source parameters from a compiled set of sources such as existing moment tensor catalogues and various reference studies, together with the Mwmax assigned in the literature, where possible. Results from 2,415 scenarios show that in the Eastern Mediterranean and its connected seas (Aegean and Black Sea), shallow earthquakes with Mw ≥ 6.5 may result in coastal wave heights of 0.5 m, whereas the same wave height would be expected only from intermediate-depth earthquakes with Mw ≥ 7.0 . The distribution of maximum wave heights calculated indicate that tsunami wave heights up to 1 m could be expected in the northern Aegean, whereas in the Black Sea, Cyprus, Levantine coasts, northern Libya, eastern Sicily, southern Italy, and western Greece, up to 3-m wave height could be possible. Crete, the southern Aegean, and the area between northeast Libya and Alexandria (Egypt) is prone to maximum tsunami wave heights of >3 m. Considering that calculations are performed at a minimum bathymetry depth of 20 m, these wave heights may, according to Green's Law, be amplified by a factor of 2 at the coastline. The study can provide a basis for detailed tsunami hazard studies in the region.

  15. Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas

    Science.gov (United States)

    Necmioglu, Ocal; Meral Ozel, Nurcan

    2015-04-01

    Accurate earthquake source parameters are essential for any tsunami hazard assessment and mitigation, including early warning systems. Complex tectonic setting makes the a priori accurate assumptions of earthquake source parameters difficult and characterization of the faulting type is a challenge. Information on tsunamigenic sources is of crucial importance in the Eastern Mediterranean and its Connected Seas, especially considering the short arrival times and lack of offshore sea-level measurements. In addition, the scientific community have had to abandon the paradigm of a ''maximum earthquake'' predictable from simple tectonic parameters (Ruff and Kanamori, 1980) in the wake of the 2004 Sumatra event (Okal, 2010) and one of the lessons learnt from the 2011 Tohoku event was that tsunami hazard maps may need to be prepared for infrequent gigantic earthquakes as well as more frequent smaller-sized earthquakes (Satake, 2011). We have initiated an extensive modeling study to perform a deterministic Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas. Characteristic earthquake source parameters (strike, dip, rake, depth, Mwmax) at each 0.5° x 0.5° size bin for 0-40 km depth (total of 310 bins) and for 40-100 km depth (total of 92 bins) in the Eastern Mediterranean, Aegean and Black Sea region (30°N-48°N and 22°E-44°E) have been assigned from the harmonization of the available databases and previous studies. These parameters have been used as input parameters for the deterministic tsunami hazard modeling. Nested Tsunami simulations of 6h duration with a coarse (2 arc-min) grid resolution have been simulated at EC-JRC premises for Black Sea and Eastern and Central Mediterranean (30°N-41.5°N and 8°E-37°E) for each source defined using shallow water finite-difference SWAN code (Mader, 2004) for the magnitude range of 6.5 - Mwmax defined for that bin with a Mw increment of 0.1. Results show that not only the earthquakes resembling the

  16. Deterministic Tectonic Origin Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas

    Science.gov (United States)

    Necmioglu, O.; Meral Ozel, N.

    2014-12-01

    Accurate earthquake source parameters are essential for any tsunami hazard assessment and mitigation, including early warning systems. Complex tectonic setting makes the a priori accurate assumptions of earthquake source parameters difficult and characterization of the faulting type is a challenge. Information on tsunamigenic sources is of crucial importance in the Eastern Mediterranean and its Connected Seas, especially considering the short arrival times and lack of offshore sea-level measurements. In addition, the scientific community have had to abandon the paradigm of a ''maximum earthquake'' predictable from simple tectonic parameters (Ruff and Kanamori, 1980) in the wake of the 2004 Sumatra event (Okal, 2010) and one of the lessons learnt from the 2011 Tohoku event was that tsunami hazard maps may need to be prepared for infrequent gigantic earthquakes as well as more frequent smaller-sized earthquakes (Satake, 2011). We have initiated an extensive modeling study to perform a deterministic Tsunami Hazard Analysis for the Eastern Mediterranean and its Connected Seas. Characteristic earthquake source parameters (strike, dip, rake, depth, Mwmax) at each 0.5° x 0.5° size bin for 0-40 km depth (total of 310 bins) and for 40-100 km depth (total of 92 bins) in the Eastern Mediterranean, Aegean and Black Sea region (30°N-48°N and 22°E-44°E) have been assigned from the harmonization of the available databases and previous studies. These parameters have been used as input parameters for the deterministic tsunami hazard modeling. Nested Tsunami simulations of 6h duration with a coarse (2 arc-min) and medium (1 arc-min) grid resolution have been simulated at EC-JRC premises for Black Sea and Eastern and Central Mediterranean (30°N-41.5°N and 8°E-37°E) for each source defined using shallow water finite-difference SWAN code (Mader, 2004) for the magnitude range of 6.5 - Mwmax defined for that bin with a Mw increment of 0.1. Results show that not only the

  17. Mitochondrial DNA reveals genetic structuring of Pinna nobilis across the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Daria Sanna

    Full Text Available 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.

  18. Indo-Pacific sea surface temperature influences on failed consecutive rainy seasons over eastern Africa

    Science.gov (United States)

    Hoell, Andrew; Funk, Christopher C.

    2014-01-01

    Rainfall over eastern Africa (10°S–10°N; 35°E–50°E) is bimodal, with seasonal maxima during the "long rains" of March–April–May (MAM) and the "short rains" of October–November–December (OND). Below average precipitation during consecutive long and short rains seasons over eastern Africa can have devastating long-term impacts on water availability and agriculture. Here, we examine the forcing of drought during consecutive long and short rains seasons over eastern Africa by Indo-Pacific sea surface temperatures (SSTs). The forcing of eastern Africa precipitation and circulation by SSTs is tested using ten ensemble simulations of a global weather forecast model forced by 1950–2010 observed global SSTs. Since the 1980s, Indo-Pacific SSTs have forced more frequent droughts spanning consecutive long and short rains seasons over eastern Africa. The increased frequency of dry conditions is linked to warming SSTs over the Indo-west Pacific and to a lesser degree to Pacific Decadal Variability. During MAM, long-term warming of tropical west Pacific SSTs from 1950–2010 has forced statistically significant precipitation reductions over eastern Africa. The warming west Pacific SSTs have forced changes in the regional lower tropospheric circulation by weakening the Somali Jet, which has reduced moisture and rainfall over the Horn of Africa. During OND, reductions in precipitation over recent decades are oftentimes overshadowed by strong year-to-year precipitation variability forced by the Indian Ocean Dipole and the El Niño–Southern Oscillation.

  19. 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.

  20. Diet compositions and trophic guild structure of the eastern Chukchi Sea demersal fish community

    Science.gov (United States)

    Whitehouse, George A.; Buckley, Troy W.; Danielson, Seth L.

    2017-01-01

    Fishes are an important link in Arctic marine food webs, connecting production of lower trophic levels to apex predators. We analyzed 1773 stomach samples from 39 fish species collected during a bottom trawl survey of the eastern Chukchi Sea in the summer of 2012. We used hierarchical cluster analysis of diet dissimilarities on 21 of the most well sampled species to identify four distinct trophic guilds: gammarid amphipod consumers, benthic invertebrate generalists, fish and shrimp consumers, and zooplankton consumers. The trophic guilds reflect dominant prey types in predator diets. We used constrained analysis of principal coordinates (CAP) to determine if variation within the composite guild diets could be explained by a suite of non-diet variables. All CAP models explained a significant proportion of the variance in the diet matrices, ranging from 7% to 25% of the total variation. Explanatory variables tested included latitude, longitude, predator length, depth, and water mass. These results indicate a trophic guild structure is present amongst the demersal fish community during summer in the eastern Chukchi Sea. Regular monitoring of the food habits of the demersal fish community will be required to improve our understanding of the spatial, temporal, and interannual variation in diet composition, and to improve our ability to identify and predict the impacts of climate change and commercial development on the structure and functioning of the Chukchi Sea ecosystem.

  1. Identification of new deep sea sinuous channels in the eastern Arabian Sea.

    Science.gov (United States)

    Mishra, Ravi; Pandey, D K; Ramesh, Prerna; Clift, Peter D

    2016-01-01

    Deep sea channel systems are recognized in most submarine fans worldwide as well as in the geological record. The Indus Fan is the second largest modern submarine fan, having a well-developed active canyon and deep sea channel system. Previous studies from the upper Indus Fan have reported several active channel systems. In the present study, deep sea channel systems were identified within the middle Indus Fan using high resolution multibeam bathymetric data. Prominent morphological features within the survey block include the Raman Seamount and Laxmi Ridge. The origin of the newly discovered channels in the middle fan has been inferred using medium resolution satellite bathymetry data. Interpretation of new data shows that the highly sinuous deep sea channel systems also extend to the east of Laxmi Ridge, as well as to the west of Laxmi Ridge, as previously reported. A decrease in sinuosity southward can be attributed to the morphological constraints imposed by the elevated features. These findings have significance in determining the pathways for active sediment transport systems, as well as their source characterization. The geometry suggests a series of punctuated avulsion events leading to the present array of disconnected channels. Such channels have affected the Laxmi Basin since the Pliocene and are responsible for reworking older fan sediments, resulting in loss of the original erosional signature supplied from the river mouth. This implies that distal fan sediments have experienced significant signal shredding and may not represent the erosion and weathering conditions within the onshore basin at the time of sedimentation.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Recently studied sedimentary records from the eastern Arabian Sea: Implications to Holocene monsoonal variability

    Digital Repository Service at National Institute of Oceanography (India)

    Agnihotri, R.; Kurian, S.

    stream_size 72460 stream_content_type text/plain stream_name Earth_Sci_India_1_258.pdf.txt stream_source_info Earth_Sci_India_1_258.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Agnihotri http://www....earthscienceindia.info/Agnihotri.htm 1 of 14 10/15/2008 9:41 AM Earth Science India Vol.1 (IV), October, 2008, pp. 258-287 http://www.earthscienceindia.info/ Recently studied sedimentary records from the eastern Arabian Sea: Implications to Holocene monsoonal variability Rajesh...

  4. Maturity and Fecundity of Spiny Dogfish (Squalus acanthias L., 1758) in the Eastern Black Sea

    OpenAIRE

    DEMİRHAN, Sefa Ayhan; SEYHAN, Kadir

    2014-01-01

    The maturity and fecundity of Squalus acanthias spiny dogfish sampled from the south-eastern Black Sea were studied. Age and length at 50% maturity were 10.49 years and 87.57 cm for males, and 11.99 years and 102.97 cm for females, respectively. Mean biennial fecundity was 19.4 eggs and 12.9 pups. A linear relationship between fecundities and length was found: Fe = 0.09 x TLp + 2.12 (r = 0.5) for pups and Fo = 0.27 x TLp - 21.59 (r = 0.7) for eggs.

  5. Barium as a productivity proxy in continental margin sediments: A study from the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrakashBabu, C.; Brumsack, H.-J.; Schnetger, B.; Boettcher, M.E.

    that Ba is almost entirely involved in the deep regeneration cycle like the nutrient silica (Chan et al., 1977). The accumulation of both Ba and opal implies the possibility of barite formation in microenviron- ments of decaying remains of siliceous....M.A., Pant, A., Sawant, S., Gauns, M., Ma- tondkar, S.G.P., Mohanraju, R., 1996. Phytoplankton pro- duction and chlorophyll distribution in the eastern and cen- tral Arabian Sea in 1994^1995. Curr. Sci. 71, 857^862. Bishop, J.K.B., 1988. The barite-opal...

  6. Oceanographic and Acoustical Survey of the East Ionian Sea

    Science.gov (United States)

    1990-09-01

    Notation The views expressed-in this thesis are those of the author and do not reflect the official policy or po- sition -of-the Department of Defense...8217 ,_ ,=--- . OLo • :. LU _ -09 5 /- S US8 0)6 0 • OU G I:: -CD *.. LU Uz CD_ _ _ Li C) . LU M -- cN C.8 C C - ------- CD CnCD C:) C81 m 0- ’an 0 0

  7. Early Permian intrusions in the Paleozoic sediments of the Eastern North Sea area

    DEFF Research Database (Denmark)

    Clausen, O.R.; Andresen, Katrine Juul; Rasmussen, Jens Andreas

    in the Northern Permian Basin which in the eastern North Sea is separated from the Southern Permian Basin by the Ringkøbing-Fyn High. The Permian basins were initiated during thermal subsidence following a late Carboniferous- early Permian rifting phase associated with extensive igneous activity recorded across...... the entire North Sea Basin. The easternmost intrusions and extrusions have been associated to the “Skagerrak-Centered Large Igneous Province” that has an early Permian age of c. 297 Ma. Compared to the Southern Permian Basin which historically has been intensely investigated because of the known presence...... of hydrocarbons within the Paleozoic sediments, the Northern Permian Basin has gained much less interest outside the hydrocarbon producing Mesozoic graben systems. This is mainly due to an apparent lack of potential source rocks. A major E-W striking northward dipping fault system characterizes the study area...

  8. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Evidence of increased toxic Alexandrium tamarense dinoflagellate blooms in the eastern Bering Sea in the summers of 2004 and 2005.

    Science.gov (United States)

    Natsuike, Masafumi; Saito, Rui; Fujiwara, Amane; Matsuno, Kohei; Yamaguchi, Atsushi; Shiga, Naonobu; Hirawake, Toru; Kikuchi, Takashi; Nishino, Shigeto; Imai, Ichiro

    2017-01-01

    The eastern Bering Sea has a vast continental shelf, which contains various endangered marine mammals and large fishery resources. Recently, high numbers of toxic A. tamarense resting cysts were found in the bottom sediment surface of the eastern Bering Sea shelf, suggesting that the blooms have recently occurred. However, little is known about the presence of A. tamarense vegetative cells in the eastern Bering Sea. This study's goals were to detect the occurrence of A. tamarense vegetative cells on the eastern Bering Sea shelf and to find a relationship between environmental factors and their presence. Inter-annual field surveys were conducted to detect A. tamarense cells and environmental factors, such as nutrients, salinity, chlorophyll a, and water temperature, along a transect line on the eastern Bering Sea shelf during the summers of 2004, 2005, 2006, 2009, 2012, and 2013. A. tamarense vegetative cells were detected during every sampling year, and their quantities varied greatly from year to year. The maximum cell densities of A. tamarense observed during the summers of 2004 and 2005 were much higher than the Paralytic shellfish poisoning warning levels, which are greater than 100-1,000 cells L-1, in other subarctic areas. Lower quantities of the species occurred during the summers of 2009, 2012, and 2013. A significant positive correlation between A. tamarense quantity and water temperature and significant negative correlations between A. tamarense quantity and nutrient concentrations (of phosphate, silicate, and nitrite and nitrate) were detected in every sampling period. The surface- and bottom-water temperatures varied significantly from year to year, suggesting that water temperatures, which have been known to affect the cell growth and cyst germination of A. tamarense, might have affected the cells' quantities in the eastern Bering Sea each summer. Thus, an increase in the Bering Sea shelf's water temperature during the summer will increase the

  10. A survey of 137Cs in sediments of the eastern mediterranean marine environment from the pre-Chernobyl age to the present

    International Nuclear Information System (INIS)

    Evangeliou, Nikolaos; Florou, Heleny; Kritidis, Panayotis

    2014-01-01

    A survey of 137 Cs in sediments from the eastern Mediterranean Sea (Aegean and Ionian Seas) during the period from 1984 to 2007 is presented. Data have been collected and analyzed in the framework of the monitoring system of Greece performed by the Environmental Radioactivity Laboratory (NCSR 'Demokritos') over the past 30 years. Sediment activities reflect the impact from the Chernobyl accident one year later (1987). It is evident that sediment acts as the final receptor of 137 Cs, showing that fast depollution of the Mediterranean still remains a utopia. Radioactive 'hot spots' were observed in the northern Aegean Sea and lower values in the southern Aegean Sea and Ionian Sea. Finally, an effort to evaluate the risk of ionizing radiation (from 137 Cs) to the biota inhabiting sediments was made using ERICA. The respective dose rates for two reference organisms (benthic fish and mollusks) were estimated to be far below the screening dose, at which the radiological impact on the abundance of the population begins. (authors)

  11. Trophic ecology of deep-sea Asteroidea (Echinodermata) from eastern Canada

    Science.gov (United States)

    Gale, Katie S. P.; Hamel, Jean-François; Mercier, Annie

    2013-10-01

    Asteroids (sea stars) can be important predators in benthic communities and are often present in ecologically important and vulnerable deep-sea coral and sponge habitats. However, explicit studies on the trophic ecology of deep-sea asteroids are rare. We investigated the diets of seven species of deep-sea asteroid from the bathyal zone of Newfoundland and Labrador, eastern Canada. A multifaceted approach including live animal observations, stomach content analysis, and stable isotope analysis revealed the asteroids to be either top predators of megafauna or secondary consumers (mud ingesters, infaunal predators, and suspension feeders). The stable isotope signatures of Ceramaster granularis, Hippasteria phrygiana, and Mediaster bairdi are characteristic of high-level predators, having δ15N values 4.4‰ (more than one trophic level) above Ctenodiscus crispatus, Leptychaster arcticus, Novodinia americana, and Zoroaster fulgens. We present strong evidence that corals and sponges are common food items for two of the predatory species, C. granularis and H. phrygiana. During laboratory feeding trials, live H. phrygiana fed on several species of soft coral and C. granularis fed on sponges. Stomach content analysis of wild-caught individuals revealed sclerites from sea pens (e.g. Pennatula sp.) in the stomachs of both asteroid species; H. phrygiana also contained sclerites from at least two other species of octocoral and siliceous sponge spicules were present in the stomachs of C. granularis. The stomach contents of the secondary consumers contained a range of invertebrate material. Leptychaster arcticus and Ctenodiscus crispatus feed infaunally on bulk sediment and molluscs, Zoroaster fulgens is a generalist infaunal predator, and the brisingid Novodinia americana is a specialist suspension feeder on benthopelagic crustaceans. This study provides a foundation for understanding the ecological roles of bathyal asteroids, and suggests that some species may have the

  12. Submarine canyons as coral and sponge habitat on the eastern Bering Sea slope

    Directory of Open Access Journals (Sweden)

    Robert J. Miller

    2015-07-01

    Full Text Available Submarine canyons have been shown to positively influence pelagic and benthic biodiversity and ecosystem function. In the eastern Bering Sea, several immense canyons lie under the highly productive “green belt” along the continental slope. Two of these, Pribilof and Zhemchug canyons, are the focus of current conservation interest. We used a maximum entropy modeling approach to evaluate the importance of these two canyons, as well as canyons in general, as habitat for gorgonian (alcyonacean corals, pennatulacean corals, and sponges, in an area comprising most of the eastern Bering Sea slope and outer shelf. These invertebrates create physical structure that is a preferred habitat for many mobile species, including commercially important fish and invertebrates. We show that Pribilof canyon is a hotspot of structure-forming invertebrate habitat, containing over 50% of estimated high-quality gorgonian habitat and 45% of sponge habitat, despite making up only 1.7% of the total study area. The amount of quality habitat for gorgonians and sponges varied in other canyons, but canyons overall contained more high-quality habitat for structure-forming invertebrates compared to other slope areas. Bottom trawling effort was not well correlated with habitat quality for structure-forming invertebrates, and bottom-contact fishing effort in general, including longlining and trawling, was not particularly concentrated in the canyons examined. These results suggest that if conserving gorgonian coral habitat is a management goal, canyons, particularly Pribilof Canyon, may be a prime location to do this without excessive impact on fisheries.

  13. Flatfish recruitment response to decadal climatic variability and ocean conditions in the eastern Bering Sea

    Science.gov (United States)

    Wilderbuer, T. K.; Hollowed, A. B.; Ingraham, W. J.; Spencer, P. D.; Conners, M. E.; Bond, N. A.; Walters, G. E.

    2002-10-01

    This paper provides a retrospective analysis of the relationship of physical oceanography and biology and recruitment of three Eastern Bering Sea flatfish stocks: flathead sole ( Hippoglossoides elassodon), northern rock sole ( Lepidopsetta polyxystra), and arrowtooth flounder ( Atheresthes stomias) for the period 1978-1996. Temporal trends in flatfish production in the Eastern Bering Sea are consistent with the hypothesis that decadal scale climate variability influences marine survival during the early life history period. Density-dependence (spawning stock size) is statistically significant in a Ricker model of flatfish recruitment, which includes environmental terms. Wind-driven advection of flatfish larvae to favorable nursery grounds was also found to coincide with years of above-average recruitment through the use of an ocean surface current simulation model (OSCURS). Ocean forcing of Bristol Bay surface waters during springtime was mostly shoreward (eastward) during the 1980s and seaward (westerly) during the 1990s, corresponding with periods of good and poor recruitment. Distance from shore and water depth at the endpoint of 90-day drift periods (estimated time of settlement) were also found to correspond with flatfish productivity.

  14. Coastal Sea Level along the North Eastern Atlantic Shelf from Delay Doppler Altimetry

    Science.gov (United States)

    Fenoglio-Marc, L.; Benveniste, J.; Andersen, O. B.; Gravelle, M.; Dinardo, S.; Uebbing, B.; Scharroo, R.; Kusche, J.; Kern, M.; Buchhaupt, C.

    2017-12-01

    Satellite altimetry data of the CryoSat-2 and Sentinel-3 missions processed with Delay Doppler methodology (DDA) provide improved coastal sea level measurements up to 2-4 km from coast, thanks to an along-track resolution of about 300m and a higher signal to noise ratio. We investigate the 10 Kilometre stripe along the North-Eastern Atlantic shelf from Lisbon to Bergen to detect the possible impacts in sea level change studies of this enhanced dataset. We consider SAR CryoSat-2 and Sentinel-3 altimetry products from the ESA GPOD processor and in-house reduced SAR altimetry (RDSAR) products. Improved processing includes in RDSAR the application of enhanced retrackers for the RDSAR waveform. Improved processing in SAR includes modification both in the generation of SAR waveforms, (as Hamming weighting window on the burst data prior to the azimuth FFT, zero-padding prior to the range FFT, doubling of the extension for the radar range swath) and in the SAMOSA2 retracker. Data cover the full lifetime of CryoSat-2 (6 years) and Sentinel-3 (1 year). Conventional altimetry are from the sea level CCI database. First we analyse the impact of these SAR altimeter data on the sea level trend and on the estimation of vertical motion from the altimeter minus tide gauge differences. VLM along the North-Eastern Atlantic shelf is generally small compared to the North-Western Atlantic Coast VLM, with a smaller signal to noise ratio. Second we investigate impact on the coastal mean sea level surface and the mean dynamic topography. We evaluate a mean surface from the new altimeter data to be combined to state of the art geoid models to derive the mean dynamic topography. We compare the results to existing oceanographic and geodetic mean dynamic topography solutions, both on grid and pointwise at the tide gauge stations. This study is supported by ESA through the Sea Level CCI and the GOCE++DYCOT projects

  15. Multiple distant origins for green sea turtles aggregating off Gorgona Island in the Colombian eastern Pacific.

    Directory of Open Access Journals (Sweden)

    Diego F Amorocho

    Full Text Available Mitochondrial DNA analyses have been useful for resolving maternal lineages and migratory behavior to foraging grounds (FG in sea turtles. However, little is known about source rookeries and haplotype composition of foraging green turtle aggregations in the southeastern Pacific. We used mitochondrial DNA control region sequences to identify the haplotype composition of 55 green turtles, Chelonia mydas, captured in foraging grounds of Gorgona National Park in the Colombian Pacific. Amplified fragments of the control region (457 bp revealed the presence of seven haplotypes, with haplotype (h and nucleotide (π diversities of h = 0.300±0.080 and π = 0.009±0.005 respectively. The most common haplotype was CMP4 observed in 83% of individuals, followed by CMP22 (5%. The genetic composition of the Gorgona foraging population primarily comprised haplotypes that have been found at eastern Pacific rookeries including Mexico and the Galapagos, as well as haplotypes of unknown stock origin that likely originated from more distant western Pacific rookeries. Mixed stock analysis suggests that the Gorgona FG population is comprised mostly of animals from the Galapagos rookery (80%. Lagrangian drifter data showed that movement of turtles along the eastern Pacific coast and eastward from distant western and central Pacific sites was possible through passive drift. Our results highlight the importance of this protected area for conservation management of green turtles recruited from distant sites along the eastern Pacific Ocean.

  16. Multiple distant origins for green sea turtles aggregating off Gorgona Island in the Colombian eastern Pacific.

    Science.gov (United States)

    Amorocho, Diego F; Abreu-Grobois, F Alberto; Dutton, Peter H; Reina, Richard D

    2012-01-01

    Mitochondrial DNA analyses have been useful for resolving maternal lineages and migratory behavior to foraging grounds (FG) in sea turtles. However, little is known about source rookeries and haplotype composition of foraging green turtle aggregations in the southeastern Pacific. We used mitochondrial DNA control region sequences to identify the haplotype composition of 55 green turtles, Chelonia mydas, captured in foraging grounds of Gorgona National Park in the Colombian Pacific. Amplified fragments of the control region (457 bp) revealed the presence of seven haplotypes, with haplotype (h) and nucleotide (π) diversities of h = 0.300±0.080 and π = 0.009±0.005 respectively. The most common haplotype was CMP4 observed in 83% of individuals, followed by CMP22 (5%). The genetic composition of the Gorgona foraging population primarily comprised haplotypes that have been found at eastern Pacific rookeries including Mexico and the Galapagos, as well as haplotypes of unknown stock origin that likely originated from more distant western Pacific rookeries. Mixed stock analysis suggests that the Gorgona FG population is comprised mostly of animals from the Galapagos rookery (80%). Lagrangian drifter data showed that movement of turtles along the eastern Pacific coast and eastward from distant western and central Pacific sites was possible through passive drift. Our results highlight the importance of this protected area for conservation management of green turtles recruited from distant sites along the eastern Pacific Ocean.

  17. Crustal architecture of the eastern margin of Japan Sea: back-arc basin opening and contraction

    Science.gov (United States)

    No, T.; Sato, T.; Takahashi, N.; Kodaira, S.; Kaneda, Y.; Ishiyama, T.; Sato, H.

    2012-12-01

    Although large earthquakes such as the 1964 Niigata earthquake (M 7.5), 1983 Nihonkai-Chubu earthquake (M 7.8), and 1993 Hokkaido Nansei-Oki earthquake (M 7.8) have caused large amounts of damage to the eastern margin of the Japan Sea, a substantial number of seismic studies have been conducted for the seismogenic zone on the Pacific Ocean side of Japan. In addition, the detail of the source fault model for the eastern margin of the Japan Sea is not well defined for all cases. This highlights the need for further studies to investigate seismic imaging. Therefore, we have collaborated with other Japanese research institutions for a project titled "Priority Investigations of Strain Concentration Areas" (which is funded by Special Coordination Funds for Promoting Science and Technology, Japan). This project has conducted seismic surveys from 2009 to 2012 using the deep-sea research vessel, Kairei, from the Japan Agency for Marine-Earth Science and Technology. There is a strain concentration area in the eastern part of the survey area (Okamura et al., 1995). The western part of the survey area includes the Yamato Basin and Japan Basin. It is very important to study the crustal structure in the seismotectonic studies of the eastern margin of the Japan Sea. We conducted a marine seismic survey by using a multichannel seismic (MCS) system and ocean bottom seismographs (OBSs) along the eastern margin of the Japan Sea. Seismic data were acquired along 42 lines with a total length of approximately 9,000 km. The following results were obtained from seismic imaging. On the basis of the results of the MCS imaging, active reverse faults and folds were observed in the margin of the Toyama Trough; however, the sedimentary layers in the trough were flat. In the sedimentary layers and crusts of the Sado Ridge, Mogami Trough, and source area of the 1964 Niigata earthquake located north of the Sado Island, greater deformation was observed. The deformation weakened toward the Yamato

  18. Assessment of microphysical and chemical factors of aerosols over seas of the Russian Artic Eastern Section

    Science.gov (United States)

    Golobokova, Liudmila; Polkin, Victor

    2014-05-01

    The newly observed kickoff of the Northern Route development drew serious attention to state of the Arctic Resource environment. Occurring climatic and environmental changes are more sensitively seen in polar areas in particular. Air environment control allows for making prognostic assessments which are required for planning hazardous environmental impacts preventive actions. In August - September 2013, RV «Professor Khlustin» Northern Sea Route expeditionary voyage took place. En-route aerosol sampling was done over the surface of the Beringov, Chukotka and Eastern-Siberia seas (till the town of Pevek). The purpose of sampling was to assess spatio-temporal variability of optic, microphysical and chemical characteristics of aerosol particles of the surface layer within different areas adjacent to the Northern Sea Route. Aerosol test made use of automated mobile unit consisting of photoelectric particles counter AZ-10, aetalometr MDA-02, aspirator on NBM-1.2 pump chassis, and the impactor. This set of equipment allows for doing measurements of number concentration, dispersed composition of aerosols within sizes d=0.3-10 mkm, mass concentration of submicron sized aerosol, and filter-conveyed aerosols sampling. Filter-conveyed aerosols sampling was done using method accepted by EMEP and EANET monitoring networks. The impactor channel was upgraded to separate particles bigger than 1 mkm in size, and the fine grain fraction settled down on it. Reverse 5-day and 10-day trajectories of air mass transfer executed at heights of 10, 1500 and 3500 m were analyzed. The heights were selected by considerations that 3000 m is the height which characterizes air mass trend in the lower troposphere. 1500 m is the upper border of the atmospheric boundary layer, and the sampling was done in the Earth's surface layer at less than 10 m. Minimum values of the bespoken microphysical characteristics are better characteristic of higher latitudes where there are no man induced sources of

  19. Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr

    Directory of Open Access Journals (Sweden)

    C. V. Dylmer

    2013-07-01

    Full Text Available Three marine sediment cores distributed along the Norwegian (MD95-2011, Barents Sea (JM09-KA11-GC, and Svalbard (HH11-134-BC continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic waters (AW and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set of coccolith proxies: the abundance ratio between Emiliania huxleyi and Coccolithus pelagicus, an index of Atlantic vs. Polar/Arctic surface water masses; and Gephyrocapsa muellerae, a drifted coccolith species from the temperate North Atlantic, whose abundance changes are related to variations in the strength of the North Atlantic Current. The entire investigated area, from 66 to 77° N, was affected by an overall increase in AW flow from 3000 cal yr BP (before present to the present. The long-term modulation of westerlies' strength and location, which are essentially driven by the dominant mode of the North Atlantic Oscillation (NAO, is thought to explain the observed dynamics of poleward AW flow. The same mechanism also reconciles the recorded opposite zonal shifts in the location of the Arctic front between the area off western Norway and the western Barents Sea–eastern Fram Strait region. The Little Ice Age (LIA was governed by deteriorating conditions, with Arctic/Polar waters dominating in the surface off western Svalbard and western Barents Sea, possibly associated with both severe sea ice conditions and a strongly reduced AW strength. A sudden short pulse of resumed high WSC (West Spitsbergen Current flow interrupted this cold spell in eastern Fram Strait from 330 to 410 cal yr BP. Our dataset not only confirms the high amplitude warming of surface waters at the turn of the 19th century off western Svalbard, it also shows that such a warming was primarily induced by an excess flow of AW which stands as unprecedented over the last 3000 yr.

  20. Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Jesbin, G.

    –885, 2016 www.ann-geophys.net/34/871/2016/ doi:10.5194/angeo-34-871-2016 © Author(s) 2016. CC Attribution 3.0 License. Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea V. Sanil Kumar and Jesbin... of the period. The annual average value is ∼ 1.5 m (Anoop et al., 2015). During the non-monsoon period, the land and sea breeze has a signif- icant influence on the wave climate of eastern AS (Glejin Ann. Geophys., 34, 871–885, 2016 www.ann-geophys.net/34...

  1. The relationship between volatile halocarbons and phytoplankton pigments during a Trichodesmium bloom in the coastal eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Roy, R.; Pratihary, A.; Narvenkar, G.; Mochemadkar, S.; Gauns, M.; Naqvi, S.W.A.

    and 5 th April 2007 during regular visits to the Candolim Time Series (CaTS) station G3 located in the eastern Arabian Sea off Goa, India (Figure 1a). In order to investigate the phenomenon in detail and to extend the observations further offshore.... Chemosphere 45, 371-377. 14 Figure Captions Figure 1. a) Sampling locations in the eastern Arabian Sea off Goa; b) picture showing patchy Trichodesmium bloom observed at CaTS station G3. April. Figure 2. MODIS satellite observations from (showing...

  2. Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic

    Directory of Open Access Journals (Sweden)

    S. GARCIA-SANZ

    2014-03-01

    Full Text Available Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula at Gran Canaria Island (eastern Atlantic via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula with the most conspicuous species (D. africanum in the study area.

  3. Integrated survey of elemental stoichiometry (C, N, P from the western to eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    M. Pujo-Pay

    2011-04-01

    Full Text Available This paper provides an extensive vertical and longitudinal description of the biogeochemistry along an East-West transect of 3000 km across the Mediterranean Sea during summer 2008 (BOUM cruise. During this period of strong stratification, the distribution of nutrients, particulate and dissolved organic carbon (DOC, nitrogen (DON and phosphorus (DOP were examined to produce a detailed spatial and vertically extended description of the elemental stoichiometry of the Mediterranean Sea. Surface 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, with the phosphacline deepening to a greater extent than that for corresponding nitracline and thermocline depths. We used the minimum oxygen concentration through the water column in combination with 2 fixed concentrations of dissolved oxygen to distinguish an intermediate layer (Mineralization Layer; ML from surface (Biogenic Layer; BL, and deep layers (DL. Whilst each layer was represented by different water masses, this approach allowed us to propose a schematic box-plot representation of the biogeochemical functioning of the two Mediterranean basins. Despite the increasing oligotrophic nature and the degree of P-depletion along the West to East gradient strong similarities were encountered between eastern and western ecosystems. Within the BL, the C:N:P ratios in all pools largely exceeded the Redfield ratios, but surprisingly, the nitrate vs. phosphate ratios in the ML and DL tended towards the canonical Redfield values in both basins. A change in particulate matter composition has been identified 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. Our data showed a noticeable stability of the DOC:DON ratio (12–13 throughout the Mediterranean Sea. This is in good agreement with a P-limitation of

  4. Sea-Floor geology and character of Eastern Rhode Island Sound West of Gay Head, Massachusetts

    Science.gov (United States)

    Poppe, L.J.; McMullen, K.Y.; Ackerman, S.D.; Blackwood, D.S.; Irwin, B.J.; Schaer, J.D.; Forrest, M.R.

    2011-01-01

    Gridded multibeam bathymetry covers approximately 102 square kilometers of sea floor in eastern Rhode Island Sound west of Gay Head, Massachusetts. Although originally collected for charting purposes during National Oceanic and Atmospheric Administration hydrographic survey H11922, these acoustic data and the sea-floor stations subsequently occupied to verify them (1) show the composition and terrain of the seabed, (2) provide information on sediment transport and benthic habitat, and (3) are part of an expanding series of studies that provide a fundamental framework for research and management activities (for example, windfarms and fisheries) along the Massachusetts inner continental shelf. Most of the sea floor in the study area has an undulating to faintly rippled appearance and is composed of bioturbated muddy sand, reflecting processes associated with sediment sorting and reworking. Shallower areas are composed of rippled sand and, where small fields of megaripples are present, indicate sedimentary environments characterized by processes associated with coarse bedload transport. Boulders and gravel were found on the floors of scour depressions and on top of an isolated bathymetric high where erosion has removed the Holocene marine sediments and exposed the underlying relict lag deposits of Pleistocene drift. The numerous scour depressions, which formed during storm-driven events, result in the juxtaposition of sea-floor areas with contrasting sedimentary environments and distinct gravel, sand, and muddy sand textures. This textural heterogeneity in turn creates a complex patchwork of habitats. Our observations of local variations in community structure suggest that this small-scale textural heterogeneity adds dramatically to the sound-wide benthic biological diversity.

  5. Comparison of ERA-Interim waves with buoy data in the eastern Arabian Sea during high waves

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.

    at two locations in eastern Arabian Sea One location is a deep water location and another one is a shallow water location The comparison of significant wave height (SWH) between ERA dataset and buoy data at both the locations shows good correlation...

  6. Wave hindcast studies using SWAN nested in WAVEWATCH III - comparison with measured nearshore buoy data off Karwar, eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Amrutha, M.M.; SanilKumar, V.; Sandhya, K.G.; Nair, T.M.B; Rathod, J.L.

    Waves in the nearshore waters (~15 m water-depth) of eastern Arabian Sea were simulated using SWAN nested in WAVEWATCH III (WW3) for the year 2014. The sensitivity of the numerical wave model WW3 towards different source term (ST) packages...

  7. On an upwelling front, propagation of upwelling and vertical velocity in the eastern Arabian sea during monsoon, 1987

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Unnikrishnan, A.S.

    A coastal upwelling front parallel to the coast and identifiable upto a depth of 75 m was observed between 12.5 and 16 degrees N along the eastern Arabian Sea in September, 1987 from closely spaced digital BT data. With a north-south slope...

  8. Early- to late-Holocene contrast in productivity, OMZ intensity and calcite dissolution in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.S.; Godad, S.P.; Naidu, P.D.; Tiwari, M.; Paropkari, A.L.

    ) Concentrations and burial fluxes of organic and inorganic carbon on the eastern margins of the Arabian Sea. Marine Geology 178: 95-112. Böning P, and Bard E (2009) Millennial/centennial-scale thermocline ventilation changes in the Indian Ocean as reflected...

  9. Temporal and spatial variations in provenance of Eastern Mediterranean Sea sediments: Implications for Aegean and Aeolian arc volcanism

    NARCIS (Netherlands)

    Klaver, M.; Djuly, T.; de Graaf, S.; Sakes, A.; Wijbrans, J.R.; Davies, G.R.; Vroon, P.Z.

    2015-01-01

    The Eastern Mediterranean Sea (EMS) is the last remnant of the Tethys Ocean that has been subducted to the north since the Jurassic. Subduction has led to the formation of multiple island arcs in the EMS region where the Aeolian and Aegean arcs are currently active. The EMS is surrounded by

  10. Vertical distributions and speciation of dissolved rare earth elements in the anoxic brines of Bannock Basin, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Schijf, Johan; Baar, Hein J.W. de; Millero, Frank J.; Byrne, R.H.

    1995-01-01

    Vertical distributions of dissolved rare earth elements (REEs) are presented for the anoxic, highly sulfidic brines of Bannock Basin in the eastern Mediterranean Sea. REE concentrations at the seawater-brine interface are the highest ever recorded in the water column of an anoxic basin and

  11. Methane-related authigenic carbonates of the eastern Mediterranean Sea mud volcanoes and their possible relation to gas hydrate destabilisation

    NARCIS (Netherlands)

    Aloisi, G; Pierre, C; Rouchy, J.-M.; Foucher, J.P.; Woodside, J.M.; MEDINAUT scientific party, NN

    2000-01-01

    Nautile submersible investigations of mud volcanoes and brine seep areas of the eastern Mediterranean Sea during the MEDINAUT cruise in November 1998 discovered extensive areas of authigenic carbonate crusts associated with methane emissions. Carbonate crusts form pavements, round slabs and circular

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

    NARCIS (Netherlands)

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

    2006-01-01

    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

  13. Spatial patterns of bacterial abundance, activity and community composition in relation to water masses in the eastern Mediterranean Sea

    NARCIS (Netherlands)

    Yokokawa, Taichi; De Corte, Daniele; Sintes, Eva; Herndl, Gerhard J.

    2010-01-01

    To determine the variation of bacterial activity and community composition between and within specific water masses, samples were collected throughout the water column at 5 stations in the eastern Mediterranean Sea corresponding to the regions of the northern Aegean, mid-Aegean, western Cretan,

  14. Isotopic characteristics of shells Mytilus galloprovincialis from eastern coastal area of Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Tjaša Kanduč

    2006-06-01

    Full Text Available Samples of Mytilus galloprovincialis were collected from entire Eastern Adriatic coast to determine δ18O and δ13C performed on calcite and aragonite shell layers. The aim of this work was to check whether shells of M. galloprovincialis are good environmental indicators (water temperature, salinity. Based on measured isotopic composition of oxygen in shell layers and assumed isotopic composition in water temperatures of calcite and aragonite of shell layers were calculated. The calculated temperatures for M. galloprovincialis shell growth of calcite and aragonite shell layer are in good agreement with measured temperatures of sea water. According to our results of δ18O and δ13C in shell layers we canseparate the locations of the investigated area into three groups: those with more influence of fresh water, those with less influence of fresh water and those of marine environments.

  15. 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.

  16. Biogeographical homogeneity in the eastern Mediterranean Sea - I: the opisthobranchs (Mollusca: Gastropoda from Lebanon

    Directory of Open Access Journals (Sweden)

    F. CROCETTA

    2013-07-01

    Full Text Available A reviewed knowledge of the opisthobranch species from Lebanon (eastern Mediterranean Sea, based on literature records (scattered throughout various papers published over a period of more than 150 years and recently collected material (1999-2002 within the CEDRE framework and other samples, is presented, yielding a total number of 35 taxa recorded from the Lebanese shores identified to species level. Special emphasis has mainly been given to the alien species, for which scattered notes are also given. The known opisthobranch biota is composed of 22 native (~ 63%, 12 alien (~ 34% and one cryptogenic (~ 3% taxa. Eleven of these (Berthella aurantiaca, B. ocellata, Aplysia fasciata, Felimare picta, Felimida britoi, F. luteorosea, F. purpurea, Phyllidia flava, Dendrodoris grandiflora, D. limbata and Aeolidiella alderi constitute new records for the Lebanese fauna, whilst the examined material of a further seven species (Elysia grandifolia, Pleurobranchus forskalii, Aplysia dactylomela, Bursatella leachii, Syphonota geographica, Goniobranchus annulatus, Flabellina rubrolineata anecdotally cited from Lebanon on the basis of the samples here studied, is here first explained. One additional taxon belonging to the genus Haminoea has been identified to genus level only. Despite the searching effort poning the basis of the material analyzed here, data reported clearly suggest that strong investments are still needed for a better understanding of the eastern Mediterranean opisthobranch fauna.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Rapid Response of Eastern Mediterranean Deep Sea Microbial Communities to Oil

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiang; Techtmann, Stephen M.; Woo, Hannah L.; Ning, Daliang; Fortney, Julian L.; Hazen, Terry C.

    2017-07-18

    Deep marine oil spills like the Deepwater Horizon (DWH) in the Gulf of Mexico have the potential to drastically impact marine systems. Crude oil contamination in marine systems remains a concern, especially for countries around the Mediterranean Sea with off shore oil production. The goal of this study was to investigate the response of indigenous microbial communities to crude oil in the deep Eastern Mediterranean Sea (E. Med.) water column and to minimize potential bias associated with storage and shifts in microbial community structure from sample storage. 16S rRNA amplicon sequencing was combined with GeoChip metagenomic analysis to monitor the microbial community changes to the crude oil and dispersant in on-ship microcosms set up immediately after water collection. After 3 days of incubation at 14 °C, the microbial communities from two different water depths: 824 m and 1210 m became dominated by well-known oil degrading bacteria. The archaeal population and the overall microbial community diversity drastically decreased. Similarly, GeoChip metagenomic analysis revealed a tremendous enrichment of genes related to oil biodegradation, which was consistent with the results from the DWH oil spill. These results highlight a rapid microbial adaption to oil contamination in the deep E. Med., and indicate strong oil biodegradation potentia

  19. Climatology of the Eastern Arabian Sea during the last glacial cycle reconstructed from paired measurement of foraminiferal delta sup(18)O and Mg/Ca

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Mahesh, B.S.; Burr, G.; Chodankar, A

    Paired measurements of Mg/Ca and delta sup(18)O of Globigerenoides sacculifer from an Eastern Arabian Sea (EAS) sediment core indicate that sea-surface temperature (SST) varied within 2 degrees C and sea-surface salinity within 2 psu during the last...

  20. Numerical modelling of the buoyant marine microplastics in the South-Eastern Baltic Sea

    Science.gov (United States)

    Bagaev, Andrei; Mizyuk, Artem; Chubarenko, Irina; Khatmullilna, Liliya

    2017-04-01

    Microplastics is a burning issue in the marine pollution science. Its sources, ways of propagation and final destiny pose a lot of questions to the modern oceanographers. Hence, a numerical model is an optimal tool for reconstruction of microplastics pathways and fate. Within the MARBLE project (lamp.ocean.ru), a model of Lagrangian particles transport was developed. It was tested coupled with oceanographic transport fields from the operational oceanography product of Copernicus Marine Monitoring Environment Service. Our model deals with two major types of microplastics such as microfibres and buoyant spheroidal particles. We are currently working to increase the grid resolution by means of the NEMO regional configuration for the south-eastern Baltic Sea. Several expeditions were organised to the three regions of the Baltic Sea (the Gotland, the Bornholm, and the Gdansk basins). Water samples from the surface and different water layers were collected, processed, and analysed by our team. A set of laboratory experiments was specifically designed to establish the settling velocity of particles of various shapes and densities. The analysis in question provided us with the understanding necessary for the model to reproduce the large-scale dynamics of microfibres. In the simulation, particles were spreading from the shore to the deep sea, slowly sinking to the bottom, while decreasing in quantity due to conditional sedimentation. Our model is expected to map out the microplastics life cycle and to account for its distribution patterns under the impact of wind and currents. For this purpose, we have already included the parameterization for the wind drag force applied to a particle. Initial results of numerical experiments seem to indicate the importance of proper implicit parameterization of the particle dynamics at the vertical solid boundary. Our suggested solutions to that problem will be presented at the EGU-2017. The MARBLE project is supported by Russian Science

  1. Evidence of increased toxic Alexandrium tamarense dinoflagellate blooms in the eastern Bering Sea in the summers of 2004 and 2005.

    Directory of Open Access Journals (Sweden)

    Masafumi Natsuike

    Full Text Available The eastern Bering Sea has a vast continental shelf, which contains various endangered marine mammals and large fishery resources. Recently, high numbers of toxic A. tamarense resting cysts were found in the bottom sediment surface of the eastern Bering Sea shelf, suggesting that the blooms have recently occurred. However, little is known about the presence of A. tamarense vegetative cells in the eastern Bering Sea. This study's goals were to detect the occurrence of A. tamarense vegetative cells on the eastern Bering Sea shelf and to find a relationship between environmental factors and their presence. Inter-annual field surveys were conducted to detect A. tamarense cells and environmental factors, such as nutrients, salinity, chlorophyll a, and water temperature, along a transect line on the eastern Bering Sea shelf during the summers of 2004, 2005, 2006, 2009, 2012, and 2013. A. tamarense vegetative cells were detected during every sampling year, and their quantities varied greatly from year to year. The maximum cell densities of A. tamarense observed during the summers of 2004 and 2005 were much higher than the Paralytic shellfish poisoning warning levels, which are greater than 100-1,000 cells L-1, in other subarctic areas. Lower quantities of the species occurred during the summers of 2009, 2012, and 2013. A significant positive correlation between A. tamarense quantity and water temperature and significant negative correlations between A. tamarense quantity and nutrient concentrations (of phosphate, silicate, and nitrite and nitrate were detected in every sampling period. The surface- and bottom-water temperatures varied significantly from year to year, suggesting that water temperatures, which have been known to affect the cell growth and cyst germination of A. tamarense, might have affected the cells' quantities in the eastern Bering Sea each summer. Thus, an increase in the Bering Sea shelf's water temperature during the summer will

  2. Caesium-137 in Marine Sediments of the Eastern Mediterranean from the Pre-Chernobyl Age to the Present

    International Nuclear Information System (INIS)

    Florou, Heleny; Evangeliou, Nikolaos; Kritidis, Panagiotis

    2011-01-01

    Caesium-137 (half-life 30.2 years) was first introduced into the marine environment as a result of the atmospheric nuclear weapon testing during 1953-1963. The second and largest contamination was the fallout after the Chernobyl accident in April 1986. Since 1986 the radiological status of the Mediterranean has been changed. During 1986 the average deposition of 137 Cs from the fallout in the Aegean Sea has been estimated to be approximately 4 kBq m -2 , whereas the respective value for the Ionian Sea (the area of 24,300 km 2 along the coasts) was 2.5 kBq m -2 . The total caesium ( 137 Cs + 134 Cs) input from Chernobyl fallout has been estimated to be 2400 TBq for the Black Sea, 820 TBq for the Aegean Sea and 600 TBq in the Ionian Sea (60 TBq in the zone of 50 km across the coasts). Although, the residence time of 137 Cs in seawater is long, it has been observed that 137 Cs has reached the bottom sediments, as the remaining period is long enough if compared to the estimated sinking time for the Mediterranean environment. The Mediterranean Sea is a semi-enclosed marine area, exchanging water, salt, heat and other physicochemical properties through the strait of Gibraltar with the Atlantic Ocean.The basin is characterized by low precipitation and high evaporation, which causes accumulation of contaminants in seawater and sediment. Taking into account the topography,one could note the importance of the eastern part of the Mediterranean,since it comprises a continuous source of interregional input (Black Sea). However,the motive of determining 137 Cs in the Greek marine territory was basic research (pre-Chernobyl age) and monitoring reasons (after Chernobyl accident). Several Greek marine systems have been examined throughout these years and the results are evaluated in the present study.

  3. Contrasting records of sea-level change in the eastern and western North Atlantic during the last 300 years

    Science.gov (United States)

    Long, A. J.; Barlow, N. L. M.; Gehrels, W. R.; Saher, M. H.; Woodworth, P. L.; Scaife, R. G.; Brain, M. J.; Cahill, N.

    2014-02-01

    We present a new 300-year sea-level reconstruction from a salt marsh on the Isle of Wight (central English Channel, UK) that we compare to other salt-marsh and long tide-gauge records to examine spatial and temporal variability in sea-level change in the North Atlantic. Our new reconstruction identifies an overall rise in relative sea level (RSL) of c. 0.30 m since the start of the eighteenth century at a rate of 0.9±0.3 mm yr. Error-in-variables changepoint analysis indicates that there is no statistically significant deviation from a constant rate within the dataset. The reconstruction is broadly comparable to other tide-gauge and salt-marsh records from the European Atlantic, demonstrating coherence in sea level in this region over the last 150-300 years. In contrast, we identify significant differences in the rate and timing of RSL with records from the east coast of North America. The absence of a strong late 19th/early 20th century RSL acceleration contrasts with that recorded in salt marsh sediments along the eastern USA coastline, in particular in a well-dated and precise sea-level reconstruction from North Carolina. This suggests that this part of the North Carolina sea level record represents a regionally specific sea level acceleration. This is significant because the North Carolina record has been used as if it were globally representative within semi-empirical parameterisations of past and future sea-level change. We conclude that regional-scale differences of sea-level change highlight the value of using several, regionally representative RSL records when calibrating and testing semi-empirical models of sea level against palaeo-records. This is because by using records that potentially over-estimate sea-level rise in the past such models risk over-estimating sea-level rise in the future.

  4. Evidence for eddy formation in the eastern Arabian Sea during the northeast monsoon

    Science.gov (United States)

    Bruce, John G.; Johnson, Donald R.; Kindle, John C.

    1994-01-01

    The seasonal formation of a large (500-800 km diameter) anticyclonic eddy in the upper 300-400 m of the eastern Arabian Sea during the northest monsoon period (December-April) is indicated fom hydrographic and satellite altimetry sea level observations, as well as from numerical model experiments. The center of the eddy circulation is approximately 10 deg N, 70 deg E, just to the west of the north-south Laccadive Island chain. In this paper the eddy is called the Laccadive High (LH). In some ways it is like a mirrorlike counterpart to the Great Whirl that develops during the southwest monsoon of the Somali coast (western Arabian Sea). The LH occurs at the same latitude but on the opposite side of the basin during the reversed monsoon. It is different from the Great Whirl, however, in its formation process, its intensity, and its decay. The hydrographic data obtained from surveys all during a single season give sufficiently close station spacing to allow reasonable contouring of the geopotential surfaces and of the properties within and around the LH region with minimum time aliasing. The Geostat altimeter record extends over 4 years, during which the seasonal variability of the LH indicates a dynamic relief of approximately 15-20 cm, which is in good agreement with the hydrographics observations. The altimetry time series also suggests a westward translation of the LH by January with a subsequent dissipation in midbasin. The model used is a wind-forced three-layer primitive equation model which depicts a LH agreement with the timing, position, and amplitude of both the hydrographic and altimetric measurements. The numerical simulation includes a passive tracer located in the Western Bay of Bengal; the western advection of the tracer around the south coasts of Sri Lanka and India in December and January is consistent with the appearance of low-salinity water observed to extend into the Arabian Sea during this period. The modeling studies suggest that both local and

  5. Tectonostratigraphy of the Southern Part of Papua and Arafura Sea, Eastern Indonesia

    Directory of Open Access Journals (Sweden)

    Bhakti H. Harahap

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v7i3.145Sedimentary history and stratigraphy of the Papua and Arafura Sea areas, eastern Indonesia, are gained from surface geological mapping combined with published data from oil companies. Development of some sedimentary units demonstrates that the tectonism have influenced sedimentation of such units comprising a succession of Phanerozoic rocks developing in a stable continental margin. The succession underlain by Cambrian-Silurian-Devonian metamorphic rocks consists of Tuaba, Kariem, Awitagoh, and Kemum Formation, and Modio Dolomite (Pre-Rift Phase. These rocks having been intruded by Late Permian-Middle Triassic granitoids and Carboniferous granite, are unconformably overlain by Late Carboniferous to Cretaceous siliciclastic-rich units comprising Aifam Group and Tipuma Formation (syn-Rift Phase and Kembelangan Group (Mesozoic Passive Margin Post-Rift. The Aifam Group is separated by a regionally continuous boundary on its top contact from the Triassic-Early Jurassic Tipuma Formation, which filled the block-faulted rift valley subbasins of continentally deposited red beds in the breakup stage. Regionally, developed erosion surfaces of the breakup unconformity have separated these red beds from generally transgressive post-breakup deposits of the Jurassic to Cretaceous marine sediments of the Kembelangan Group. Beach to shallow marine-glauconitic sandstone and shale of the group pass upward into shelf mudstone. Relative sea level fall related to the tectonic stability of the area led to the development of Eocene to Late Miocene platform carbonates of the New Guinea Limestone Supergroup which occurred in the entire island of Papua and the southern of Arafura that overlie these non-carbonate units (Tertiary passive margin. It is separated from the siliciclastic-rich packages by the Tertiary - Pre-Tertiary boundary. The sea level fluctuation within the group was also recorded during the formation of thin, discontinuous

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Geological and geomechanical properties of the carbonate rocks at the eastern Black Sea Region (NE Turkey)

    Science.gov (United States)

    Ersoy, Hakan; Yalçinalp, Bülent; Arslan, Mehmet; Babacan, Ali Erden; Çetiner, Gözde

    2016-11-01

    Turkey located in the Alpine-Himalayan Mountain Belt has 35% of the natural stone reserves of the world and has good quality marble, limestone, travertine and onyx reserves especially in the western regions of the country. The eastern Black Sea Region with a 1.4 million meters cubes reserve has a little role on the natural stone production in the country. For this reason, this paper deals with investigation on the potential of carbonate stone in the region and determination of the geological and geo-mechanical properties of these rocks in order to provide economic contribution to the national economy. While the study sites are selected among the all carbonate rock sites, the importance as well as the representative of the sites were carefully considered for the region. After representative samples were analyzed for major oxide and trace element compositions to find out petrochemical variations, the experimental program conducted on rock samples for determination of both physical and strength properties of the carbonate rocks. The results of the tests showed that there are significant variations in the geo-mechanical properties of the studied rock groups. The density values vary from 2.48 to 2.70 gr/cm3, water absorption by weight values range from 0.07 to 1.15% and the apparent porosity of the carbonate rocks are between 0.19 and 3.29%. However, the values of the UCS shows variation from 36 to 80 MPa. Tensile and bending strength values range from 3.2 to 7.5 MPa and 6.0-9.2 MPa respectively. Although the onyx samples have the lowest values of apparent porosity and water absorption by weight, these samples do not have the highest values of UCS values owing to occurrence of the micro-cracks. The UCS values of the rock samples were also found after cycling tests However, the limestone samples have less than 5% deterioration after freezing-thawing and wetting-drying tests, but travertine and onyx samples have more than 15% deterioration. Exception of the apparent

  8. Age and sex composition of seals killed by polar bears in the eastern Beaufort Sea.

    Directory of Open Access Journals (Sweden)

    Nicholas W Pilfold

    Full Text Available Polar bears (Ursus maritimus of the Beaufort Sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. We collected information on seals killed by polar bears (n=650 and hunting attempts on ringed seal (Pusa hispida lairs (n=1396 observed from a helicopter during polar bear mark-recapture studies in the eastern Beaufort Sea in spring in 1985-2011. We investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspecific vulnerabilities of ringed seals to polar bear predation.Polar bears primarily preyed on ringed seals (90.2% while bearded seals (Erignathus barbatus only comprised 9.8% of the kills, but 33% of the biomass. Adults comprised 43.6% (150/344 of the ringed seals killed, while their pups comprised 38.4% (132/344. Juvenile ringed seals were killed at the lowest proportion, comprising 18.0% (62/344 of the ringed seal kills. The proportion of ringed seal pups was highest between 2007-2011, in association with high ringed seal productivity. Half of the adult ringed seal kills were ≥ 21 years (60/121, and kill rates of adults increased following the peak of parturition. Determination of sex from DNA revealed that polar bears killed adult male and adult female ringed seals equally (0.50, n=78. The number of hunting attempts at ringed seal subnivean lair sites was positively correlated with the number of pup kills (r(2 =0.30, P=0.04, but was not correlated with the number of adult kills (P=0.37.Results are consistent with decadal trends in ringed seal productivity, with low numbers of pups killed by polar bears in spring in years of low pup productivity, and conversely when pup productivity was high. Vulnerability of adult ringed seals to predation increased in relation to reproductive activities and age, but not gender.

  9. Age and sex composition of seals killed by polar bears in the eastern Beaufort Sea.

    Science.gov (United States)

    Pilfold, Nicholas W; Derocher, Andrew E; Stirling, Ian; Richardson, Evan; Andriashek, Dennis

    2012-01-01

    Polar bears (Ursus maritimus) of the Beaufort Sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. We collected information on seals killed by polar bears (n=650) and hunting attempts on ringed seal (Pusa hispida) lairs (n=1396) observed from a helicopter during polar bear mark-recapture studies in the eastern Beaufort Sea in spring in 1985-2011. We investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspecific vulnerabilities of ringed seals to polar bear predation. Polar bears primarily preyed on ringed seals (90.2%) while bearded seals (Erignathus barbatus) only comprised 9.8% of the kills, but 33% of the biomass. Adults comprised 43.6% (150/344) of the ringed seals killed, while their pups comprised 38.4% (132/344). Juvenile ringed seals were killed at the lowest proportion, comprising 18.0% (62/344) of the ringed seal kills. The proportion of ringed seal pups was highest between 2007-2011, in association with high ringed seal productivity. Half of the adult ringed seal kills were ≥ 21 years (60/121), and kill rates of adults increased following the peak of parturition. Determination of sex from DNA revealed that polar bears killed adult male and adult female ringed seals equally (0.50, n=78). The number of hunting attempts at ringed seal subnivean lair sites was positively correlated with the number of pup kills (r(2) =0.30, P=0.04), but was not correlated with the number of adult kills (P=0.37). Results are consistent with decadal trends in ringed seal productivity, with low numbers of pups killed by polar bears in spring in years of low pup productivity, and conversely when pup productivity was high. Vulnerability of adult ringed seals to predation increased in relation to reproductive activities and age, but not gender.

  10. AFSC/RACE/FBEP/Hurst: Distributional patterns of 0-group Pacific cod (Gadus macrocephalus) in the eastern Bering Sea under variable recruitment and thermal conditions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a study that analyzed the late summer distribution of juvenile Pacific cod in the eastern Bering Sea for 6 cohorts (2004-2009), based on catches...

  11. AFSC/RACE/EcoFOCI: Chlorophyll: variability in spring chlorophyll concentrations and zooplankotn on the eastern Bering Sea shelf - cruise Healy 07-01

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected under NSF Grant # ARC-0722448 ("BEST: Impacts of Sea-ice on the Hydrographic Structure, Nutrients, and Mesozooplankton over the Eastern...

  12. Chemical oceanography of the Arabian Sea: Part III - Studies on nutrient fraction and stoichiometric relationship in the Northern and the Eastern Basins

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Sankaranarayanan, V.N.; DeSousa, S.N.; Fondekar, S.P.

    Phosphorus and inorganic nitrogen compounds have been divided into 'reserved' andoxidative fractions based on their relationships with apparent oxygen utilization in the northern and the north-eastern basins of the Arabian Sea.Two oxygen minima...

  13. AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service Annual Eastern Bering Sea Summer Bottom Trawl Surveys 1975 - 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detailed crab data collected from the annual NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the eastern Bering Sea continental...

  14. Seasonal Variations of Oceanographic Variables and Eastern Little Tuna (Euthynnus affinis) Catches in the North Indramayu Waters Java Sea

    Science.gov (United States)

    Syamsuddin, Mega; Sunarto; Yuliadi, Lintang

    2018-02-01

    The remotely derived oceanographic variables included sea surface temperature (SST), chlorophyll-a (Chl-a) and Eastern Little Tuna (Euthynnus affinis) catches are used as a combined dataset to understand the seasonal variation of oceanographic variables and Eastern Little Tuna catches in the north Indramayu waters, Java Sea. The fish catches and remotely sensed data were analysed for the 5 years datasets from 2010-2014. This study has shown the effect of monsoon inducing oceanographic condition in the study area. Seasonal change features were dominant for all the selected oceanographic parameters of SST and Chl-a, and also Eastern Little Tuna catches, respectively. The Eastern Little Tuna catch rates have the peak season from September to December (700 to 1000) ton that corresponded with the value of SST ranging from 29 °C to 30 °C following the decreasing of Chl-a concentrations in September to November (0.4 to 0.5) mg m-3. The monsoonal system plays a great role in determining the variability of oceanographic conditions and catch in the north Indramayu waters, Java Sea. The catches seemed higher during the northwest monsoon than in the southeast monsoon for all year observations except in 2010. The wavelet spectrum analysis results confirmed that Eastern Little Tuna catches had seasonal and inter-annual variations during 2012-2014. The SST had seasonal variations during 2010-2014. The Chl-a also showed seasonal variations during 2010-2011 and interannual variations during 2011-2014. Our results would benefit the fishermen and policy makers to have better management for sustainable catch in the study area.

  15. Variability and connectivity of plaice populations from the Eastern North Sea to the Baltic Sea, part II. Biological evidence of population mixing

    DEFF Research Database (Denmark)

    Ulrich, Clara; Hansen, Jakob Hemmer; Boje, Jesper

    2016-01-01

    in parallel. Genetic markers suggested the existence of different genetic populations in the transition area. Growth backcalculation with otoliths resulted in significant although limited differences in growth rates between North Sea and Skagerrak, indicating weak differentiation or important mixing......A multi-disciplinary study was conducted to clarify stock identity and connectivity patterns in the populations of European plaice (Pleuronectes platessa) in the Skagerrak-Kattegat transition area between the Eastern North Sea and the Baltic Sea. Five independent biological studies were carried out...... constitute a large share of the catches in this area. The mixing of different populations within a management area has implications for stock assessment and management. Choice must be made to either lump or split the populations, and the feasibility and constraints of both options are discussed. The outcomes...

  16. Buried paleo-sedimentary basins in the north-eastern Black Sea-Azov Sea area and tectonic implications (DOBRE-2)

    Science.gov (United States)

    Starostenko, Vitaly; Stephenson, Randell; Janik, Tomasz; Tolkunov, Anatoly

    2014-05-01

    A number of independent but inter-related projects carried out under the auspices of various national and international programmes in Ukraine including DARIUS were aimed at imaging the upper lithosphere, crustal and sedimentary basin architecture in the north-eastern Black Sea, southern Crimea and Kerch peninsulas and the Azov Sea. This region marks the transition from relatively undisturbed Precambrian European cratonic crust and lithosphere north of the Azov Sea to areas of significant Phanerozoic tectonics and basin development, in both extensional as well as compressional environments, to the south, including the eastern Black Sea rift, which is the main sedimentary basin of the study area. The wide-angle reflection and refraction (WARR) profile DOBRE-2, a Ukrainian national project with international participation (see below), overlapping some 115 km of the southern end of the DOBREfraction'99 profile (that crosses the intracratonic Donbas Foldbelt) in the north and running to the eastern Black Sea basin in the south, utilised on- and offshore recording and energy sources. It maps crustal velocity structure across the craton margin and documents, among other things, that the Moho deepens from 40 km to ~47 km to the southwest below the Azov Sea and Crimean-Caucasus deformed zone. A regional CDP seismic profile coincident with DOBRE-2, crossing the Azov Sea, Kerch Peninsula and the north-eastern Black Sea southwest to the Ukraine-Turkey border, acquired by Ukrgeofisika (the Ukrainian national geophysical company) reveals in its inferred structural relationships the ages of Cretaceous and younger extensional and subsequent basin inversion tectonic events as well as the 2D geometry of basement displacement associated with post mid-Eocene inversion. A direct comparison of the results of the WARR velocity model and the near-vertical reflection structural image has been made by converting the former into the time domain. The results dramatically demonstrate that

  17. Assessment of big floods in the Eastern Black Sea Basin of Turkey.

    Science.gov (United States)

    Yüksek, Ömer; Kankal, Murat; Üçüncü, Osman

    2013-01-01

    In this study, general knowledge and some details of the floods in Eastern Black Sea Basin of Turkey are presented. Brief hydro-meteorological analysis of selected nine floods and detailed analysis of the greatest flood are given. In the studied area, 51 big floods have taken place between 1955-2005 years, causing 258 deaths and nearly US $500,000,000 of damage. Most of the floods have occurred in June, July and August. It is concluded that especially for the rainstorms that have caused significantly damages, the return periods of the rainfall heights and resultant flood discharges have gone up to 250 and 500 years, respectively. A general agreement is observed between the return periods of rains and resultant floods. It is concluded that there has been no significant climate change to cause increases in flood harms. The most important human factors to increase the damage are determined as wrong and illegal land use, deforestation and wrong urbanization and settlement, psychological and technical factors. Some structural and non-structural measures to mitigate flood damages are also included in the paper. Structural measures include dykes and flood levees. Main non-structural measures include flood warning system, modification of land use, watershed management and improvement, flood insurance, organization of flood management studies, coordination between related institutions and education of the people and informing of the stakeholders.

  18. Trace elements in loggerhead turtles (Caretta caretta) from the eastern Mediterranean Sea: overview and evaluation

    International Nuclear Information System (INIS)

    Storelli, M.M.; Storelli, A.; D'Addabbo, R.; Marano, C.; Bruno, R.; Marcotrigiano, G.O.

    2005-01-01

    Concentrations of trace elements (Hg, Cd, Pb, Zn, Cu, Fe, and Se) in different organs and tissues (liver, kidney, muscle tissue, spleen, heart, lung, and fat tissue) of loggerhead turtles Caretta caretta from eastern Mediterranean Sea were determined. The highest levels of mercury and cadmium were found in liver (Hg: 0.43 μg g -1 wet weight; Cd: 3.36 μg g -1 wet weight) and kidney (Hg: 0.16 μg g -1 wet weight; Cd: 8.35 μg g -1 wet weight). For lead the overall concentrations were low and often below the limit of detection. Copper and selenium tended to be higher in liver than in other tissues and organs, while for zinc the concentrations were quite homogenous in the different organs and tissues, except fat tissue (64.7 μg g -1 wet weight) which showed a higher accumulation of this element. For iron the greatest concentrations were observed in liver (409 μg g -1 wet weight) and spleen (221 μg g -1 wet weight). - Cadmium concentrations in samples from turtles may be high enough to affect their health

  19. Biosynthetic potential of actinomycetes in brown forest soil on the eastern coast of the aegean sea

    Science.gov (United States)

    Shirokikh, I. G.; Shirokikh, A. A.

    2017-11-01

    The taxonomic and functional structures of the actinomycetal complex in the litter and upper horizon of the brown forest soil was studied in a Pinus brutia var. pendulifolia forest on the eastern coast of the Aegean Sea. The complex of actinomycetes included representatives of the Streptomyces and Micromonospora genera and oligosporus forms. Streptomycetes predominated (73.8%) in the soil, and micromonospores (66.7%) were dominants in the litter. Thirty isolates of ten Streptomyces species from five series and three sections prevailed. In the upper soil horizon, species of the Helvolo-Flavus Helvolus section predominated (48%); the S. felleus species occurred most frequently. Among the isolated cultures, the S. globisporus and S. sindenensis species capable to produce antitumor antibiotics were found. The testing of the antimicrobial activity of the natural isolates showed that five strains inhibit the growth of pathogenic Fusarium sp., Alternaria sp., Acremonium sp., and Bipolaris sorokiniana fungi. When testing the effect of streptomycetes on the production of cellulases, a high-efficient strain belonging to the S. noboritoensis species was revealed. All the streptomycetes isolated from the brown forest soil produced auxins at the rate of 7.8 to 19.7 μg of indole acetic acid/mL of the liquid medium in the presence of 200 mg/L of tryptophan. Twelve isolates of streptomycetes were transferred to the collection of biotechnologically promising cultures for studying their properties.

  20. Multichannel seismic-reflection data collected in 1980 in the eastern Chukchi Sea

    Science.gov (United States)

    Grantz, Arthur; Mann, Dennis M.; May, Steven D.

    1986-01-01

    The U.S. Geological Survey (USGS) collected approximately 2,652 km of 24-channel seismic-reflection data in early September, 1980, over the continental shelf in the eastern Chukchi Sea (Fig. 1). The profiles were collected on the USGS Research Vessel S.P. Lee. The seismic energy source consisted of a tuned array of five airguns with a total volume of 1213 cubic inches of air compressed to approximately 1900 psi. The recording system consisted of a 24-channel, 2400 meter long streamer with a group interval of 100 m, and a GUS (Global Universal Science) model 4200 digital recording instrument. Shots were fired every 50 meters. Navigational control for the survey was provided by a Magnavox integrated navigation system using transit satellites and doppler-sonar augmented by Loran C (Rho-Rho). A 2-millisecond sampling rate was used in the field; the data were later desampled to 4-milliseconds during the demultiplexing process. 8 seconds data length was recorded. Processing was done at the USGS Pacific Marine Geology Multichannel Processing Center in Menlo Park, California, in the sequence: editing-demultiplexing, velocity analysis, CDP stacking, deconvolution-filtering, and plotting on an electrostatic plotter. Plate 1 is a trackline chart showing shotpoint navigation.

  1. Relationship of spontaneous pneumothorax cases seen in Eastern Black Sea region with meteorological changes

    Science.gov (United States)

    Yamac, Mustafa Esat; Karapolat, Sami; Turkyilmaz, Atila; Seyis, Kubra Nur; Tekinbas, Celal

    2017-08-01

    The relationship of climate changes or weather conditions with the incidence of pneumothorax has been explored for many years. We aimed at revealing the effects of meteorological changes on the incidence of pneumothorax in the Eastern Black Sea region where spontaneous pneumothorax cases are seen relatively more frequently. The records of 195 subjects (179 males and 16 females) who had been monitored and treated due to spontaneous pneumothorax between January 2006 and December 2012 at our clinic were reviewed retrospectively, and their relationship was investigated with the meteorological data obtained by going through the database archive records of the 11th Regional Meteorology Directorate for the years between 2006 and 2012. Wind velocity was observed to be less in the days of having spontaneous pneumothorax than in the days of having no spontaneous pneumothorax, and the difference was found statistically significant ( P = 0.026). The people of our region whose active lifestyle is reflected in their working life, social life, and even in their folk dances usually take a rest in the days of slower wind speed. We think that this state of resting leads to an increase in the frequency of spontaneous pneumothorax.

  2. Natural and artificial radioactivity measurements in Eastern Black Sea region of Turkey

    International Nuclear Information System (INIS)

    Celik, N.; Cevik, U.; Celik, A.; Koz, B.

    2009-01-01

    In the present work, naturally occurring radionuclides of 226 Ra, 232 Th and 40 K were measured in soil samples collected from the Eastern Black Sea region of Turkey. It was found that the activity concentrations ranged from 12 to 120 Bq kg -1 for 226 Ra, from 13 to 121 Bq kg -1 for 232 Th and from 204 to 1295 Bq kg -1 for 40 K. Besides naturally occurring radionuclides, 137 Cs activity concentration was measured in soil, lichen and moss samples and it was found that 137 Cs activity concentration ranged from 27 to 775 Bq kg -1 with for soil, from 29 to 879 Bq kg -1 for lichen and from 67 to 1396 Bq kg -1 for moss samples. Annual effective doses due to the naturally occurring radionuclides and 137 Cs were estimated. Ecological half-lives of 137 Cs in lichen and moss species were estimated. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1993 indicated ecological half-lives between 1.36 and 2.96 years for lichen and between 1.35 and 2.85 years for moss species

  3. Movement Ecology of the Reef Manta Ray Manta alfredi in the Eastern Red Sea

    KAUST Repository

    Braun, Camrin D.

    2013-07-01

    Many well-studied elasmobranch populations have recently exhibited significant decline. The limited data related to fisheries and sightings for many unstudied or poorly understood populations indicate that these are also suffering. Directed fisheries and more cryptic threats such as entanglement and vessel strike represent significant risk to mobulid rays, arguably one of the most vulnerable elasmobranch groups. Very little information currently exists describing the basic ecology of manta rays or quantifying anthropogenic threats and impacts; however, recent efforts have drastically improved the body of knowledge available for these species, including oceanographic influences on movement, seasonal migration, and mating behaviors. Nevertheless, Red Sea mantas remain completely enigmatic. In this thesis, Chapter 1 details results from tagging 18 reef manta rays Manta alfredi in the eastern Red Sea using satellite and acoustic tag technology and demonstrates that mantas occupy areas with high human traffic. The combined satellite and acoustic techniques define both regional movements and ‘hotspots’ of habitat use where there is significant potential for manta-human interaction. I also present opportunistic sighting data that corroborate anthropogenic impacts on this population. Chapter 2 explores the vertical component of the nine satellite tags that were deployed on Manta alfredi as described in the previous chapter. Seven tags returned adequate data for analysis. Three of the seven were physically recovered yielding full archival datasets of depth, temperature, and light levels every 10-15 seconds for over 2.6 5 million cumulative data points. Mantas frequented the upper 10 m during the day and occupied deeper water through nocturnal periods. Individuals also exhibited deep diving behavior as deep as 432 m, extending the known depth range of the species. An investigation of 76 high-resolution deep dives suggests gliding is a significant behavioral component of

  4. Main Introduction Way of Indo-Pacific and Red Sea Originated Benthic Foraminifers to the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    Engin MERİÇ

    2015-12-01

    Full Text Available Majority of the alien foraminifers recorded in the eastern Mediterranean are Indo-Pacific originated and entered the Mediterranean via Suez Canal. In this study, current literature on the alien benthic foraminiferal fauna of the eastern Mediterranean was reviewed and the main dispersal pathways are determined. Distribution patterns of the alien species suggests that most of the species are introduced via Suez Canal and expand their range of distributions in a counter-clockwise manner by the general surface currents of the eastern Mediterranean. However, not all, but some of the species have also been dispersed westwards along the North African coast and reached central Mediterranean. Locally abundant records of Euthymonacha polita (Chapman, Coscinospira acicularis (Batsch and Amphistegina lobifera in the Aegean Sea indicates that Suez Canal may not be the only vector for the Indo-Pacific species to enter eastern Mediterranean and submarine springs help these thermophilic species to form establish populations in cool waters of the northern Aegean and the Sea of Marmara

  5. Miocene to recent tectonic and sedimentary evolution of the Anaximander Seamounts; eastern Mediterranean Sea

    Science.gov (United States)

    Cranshaw, Jennifer

    This thesis is focused on the Messinian to Recent tectonic and sedimentary evolution of the Anaximander Mountains and surrounding environs in the eastern Mediterranean Sea. It is based on processing of high-resolution seismic reflection data and the interpretation and mapping of seismic reflection profiles collected from this area during the 2001 and 2007 research cruises. The data show that the greater Anaximander Mountains region experienced a short interval of tectonic quiescence during the Messinian when a thin evaporite unit was deposited across a major erosional surface. This phase of limited tectonic activity ended in the latest Miocene and was replaced by an erosional phase. Major unconformities in the area are interpreted to develop during the desiccation of the eastern Mediterranean associated with the so-called Messinian salinity crisis. During the early Pliocene, the region experienced an increase in tectonic activity, dominated by transpression. Small amounts of growth observed in Pliocene-Quaternary sediments suggested that the tectonic activity remained low during the early Pliocene-Quaternary. However, the extensive growth strata wedges developed in older sediments indicate a period of accelerated tectonic activity during the mid-late Pliocene-Quaternary. This study suggests that the Anaximander Mountain (sensu stricto ) and the Anaximenes Mountain developed during the Pliocene-Quaternary as the result of a crustal-scale thick-skinned linked imbricate thrust fan. The development of back thrusts in both mountains heightened the seafloor morphology of these submarine mountains and brought Eocene-Oligocene sediments into the core of these mountains. The Sim Erinc Plateau represents a 30-40 km wide transpressional fault zone developed during the Pliocene-Quaternary. In this region the corrugated seafloor morphology observed in the multibeam bathymetry map is the reflection of high-angle faults. It is speculated that this transpressional fault zone

  6. Aerosol direct effect on solar radiation over the eastern Mediterranean Sea based on AVHRR satellite measurements

    Science.gov (United States)

    Georgakaki, Paraskevi; Papadimas, Christos D.; Hatzianastassiou, Nikos; Fotiadi, Aggeliki; Matsoukas, Christos; Stackhouse, Paul; Kanakidou, Maria; Vardavas, Ilias M.

    2017-04-01

    Despite the improved scientific understanding of the direct effect of aerosols on solar radiation (direct radiative effect, DRE) improvements are necessary, for example regarding the accuracy of the magnitude of estimated DREs and their spatial and temporal variability. This variability cannot be ensured by in-situ surface and airborne measurements, while it is also relatively difficult to capture through satellite observations. This becomes even more difficult when complete spatial coverage of extended areas is required, especially concerning areas that host various aerosol types with variable physico-chemical and optical aerosol properties. Better assessments of aerosol DREs are necessary, relying on aerosol optical properties with high spatial and temporal variation. The present study aims to provide a refined, along these lines, assessment of aerosol DREs over the eastern Mediterranean (EM) Sea, which is a key area for aerosol studies. Daily DREs are computed for 1˚ x1˚ latitude-longitude grids with the FORTH detailed spectral radiation transfer model (RTM) using input data for various atmospheric and surface parameters, such as clouds, water vapor, ozone and surface albedo, taken from the NASA-Langley Global Earth Observing System (GEOS) database. The model spectral aerosol optical depth (AOD), single scattering albedo and asymmetry parameter are taken from the Global Aerosol Data Set and the NOAA Climate Data Record (CDR) version 2 of Advanced Very High resolution Radiometer (AVHRR) AOD dataset which is available over oceans at 0.63 microns and at 0.1˚ x0.1˚ . The aerosol DREs are computed at the surface, the top-of-atmosphere and within the atmosphere, over the period 1985-1995. Preliminary model results for the period 1990-1993 reveal a significant spatial and temporal variability of DREs over the EM Sea, for example larger values over the Aegean and Black Seas, surrounded by land areas with significant anthropogenic aerosol sources, and over the

  7. Indian Monsoon and denitrification change in the Laxmi Basin (IODP Exp. 355 Site U1456) of the Eastern Arabian Sea during the last 800 kyrs

    Science.gov (United States)

    Kim, J. E.; Khim, B. K.; Ikehara, M.; Lee, J.

    2017-12-01

    The Arabian Sea is a famous site for the basin-wide denitrification in the globe. The Western Arabian Sea has been acknowledged by its upwelling-induced denitrification related to the Indian Monsoon system (Altabet et al., 1999). It was recently reported that the denitrification in the Eastern Arabian Sea (IODP Exp. 355 Site U1456) has been persistent and consistent during the mid-Pleistocene as reflected in the bulk sediment δ15N values (Tripathi et al., 2017). Based on the age model reconstructed by δ18O stratigraphy of planktonic foraminifera (Globigerinoides ruber) together with shipboard biostratigraphic and paleomagnetic data at Site U1456 drilled in the Laxmi Basin of the Eastern Arabian Sea, the glacial-interglacial fluctuations of denitrification in association with the development of oxygen minimum zone (OMZ) were resolved in the context of Indian Monsoon activity. One of striking features in the Eastern Arabian Sea is that the δ15N values of bulk sediment show clear and consistent denitrification with minimum δ15N values exceeding 6‰ even during glacial periods, when its western counterpart experienced a temporal collapse of OMZ and denitrification. The Eastern Arabian Sea is fed not only by the upwelling-induced productivity in the western margin during the summer monsoon but also by the high productivity during the winter monsoon, both of which maintain the increased productivity affecting the OMZ through the consumption of dissolved oxygen by the degradation of sinking organic particles. The Eastern Arabian Sea is further influenced by the clockwise surface currents, intermediate water ventilation change by the blockage of Antarctic Intermediate Water, limited inflow from the Red Sea/Persian Gulf, and the freshwater salinity stratification due to nearby riverine discharges, all of which make the denitrification process more complicated than the Western Arabian Sea. Nonetheless, the glacial-interglacial denitrification change in the Eastern

  8. On the forcing mechanisms of mesocyclones in the eastern Weddell Sea region, Antarctica: Process studies using a mesoscale numerical model

    Directory of Open Access Journals (Sweden)

    Thomas Klein

    2001-04-01

    Full Text Available Development mechanisms of Antarctic mesocyclones in the eastern Weddell Sea area are examined by means of simulations with a mesoscale model using different idealized initial conditions. In one of the experiments, a mesocyclone develops over an area of open water close to the coast of the Antarctic continent. The forcing mechanisms of this mesocyclogenesis are investigated by means of sensitivity studies in which certain physical processes and the relevance of the surface conditions topography, sea surface temperature and sea ice coverage are examined. The sensitivity experiments show that the simulated mesocyclone is forced by an interaction of several forcing mechanisms at different stages of the development rather than by a single mechanism. The topography of the eastern Weddell Sea region and the summertime coastal polynia are shown to be of great importance for the mesocyclogenesis. A suitable synoptic-scale flow is necessary to support the katabatic flow over the sloped ice sheet, and to enhance the generation of cyclonic vorticity due to vertical stretching for the initial mesocyclogenesis. The diabatic process of the convergence of the sensible and latent heat fluxes in the boundary layer over the coastal polynia then becomes the dominant forcing mechanism for the further development of the mesocyclone.

  9. Secular painting in the Ionian islands and Italian art: Aspects of a multi-faceted relationship

    Directory of Open Access Journals (Sweden)

    Aphrodite Kouria

    2017-02-01

    Full Text Available The contribution of Italian art, especially Venetian, was decisive to the secularisation of art in the Ionian Islands and the shaping of the so-called Ionian School, in the context of a broader Western influence affecting all aspects of life and culture, especially on the islands of Zakynthos and Corfu. Italian influences, mainly of Renaissance, Mannerism and Baroque art, can be identified both on the iconographic and the stylistic level of artworks, with theoretical support. This article explores facets of the dialogue of secular painting in the Ionian with Italian art in the eighteenth and nineteenth centuries, focussing on works and artists that highlight significant aspects of this multilayered phenomenon and also through secondary channels that expand the horizon of analysis. Procession paintings, with their various connotations, and portraiture, which flourished in secular Ionian art, offer the most interesting material as regards the selection, reception and management of Italian models and points of reference.

  10. Last Interglacial (Eemian) hydrographic conditions in the south-eastern Baltic Sea, NE Europe, based on dinoflagellates and pollen

    DEFF Research Database (Denmark)

    Head, Martin J.; Seidenkrantz, Marit Solveig Louise Schramm; Janczyk-Kopikowa, Zofia

    2005-01-01

    of arctic waters. Warm and saline conditions of 15–20 psu or more, at least twice present levels, persisted throughout the early Eemian. A rise in sea level at Licze appears to correlate with a similar event in eastern Denmark, as both coincide with the increase in Corylus (ca. 750 years...... into the interglacial). This sea-level rise might therefore have a basinwide extent, and has been attributed to an opening of the Danish Belts. Whereas dinoflagellate cysts reflect sustained high salinites within the upper water column, a concomitant increase in abundance of the chlorococcalean alga Pediastrum within......A rich organic-walled dinoflagellate cyst and pollen record from the Licze borehole in northern Poland has been used to reconstruct the hydrographic history of the southeastern Baltic Sea during the Eemian Stage (Last Interglacial) of the Upper Pleistocene. Warm and saline waters (ca. 10–15 psu...

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

    Science.gov (United States)

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

    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.

  12. 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.

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

    KAUST Repository

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

    2015-01-01

    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.

  14. Ensemble-based evaluation of extreme water levels for the eastern Baltic Sea

    Science.gov (United States)

    Eelsalu, Maris; Soomere, Tarmo

    2016-04-01

    The risks and damages associated with coastal flooding that are naturally associated with an increase in the magnitude of extreme storm surges are one of the largest concerns of countries with extensive low-lying nearshore areas. The relevant risks are even more contrast for semi-enclosed water bodies such as the Baltic Sea where subtidal (weekly-scale) variations in the water volume of the sea substantially contribute to the water level and lead to large spreading of projections of future extreme water levels. We explore the options for using large ensembles of projections to more reliably evaluate return periods of extreme water levels. Single projections of the ensemble are constructed by means of fitting several sets of block maxima with various extreme value distributions. The ensemble is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. A hindcast by the Rossby Centre Ocean model is sampled with a resolution of 6 h and a similar hindcast by the circulation model NEMO with a resolution of 1 h. As the annual maxima of water levels in the Baltic Sea are not always uncorrelated, we employ maxima for calendar years and for stormy seasons. As the shape parameter of the Generalised Extreme Value distribution changes its sign and substantially varies in magnitude along the eastern coast of the Baltic Sea, the use of a single distribution for the entire coast is inappropriate. The ensemble involves projections based on the Generalised Extreme Value, Gumbel and Weibull distributions. The parameters of these distributions are evaluated using three different ways: maximum likelihood method and method of moments based on both biased and unbiased estimates. The total number of projections in the ensemble is 40. As some of the resulting estimates contain limited additional information, the members of pairs of projections that are highly correlated are assigned weights 0.6. A comparison of the ensemble-based projection of

  15. Estimates of Eastern Equatorial Pacific Sea Surface Temperatures During the Pliocene From Carbonate 'Clumped Isotope' Thermometry

    Science.gov (United States)

    Thiagarajan, N.; Tripati, A.; Eiler, J.

    2007-12-01

    The early Pliocene (5 to 3 Ma) was an interval in Earth history that was globally warmer than the present; thus, study of the details of Pliocene climate can provide insights into the dynamics of warm climates. There are two competing models of the temperature structure of the tropical Pacific upper-ocean during the early Pliocene: the dynamical 'ocean thermostat' model [1,2] and the 'El Padre' (or permanent 'El Nino') model [3], each of which predict zonal temperature gradients and mean conditions in the Eastern Equatorial Pacific (EEP), and which differ markedly from one another in these predictions. The dynamical 'ocean thermostat' model predicts an increased temperature contrast between the Western Equatorial Pacific (WEP) and EEP, enhanced thermocline tilt and intensified upwelling under warmer conditions. In contrast, the 'El Padre' model postulates a collapse of the zonal temperature gradient, reduced thermocline tilt and a reduction in upwelling and/or warmer temperatures of upwelled waters. Existing reconstructions of tropical temperatures produce WEP sea surface temperatures which agree with each other, but yield very different results in the EEP [4,5]. We have reconstructed EEP sea surface temperatures at Ocean Drilling Program (ODP) Site 847 using a few samples spanning key intervals of the last 6 million years using carbonate clumped isotope thermometer [6,7,8]. This technique is based on the temperature dependence of the abundances of 13C-18O bonds in carbonate minerals. Initial measurements of planktonic foraminifera and coccoliths from ODP Site 847 indicate cool EEP sea surface temperatures, supporting models of Pliocene climate that have enhanced zonal temperature gradients, relative to modern. Analyses of Globigerinoides sacculifer (with sac) from sediments indicate calcification temperatures of 20.3°C ± 0.1°C and seawater δ18O values of -0.8‰ ± 0.1‰ from ~6.1 to 5.1 million years ago. Measurements of a mixed coccolith assemblage from the

  16. Sightings of Delphinus delphis (Cetacea, Odontoceti in the Otranto Channel (Southern Adriatic Sea and Northern Ionian Sea / Avvistamenti di Delphinus delphis (Cetacea, Odontoceti nel Canale d'Otranto (Mar Adriatico Meridionale e Mar Ionio Settentrionale

    Directory of Open Access Journals (Sweden)

    Francesco Maria Angelici

    1992-07-01

    Full Text Available Abstract Two sightings of Common dolphin Delphinus delphis in the Channel of Otranto are reported, and the status of this species in the Mediterranean Sea is briefly discussed. Riassunto Sono riportati due avvistamenti di Delfino comune Delphinus delphis nel Canale d'Otranto, lungo la costa greca e quella italiana. Viene inoltre brevemente commentata la frequenza degli avvistamenti e degli spiaggiamenti di tale specie nel Mar Mediterraneo.

  17. Preserved Crevasse Casts in the Whales Deep Basin, eastern Ross Sea

    Science.gov (United States)

    Bart, P. J.; Tulaczyk, S. M.

    2017-12-01

    A recent seismic stratigraphic study showed that the large bathymetric saddle in the Whales Deep Basin in eastern Ross Sea is a compound grounding zone wedge (CGZW). The basin was occupied by the paleo Bindschadler Ice Stream when grounded ice advanced to the outer continental shelf during the last glacial maximum (LGM). The CGZW is composed of at least seven overlapping GZWs. The crest of the bathymetric saddle corresponds to the grounding zone of GZW7, i.e., the seventh GZW. The north face of the saddle is essentially equivalent to the GZW7 foreset and the south side of the saddle is the GZW7 topset, i.e., the seafloor surface to which the paleo Bindschadler Ice Stream was grounded. The GZW7 topset is mantled by a series of relatively small-amplitude, but very long, ridges with low sinuosity. These ridges were previously imaged by Mosola and Anderson (2006). Here we show a larger-area multibeam survey that was acquired in 2015 during expedition NBP1502B. The larger-area multibeam survey shows that the ridges have amplitudes ranging from 2 to 11 m above grade and have an overall northeast-southwest orientation over an area of at least 500 km2 on the central and western flank of Whales Deep Basin middle continental shelf in water depths ranging from 500 to 550 m. The ridges have spacing that mostly range between 1 and 2 km. The longest ridges are observed to be 40 km. The ridges in the center of the trough have flatter tops than those in the shallower water on the flank of Houtz Bank. In our ongoing investigation of these interesting features, we hypothesize that the ridges formed below a rapidly flowing ice stream as it thinned and was decoupling from the bed towards the end of GZW7 deposition. High ice deformation rates accompanying this process caused the development of large basal crevasses or ice shelf rifts that reached the seafloor. Subglacial till was scraped and collected into lower parts of these crevasses/rifts. Chronologic data indicates that these

  18. Mesopelagic Prokaryotes Alter Surface Phytoplankton Production during Simulated Deep Mixing Experiments in Eastern Mediterranean Sea Waters

    Directory of Open Access Journals (Sweden)

    Or Hazan

    2018-01-01

    Full Text Available Mesopelagic prokaryotes (archaea and bacteria, which are transported together with nutrient-rich intermediate-water to the surface layer by deep convection in the oceans (e.g., winter mixing, upwelling systems, can interact with surface microbial populations. This interaction can potentially affect production rates and biomass of surface microbial populations, and thus play an important role in the marine carbon cycle and oceanic carbon sequestration. The Eastern Mediterranean Sea (EMS is one of the most oligotrophic and warm systems in the world's oceans, with usually very shallow winter mixing (<200 m and lack of large-size spring algal blooms. In this study, we collected seawater (0–1,500 m in 9 different cruises at the open EMS during both the stratified and the mixed seasons. We show that the EMS is a highly oligotrophic regime, resulting in low autotrophic biomass and primary productivity and relatively high heterotrophic prokaryotic biomass and production. Further, we simulated deep water mixing in on-board microcosms using Levantine surface (LSW, ~0.5 m and intermediate (LIW, ~400 m waters at a 9:1 ratio, respectively and examined the responses of the microbial populations to such a scenario. We hypothesized that the LIW, being nutrient-rich (e.g., N, P and a “hot-spot” for microbial activity (due to the warm conditions that prevail in these depths, may supply the LSW with not only key-limiting nutrients but also with viable and active heterotrophic prokaryotes that can interact with the ambient surface microbial population. Indeed, we show that LIW heterotrophic prokaryotes negatively affected the surface phytoplankton populations, resulting in lower chlorophyll-a levels and primary production rates. This may be due to out-competition of phytoplankton by LIW populations for resources and/or by a phytoplankton cell lysis via viral infection. Our results suggest that phytoplankton in the EMS may not likely form blooms, even after

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Looking for evidence of climate change impacts in the eastern Irish Sea

    Directory of Open Access Journals (Sweden)

    L. S. Esteves

    2011-06-01

    Full Text Available Although storminess is often cited as a driver of long-term coastal erosion, a lack of suitable datasets has only allowed objective assessment of this claim in a handful of case studies. This reduces our ability to understand and predict how the coastline may respond to an increase in "storminess" as suggested by global and regional climate models. With focus on 16 km of the Sefton coastline bordering the eastern Irish Sea (UK, this paper analyses available measured datasets of water level, surge level, wave height, wind speed and barometric pressure with the objective of finding trends in metocean climate that are consistent with predictions. The paper then examines rates of change in shoreline position over the period 1894 to 2005 with the aim of establishing relationships with climatic variability using a range of measured and modelled metocean parameters (with time spans varying from two to eight decades. With the exception of the mean monthly wind speed, available metocean data do not indicate any statistically significant changes outside seasonal and decadal cycles. No clear relationship was found between changes in metocean conditions and rates of shoreline change along the Sefton coast. High interannual variability and the lack of long-term measurements make unambiguous correlations between climate change and shoreline evolution problematic. However, comparison between the North Atlantic Oscillation winter index (NAOw and coastline changes suggest increased erosion at times of decreasing NAOw values and reduced erosion at times of increasing NAOw values. Erosion tends to be more pronounced when decreasing NAOw values lead to a strong negative NAO phase. At present, anthropogenic changes in the local sediment budget and the short-term impact of extreme events are still the largest threat likely to affect coastal flooding and erosion risk in the short- and medium-term. Nevertheless, the potential impacts of climate change in the long

  2. Acoustic insights into the zooplankton dynamics of the eastern Weddell Sea

    Science.gov (United States)

    Cisewski, Boris; Strass, Volker H.

    2016-05-01

    The success of any efforts to determine the effects of climate change on marine ecosystems depends on understanding in the first instance the natural variations, which contemporarily occur on the interannual and shorter time scales. Here we present results on the environmental controls of zooplankton distribution patterns and behaviour in the eastern Weddell Sea, Southern Ocean. Zooplankton abundance and vertical migration are derived from the mean volume backscattering strength (MVBS) and the vertical velocity measured by moored acoustic Doppler current profilers (ADCPs), which were deployed simultaneously at 64°S, 66.5°S and 69°S along the Greenwich Meridian from February, 2005, until March, 2008. While these time series span a period of full three years they resolve hourly changes. A highly persistent behavioural pattern found at all three mooring locations is the synchronous diel vertical migration (DVM) of two distinct groups of zooplankton that migrate between a deep residence depth during daytime and a shallow depth during nighttime. The DVM was closely coupled to the astronomical daylight cycles. However, while the DVM was symmetric around local noon, the annual modulation of the DVM was clearly asymmetric around winter solstice or summer solstice, respectively, at all three mooring sites. DVM at our observation sites persisted throughout winter, even at the highest latitude exposed to the polar night. Since the magnitude as well as the relative rate of change of illumination is minimal at this time, we propose that the ultimate causes of DVM separated from the light-mediated proximal cue that coordinates it. In all three years, a marked change in the migration behaviour occurred in late spring (late October/early November), when DVM ceased. The complete suspension of DVM after early November is possibly caused by the combination of two factors: (1) increased availability of food in the surface mixed layer provided by the phytoplankton spring bloom, and

  3. GHRSST Level 4 ODYSSEA Eastern Central Pacific Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  4. Extending the Instrumental Record of Sea-Level Change: A 1300-Year Sea-Level Record From Eastern Connecticut

    Science.gov (United States)

    Donnelly, J. P.; Cleary, P.

    2002-12-01

    The instrumental record of sea-level change in the northeastern United States extends back to the early 20th century and at New York City (NYC) extends back to 1856. These tide gauge records indicate that sea level has risen at a rate of 2.5 to 4 mm/year over the last 100-150 years. Geologic evidence of sea-level change in the region over the last 2,000 years indicates rates of sea-level rise of about 1 mm/year or less. The discordance between the instrumental and geologic records is frequently cited as potentially providing evidence that anthropogenic warming of the climate system has resulted in an increase in the rate of sea-level rise. In order to begin to test the hypothesis that acceleration in the rate of sea-level rise has occurred in the last 150 years due to anthropogenic climate warming, accurate and precise information on the timing of the apparent acceleration in sea-level rise are needed. Here we construct a high-resolution relative sea-level record for the past 1350 years by dating basal salt marsh peat samples above a glacial erratic in a western Connecticut salt marsh. Preservation of marsh vegetation remains in the sediment record that has a narrow vertical habitat range at the upper end of the tidal range provides information on past sea levels. { \\it Spartina patens} (marsh hay) and { \\it Juncus gerardi} (black rush) dominate both the modern marsh and their remains are the major constituent of the marsh sediments and occur in the modern marsh between mean high water (MHW) and mean highest high water. We use the elevation distribution of modern plant communities to estimate the relationship of sediment samples to paleo-mean high water. The chronology is based on 15 radiocarbon ages, supplemented by age estimates derived from the horizons of industrial Pb pollution and pollen indicative of European land clearance. Thirteen of the radiocarbon ages and the Pb and pollen data come from samples taken along a contact between marsh peat and a glacial

  5. Assessment of MODIS-Aqua chlorophyll-a algorithms in coastal and shelf waters of the eastern Arabian Sea

    Science.gov (United States)

    Tilstone, Gavin H.; Lotliker, Aneesh A.; Miller, Peter I.; Ashraf, P. Muhamed; Kumar, T. Srinivasa; Suresh, T.; Ragavan, B. R.; Menon, Harilal B.

    2013-08-01

    The use of ocean colour remote sensing to facilitate the monitoring of phytoplankton biomass in coastal waters is hampered by the high variability in absorption and scattering from substances other than phytoplankton. The eastern Arabian Sea coastal shelf is influenced by river run-off, winter convection and monsoon upwelling. Bio-optical parameters were measured along this coast from March 2009 to June 2011, to characterise the optical water type and validate three Chlorophyll-a (Chla) algorithms applied to Moderate Resolution Imaging Spectroradiometer on Aqua (MODIS-Aqua) data against in situ measurements. Ocean Colour 3 band ratio (OC3M), Garver-Siegel-Maritorena Model (GSM) and Generalized Inherent Optical Property (GIOP) Chla algorithms were evaluated. OC3M performed better than GSM and GIOP in all regions and overall, was within 11% of in situ Chla. GSM was within 24% of in situ Chla and GIOP on average was 55% lower. OC3M was less affected by errors in remote sensing reflectance Rrs(λ) and by spectral variations in absorption coefficient (aCDOM(λ)) of coloured dissolved organic material (CDOM) and total suspended matter (TSM) compared to the other algorithms. A nine year Chla time series from 2002 to 2011 was generated to assess regional differences between OC3M and GSM. This showed that in the north eastern shelf, maximum Chla occurred during the winter monsoon from December to February, where GSM consistently gave higher Chla compared to OC3M. In the south eastern shelf, maximum Chla occurred in June to July during the summer monsoon upwelling, and OC3M yielded higher Chla compared to GSM. OC3M currently provides the most accurate Chla estimates for the eastern Arabian Sea coastal waters.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. 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

  9. Study of dissolved oxygen content in the Eastern Bosporus Strait (Peter the Great Bay, Sea of Japan)

    Science.gov (United States)

    Grigoryeva, N. I.

    2017-09-01

    Seasonal changes in the dissolved oxygen (DO) content in water were analyzed based on long-term observations (2006-2013) in the Eastern Bosporus Strait (Peter the Great Bay, Sea of Japan). It was found that the monthly average DO concentrations at the bottom of the strait were significantly lower in summer than the average annual long-term data. The minimum DO contents were recorded during four months, from July to October. It was shown that the DO content in water depended on changes in current directions in the strait: lower DO contents resulted from hypoxic water inflow, mostly from Amur Bay.

  10. Short-term variability in halocarbons in relation to phytoplankton pigments in coastal waters of the central eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Roy, R.

    The sampling locations, along the Candolim Time-Series Section (CaTS), in coastal waters of the eastern Arabian Sea, are shown in Fig. 1. Water depth at these stations varied between 6 m (G1) and 28 m (G5) whereas samples at G5 were generally collected from a... times. 6 3. Results The short-term variability of halocarbons and pigments has been presented for CaTS station G5, with a brief on hydrography. However, data from stations G1- G4 have been used to derive statistically significant relationships among...

  11. Seasonality of Reproduction and Embryonic Growth of Spiny Dogfish (Squalus acanthias L., 1758) in the Eastern Black Sea

    OpenAIRE

    DEMİRHAN, Sefa Ayhan; SEYHAN, Kadir

    2006-01-01

    The seasonality of reproduction and embryonic development of spiny dogfish (Squalus acanthias) sampled from the Eastern Black Sea were studied. The gestation period of spiny dogfish, starting in August, September and October, takes around 23-24 months. Fertilized females were caught at a depth of 30-45 m in July and August. Females with full-term pups and empty uteri were found at 50-60 m depth, where the temperature was 10 °C. Lengths of pups at birth were around 28-29 cm, whereas their weig...

  12. Decapod crustaceans on the Gökçeada (Imbros island continental shelf (north-eastern Aegean Sea

    Directory of Open Access Journals (Sweden)

    A.S. ATES

    2006-12-01

    Full Text Available The present composition of decapod crustaceans found at the sublittoral depths (5-104 m off the coast of the island of Gökçeada (north-eastern Aegean Sea is presented. A total of 28 species (11 caridean shrimps, 1 thalassinid ghost crab, 7 anomurans and 9 brachyuran crabs and 277 specimens were recorded. The caridean shrimp, Athanas nitescens had the highest abundance with a dominance value of 20.94% in samples. The dominant group is caridean, represented by a total of 11 species and an occurrence frequency of 39.29%.

  13. Inter-cohort growth patterns of pharaoh cuttlefish Sepia pharaonis (Sepioidea: Sepiidae in Eastern Arabian Sea

    Directory of Open Access Journals (Sweden)

    Geetha Sasikumar

    2013-03-01

    Full Text Available Sepia pharaonis is an important commercial species endemic to the tropical Indo-Pacific region. Despite its commercial significance, only few information on natural populations is available. This study was aimed to describe the aspects of size-composition, length-weight relationship, catch rates, seasonal recruitment and inter-cohort growth patterns of S. pharaonis population (Clade C, distributed along the Eastern Arabian Sea (South-West coast of India. For this, the Dorsal Mantle Length (DML and weight of cuttlefishes was obtained from commercial trawl catches, from April 2002 to October 2006. Data was analyzed by normal length-weight methods such as von Bertalanffy. A total of 12 454 cuttlefishes, ranging in length from four to 41cm were analyzed. Size-composition patterns discriminated two pulses in recruitment to the fishery, discernible by a decrease in the monthly mean size of the population. The DMLs of the two seasonal cohorts were subjected to modalprogression analysis using the Bhattacharya’s method for the estimation of growth. The estimated parameters L∞ and K in von Bertalanffy Growth Function (VBGF were used to model growth curves in length for the cohorts. The first cohort, (post-monsoon cohort which supports the major fishery, was composed of mediumsized, fast growing individuals, whereas the second cohort (pre-monsoon cohort, comprised of slow growing and large-sized individuals. There were differential growth characteristics between the sexes and the life span was estimated at less than 2.3years for males and 2.1years for females. Negative allometric growth in weight (W with length (L was observed for males (W=0.33069.L2.5389 and females (W=0.32542.L2.6057. The females were heavier compared to males at any given mantle length, and the males were found to attain larger ultimate lengths. The major fishing season for cuttlefish was from May to November, when higher monthly catch rates of 1.67-13.02kg/h were observed in

  14. Inter-cohort growth patterns of pharaoh cuttlefish Sepia pharaonis (Sepioidea: Sepiidae) in Eastern Arabian Sea.

    Science.gov (United States)

    Sasikumarl, Geetha; Mohamed, K S; Bhat, U S

    2013-03-01

    Sepia pharaonis is an important commercial species endemic to the tropical Indo-Pacific region. Despite its commercial significance, only few information on natural populations is available. This study was aimed to describe the aspects of size-composition, length-weight relationship, catch rates, seasonal recruitment and inter-cohort growth patterns of S. pharaonis population (Clade C), distributed along the Eastern Arabian Sea (South-West coast of India). For this, the Dorsal Mantle Length (DML) and weight of cuttlefishes was obtained from commercial trawl catches, from April 2002 to October 2006. Data was analyzed by normal length-weight methods such as von Bertalanffy. A total of 12454 cuttlefishes, ranging in length from four to 41cm were analyzed. Size-composition patterns discriminated two pulses in recruitment to the fishery, discernible by a decrease in the monthly mean size of the population. The DMLs of the two seasonal cohorts were subjected to modal-progression analysis using the Bhattacharya's method for the estimation of growth. The estimated parameters Linfinity and K in von Bertalanffy Growth Function (VBGF) were used to model growth curves in length for the cohorts. The first cohort, (post-monsoon cohort) which supports the major fishery, was composed of medium-sized, fast growing individuals, whereas the second cohort (pre-monsoon cohort), comprised of slow growing and large-sized individuals. There were differential growth characteristics between the sexes and the life span was estimated at less than 2.3 years for males and 2.1 years for females. Negative allometric growth in weight (W) with length (L) was observed for males (W=0.33069.L2.5389) and females (W=0.32542.L26057). The females were heavier compared to males at any given mantle length, and the males were found to attain larger ultimate lengths. The major fishing season for cuttlefish was from May to November, when higher monthly catch rates of 1.67-13.02kg/h were observed in comparison

  15. Absolute sea levels and isostatic changes of the eastern North Sea to central Baltic region during the last 900 years

    DEFF Research Database (Denmark)

    Hansen, Jens Morten; Aagaard, Troels; Binderup, Merete

    2012-01-01

    that ice-cap growth can be faster than ice-cap melting. By comparison with 29 long-term tide gauge measurements of the region we show that the isostatic implications of the sea-level curve are in nearly perfect agreement with Peltier's global isostatic VM2 model (applied by IPCC and PSMSL) and yield a 3...

  16. Glacial-interglacial vegetation dynamics in South Eastern Africa coupled to sea surface temperature variations in the Western Indian Ocean

    Directory of Open Access Journals (Sweden)

    L. M. Dupont

    2011-11-01

    Full Text Available Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a pollen record of the marine core MD96-2048 retrieved by the Marion Dufresne from the Indian Ocean ∼120 km south of the Limpopo River mouth. The sedimentation at the site is slow and continuous. The upper 6 m (spanning the past 342 Ka have been analysed for pollen and spores at millennial resolution. The terrestrial pollen assemblages indicate that during interglacials, the vegetation of eastern South Africa and southern Mozambique largely consisted of evergreen and deciduous forests. During glacials open mountainous scrubland dominated. Montane forest with Podocarpus extended during humid periods was favoured by strong local insolation. Correlation with the sea surface temperature record of the same core indicates that the extension of mountainous scrubland primarily depends on sea surface temperatures of the Agulhas Current. Our record corroborates terrestrial evidence of the extension of open mountainous scrubland (including fynbos-like species of the high-altitude Grassland biome for the last glacial as well as for other glacial periods of the past 300 Ka.

  17. Microfossils, a Key to Unravel Cold-Water Carbonate Mound Evolution through Time: Evidence from the Eastern Alboran Sea.

    Directory of Open Access Journals (Sweden)

    Claudio Stalder

    Full Text Available Cold-water coral (CWC ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago. However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds Field in the Eastern Alboran Sea with the associated microfauna and we highlight the importance of foraminifera and ostracods as indicators of CWC mound evolution in the paleorecord. Abundances of macrofauna along the core reveal alternating periods dominated by distinct CWC taxa (mostly Lophelia pertusa, Madrepora oculata that correspond to major shifts in foraminiferal and ostracod assemblages. The period dominated by M. oculata coincides with a period characterized by increased export of refractory organic matter to the seafloor and rather unstable oceanographic conditions at the benthic boundary layer with periodically decreased water energy and oxygenation, variable bottom water temperature/density and increased sediment flow. The microfaunal and geochemical data strongly suggest that M. oculata and in particular Dendrophylliidae show a higher tolerance to environmental changes than L. pertusa. Finally, we show evidence for sustained CWC growth during the Alleröd-Younger-Dryas in the Eastern Alboran Sea and that this period corresponds to stable benthic conditions with cold/dense and well oxygenated bottom waters, high fluxes of labile organic matter and relatively strong bottom currents.

  18. Coupled wave and surge modelling for the eastern Irish Sea and implications for model wind-stress

    Science.gov (United States)

    Brown, Jennifer M.; Wolf, Judith

    2009-05-01

    We revisit the surge of November 1977, a storm event which caused damage on the Sefton coast in NW England. A hindcast has been made with a coupled surge-tide-wave model, to investigate whether a wave-dependent surface drag is necessary for accurate surge prediction, and also if this can be represented by an optimised Charnock parameter. The Proudman Oceanographic Laboratory Coastal Modelling System-Wave Model (POLCOMS-WAM) has been used to model combined tides, surges, waves and wave-current interaction in the Irish Sea on a 1.85 km grid. This period has been previously thoroughly studied, e.g. Jones and Davies [Jones, J.E., Davies, A.M., 1998. Storm surge computations for the Irish Sea using a three-dimensional numerical model including wave-current interaction. Continental Shelf Research 18(2), 201-251] and we build upon this previous work to validate the POLCOMS-WAM model to test the accuracy of surge elevation predictions in the study area. A one-way nested approach has been set up from larger scale models to the Irish Sea model. It was demonstrated that (as expected) swell from the North Atlantic does not have a significant impact in the eastern Irish Sea. To capture the external surge generated outside of the Irish Sea a (1/9° by 1/6°) model extending beyond the continental shelf edge was run using the POLCOMS model for tide and surge. The model results were compared with tide gauge observations around the eastern Irish Sea. The model was tested with different wind-stress formulations including Smith and Banke [Smith, S.D., Banke, E.G., 1975. Variation of the surface drag coefficient with wind speed. Quarterly Journal of the Royal Meteorology Society, 101(429), 665-673] and Charnock [Charnock, H., 1955. Wind-stress on a water surface. Quarterly Journal of the Royal Meteorological Society, 81(350), 639-640]. In order to get a single parameterisation that works with wave-coupling, the wave-derived surface roughness length has been imposed in the surge model

  19. The interaction of prehistoric human settlement, sea level change and tectonic uplift of the Coastal Range, eastern Taiwan

    Science.gov (United States)

    Yang, H.; Chen, W. S.

    2017-12-01

    The late Cenozoic mountain belt of Taiwan, resulting from the collision between the Eurasian and Philippine Sea plates, is known for its rapid tectonic uplift. As postglacial sea level rose ca. 15,000 yr ago, the eastern coast of Taiwan, due to the rapid tectonic uplift rate, displayed a totally different scenario comparing with most of the coastal plains around the world. At the beginning of postglacial era, the sea level rising rate was greater than the tectonic uplift rate which induced the original piedmont alluvial fan or coastal plain to be overwhelmed by sea water rapidly. Around 13.5 ka, the tectonic uplift rate caught up with the sea level rising and broad wave-cut platform formed. The approximation of tectonic uplift and sea level rising rates was lasting from 13.5 to 5ka, but shoreline progradation may have been enhanced by increased slope erosion which resulted in the alluvial fan forming at the later time of this period. As soon as the eustasy stabilized, the landmass continued to uplift which might have enhanced the river incising and wave erosion rapidly. Therefore the topographic expression along the eastern fringing of Coastal Range forms extended alluvial-fan, stream, and marine terraces and are covered by late Holocene colluvium and marine deposits. 88 archaeological sites were chosen in this study based on surface survey where the archaeological chronology of cultural stage is established primarily through examining pottery series and associated manual excavation. It is interesting that most of the archaeological sites were located on the alluvial fan although the Holocene marine terraces have formed after 5ka. There are no clear evidences to support a shore-oriented settlement, but the abundant alluvial depositional structures observed from the overlaying formation reveals the stream depositional system was still active at this time. If the Neolithic people wanted to come to the "new born" coastal region for the abundant ocean resources, they

  20. Water masses, ocean fronts, and the structure of Antarctic seabird communities: putting the eastern Bellingshausen Sea in perspective

    Science.gov (United States)

    Ribic, Christine A.; Ainley, David G.; Ford, R. Glenn; Fraser, William R.; Tynan, Cynthia T.; Woehler, Eric J.

    2015-01-01

    Waters off the western Antarctic Peninsula (i.e., the eastern Bellingshausen Sea) are unusually complex owing to the convergence of several major fronts. Determining the relative influence of fronts on occurrence patterns of top-trophic species in that area, therefore, has been challenging. In one of the few ocean-wide seabird data syntheses, in this case for the Southern Ocean, we analyzed ample, previously collected cruise data, Antarctic-wide, to determine seabird species assemblages and quantitative relationships to fronts as a way to provide context to the long-term Palmer LTER and the winter Southern Ocean GLOBEC studies in the eastern Bellingshausen Sea. Fronts investigated during both winter (April–September) and summer (October–March) were the southern boundary of the Antarctic Circumpolar Current (ACC), which separates the High Antarctic from the Low Antarctic water mass, and within which are embedded the marginal ice zone and Antarctic Shelf Break Front; and the Antarctic Polar Front, which separates the Low Antarctic and the Subantarctic water masses. We used clustering to determine species' groupings with water masses, and generalized additive models to relate species' densities, biomass and diversity to distance to respective fronts. Antarctic-wide, in both periods, highest seabird densities and lowest species diversity were found in the High Antarctic water mass. In the eastern Bellingshausen, seabird density in the High Antarctic water mass was lower (as low as half that of winter) than found in other Antarctic regions. During winter, Antarctic-wide, two significant species groups were evident: one dominated by Adélie penguins (Pygoscelis adeliae) (High Antarctic water mass) and the other by petrels and prions (no differentiation among water masses); in eastern Bellingshausen waters during winter, the one significant species group was composed of species from both Antarctic-wide groups. In summer, Antarctic-wide, a High Antarctic group

  1. Sea-to-air and diapycnal nitrous oxide fluxes in the eastern tropical North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    A. Kock

    2012-03-01

    Full Text Available Sea-to-air and diapycnal fluxes of nitrous oxide (N2O into the mixed layer were determined during three cruises to the upwelling region off Mauritania. Sea-to-air fluxes as well as diapycnal fluxes were elevated close to the shelf break, but elevated sea-to-air fluxes reached further offshore as a result of the offshore transport of upwelled water masses. To calculate a mixed layer budget for N2O we compared the regionally averaged sea-to-air and diapycnal fluxes and estimated the potential contribution of other processes, such as vertical advection and biological N2O production in the mixed layer. Using common parameterizations for the gas transfer velocity, the comparison of the average sea-to-air and diapycnal N2O fluxes indicated that the mean sea-to-air flux is about three to four times larger than the diapycnal flux. Neither vertical and horizontal advection nor biological production were found sufficient to close the mixed layer budget. Instead, the sea-to-air flux, calculated using a parameterization that takes into account the attenuating effect of surfactants on gas exchange, is in the same range as the diapycnal flux. From our observations we conclude that common parameterizations for the gas transfer velocity likely overestimate the air-sea gas exchange within highly productive upwelling zones.

  2. Diversity, abundance and niche differentiation of ammonia-oxidizing prokaryotes in mud deposits of the eastern China marginal seas

    Directory of Open Access Journals (Sweden)

    Shaolan eYu

    2016-02-01

    Full Text Available The eastern China marginal seas are prominent examples of river-dominated ocean margins, whose most characteristic feature is the existence of isolated mud patches on sandy sediments. Ammonia-oxidizing prokaryotes play a crucial role in the nitrogen cycles of many marine environments, including marginal seas. However, few studies have attempted to address the distribution patterns of ammonia-oxidizing prokaryotes in mud deposits of these seas. The horizontal and vertical community composition and abundance of ammonia-oxidizing archaea (AOA and bacteria (AOB were investigated in mud deposits of the South Yellow Sea (SYS and the East China Sea (ECS by using amoA clone libraries and quantitative PCR. The diversity of AOB was comparable or higher in the mud zone of SYS and lower in ECS when compared with AOA. Vertically, surface sediments had generally higher diversity of AOA and AOB than middle and bottom layers. Diversity of AOA and AOB showed significant correlation with latitude. Nitrosopumilus and Nitrosospira lineages dominated AOA and AOB communities, respectively. Both AOA and AOB assemblages exhibited greater variations across different sites than those among various depths at one site. The abundance of bacterial amoA was generally higher than that of archaeal amoA, and both of them decreased with depth. Niche differentiation, which was affected by dissolved oxygen, salinity, ammonia and silicate (SiO32-, was observed between AOA and AOB and among different groups of them. The spatial distribution of AOA and AOB was significantly correlated with δ15NTN and SiO32-, and nitrate and δ13C, respectively. Both archaeal and bacterial amoA abundance correlated strongly with SiO32-. This study improves our understanding of spatial distribution of AOA and AOB in ecosystems featuring oceanic mud deposits.

  3. Diversity, Abundance, and Niche Differentiation of Ammonia-Oxidizing Prokaryotes in Mud Deposits of the Eastern China Marginal Seas.

    Science.gov (United States)

    Yu, Shaolan; Yao, Peng; Liu, Jiwen; Zhao, Bin; Zhang, Guiling; Zhao, Meixun; Yu, Zhigang; Zhang, Xiao-Hua

    2016-01-01

    The eastern China marginal seas (ECMS) are prominent examples of river-dominated ocean margins, whose most characteristic feature is the existence of isolated mud patches on sandy sediments. Ammonia-oxidizing prokaryotes play a crucial role in the nitrogen cycles of many marine environments, including marginal seas. However, few studies have attempted to address the distribution patterns of ammonia-oxidizing prokaryotes in mud deposits of these seas. The horizontal and vertical community composition and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) were investigated in mud deposits of the South Yellow Sea (SYS) and the East China Sea (ECS) by using amoA clone libraries and quantitative PCR. The diversity of AOB was comparable or higher in the mud zone of SYS and lower in ECS when compared with AOA. Vertically, surface sediments had generally higher diversity of AOA and AOB than middle and bottom layers. Diversity of AOA and AOB showed significant correlation with latitude. Nitrosopumilus and Nitrosospira lineages dominated AOA and AOB communities, respectively. Both AOA and AOB assemblages exhibited greater variations across different sites than those among various depths at one site. The abundance of bacterial amoA was generally higher than that of archaeal amoA, and both of them decreased with depth. Niche differentiation, which was affected by dissolved oxygen, salinity, ammonia, and silicate (SiO[Formula: see text]), was observed between AOA and AOB and among different groups of them. The spatial distribution of AOA and AOB was significantly correlated with δ(15)NTN and SiO[Formula: see text], and nitrate and δ(13)C, respectively. Both archaeal and bacterial amoA abundance correlated strongly with SiO[Formula: see text]. This study improves our understanding of spatial distribution of AOA and AOB in ecosystems featuring oceanic mud deposits.

  4. Retrospective analysis of seasonal ocean growth rates of two sea winter Atlantic Salmon in eastern Maine using historic scales

    Science.gov (United States)

    Izzo, Lisa K.; Zydlewski, Joseph D.

    2017-01-01

    Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout its range, with many populations at the southern extent of the distribution currently extirpated or endangered. While both one sea winter (1SW) and two sea winter (2SW) spawner numbers for the North American stocks have declined since the 1950s, the decline has been most severe in 2SW spawners. The first months at sea are considered a period of high mortality. However, early ocean mortality alone cannot explain the more pronounced decline of 2SW spawners, suggesting that the second year at sea may be more critical than previously thought. Atlantic Salmon scales collected by anglers and the state agency from 1946 to 2013 from five rivers in eastern Maine were used to estimate smolt age and ocean age of returning adults. Additionally, seasonal growth rates of maiden 2SW spawners were estimated using intercirculi measurements and linear back-calculation methods. Generalized linear mixed models (Gaussian family, log link function) were used to investigate the influence of average sea surface temperature, accumulated thermal units, the Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation indices, smolt age, smolt length, postsmolt growth, and river of origin on growth rate during the oceanic migration of North American Atlantic Salmon. Results suggest that different factors influence salmon growth throughout their oceanic migration, and previous growth can be a strong predictor of future size. Growth was negatively impacted by the phase of the AMO, which has been linked to salmon abundance trends, in early spring following the postsmolt period. This is likely when the 1SW and 2SW stock components separate, and our results suggest that this period may be of interest in future work examining the disproportionate decline in 2SW spawners.

  5. ENSO signals on sea-surface salinity in the eastern tropical pacific ocean

    Directory of Open Access Journals (Sweden)

    1998-01-01

    types collected in the tropical Pacific are analyzed to assess the regional impacts of past (1972-1996 El Niño Southern Oscillation (ENSO events. Focus is made on the regional changes in sea-surface temperature and salinity. Commercial vessels were recently equipped with automated thermosalinographs which allows to monitor the location of salinity front along the Panama-Tahiti line, separating the Panama Gulf from the South Pacific water masses. The latitudinal change of the salinity front is well correlated with the latitudinal change of the ITCZ. Salinity distribution gives additional information on El-Niño development. How future real time SSS data might provide interesting information on the development of ENSO phenomenon in the eastern tropical Pacific area will be discussed.

  6. Small river plumes near the north-eastern coast of the Black Sea under climatic mean and flooding discharge conditions

    Science.gov (United States)

    Osadchiev, Alexander; Korshenko, Evgeniya

    2017-04-01

    The study is focused on the impact of discharge from small rivers on propagation and final location of fluvial waters and suspended matter at the north-eastern part of the Black Sea under different local precipitation conditions. Several dozens of mountainous rivers inflow into the sea at the studied region and most of them, except the several largest of them, have small annual runoff and limitedly affect adjacent coastal waters under climatic mean conditions. However, discharges of these small rivers are characterized by quick response to precipitation events and can dramatically increase during and shortly after heavy rains, which are frequent in the area under consideration. Propagation and final location of fluvial waters and terrigenous sediments at the studied region under climatic mean and rain-induced flooding conditions were explored and compared using in situ data, satellite imagery and numerical modelling. It was shown that the point-source spread of continental discharge dominated by several large rivers during climatic mean conditions can change to the line-source discharge from numerous small rivers situated along the coast in response to heavy rains. Intense line-source runoff of water and suspended sediments form a geostrophic alongshore current of turbid and freshened water, which induces intense transport of suspended and dissolved constituents discharged with river waters in a north-western direction. This process significantly influences water quality and causes active sediment load at large segments of narrow shelf at the north-eastern part of the Black Sea as compared to climatic mean discharge conditions.

  7. Qualitative and quantitative composition of microplastics particles during the expeditionary measurement program in the South-Eastern Baltic Sea

    Science.gov (United States)

    Esiukova, Elena; Bagaeva, Margarita; Chubarenko, Natalia

    2016-04-01

    According to the tasks of the Russian Science Foundation project "Physical and dynamical properties of marine microplastics particles and their transport in a basin with vertical and horizontal salinity gradient on the example of the Baltic Sea" number 15-17-10020, a comprehensive expeditionary program of measurements in the South-Eastern Baltic started. The project is aimed at finding solutions for a number of problems caused by superfluous plastic pollution in the World Ocean and, in particular, in the Baltic Sea. This pollution has been accumulating for years and just recently it has become obvious that only multidisciplinary approach (geographical, biological, chemical, etc.) to the issues related to the processes of transformation of properties and propagation of plastic particles will allow the study of physical aspects of the problem. During the first stage of the study samples should be selected from the water surface, water column at various horizons, bottom sediments in the Baltic Sea, from different areas at the beaches - in order to further examine the qualitative and quantitative composition of microplastic particles in different seasons for different hydrophysical situations. Reconnaissance survey was begun to choose the fields for research close to point and distributed sources of microplastics. Preference is given to those beaches that are exposed to maximum anthropogenic pollution: areas around the town of Baltiysk, the northern part of the Vistula Spit (near the settlement of Kosa), and the Sambia peninsula coast (settlements of Yantarny, Donskoye, Primorye, Kulikovo, towns of Svetlogorsk, Pionersky, Zelenogradsk). Locations for experimental sites were found in order to assess time for formation of microplastics (Vistula Spit, Kosa settlement). In June-November, 2015 there were 5 expeditions in the waters of the South-Eastern Baltic, 7 expeditions along the coast line of the Baltic Sea (in Kaliningrad Oblast), and 5 expeditions to the Vistula

  8. Comparative Morphometric Analysis of the Smallscaled Scorpionfish, Scorpaena Porcus (Scorpaenidae, Scorpaeniformes, from the Southern Coast of the Crimea and Eastern Part of the Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Manilo L. G.

    2016-12-01

    Full Text Available Comparative analysis of morphometric characters of small-scaled scorpionfish from the Black Sea (near the southern coast of the Crimea and from the eastern part of the Adriatic Sea showed significant differences in males and females on thirteen plastic and three meristic characters. These differences may be due to unequal abiotic and biotic habitat conditions, and refer about the geographical variability of the species, indicating the presence of two different populations in the study area.

  9. Monsoonal reversal of remote sensing biases in latent heat flux over eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Pankajakshan, T.; Sathe, P.V.; Murty, V.S.N.; Santosh, K.R.

    The Arabian Sea is a unique basin where a number of atmospheric and oceanographic processes occur due to the contrasting climatic conditions, which it experiences. The drastic monsoonal variability occurring in the boundary layer adversely affects...

  10. Seasonal variations in inorganic carbon components in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S; DileepKumar, M.; George, M.D.; Rajendran, A

    Extensive observations have been made on the carbon dioxide system in the Arabian Sea during three different seasons as part of the Indian Joint Global Ocean Flux Study (JGOFS) Programme. Concentrations of total carbon dioxide and partial pressure...

  11. Temperature profile and water depth data collected from USS JOHN RODGERS using BT and XBT casts in the NE/NW Atlantic Ocean and other seas from 03 August 1988 to 03 October 1988 (NODC Accession 8900041)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS JOHN RODGERS in the Northeast / Northwest Atlantic Ocean, Ionian Sea,...

  12. Mud volcanoes and gas hydrates in the Anaximander mountains (Eastern Mediterranean Sea)

    NARCIS (Netherlands)

    Lykousis, V.; Alexandri, S.; Woodside, J.M.; de Lange, G.; Dahlmann, A.; Perissoratis, C.; Heeschen, K.; Ioakim, Chr.; Sakellariou, D.; Nomikou, P.; Rousakis, G.; Casas, D.; Ballas, D.; Ercilla, G.

    2009-01-01

    Detailed multibeam, sedimentological, and geophysical surveys provide ample new data to confirm that the Anaximander Mountains (Eastern Mediterranean) are an important area for active mud volcanism and gas hydrate formation. More than 3000 km of multibeam track length was acquired during two recent

  13. Sequence stratigraphy and a revised sea-level curve for the Middle Devonian of eastern North America

    Science.gov (United States)

    Brett, Carlton E.; Baird, G.C.; Bartholomew, A.J.; DeSantis, M.K.; Ver Straeten, C.A.

    2011-01-01

    The well-exposed Middle Devonian rocks of the Appalachian foreland basin (Onondaga Formation; Hamilton Group, Tully Formation, and the Genesee Group of New York State) preserve one of the most detailed records of high-order sea-level oscillation cycles for this time period in the world. Detailed examination of coeval units in distal areas of the Appalachian Basin, as well as portions of the Michigan and Illinois basins, has revealed that the pattern of high-order sea-level oscillations documented in the New York-Pennsylvania section can be positively identified in all areas of eastern North America where coeval units are preserved. The persistence of the pattern of high-order sea-level cycles across such a wide geographic area suggests that these cycles are allocyclic in nature with primary control on deposition being eustatic sea-level oscillation, as opposed to autocylic controls, such as sediment supply, which would be more local in their manifestation. There is strong evidence from studies of cyclicity and spectral analysis that these cycles are also related to Milankovitch orbital variations, with the short and long-term eccentricity cycles (100. kyr and 405. kyr) being the dominant oscillations in many settings. Relative sea-level oscillations of tens of meters are likely and raise considerable issues about the driving mechanism, given that the Middle Devonian appears to record a greenhouse phase of Phanerozoic history. These new correlations lend strong support to a revised high-resolution sea-level oscillation curve for the Middle Devonian for the eastern portion of North America. Recognized third-order sequences are: Eif-1 lower Onondaga Formation, Eif-2: upper Onondaga and Union Springs formations; Eif-Giv: Oatka Creek Formation; Giv-1: Skaneateles, Giv-2: Ludlowville, Giv-3: lower Moscow, Giv-4: upper Moscow-lower Tully, and Giv-5: middle Tully-Geneseo formations. Thus, in contrast with the widely cited eustatic curve of Johnson et al. (1985), which

  14. New data on Eimeria dicentrarchi (Apicomplexa: Eimeriidae), a common parasite of farmed European sea bass (Dicentrarchus labrax) from the mid-eastern Adriatic

    Science.gov (United States)

    This study extends the original description of Eimeria dicentrarchi Daoudi and Marquès, 1987, a common coccidian parasite of European sea bass from the mid-eastern Adriatic, by providing insights into the parasite’s site of infection, development and pathogenicity. E. dicentrarchi was found in vario...

  15. Studies on the pore water sulfate, chloride and sedimentary methane to understand the sulfate reduction process in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Borole, D.V.; Rao, B.R.; Paropkari, A.L.; Joao, H; Kocherla, M.; Sarkar, G.P.; Biswas, G.; Kumar, N.

    Sediment cores (~5 m length) from ten stations collected in the water depths of 2665-3210 m in the eastern Arabian Sea were studied for pore water sulfate (SO42-), chloride (Cl-) and lighter-hydrocarbons (methane: C1, ethane:C2 and propane: C3...

  16. The Amino Acid Composition of Blue Swimming Crab (Portunus Segnis, Forskal, 1775 from The North Eastern Mediterranean Sea of Turkey

    Directory of Open Access Journals (Sweden)

    Engin Artar

    2018-04-01

    Full Text Available This study was carried out to detect the content of amino acid in female and male specimens of blue swimming crab (Portunus segnis obtained from (including 12 male crab and also 12 female crab North Eastern Mediterranean Sea, Turkey. The protein was identified as 17.63% and 18.13% for female and male crab respevtively. Totally 9 essential amino acids were recorded in the present study. Lysine and leucine constituted the highest essential amino acid (EAA concentrations in P. segnis. This species was found to be in good score in terms of the level of EAA and the EAA/Non-EAA ratios when compared with other economical crab species.

  17. A GIS Approach for Reconstructing the Litorina Sea Lagoon in Tolkuse-Rannametsa Area, Eastern Gulf of Riga.

    Science.gov (United States)

    Habicht, Hando-Laur; Rosentau, Alar; Jõeleht, Argo; Hang, Tiit; Kohv, Marko

    2015-04-01

    The eastern coast of the Gulf of Riga in the NE Baltic Sea is characterized by slow post-glacial isostatic uplift (about 1mm/yr) and slowly undulating low topography. Therefore even small increases in sea-level can easily lead to the flooding of considerable areas. The complex deglaciation history of the Baltic Sea area left, at times, south western Estonia submerged, while at other times, it emerged as terrestrial land. Different transgressive and regressive development stages of the Baltic Sea did not only shape the landscape, but also influenced the locations of the Stone Age settlements which were closely bound to the coastal areas which also include estuaries and lagoonal systems. The coastal region of the Gulf of Riga is abundant in Meso- and Neolithic settlement sites. The present study combines LiDAR, ground-penetrating radar (GPR) and geological data to reconstruct development of the Litorina Sea lagoon in Tolkuse-Rannametsa area and to create prognostic palaeogeographic maps in order to search for Meso- and Neolithic coastal settlement sites. Over 47 km of GPR profiling was done; sediments were described and dated in 37 cores two riverbank outcrops. Diatoms were analysed in the master core. A semi-automatic method for the removal of modern anthropogenic features from LiDAR derived digital elevation model (DEM) was developed, tested and used. In modelling process the impact of sedimentary processes subsequent to the time being modelled was taken into account by employing a backstripping methodology. The differential glacio-isostatic uplift within the study area was taken into account by using interpolated water-level surfaces. Palaeogeographic reconstructions shed new light into region's post-glacial coastal evolution and enabled us to suggest the possible locations of the Stone Age settlements with some of the proposed areas buried under up to 3 m thick peat layer. The results of the current study provide new chronological and shore displacement data

  18. Inter-cohort growth patterns of pharaoh cuttlefish Sepia pharaonis (Sepioidea: Sepiidae in Eastern Arabian Sea

    Directory of Open Access Journals (Sweden)

    Geetha Sasikumar

    2013-03-01

    Full Text Available Sepia pharaonis is an important commercial species endemic to the tropical Indo-Pacific region. Despite its commercial significance, only few information on natural populations is available. This study was aimed to describe the aspects of size-composition, length-weight relationship, catch rates, seasonal recruitment and inter-cohort growth patterns of S. pharaonis population (Clade C, distributed along the Eastern Arabian Sea (South-West coast of India. For this, the Dorsal Mantle Length (DML and weight of cuttlefishes was obtained from commercial trawl catches, from April 2002 to October 2006. Data was analyzed by normal length-weight methods such as von Bertalanffy. A total of 12 454 cuttlefishes, ranging in length from four to 41cm were analyzed. Size-composition patterns discriminated two pulses in recruitment to the fishery, discernible by a decrease in the monthly mean size of the population. The DMLs of the two seasonal cohorts were subjected to modalprogression analysis using the Bhattacharya’s method for the estimation of growth. The estimated parameters L∞ and K in von Bertalanffy Growth Function (VBGF were used to model growth curves in length for the cohorts. The first cohort, (post-monsoon cohort which supports the major fishery, was composed of mediumsized, fast growing individuals, whereas the second cohort (pre-monsoon cohort, comprised of slow growing and large-sized individuals. There were differential growth characteristics between the sexes and the life span was estimated at less than 2.3years for males and 2.1years for females. Negative allometric growth in weight (W with length (L was observed for males (W=0.33069.L2.5389 and females (W=0.32542.L2.6057. The females were heavier compared to males at any given mantle length, and the males were found to attain larger ultimate lengths. The major fishing season for cuttlefish was from May to November, when higher monthly catch rates of 1.67-13.02kg/h were observed in

  19. Drought reconstruction in eastern Hulun Buir steppe, China and its linkages to the sea surface temperatures in the Pacific Ocean

    Science.gov (United States)

    Liu, Na; Liu, Yu; Bao, Guang; Bao, Ming; Wang, Yanchao; Zhang, Lizhi; Ge, Yuxiang; Bao, Wurigen; Tian, Heng

    2016-01-01

    A tree-ring width chronology covering the period 1780-2013 AD was developed from Pinus sylvestris var. mongolica for the eastern Hulun Buir steppe, a region located on the edge of the eastern Mongolian Plateau, China. Climate-growth response analysis revealed drought stress to be the primary limiting factor for tree growth. Therefore, the mean February-July standardized precipitation evapotranspiration index (SPEI) was reconstructed over the period 1819-2013, where the reconstruction could account for 32.8% of the variance in the instrumental record over the calibration period 1953-2011. Comparison with other tree-ring-based moisture sequences from nearby areas confirmed a high degree of confidence in our reconstruction. Severe drought intervals since the late 1970s in our study area consisted with the weakening East Asian summer monsoon, which modulating regional moisture conditions in semi-arid zone over northern China. Drought variations in the study area significantly correlated with sea surface temperatures (SSTs) in North Pacific Ocean, suggesting a possible connection of regional hydroclimatic variations to the Pacific Decadal Oscillation (PDO). The potential influence associated with El Niño-Southern Oscillation (ENSO) was primarily analyzed.

  20. Enrichment of Bacteria From Eastern Mediterranean Sea Involved in Lignin Degradation via the Phenylacetyl-CoA Pathway

    Directory of Open Access Journals (Sweden)

    Hannah L. Woo

    2018-05-01

    Full Text Available The degradation of allochthonous terrestrial organic matter, such as recalcitrant lignin and hemicellulose from plants, occurs in the ocean. We hypothesize that bacteria instead of white-rot fungi, the model organisms of aerobic lignin degradation within terrestrial environments, are responsible for lignin degradation in the ocean due to the ocean’s oligotrophy and hypersalinity. Warm oxic seawater from the Eastern Mediterranean Sea was enriched on lignin in laboratory microcosms. Lignin mineralization rates by the lignin-adapted consortia improved after two sequential incubations. Shotgun metagenomic sequencing detected a higher abundance of aromatic compound degradation genes in response to lignin, particularly phenylacetyl-CoA, which may be an effective strategy for marine microbes in fluctuating oxygen concentrations. 16S rRNA gene amplicon sequencing detected a higher abundance of Gammaproteobacteria and Alphaproteobacteria bacteria such as taxonomic families Idiomarinaceae, Alcanivoraceae, and Alteromonadaceae in response to lignin. Meanwhile, fungal Ascomycetes and Basidiomycetes remained at very low abundance. Our findings demonstrate the significant potential of bacteria and microbes utilizing the phenylacetyl-CoA pathway to contribute to lignin degradation in the Eastern Mediterranean where environmental conditions are unfavorable for fungi. Exploring the diversity of bacterial lignin degraders may provide important enzymes for lignin conversion in industry. Enzymes may be key in breaking down high molecular weight lignin and enabling industry to use it as a low-cost and sustainable feedstock for biofuels or other higher-value products.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Modeling the barrier-layer formation in the South-Eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Durand, F.; Shankar, D.; DeBoyer Montegut, C.; Shenoi, S.S.C.; Blanke, B.; Madec, G.

    and are partly from the SEAS, but are cooled east and south of Sri Lanka in the model. That the downwelled subsurface waters are warm and are not cooled leads to temperature inversions in the BL. The main forcing for this appears to be remotely-forced planetary...

  4. Trace metal concentrations in zooplankton from the eastern Arabian Sea and western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; Balachandran, K.K.; Nair, M.; Joseph, T.; DineshKumar, P.K.; Achuthankutty, C.T.; Nair, K.K.C.; Pillai, N.G.K.

    Trace metal contents in zooplankton samples were estimated as a part of the Marine Research-Living Resource program at 24 stations in the Bay of Bengal (November, 2002) and 29 stations in the Arabian Sea (September-October, 2003) during the Cruises...

  5. Physical control of primary productivity on a seasonal scale in central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Madhupratap, M.; DileepKumar, M.; Gauns, M.; Muraleedharan, P.M.; Sarma, V.V.S.S.; DeSouza, S.N.

    Using in situ data collected during 1992-1997, under the Indian programme of Joint Global Ocean Flux Study (JGOFS), it is shown that the biological productivity of the Arabian Sea is tightly coupled to the physical forcing mediated through nutrient...

  6. The central and eastern Arabian Sea as a perennial source of atmospheric carbon dioxide

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; George, M.D.

    circulation and biological production. In all seasons, the pCO sub(2) is higher in surface waters of the Arabian Sea, except along the Indian coast in the southwest monsoon, than that in atmosphere, and thus this region appears to be a perennial source...

  7. Influence of eastern Arabian Sea on summer monsoon rainfall over west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Rao, M.S.; Rao, M.V.

    and distant nature. In order to realise the model results and the influence of Arabian sea in the context of long range forecasting of monsoon rainfall, we have examined the correlation between the rainfall over west coast of India and premonsoon thermal...

  8. Variability of mesoscale features in the Mediterranean Sea from XBT data analysis

    Directory of Open Access Journals (Sweden)

    G. Fusco

    2003-01-01

    Full Text Available During the period 1998–2000, the Mediterranean Forecasting System Pilot Project, aiming to build a forecasting system for the physical state of the sea, has been carried out. A ship-of-opportunity programme sampled the Mediterranean upper ocean thermal structure by means of eXpendable Bathy-Thermographs (XBTs, along seven tracks, from September 1999 to May 2000. The tracks were designed to detect some of the main circulation features, such as the stream of surface Atlantic water flowing from the Alboran Sea to the Eastern Levantine Basin. The cyclonic gyres in the Liguro-Provenal Basin, the southern Adriatic and Ionian Seas and the anticyclonic gyres in the Levantine Basin were also features to be detected. The monitoring system confirmed a long-term persistence of structures (at least during the entire observing period, which were previously thought to be transient features. In particular, in the Levantine Basin anticyclonic Shikmona and Ierapetra Gyres have been observed during the monitoring period. In order to identify the major changes in the thermal structures and the dynamical implications, the XBT data are compared with historical measurements collected in the 1980s and 1990s. The results indicate that some thermal features are being restored to the situation that existed in the 1980s, after the changes induced by the so-called "Eastern Mediterranean Transient". Key words. Oceanography: physical (eddies and mesoscale processes; general circulation; instruments and techniques

  9. Distribution of metals and extent of contamination in sediments from the south-eastern Baltic Sea (Lithuanian zone

    Directory of Open Access Journals (Sweden)

    Nijolė Remeikaitė-Nikienė

    2018-04-01

    Full Text Available Summary: The distribution of metals (Pb, Cu, Cd, Ni, Cr, Zn in surface sediments and the potential pollution sources in the south-eastern part (SE of the Baltic Sea (Lithuanian zone were investigated in relation to the environmental characteristics (amount of fine-grained particles, TOC content in sediments, origin of sedimentary organic matter, salinity, water depth in 2011–2014. The higher metal concentrations were measured in sediments of the Curonian Lagoon and in the open waters. An approach using various environmental indices (enrichment factor EF, geoaccumulation index Igeo and contamination factor CF was used to quantitatively assess a contamination degree. The principal component analysis (PCA was applied in order to further scrutinize pollution from metal sources. The values of the contamination indices showed no/very low sediment contamination with Ni and Cr, minor–moderate contamination with Cu, Zn and Pb and moderate–considerable pollution with Cd. The strong relationships among metals suggested their similar distribution pattern and a combination of natural and anthropogenic sources. The higher metal concentrations coincided with an increasing amount of fine-grained fraction and organic carbon. In the territorial waters, the distribution of elements was related to the water depth. In addition, the binding of metals with insoluble iron sulphides might explain their high concentrations at the most remote and deepest stations. Keywords: Metals, Enrichment factor, Geoaccumulation index, Contamination factor, The Baltic Sea, The Curonian Lagoon

  10. First records of two planktonic Indo-Pacific diatoms: Chaetoceros bacteriastroides and C. pseudosymmetricus in the Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Marijeta Čalić

    2018-01-01

    Full Text Available Unusual occurrence of planktonic diatom species, Chaetoceros bacteriastroides and Chaetoceros pseudosymmetricus, was noticed in three different marine ecosystems of Adriatic Sea: the Krka Estuary and Telaščica Bay in the Central Adriatic, and in southern Adriatic offshore. From 2010 to 2015, these two Chaetoceros species were recorded in heterogeneous environmental conditions and in a very low abundances. Both species are regarded as very rare in world oceans, and consequently knowledge of their distribution and ecology is rather poor. Primarily described from tropical waters and showing Indo-Pacific distribution, C. bacteriastroides and C. pseudosymmetricus findings in Adriatic represent the northernmost records in world's oceans and seas. For C. pseudosymmetricus this is also the first occurrence in European seas. Areal expansion and introduction of new phytoplankton species in the Adriatic Sea might be related to different circulation regimes in the Ionian Sea and the concurrent rise in sea temperature in the Mediterranean in the last decade. Recent investigations have shown that entering currents, of either Atlantic/Western Mediterranean or Eastern Mediterranean origin, modify the composition of the plankton community in the Adriatic by bringing different newcomers.

  11. Sedimentary sources and processes in the eastern Arabian Sea: Insights from environmental magnetism, geochemistry and clay mineralogy

    Directory of Open Access Journals (Sweden)

    Kumar Avinash

    2016-03-01

    Full Text Available The spatial distribution patterns of surficial sediment samples from different sedimentary domains (shallow to deep-sea regions of the eastern Arabian Sea were studied using sediment proxies viz. environmental magnetism, geochemistry, particle size and clay mineralogy. Higher concentrations of magnetic minerals (high χlf were recorded in the deep-water sediments when compared with the shallow water sediments. The magnetic mineralogy of one of the shallow water samples is influenced by the presence of bacterial magnetite as evidenced from the χARM/χlf vs. χARM/χfd biplot. However, the other samples are catchment-derived. The high correlation documented for χlf, anhysteretic remanent magnetisation (χARM and isothermal remanent magnetisation (IRM with Al indicates that the deep-sea surficial sediments are influenced by terrigenous fluxes which have been probably derived from the southern Indian rivers, the Sindhu (the Indus and the Narmada-Tapti rivers. A lower Mn concentration is recorded in the upper slope sediments from the oxygen minimum zone (OMZ but a higher Mn/Al ratio is documented in the lower slope and deep-sea sediments. Clay minerals such as illite (24–48.5%, chlorite (14.1–34.9%, smectite (10.6–28.7% and kaolinite (11.9–27.5% dominate the sediments of shallow and deep-sea regions and may have been derived from different sources and transported by fluvial and aeolian agents. Organic carbon (OC data indicate a low concentration in the shallow/shelf region (well oxygenated water conditions and deeper basins (increased bottom-water oxygen concentration and low sedimentation rate. High OC concentrations were documented in the OMZ (very low bottom-water oxygen concentration with high sedimentation rate. The calcium carbonate concentration of the surface sediments from the continental shelf and slope regions (<1800 m up to the Chagos-Laccadive Ridge show higher concentrations (average = 58% when compared to deep basin

  12. Thick massive gas hydrate deposits were revealed by LWD in Off-Joetsu area, eastern margin of Japan Sea.

    Science.gov (United States)

    Tanahashi, M.; Morita, S.; Matsumoto, R.

    2016-12-01

    GR14 and HR15 survey cruises, which were dedicated to the LWD (Logging While Drilling), were carried out in summers of 2014 and 2015, respectively, by Meiji University and Geological Survey of Japan, AIST to explore the "gas chimney" structures in eastern margin of Japan Sea. Shallow (33 to 172m-bsf, average 136m-bsf) 33 LWD drilling were performed in Oki Trough, Off-Joetsu, and Mogami Trough areas along eastern margin of Japan Sea during two cruises. Schlumberger LWD tools, GeoVISION (resistivity), TeleScope, ProVISION (NMR) and SonicVISION were used during GR14. NeoScope (neutron) was added and SonicScope was replaced for SonicVISION during HR14. The data quality was generally good. "Gas chimney" structures with acoustic blanking columns on the high frequency seismic sections with mound and pockmark morphologic features on the sea bottom, are well developed within survey areas. Every LWD records taken from gas chimney structures during the cruises show high resistivity and acoustic velocity anomalies which suggest the development of gas hydrate. Characteristic development of massive gas hydrate was interpreted at the Umitaka CW mound structure, Off-Joetsu. The mound lies at 890-910m in water depth and has very rough bottom surface, regional high resistivity, regional high heat flow, several natural seep sites, 200m x 300m area, and 10-20m height. 8 LWD holes, J18L to J21L and J23L to J26L, were drilled on and around the mound. There are highly anomalous intervals which suggest the development of massive gas hydrate at J24L, with high resistivity, high Vp and Vs, high neutron porosity, low natural gamma ray intensity, low neutron gamma density, low NMR porosity, low NMR permeability, low formation sigma, from 10 to 110m-bsf with intercalating some thin less hydrate layers. It is interpreted that there is several tens of meter thick massive gas hydrate in the gas chimney mound. It is partly confirmed by the later nearby coring result which showed the repetition of

  13. Multiscale wind cycles and current pulses at the Black Sea eastern boundary

    Science.gov (United States)

    Melnikov, Vasiliy; Moskalenko, Lidija; Piotoukh, Vladimir; Zatsepin, Andrey

    2015-04-01

    The goal of the research is to examine meteorological descriptive elements, sea-water properties, regional hydrodynamics and energy conversion fluxes in order to study sea responses to the local and far-field weather system. The Black Sea is situated in the chain of internal basins between the North Atlantic and Central Asia deserts in the marginal interaction zone and, accordingly, is under the influence of the Azores and Siberian anticyclones, Arctic cold-air surges and subtropical desert belt to the south. The analysis is based on the data of modern oceanographic measuring network "Hydro-physical Polygon" of the Institute of oceanology, using contact and remote sensing methods, weather stations around the Black Sea coasts, including long-term (1938-2014) measurements at the Gelendzhik weather station. Various satellite and Reanalysis databases are used. Currently, there are three long-time measuring moored stations (each contains ADCP and thermistor chain) and scanning profiling system "Akvalog". Hydrological sections and field surveys using towed ADCP and CTD are performed on a regular basis. The data are accumulated in the coastal archive which allows calibration of satellite measurements and testing results of numerical modeling. Data processing includes data sets preparation, editing, time series statistical calculations using histograms, progressive vector diagrams, traditional Fourier spectral analysis including auto- and cross spectra, auto and mutual wavelet diagrams, moving spectrograms, vector data methods using rotary components, spectral invariants, empirical modes, hodograph and pre-specified spectrum representations on the basis of stochastic models with imposed dynamical assumptions. Due to the intermittent nature of the time rows, spectral representation is misleading, often. In order to identify the individual evolving dynamical phenomenon, typical background (seasonal) three-dimensional structures of the hydrological field, as well as

  14. Stratigraphy and palynology of the Lower Carboniferous Sortebakker Formation, Wandel Sea Basin, eastern North Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Dalhoff, F.; Stemmerik, L. [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Vigran, J.O. [IKU Petroleum Research, Trondheim (Norway)

    2000-07-01

    Two palynological assemblages of Early Carboniferous age have been recorded from the upper parts of the non-marine, fluvial-dominated Sortebakker Formation in the Wandel Sea Basin. The stratigraphically lower assemblage includes poorly preserved Cingulizonates spp., Densosporites spp., Lycospora spp. and Schulzospora spp. whereas the upper assemblage contains a more diversified microflora including the stratigraphically important Tripartites distinctus, Potoniespores delicatus and Savitrisporites spp. The microflora enables correlation and dating of the succession to the late Visean Perotrilites tessellatus - Schulzospora campyloptera (TC) and Raistrickia nigra - Triquitrites marginatus (NM) miospore Biozones of western Europe. The depositional facies correspond to those seen in time equivalent deposits from East Greenland, Svalbard, Bjoernoeya and the Barents Sea. (au)

  15. Postglacial sedimentary regime around northern Sylt, South-eastern North Sea, based on shallow seismic evidence

    DEFF Research Database (Denmark)

    Boldreel, Lars Ole; Kuijpers, Antoon; Madsen, Emil B

    2010-01-01

    , in the outer delta, a dune field suggesting westerly-directed sediment transport is identified. The two dune fields appear to be separated by minor indefinite bed forms. The northern part of the Lister Tief is characterised by the presence of a channel with a depth of 20-30 mbsf (meter below sea level) (30......-40 msec TWT (Two Way Traveltime)) and displaying erosion towards the north. At the western termination of the channel the sediment transport pathway appears to be divided into two directions; one towards the outer delta, and one towards the sediment depocenter SW of Rømø. The Lister Ley is characterized......During the past 5 years the coastal zone offshore the northern part of the island of Sylt, has been investigated by sparker seismics and high-resolution subbottom profiling. The North Sea sector of the area is characterized by northward-directed sediment bypass as a result of strong long...

  16. Anaerobic carbon mineralisation through sulphate reduction in the inner shelf sediments of eastern Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, R.; Naqvi, S.W.A.; Araujo, J.

    ,G.-J. .Reichart and S. W. Poulton. 2012. Sedimentary phosphorus and iron cycling in and below the oxygen minimum zone of the northern Arabian Sea.Biogeosciences Discussion. 9, 3829–3880. Pratihary A.K, S. W. A. Naqvi, H. Naik,B.R. Thorat, G. Narvenkar...). Other factors such as sedimentation rate and the presence of anaerobic electron acceptors asnitrate, Fe and Mn oxyhydroxides also affect sedimentary Corg mineralization rates.Under anoxic conditions, reductive dissolution of Fe oxyhyroxides produces...

  17. Submarine mass wasting on the Ionian Calabrian margin

    Science.gov (United States)

    Ceramicola, S.; Forlin, E.; Coste, M.; Cova, A.; Praeg, D.; Fanucci, F.; Critelli, S.

    2010-12-01

    Mass wasting processes on continental margins have strong relevance both for geohazards of coastal areas and for the emplacement and monitoring of offshore infrastructures. The seabed dynamics of the Ionian Calabrian Margin (ICM) are currently being examined in the context of the project MAGIC (Marine Geohazard along the Italian Coasts). The objective of this project is the definition of elements that may constitute geological risk for coastal areas. The ICM is a tectonically-active margin, the structures of which reflect two main processes: frontal compression and fore-arc extension during the SE advance of the Calabrian accretionary prism since the late Miocene; and a rapid uplift (up to 1mm/yr) of onshore and shallow shelf areas since the mid-Pleistocene. These processes are reflected in different tectonic settings at seabed, which is characterized by a narrow continental shelf above a slope of irregular morphology in water depths of 150-2000 m. In the north, a broad slope is dominated by ridges and intervening basins that are the morphological expression of the southern Apennine fold-and-thrust belt; in the south, the continental slope descends steeply towards the deep-water Crotone and Spartivento fore-arc basins. The overall objective of this study is to map major features of mass wasting on the slopes of the ICM, investigate possible triggering mechanisms and consider the geohazards these features may represent for coastal areas. The study is based on an integrated analysis of multibeam morpho-bathymetric data and subbottom profiles, which together allow the recognition of four main types of mass wasting phenomena along the slopes of the ICM: 1) mass transport complexes (MTCs) within intra-slope basins - these are identified in the northern area, within the piggy-back basins: seabed imagery show the slopes of all the seabed ridges to be marked by headwall scarps recording widespread failure, while Chirp profiles show the adjacent basins to contain

  18. 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.

  19. Environmental policy in the north-eastern sector of the Black sea coast

    Science.gov (United States)

    Kosyan, Ruben; Godin, Evgenii; Kosyan, Alisa

    2015-04-01

    Active economic development of the Black Sea East coastal zone has started in the beginning of 20-th century. Those days the pebble taken from beaches was used for construction of buildings, rail and motor roads. Active consumption of pebble from the beaches and river banks had caused a sharp increase of sea shores abrasion and washout rate, number of landslides had also increased. Contemporary Caucasian shores of Black Sea are being developed under increasing man-caused load. Favorable natural conditions, their variety and uniqueness determine the exceptional role of these shores as very important recreational zone of Russian South. Waste urbanized areas, agricultural territories and National Parks are located in immediate neighborhood with the sea. Important industrial facilities and federal and international communi- cations, including major seaports are located in the shore zone. At present time major gas and oil transportation facilities are commissioned and being constructed in the area. Due to the change of geopolitical situation the Russian shoreline had significantly reduced in comparison with Soviet period, especially in most developed regions. Large resort complexes in Georgia, Crimea and Baltic area were lost. Russia had also lost many major seaports that, under conditions of structural change of economy and export growth, had caused the necessity of building new industrial facilities in the Black Sea coastal zone, and, consequently, had stimulated active human invasion into natural coastal processes. At the time being, a major part (three hundred nine kilometers) of Black Sea coast within Russian sector is subject to abrasion and landslide processes. Abrasion process and beaches wash-out, landslides cause destruction of industrial and transport facilities, living and public buildings, resort complexes and valuable agricultural areas. In this light, the challenge of estimation of effective methods of shores protection against wave-induced erosion

  20. Soundscapes from a Tropical Eastern Pacific reef and a Caribbean Sea reef

    Science.gov (United States)

    Staaterman, E.; Rice, A. N.; Mann, D. A.; Paris, C. B.

    2013-06-01

    Underwater soundscapes vary due to the abiotic and biological components of the habitat. We quantitatively characterized the acoustic environments of two coral reef habitats, one in the Tropical Eastern Pacific (Panama) and one in the Caribbean (Florida Keys), over 2-day recording durations in July 2011. We examined the frequency distribution, temporal variability, and biological patterns of sound production and found clear differences. The Pacific reef exhibited clear biological patterns and high temporal variability, such as the onset of snapping shrimp noise at night, as well as a 400-Hz daytime band likely produced by damselfish. In contrast, the Caribbean reef had high sound levels in the lowest frequencies, but lacked clear temporal patterns. We suggest that acoustic measures are an important element to include in reef monitoring programs, as the acoustic environment plays an important role in the ecology of reef organisms at multiple life-history stages.

  1. Seasonal variability in oxygen and nutrients in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    De; DileepKumar, M.; Sardessai, S.; Sarma, V.V.S.S.; Shirodkar, P.V.

    5. Northhyphenminussouth variations in nitrate deficit (DELN, ?M), along 64?E. CURRENT SCIENCE, VOL. 71, NO. 11, 10 DECEMBER 1996 SPECIAL SECTION: JGOFS (INDIA) Figure 6. Dissolved oxygen (at <60 ?M) versus DELN (?M) during different seasons along 64.... This occurred to the east of 72?E where the surface temhyphenminus peratures were less than 28?C. The effect could also be Table 1. Average values of oxygen and nitrate deficit (DELN) in denitrification zone and surface Chlorophyll a in the Arabian Sea 850...

  2. Trajectory of an oil spill off Goa, eastern Arabian Sea: Field observations and simulations

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Sudheesh, K.; Babu, M.T.; Jayakumar, S.; ManiMurali, R.; Saran, A.K.; Sharma, L.H.; Rajan, B.; Srivastava, M.

    , 2000) in the coastal waters off Goa due to grounding of a vessel and ?Sea Transporter? off Aguada on 5 June 1994 (1025 tonnes of diesel). Goa has been identified as one of the major tourist destinations of the world because of its beautiful beaches... and associated recreational activities. The economy of Goa depends on tourism to a large extent. The coastal population as well as the State Government are very particular about activities which are harmful in the coastal zone. In case spill-remains arrive...

  3. Carbon budget in the eastern and central Arabian Sea: An Indian JGOFS synthesis

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Swathi, P.S.; DileepKumar, M.; PrasannaKumar, S.; Bhattathiri, P.M.A.; Madhupratap, M.; Ramaswamy, V.; Sarin, M.M.; Gauns, M.; Ramaiah, N.; Sardessai, S.; DeSousa, S.N.

    of its unique monsoon-driven, dynamic, and complex biogeochemistry. The JGOFS (India) I HydfOsphcric-!\\tlllosphcri<: Research Center. Nagoya University, Nagoya, Japan. 2CS1R Centre ti.1r 'Aathcmutical 'Aodeling and Computer Simulation, Banr,alore-: India... while it was between 161 and 203 mg m J in SWM (M. Ciauns et aI., Mierozooplankton playa major role in the food web dynamics of the Arabian Sea, submitted to ,Marine Ecologt, Progress Series, 2002) (hereinafter referred to as Gauns et aI., submitted...

  4. Distribution of organic carbon in surface sediments along the eastern Arabian Sea: a revisit

    Digital Repository Service at National Institute of Oceanography (India)

    PrakashBabu, C.; Brumsack, H.-J.; Schnetger, B.

    , 1990; Paropkari et al., 1992, 1993a,b; Calvert et al., . 1995 . OC enrichments of )8% with maxima of up ) Corresponding author. Fax: q49-441-798-3404; E-mail: brumsack@icbm.de 1 E-mail: pbabu@csnio.ren.nic.in, pbabu@darya.nio.org. 2 E-mail: schnetger@icbm.de... sediments, that are too high by up to a factor of two. Weliky et al. . 1983 already pointed out that problems are evident when OC determinations are performed exclusively by the wet oxidation method. . Our analyses of Holocene Black Sea sapropels...

  5. Speciation of phosphorus in the continental shelf sediments in the Eastern Arabian Sea

    Science.gov (United States)

    Acharya, Shiba Shankar; Panigrahi, Mruganka Kumar; Kurian, John; Gupta, Anil Kumar; Tripathy, Subhasish

    2016-03-01

    The distributions of various forms of phosphorus (P) and their relation with sediment geochemistry in two core sediments near Karwar and Mangalore offshore have been studied through the modified SEDEX procedure (Ruttenberg et al., 2009) and bulk chemical analysis. The present study provides the first quantitative analysis of complete phosphorus speciation in the core sediments of the Eastern Arabian shelf. The chemical index of alteration (CIA), chemical Index of Weathering (CIW) and Al-Ti-Zr ternary diagram suggest low to moderate source area weathering of granodioritic to tonalitic source rock composition, despite the intense orographic rainfall in the source area. Due to the presence of same source rock and identical oxic depositional environment, the studied sediments show the same range of variation of total phosphorus (24 to 83 μmol/g) with a down-depth depleting trend. Organic bound P and detrital P are the two major chemical forms followed by iron-bound P, exchangeable/loosely bound P and authigenic P. The authigenic P content in the sediments near Mangalore coast varies linearly with calcium (r=0.88) unlike that of Karwar coast. The different reactive-phosphorus pools exhibit identical depleting trend with depth. This indicates that the phosphorus released from the organic matter and Fe bound fractions are prevented from precipitating as authigenic phosphates in the deeper parts of the sediment column. The low concentration of total P, dominance of detrital non-reactive fraction of P and inhibition of formation of authigenic phosphate result in the absence of active phosphatization in the Eastern Arabian Shelf in the studied region. High sedimentation rate (35-58 cm/kyr) and absence of winnowing effect appear to be the dominant factor controlling the P-speciation in the studied sediments.

  6. Estimation of past sea-level variations based on ground-penetrating radar mapping of beach-ridges - preliminary results from Feddet, Faxe Bay, eastern Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Nielsen, Lars; Clemmensen, Lars B

    2011-01-01

    Estimates of past sea-level variations based on different methods and techniques have been presented in a range of studies, including interpretation of beach ridge characteristics. In Denmark, Holocene beach ridge plains have been formed during the last c. 7700 years, a period characterised by both...... isostatic uplift and changes in eustatic sea-level, and therefore represent an archive of past relative sea-level variations. Here, we present preliminary results from investigation of beach ridges from Feddet, a small peninsula located in Faxe Bay (Baltic Sea) in the eastern part of Denmark. Feddet has...... been chosen as a key-locality in this project, as it is located relatively close to the current 0-isobase of isostatic rebound. GPR reflection data have been acquired with shielded 250 MHz Sensors & software antennae along a number of profile lines across beach ridge and swale structures of the Feddet...

  7. Inventory, distribution, and origin of aliphatic and polyaromatic hydrocarbons in sea water, the surface microlayer, and the aerosols in the tropical Eastern Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Marty, J C; Saliot, A; Tissier, M J

    1978-03-20

    Hydrocarbons have been analyzed in several samples from ''Midlante'' cruise, Cape Verde islands-Canary islands, in the Eastern tropical Atlantic: subsurface water, sea surface microlayer collected by a metallic screen and aerosols collected by filtration of large air volumes at about 12 m. above the sea surface. Detailed analysis of aliphatic and polyaromatic hydrocarbons has been made by computerized gas chromatography/mass spectrometry. This study of the air/sea interface indicates a discontinuity in hydrocarbon composition between the underlying water and the microlayer and a similarity between the surface microlayer and the aerosols. The origin of the collected aerosols is essentially marine with a minor terrestrial contribution. The hydrocarbon pattern shows that, superimposed on the typical marine components, a contribution from smokes of natural and industrial origin and/or from pollution associated with crude oil sea slicks is present.

  8. Vegetation Analysis in the Red Sea-Eastern Desert Ecotone at the Area between Safaga and South Qusseir, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed G. Sheded

    2014-12-01

    Full Text Available The current work is concerned with the studying the impact of environmental conditions on the vegetation in the arid ecotone located between Red Sea and Eastern Desert from Safaga to south Qusseir. Ninety eight quadrats inside 13 transects were selected to cover the environmental gradient across the ecotone, from the coastal region to the boundary of Eastern Desert. Forty five species were recorded belonged to 24 different families and 38 genera. The perennial species were 38 while the annuals were seven species. Zygophyllum coccineum had the highest presence value (89.8% followed by Tamarix nilotica (56.1% and Zilla spinosa (51.02%. Chamaephytes and Hemicryptophytes were the most prevailed life-forms. Chrological analysis exhibited that SaharoSindian and Sahro-Sindian with its extension to Sudano-Zambezian elements were the most dominant. TWINSPAN classification technique produced three vegetation groups include nine clusters at the fourth level. These groups identified according to the first and second dominant species as follows: Convolvulus hystrix - Panicum turgidum, Tamarix aphylla - Limonium pruinosum and Nitraria retusa - Tamarix nilotica. DECORANA results indicated a reasonable segregation among these groups along the ordination axis 1 and 2. Vegetation analysis showed that ecotonal clusters have highest number of species/cluster, high species richness and high species turnover. Therefore, the largest group existed in the ecotone (34 species while the desert group contained eight species and the coastal group included three species. Among the estimated soil variables in this study, pH, coarse sand, HCO3-, SO42- , clay and PO43- have the highest effect on species distribution. Sodium adsorption ratio (SAR was the effective factor in detecting the ecotonal species, Aeluropus lagopoides and Limonium pruinosum.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Environmental changes of the last 30,000 years in the gas hydrate area of Joetsu Basin, eastern margin of Japan Sea

    Energy Technology Data Exchange (ETDEWEB)

    Freire, A.F.M.; Sugai, T. [Tokyo Univ., Kashiwanoha Campus, Chiba (Japan). Dept. of Natural Environmental Studies; Takeuchi, E.; Nagasaka, A.; Hiruta, A.; Ishizaki, O.; Matsumoto, R. [Tokyo Univ., Hongo Campus, Bunkyo-ku, Tokyo (Japan). Dept. of Earth and Planetary Science

    2008-07-01

    The Japan Sea is a semi-isolated marginal sea with an average depth of 1350 metres and a maximum water depth of approximately 3700 metres in the northern basin. This paper presented a study that inferred the age and the nature of the environmental events of the last 30 thousand years using geochemical and sedimentary records from piston cores collected on the gas hydrates bearing-sediments of Joetsu Basin, eastern margin of Japan Sea, south of Sado Islands. Interbedded dark gray thinly laminates and dark brown to gray bioturbated units are common throughout the quaternary sediments of the Japan Sea. They have been explained in terms of glacio-eustatic sea-level change. Active methane venting and gas hydrates have also been recognized, which are widely distributed just beneath the sea floor in the Joetsu Basin, in the eastern margin of the Japan Sea. In order to identify the nature of the organic matter present in the study area and to make a correlation with samples collected in the Pacific Ocean, the study utilized total organic carbon contents and carbon isotopic composition of the gas hydrates bearing-sediments. Using X-ray diffraction analysis, these data were used to apply sequence stratigraphy concepts to locate the holocene/pleistocene boundary and to identify key stratigraphic surfaces, and also to recognize methane flux variations and sulfate-methane interfaces. The paper discussed total organic carbon in the Holocene/Pleistocene boundaries; nature of the organic matter and terrestrial versus marine phytoplankton production; and terrigenous material input. Sulfate oxidation of methane was also discussed. It was concluded that the correlation between the Japan Sea and Pacific Ocean was possible using piston cores. 13 refs., 13 figs.

  12. Fog composition at Baengnyeong Island in the eastern Yellow Sea: detecting markers of aqueous atmospheric oxidations

    Directory of Open Access Journals (Sweden)

    A. J. Boris

    2016-01-01

    Full Text Available Samples of fog water were collected at Baengnyeong Island (BYI in the Yellow Sea during the summer of 2014. The most abundant chemical species in the fog water were NH4+ (mean of 2220 µM, NO3− (1260 µM, SO4−2 (730 µM, and Na+ (551 µM, with substantial contributions from other species consistent with marine and biomass burning influence on some dates. The pH of the samples ranged between 3.48 and 5.00, with a mean of 3.94, intermediate within pH values of fog/cloud water reported previously in Southeast Asia. Back trajectories (72 h showed that high relative humidity ( >  80 % was encountered upwind of the sampling site by all but one of the sampled air masses, and that the fog composition at BYI can be impacted by several different source regions, including the Sea of Japan, southeastern China, northeastern China, and the East China Sea. Sulfur in the collected fog was highly oxidized: low S(IV concentrations were measured (mean of 2.36 µM in contrast to SO4−2 and in contrast to fog/cloud S(IV concentrations from pollutant source regions; organosulfate species were also observed and were most likely formed through aging of mainly biogenic volatile organic compounds. Low-molecular-mass organic acids were major contributors to total organic carbon (TOC; 36–69 %, comprising a fraction of TOC at the upper end of that seen in fogs and clouds in other polluted environments. Large contributions were observed from not only acetic and formic acids but also oxalic, succinic, maleic, and other organic acids that can be produced in aqueous atmospheric organic processing (AAOP reactions. These samples of East Asian fog water containing highly oxidized components represent fog downwind of pollutant sources and can provide new insight into the fate of regional emissions. In particular, these samples demonstrate the result of extensive photochemical aging during multiday transport, including oxidation within wet aerosols and

  13. Fog composition at Baengnyeong Island in the eastern Yellow Sea: detecting markers of aqueous atmospheric oxidations

    Science.gov (United States)

    Boris, A. J.; Lee, T.; Park, T.; Choi, J.; Seo, S. J.; Collett, J. L., Jr.

    2016-01-01

    Samples of fog water were collected at Baengnyeong Island (BYI) in the Yellow Sea during the summer of 2014. The most abundant chemical species in the fog water were NH4+ (mean of 2220 µM), NO3- (1260 µM), SO4-2 (730 µM), and Na+ (551 µM), with substantial contributions from other species consistent with marine and biomass burning influence on some dates. The pH of the samples ranged between 3.48 and 5.00, with a mean of 3.94, intermediate within pH values of fog/cloud water reported previously in Southeast Asia. Back trajectories (72 h) showed that high relative humidity ( > 80 %) was encountered upwind of the sampling site by all but one of the sampled air masses, and that the fog composition at BYI can be impacted by several different source regions, including the Sea of Japan, southeastern China, northeastern China, and the East China Sea. Sulfur in the collected fog was highly oxidized: low S(IV) concentrations were measured (mean of 2.36 µM) in contrast to SO4-2 and in contrast to fog/cloud S(IV) concentrations from pollutant source regions; organosulfate species were also observed and were most likely formed through aging of mainly biogenic volatile organic compounds. Low-molecular-mass organic acids were major contributors to total organic carbon (TOC; 36-69 %), comprising a fraction of TOC at the upper end of that seen in fogs and clouds in other polluted environments. Large contributions were observed from not only acetic and formic acids but also oxalic, succinic, maleic, and other organic acids that can be produced in aqueous atmospheric organic processing (AAOP) reactions. These samples of East Asian fog water containing highly oxidized components represent fog downwind of pollutant sources and can provide new insight into the fate of regional emissions. In particular, these samples demonstrate the result of extensive photochemical aging during multiday transport, including oxidation within wet aerosols and fogs.

  14. Investigation of environmental radioactivity in waste dumping areas of the far eastern seas. JAERI`s activities in the 1st Japanese-Korean-Russian joint expedition 1994

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Hikaru; Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yabuuchi, Noriaki

    1996-10-01

    Large quantities of radioactive waste have been dumped in the Far Eastern Sea by the former USSR and Russia. In order to survey marine radioactive contamination in the Far Eastern Sea, the first Japanese-Korean-Russian joint expedition was conducted according to the governmental agreement. The joint expedition was conducted at the areas of the Russian radioactive waste dumping site from March 18 1994 to April 6, 1994. JAERI participated in this expedition according to the request from STA Japan, and conducted mainly on-board measurement of marine radioactivities. The results showed that the radionuclides concentrations in seawater and seabed sediment samples from the study site were not different from those in the western North Pacific. This report summarises JAERI`s activities in the expedition. Final report by Japanese-Korean-Russian government and IAEA is annexed. (author)

  15. Investigation of environmental radioactivity in waste dumping areas of the far eastern seas. JAERI's activities in the 1st Japanese-Korean-Russian joint expedition 1994

    International Nuclear Information System (INIS)

    Amano, Hikaru; Matsunaga, Takeshi; Yabuuchi, Noriaki.

    1996-10-01

    Large quantities of radioactive waste have been dumped in the Far Eastern Sea by the former USSR and Russia. In order to survey marine radioactive contamination in the Far Eastern Sea, the first Japanese-Korean-Russian joint expedition was conducted according to the governmental agreement. The joint expedition was conducted at the areas of the Russian radioactive waste dumping site from March 18 1994 to April 6, 1994. JAERI participated in this expedition according to the request from STA Japan, and conducted mainly on-board measurement of marine radioactivities. The results showed that the radionuclides concentrations in seawater and seabed sediment samples from the study site were not different from those in the western North Pacific. This report summarises JAERI's activities in the expedition. Final report by Japanese-Korean-Russian government and IAEA is annexed. (author)

  16. Hydrological, plankton and pigment observations in the Makassar Strait, Madura Strait and Eastern Java Sea by the R.V. Samudera, April 16 to May 19, 1975 (NODC Accession 7700306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton and chemical data were collected using net and bottle casts from the R.V. SAMUDERA in the Makassar Strait, Madura Strait and Eastern Java Sea from 16...

  17. Cetacean line-transect survey conducted in the eastern Bering Sea shelf by Alaska Fisheries Science Center, National Marine Mammal Laboratory from NOAA Ship Miller Freeman from 1999-07-07 to 2004-06-30 (NCEI Accession 0131862)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visual surveys for cetaceans were conducted on the eastern Bering Sea shelf along transect lines, in association with the AFSC’s echo integration trawl surveys for...

  18. AFSC/RACE/EcoFOCI: NPRB project number 926: Assessing the condition of walleye pollock, Theragra chalcogramma, larvae in the eastern Bering Sea with muscle-based flow cytometry cell cycle analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Walleye pollock are an important component of the eastern Bering Sea ecosystem due to their vast numbers and biomass and are of great commercial importance. Their...

  19. Groundwater balance in the Khor Arbaat basin, Red Sea State, eastern Sudan

    Science.gov (United States)

    Elsheikh, Abdalla E. M.; Zeielabdein, Khalid A. Elsayed; Babikir, Ibrahim A. A.

    2009-12-01

    The Khor Arbaat basin is the main source of potable water supply for the more than 750,000 inhabitants of Port Sudan, eastern Sudan. The variation in hydraulic conductivity and storage capacity is due to the heterogeneity of the sediments, which range from clay and silt to gravely sand and boulders. The water table rises during the summer and winter rainy seasons; it reaches its lowest level in the dry season. The storage capacity of the Khor Arbaat aquifer is estimated to be 21.75 × 106 m3. The annual recharge through the infiltration of flood water is about 1.93 × 106 m3. The groundwater recharge, calculated as underground inflow at the ‘upper gate’, is 1.33 × 105 m3/year. The total annual groundwater recharge is 2.06 × 106 m3. The annual discharge through underground outflow at the ‘lower gate’ (through which groundwater flows onto the coastal plain) is 3.29 × 105 m3/year. Groundwater discharge due to pumping from Khor Arbaat basin is 4.38 × 106 m3/year on average. The total annual groundwater discharge is about 4.7 × 106 m3. A deficit of 2.6 × 106 m3/year is calculated. Although the total annual discharge is twice the estimated annual recharge, additional groundwater flow from the fractured basement probably balances the annual groundwater budget since no decline is observed in the piezometric levels.

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

    OpenAIRE

    Dimitrios Damalas; Persefoni Megalofonou

    2012-01-01

    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 variation...

  1. Eastern equatorial Pacific sea surface temperature annual cycle in the Kiel climate model: simulation benefits from enhancing atmospheric resolution

    Science.gov (United States)

    Wengel, C.; Latif, M.; Park, W.; Harlaß, J.; Bayr, T.

    2018-05-01

    A long-standing difficulty of climate models is to capture the annual cycle (AC) of eastern equatorial Pacific (EEP) sea surface temperature (SST). In this study, we first examine the EEP SST AC in a set of integrations of the coupled Kiel Climate Model, in which only atmosphere model resolution differs. When employing coarse horizontal and vertical atmospheric resolution, significant biases in the EEP SST AC are observed. These are reflected in an erroneous timing of the cold tongue's onset and termination as well as in an underestimation of the boreal spring warming amplitude. A large portion of these biases are linked to a wrong simulation of zonal surface winds, which can be traced back to precipitation biases on both sides of the equator and an erroneous low-level atmospheric circulation over land. Part of the SST biases also is related to shortwave radiation biases related to cloud cover biases. Both wind and cloud cover biases are inherent to the atmospheric component, as shown by companion uncoupled atmosphere model integrations forced by observed SSTs. Enhancing atmosphere model resolution, horizontal and vertical, markedly reduces zonal wind and cloud cover biases in coupled as well as uncoupled mode and generally improves simulation of the EEP SST AC. Enhanced atmospheric resolution reduces convection biases and improves simulation of surface winds over land. Analysis of a subset of models from the Coupled Model Intercomparison Project phase 5 (CMIP5) reveals that in these models, very similar mechanisms are at work in driving EEP SST AC biases.

  2. Restructuring of Turkey's electricity market and the share of hydropower energy: The case of the Eastern Black Sea Basin

    International Nuclear Information System (INIS)

    Uzlu, Ergun; Koemuercue, Murat ihsan; Akpinar, Adem

    2011-01-01

    This paper presents the historical development of Turkey's electricity power sector, the efforts for introducing competition in the power industry in Turkey, and the concerns regarding restructuring in Turkey. The contribution of the hydropower energy potential in Turkey to the reconstruction of the electricity structure in Turkey is also investigated. Then, among the 25 hydrological basins in Turkey, the Eastern Black Sea Basin located in the northeast of Turkey, which has great advantages from the view point of small hydropower potential or hydropower potential without storage, is chosen as the case study to carry out some investigations concerning its potential and to analyze the contribution of the private sector (the corporate body) in regard to the development of hydro potential in this basin within the scope of the 4628 Electricity Market Law. With this law, concerning the restructuring of the electricity market, private sector investments in this segment have increased. In total, 1524 hydroelectric power projects with 22 360 MW installed capacity has been implemented until January 22nd, 2009 and this figure is continuously rising. (author)

  3. Mercury Redox Chemistry in Waters of the Eastern Asian Seas: From Polluted Coast to Clean Open Ocean.

    Science.gov (United States)

    Ci, Zhijia; Zhang, Xiaoshan; Yin, Yongguang; Chen, Jinsheng; Wang, Shiwei

    2016-03-01

    We performed incubation experiments using seawaters from representative marine environments of the eastern Asian seas to determine the mercury (Hg) available for photoreduction (Hgr(II)), to investigate the Hg redox reaction kinetics, and to explore the effect of environmental factors and water chemistry on the Hg redox chemistry. Results show that Hgr(II) accounted for a considerable fraction of total Hg (THg) (%Hgr(II)/THg: 24.90 ± 10.55%, n = 27) and positively correlated with THg. Filtration decreased the Hgr(II) pool of waters with high suspended particulate matter (SPM). The positive linear relationships were found between pseudo-first order rate constants of gross Hg(II) photoreduction (kr) and gross Hg(0) photo-oxidation (ko) with photosynthetically active radiation (PAR). Under the condition of PAR of 1 m mol m(-2) s(-1), the kr were significantly (p < 0.05) lower than ko (kr/ko: 0.86 ± 0.22). The Hg(0) dark oxidation were significantly higher than the Hg(II) dark reduction. The Hg(II) dark reduction was positively correlated to THg, and the anaerobic condition favored the Hg(II) dark reduction. Filtration significantly influenced the Hg photoredox chemistry of waters with high SPM. UVB radiation was important for both Hg(II) photoreduction and Hg(0) photo-oxidation, and the role of other wavebands in photoinduced transformations of Hg varied with the water chemistry.

  4. Body Size Regression Formulae, Proximate Composition and Energy Density of Eastern Bering Sea Mesopelagic Fish and Squid.

    Science.gov (United States)

    Sinclair, Elizabeth H; Walker, William A; Thomason, James R

    2015-01-01

    The ecological significance of fish and squid of the mesopelagic zone (200 m-1000 m) is evident by their pervasiveness in the diets of a broad spectrum of upper pelagic predators including other fishes and squids, seabirds and marine mammals. As diel vertical migrators, mesopelagic micronekton are recognized as an important trophic link between the deep scattering layer and upper surface waters, yet fundamental aspects of the life history and energetic contribution to the food web for most are undescribed. Here, we present newly derived regression equations for 32 species of mesopelagic fish and squid based on the relationship between body size and the size of hard parts typically used to identify prey species in predator diet studies. We describe the proximate composition and energy density of 31 species collected in the eastern Bering Sea during May 1999 and 2000. Energy values are categorized by body size as a proxy for relative age and can be cross-referenced with the derived regression equations. Data are tabularized to facilitate direct application to predator diet studies and food web models.

  5. Seasonal and spatial variations of marine litter on the south-eastern Black Sea coast.

    Science.gov (United States)

    Terzi, Yahya; Seyhan, Kadir

    2017-07-15

    The south-eastern Black Sea coast in Turkey was evaluated for marine litter composition and density covering nine beaches during four seasons. The marine litter (>2cm in size), was collected from the coast and categorized into material and usage categories. The data analysis showed that plastic was the most abundant litter (≥61.65%) by count and weight followed by styrofoam and fabric. The marine litter density ranged from 0.03 to 0.58 with a mean (±SD) of 0.16±0.02 items/m 2 by count. Based on weight, it varied between 0.44 and 14.74g/m 2 with 3.35±1.63. The east side had a higher marine litter density than the west side with significant differences between beaches. The variations due to different seasons were not significant for any beach. The results of this study should provide baseline information about the coastal marine pollution and will assist the mitigation strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Absorption properties of chromophoric dissolved organic matter (CDOM) in the East China Sea and the waters off eastern Taiwan

    Science.gov (United States)

    Zhou, Fengxia; Gao, Xuelu; Song, Jinming; Chen, Chen-Tung Arthur; Yuan, Huamao; Xing, Qianguo

    2018-05-01

    The absorption properties of chromophoric dissolved organic matter (CDOM) in the East China Sea (ECS) and the waters off eastern Taiwan (WET) were studied during May 2014. CDOM absorption coefficient (a280) and spectral slope (S275-295) revealed considerable spatial variations. In the ECS, the values of a280 and S275-295 presented a reverse distribution pattern. In the WET, a280 values were generally low while S275-295 values were generally high. Vertical distributions of a280 and S275-295 also varied in different regions. Terrestrial input, phytoplankton production, sediment release or photobleaching may be responsible for the dynamics of CDOM. Relationships among CDOM related parameters could partly support this conclusion. a280 were also used to trace different water masses and the result showed that the influence of Changjiang Diluted Water could reach the outer shelf of the northern ECS, and that the Kuroshio Current had a strong influence on the middle shelf of the southern ECS.

  7. Effects of habitat and substrate complexity on shallow sublittoral fish assemblages in the Cyclades Archipelago, North-eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    S. GIAKOUMI

    2013-02-01

    Full Text Available This is the first study to explore fish community structure and its relations to habitat and topographic complexity in the shallow coastal waters of the Cyclades Archipelago, North-eastern Mediterranean Sea. In situ visual surveys were carried out at 233 sampling sites in 26 islands of the Cyclades Archipelago. Fish community parameters and biomass were estimated across seven substrate types: sand, seagrass, vertical walls, boulders, horizontal/subhorizontal continuous rock, rocky substrate with patches of sand, and rocky substrate with patches of sand and Posidonia oceanica. Topographic complexity and percentage of algal cover were estimated on hard substrate. Substrate type was found to be a determining factor affecting the structure and composition of fish assemblages. Species number, abundance and biomass were significantly lower in sandy areas and always higher on hard substrates, with seagrass habitats presenting intermediate values. Topographic complexity in rocky bottoms did not seem to affect species richness, density or biomass. This study provides a baseline for future evaluation of changes produced by potential management actions such as the creation of marine protected areas in the study region.

  8. Patterns in connectivity and retention of simulated Tanner crab (Chionoecetes bairdi) larvae in the eastern Bering Sea

    Science.gov (United States)

    Richar, Jonathan I.; Kruse, Gordon H.; Curchitser, Enrique; Hermann, Albert J.

    2015-11-01

    The eastern Bering Sea (EBS) population of Tanner crab (Chionoecetes bairdi) has exhibited high variability in recruitment to the commercially exploited stock since the late 1970s. Concurrently, apparent shifts in crab distribution have also been observed. Larval advection patterns and associated local retention offer a potential mechanism for these observations. The Regional Ocean Modeling System (ROMS) was used to simulate larval Tanner crab advection patterns over 1978-2004 based on larval hatching sites inferred from the distributions of reproductive females sampled during annual National Marine Fisheries Service trawl surveys. Connectivity among EBS subregions was examined by comparing start and end float locations after 60 days of simulated drift. High levels of retention (>50% of floats) were observed in the majority of source subregions, and contributed significantly to the total number of endpoints in each region. Patterns in advection and resultant interregional connectivity were variable, with strongest sustained connectivity occurring along shelf, within individual domains. Increased settlement potential in the outer domain and southern middle domain after 1990 is consistent with an observed geographic shift in fishery productivity. Apparent reliance of Bristol Bay on local larval retention validates recent spatial fishery management to conserve this area as a subpopulation.

  9. Vertical nutrient fluxes, turbulence and the distribution of chlorophyll a in the north-eastern North Sea

    Science.gov (United States)

    Bendtsen, Jørgen; Richardson, Katherine

    2017-04-01

    During summer the northern North Sea is characterized by nutrient rich bottom water masses and nutrient poor surface layers. This explains the distribution of chlorophyll a in the water column where a subsurface maximum, referred to as the deep chlorophyll maximum (DCM), often is present during the growth season. Vertical transport of nutrients between bottom water masses and the well lit surface layer stimulates phytoplankton growth and this generally explains the location of the DCM. However, a more specific understanding of the interplay between vertical transports, nutrient fluxes and phytoplankton abundance is required for identifying the nature of the vertical transport processes, e.g the role of advection versus vertical turbulent diffusion or the role of localized mixing associated with mesoscale eddies. We present results from the VERMIX study in the north-eastern North Sea where nutrients, chlorophyll a and turbulence profiles were measured along five north-south directed transects in July 2016. A high-resolution sampling program, with horizontal distances of 1-10 km between CTD-stations, resolved the horizontal gradients of chlorophyll a across the steep bottom slope from the relatively shallow central North Sea ( 50-80 m) towards the deep Norwegian Trench (>700 m). Low oxygen concentrations in the bottom water masses above the slope indicated enhanced biological production where vertical mixing would stimulate phytoplankton growth around the DCM. Measurements of variable fluorescence (Fv/Fm) showed elevated values in the DCM which demonstrates a higher potential for electron transport in the Photosystem II in the phytoplankton cells, i.e. an indication of nutrient-rich conditions favorable for phytoplankton production. Profiles of the vertical shear and microstructure of temperature and salinity were measured by a VMP-250 turbulence profiler and the vertical diffusion of nutrients was calculated from the estimated vertical turbulent diffusivity and the

  10. Relations between tectonics and sedimentation along the Eastern Sardinian margin (Western Tyrrhenian Sea) : from rifting to reactivation

    Science.gov (United States)

    Gaullier, Virginie; Chanier, Frank; Vendeville, Bruno; Lymer, Gaël; Maillard, Agnès; Thinon, Isabelle; Lofi, Johanna; Sage, Françoise; Giresse, Pierre; Bassetti, Maria-Angela

    2014-05-01

    The offshore-onshore project "METYSS-METYSAR" aims at better understand the Miocene-Pliocene relationships between crustal tectonics, salt tectonics, and sedimentation along the Eastern Sardinian margin, Western Tyrrhenian Sea. In this key-area, the Tyrrhenian back-arc basin underwent recent rifting (9-5 Ma), pro parte coeval with the Messinian Salinity Crisis (MSC, 5.96-5.33 Ma), sea-floor spreading starting during Pliocene times. Thereby, the Tyrrhenian basin and the Eastern Sardinian margin are excellent candidates for studying the mechanisms of extreme lithospheric stretching and thinning, the role of pre-existing structural fabric during and after rifting, and the reactivation of a passive margin and the associated deformation and sedimentation patterns during the MSC. We looked at the respective contributions of crustal and salt tectonics in quantifying vertical and horizontal movements, using especially the seismic markers of the MSC. Overall, we delineate the history of rifting and tectonic reactivation in the area. The distribution maps respectively of the Messinian Erosion Surface and of Messinian units (Upper Unit and Mobile Unit) show that a rifted basin already existed by Messinian time. This reveals a major pre-MSC rifting across the entire domain. Because salt tectonics can create fan-shaped geometries in sediments, syn-rift deposits have to be carefully re-examined in order to decipher the effects of crustal tectonics (rifting) and thin-skinned salt tectonics. Our data surprisingly show that there are no clues for Messinian syn-rift sediments along the East-Sardinia Basin and Cornaglia Terrace, hence no evidence for rifting after Late Tortonian times. Nevertheless, widespread deformation occurred during the Pliocene and can only be attributed to post-rift reactivation. This reactivation is characterized not only by normal faulting but also by contractional structures. Some Pliocene vertical movements caused localized gravity gliding of the mobile

  11. The Rough-Toothed Dolphin, Steno bredanensis, in the Eastern Mediterranean Sea: A Relict Population?

    Science.gov (United States)

    Kerem, D; Goffman, O; Elasar, M; Hadar, N; Scheinin, A; Lewis, T

    Only recently included among the cetacean species thought to regularly occur in the Mediterranean, the rough-toothed dolphin (Steno bredanensis) is an obscure and enigmatic member of this ensemble. Preliminary genetic evidence strongly indicates an Atlantic origin, yet the Mediterranean distribution for this species is conspicuously detached from the Atlantic, with all authenticated records during the last three decades being east of the Sicilian Channel and most within the bounds of the Levantine Basin. These dolphins are apparently a small, relict population, probably the remnant of a larger one, contiguous with that in the Atlantic and nowadays entrapped in the easternmost and warmest province. Abundance data are lacking for the species in the Mediterranean. Configuring acoustic detection software to recognise the apparently idiosyncratic vocalisations of rough-toothed dolphins in past and future acoustic recordings may prove useful for potential acoustic monitoring. Evidence accumulated so far, though scant, points to seasonal occupation of shallow coastal waters. Vulnerability to entanglement in gill-nets, contaminants in the region, and the occurrence of mass strandings (possibly in response to anthropogenic noise), are major conservation concerns for the population in the Mediterranean Sea. © 2016 Elsevier Ltd. All rights reserved.

  12. Changes in the Adriatic oceanographic properties induced by the Eastern Mediterranean Transient

    Directory of Open Access Journals (Sweden)

    I. Vilibić

    2012-06-01

    Full Text Available Long-term time series of physical and chemical parameters collected between 1960 and 2010 along the Palagruža Sill transect, Middle Adriatic Sea, have been investigated in terms of average water properties and their variability. Nutrients, especially orthophosphates, reached rather high levels of concentration below the euphotic zone between 1991 and 1998, the highest levels in the investigated period. Simultaneously, the N:P ratio, which is normally higher than 25:1, decreased to values less than 16:1 in the euphotic zone, indicating a switch from typical phosphorus to nitrogen- limited preconditioning for the primary production. Higher-than-usual nutrient levels peaking in the mid-1990s, coupled with lower-than-usual temperature, salinity, dissolved oxygen and pH values, are presumably related to the flow of the nutrient richer Western Mediterranean waters to the Adriatic below the euphotic layer. These waters, which keep their footprint in the N:P ratio, enter the Adriatic during the anticyclonic phase of the Bimodal Adriatic-Ionian Oscillation (BiOS, which has been uniquely strengthened by the Eastern Mediterranean Transient occurring in the early 1990s. This hypothesis should be confirmed through targeted research and modelling exercises, as it is highly relevant for the biogeochemistry of the Adriatic Sea.

  13. Changes in distributional patterns of plaice Pleuronectes platessa in the central and eastern North Sea; do declining nutrient loadings play a role?

    DEFF Research Database (Denmark)

    Støttrup, Josianne Gatt; Munk, Peter; Kodama, Masashi

    2017-01-01

    of offshore habitats as nursery areas by juvenile plaice in the North Sea appears not related to water depth per se but driven by specific processes dominating in near-shore areas and may be related to changes in nutrient loadings. This point to the importance of separating more general depth-related factors....... For the same time period available time series data on nutrient conditions in the coastalNorth Sea area showthat the freshwater nitrogen loading has decreased by about 50%. While nutrient concentrations in the ambient environment have been shown to influence growth in juvenile plaice through influence...... on their prey, we here inspect the potential linkage between distributional changes in plaice and the decline in nutrient loading.We compare plaice observations in coastal areas in the eastern North Sea,which have experienced large changes in eutrophication,with observations for the Dogger Bank, a large...

  14. Constraining back-arc basin formation in the eastern Coral Sea: preliminary results from the ECOSAT voyage

    Science.gov (United States)

    Seton, M.; Williams, S.; Mortimer, N. N.; Meffre, S.; Moore, J.; Micklethwaite, S.; Zahirovic, S.

    2013-12-01

    The eastern Coral Sea region is an underexplored area at the northeastern corner of the Australian plate, where long-lived interaction between the Pacific and Australian plate boundaries has resulted in an intricate assemblage of deep oceanic basins and ridges, continental fragments and volcanic products. A paucity of marine geophysical and geological data from this complex region has resulted in the lack of a clear conceptual framework to describe its formation, ultimately affecting our understanding of the connection between the plate boundaries of the SW Pacific and SE Asia. In particular, the tectonic relationship between two back-arc basins, the Santa Cruz and d'Entrecasteaux Basins, and the South Rennell Trough, has yet to be resolved. In October-November, 2012, we collected 6,200 km of marine magnetic, 6,800 km of gravity and over 13,600 km2 of swath bathymetry data from the eastern Coral Sea onboard the RV Southern Surveyor. A complementary dredging program yielded useful samples from 14 seafloor sites. Our preliminary geochemical interpretation of the dredge samples obtained from the South Rennell Trough reveal volcanic rocks resembling MORB or BABB-type basalts, similar in composition to the recently re-analysed and dated ORSTOM dredges from the area that yielded ~28 Ma MORB-like basalts. Swath bathymetry profiles from the Santa Cruz Basin reveal that the South Rennell Trough extends into this basin, with seafloor spreading fabric being parallel to the trough. Preliminary analysis of the three full and four partial new magnetic anomaly profiles across the Santa Cruz Basin, coupled with limited existing profiles, reveals that the basin may have formed between Chrons 13-18 (~32-38 Ma), with an extinct spreading ridge along the inferred continuation of the South Rennell Trough, consistent with ORSTOM age dates. Our results suggest that the South Rennell Trough is an extinct southwestward propagating spreading ridge, which may have initiated along a pre

  15. Aspects on gametogenesis, fertilization and embryogenesis of two deep-sea polychaetes from Eastern Atlantic cold seeps

    Science.gov (United States)

    Gaudron, S. M.; Hourdez, S.; Olu, K.

    2017-11-01

    We investigated two gonochoristic species of annelid polychaetes (one siboglinid and one polynoid) from cold seeps that ranged from 525 m to 3300 m in depth (Guiness, Worm Hole and Regab pockmarks) on the Gabon and Congo continental margins (Gulf of Guinea). Different aspects of gametogenesis (oocyte diameter, presence of ovisac, spermatozoa shape, and fecundity), fertilization (in vitro fertilization experiments: IVF) and embryogenesis (cleavage rate) were studied. The sampled siboglinid was a new species of Lamellibrachia and the second population of this genus in the Eastern Atlantic. Mean oocyte diameter was about 100 μm and fully-grown primary oocytes were stored in an ovisac, as in other studied siboglinids. The presence of a single spermatozoon was noted within an oviduct, indicating a possible internal fertilization. The rate of cell division at 6 °C was one cleavage every 20 h. Embryos developed normally to the blastula stage after 5-d post-fertilization at atmospheric pressure suggesting some pressure tolerance. The second polychaete was the scale-worm Branchipolynoe cf. seepensis that lives in commensalism in the mantle cavity of Bathymodiolus aff. boomerang. Anatomical reproductive features were similar to those described in B. seepensis from hydrothermal vents on Mid-Atlantic Ridge, with lecithotrophic larval development and continuous gametogenesis. We performed the first IVF carried out on gametes for any deep-sea polynoid species. Fertilization and development occurred but a number of abnormalities were observed demonstrating a limitation to embryogenesis at atmospheric pressure. The rate of cell division was three times faster at 8 °C than at 4 °C with a maximum stage of 8-cells reached after 72 h post-fertilization. We surprisingly observed some oocytes from the negative seawater control during IVF experiments cleaved to the 2-cell stage, demonstrating the possible occurrence of internal fertilization prior to IVF experiment or the accidental

  16. A Review of Plastic-Associated Pressures: Cetaceans of the Mediterranean Sea and Eastern Australian Shearwaters as Case Studies

    Directory of Open Access Journals (Sweden)

    Maria Cristina Fossi

    2018-05-01

    Full Text Available Impacts of debris on marine fauna occur throughout the marine ecosystems, with adverse impacts documented on over 1,400 species; impacts can be divided into those arising from entanglement, and those from ingestion. Ingestion of, and entanglement in, debris has been documented in over 60% of all cetacean species. Seabirds are also impacted by debris predominately through entanglement and ingestion, with the number of species negatively impacted increasing from 138 to 174 over the past two decades. In the marine environment, cetaceans and seabirds are widely regarded as reliable sentinels due to their position near the top of the marine food web, conspicuous nature, and reliance on marine resources; for this reason, this paper is focused on seabirds and cetaceans as sentinels of ocean change. In particular, two case studies are considered in relation to different levels of environmental anthropogenic impact: the cetaceans of the Mediterranean Sea and seabirds of eastern Australia. Here we describe two recent studies used to diagnose the toxicological stress related to debris-associated pressures in cetaceans and seabirds. These studies highlight the diversity and scale of impacts being felt by marine species and the role these organisms can play in our society as charismatic sentinels of ocean health. Seabirds and marine mammals are exposed, in these key areas, to a variety of adversities that potentially decrease their survival or reproductive success. These include weather, food shortages, predators, competitors, parasites, disease, and human-induced effects and plastic pollution. Each factor affects seabirds and marine mammals in a different way, but more importantly, factors can also interact and create impacts far greater than any one factor alone. The Australian and Mediterranean case studies presented here emphasize the need to consider multiple sources of mortality when developing management plans for the conservation of vulnerable

  17. Updated analysis of flatfish recruitment response to climate variability and ocean conditions in the Eastern Bering Sea

    Science.gov (United States)

    Wilderbuer, Thomas; Stockhausen, William; Bond, Nicholas

    2013-10-01

    This study provides a retrospective analysis of the relationship between physical oceanography, biology and recruitment of three Eastern Bering Sea flatfish stocks: flathead sole (Hippoglossoides elassodon), northern rock sole (Lepidopsetta polyxystra), and arrowtooth flounder (Atheresthes stomias) during the period 1978-2005. Stock assessment model estimates of recruitment and spawning stock size indicate that temporal patterns in productivity are consistent with decadal scale (or shorter) patterns in climate variability, which may influence marine survival during the early life history phases. Density-dependence (through spawning stock size) was statistically significant in a Ricker stock-recruit model of flatfish recruitment that included environmental terms. Wind-driven advection of northern rock sole and flathead sole larvae to favorable nursery grounds was found to coincide with years of above-average recruitment. Ocean forcing of Bristol Bay surface waters during springtime was mostly on-shelf (eastward) during the 1980s and again in the early 2000s, but was off-shelf (westerly) during the 1990s, corresponding with periods of good and poor recruitment, respectively. Finally, the Arctic Oscillation was found to be an important indicator of arrowtooth flounder productivity. Model results were applied to IPCC (Intergovernmental Panel on Climate Change) future springtime wind scenarios to predict the future impact of climate on northern rock sole productivity and indicated that a moderate future increase in recruitment might be expected because the climate trends favor on-shelf transport but that density-dependence will dampen this effect such that northern rock sole abundance will not be substantially affected by climate change.

  18. An illustrated catalogue of Rudolf Sturany’s type specimens in the Naturhistorisches Museum Wien, Austria (NHMW: deep-sea Eastern Mediterranean molluscs

    Directory of Open Access Journals (Sweden)

    Paolo G. Albano

    2018-01-01

    Full Text Available The “Pola” expeditions were the first to explore the deep Eastern Mediterranean Sea in the 1890s. They remained the most intense surveys in that area for a century and constitute today a fundamental baseline to assess change in the basin, whose fauna is still inadequately described. Solid taxonomic foundations for the study of deep-sea organisms are needed and we here contribute by revising the name-bearing types of mollusc species introduced by Rudolf Sturany on the basis of the “Pola” material from the Eastern Mediterranean Sea stored in the Natural History Museum in Vienna. Sturany introduced 15 names (Marginella occulta var. minor Sturany, 1896 shall not be considered as the introduction of a new name. He described and established two manuscript names by Monterosato: Jujubinus igneus and Pseudomurex ruderatus. The genus Isorropodon was also introduced together with its type species I. perplexum. For each name, we list the available type material, provide the original description and a translation into English and illustrate the specimens in colour and with SEM imaging.

  19. A comparison of the physics of the northern and southern shelves of the eastern Bering Sea and some implications for the ecosystem

    Science.gov (United States)

    Stabeno, Phyllis J.; Farley, Edward V., Jr.; Kachel, Nancy B.; Moore, Sue; Mordy, Calvin W.; Napp, Jeffrey M.; Overland, James E.; Pinchuk, Alexei I.; Sigler, Michael F.

    2012-06-01

    Sufficient oceanographic measurements have been made in recent years to describe the latitudinal variation in the physics of the eastern Bering Sea shelf and the potential impact of climate change on the species assemblages in the two ecosystems (north and south). Many of the predicted ecosystem changes will result from alterations in the timing and extent of sea ice. It is predicted that the sea ice in the northern Bering Sea will be less common in May, but will continue to be extensive through April. In contrast, the southern shelf will have, on average, much less sea ice than currently observed, but with large interannual and multiyear variability until at least 2050. Thus, even under current climate warming scenarios, bottom temperatures on the northern shelf will remain cold. Based on biophysical measurements, the southern and northern ecosystems were divided by a North-South Transition at ˜60°N. The northern middle shelf was characterized by a freshwater lens at the surface, cold bottom temperatures, and a thicker pycnocline than found on the southern shelf. Subsurface phytoplankton blooms were common. In contrast, the southern shelf stratification was largely determined by temperature alone; the pycnocline was thin (oftenstomias, respectively) are unlikely to become common in the north. The projected warming of the southern shelf will limit the distribution of arctic species (e.g., snow crab, Chionoecetes opilio) to the northern shelf and will likely permit expansion of subarctic species into the southern Bering Sea. The distribution and abundance of baleen whales will respond to shifts in prey availability; for instance, if prey are advected northward from the southeastern Bering Sea, an extension of range and an increase in seasonally migratory baleen whale numbers is anticipated. Thus, alteration of this ecosystem in response to climate change is expected to result in something other than a simple northward shift in the distribution of all species.

  20. Biological parameters and feeding behaviour of invasive whelk Rapana venosa Valenciennes, 1846 in the south-eastern Black Sea of Turkey

    Directory of Open Access Journals (Sweden)

    Hacer Saglam

    2014-06-01

    Full Text Available Objective: To determine length-weight relationships, growth type and feeding behavior of the benthic predator Rapa whelk at the coast of Camburnu, south-eastern Black Sea. Methods: Rapa whelk was monthly collected by dredge sampling on the south-eastern Black Sea at 20 m depth. The relationships between morphometric parameters of Rapa whelk were described by linear and exponential models. The allometric growth of each variable relative to shell length (SL was calculated from the function Y=aSLb or logY=loga+blogSL. The functional regression b values were tested by t-test at the 0.05 significance level if it was significantly different from isometric growth. The total time spent on feeding either on mussel tissue or live mussels was recorded for each individual under controlled conditions in laboratory. Results: The length-weight relationships showed positive allometric growth and no inter-sex variability. Body size in the male population was significantly higher than in the individuals of the female. All characters in males and females showed a trend towards allometry rather than isometry. While the total time spent feeding increased with increasing prey size the total time that Rapana venosa spent feeding decreased with increasing Rapa whelk size. The total average feeding time needed by Rapa whelks was 160 min. But they took 310 min on live mussels in 27-28 °C in the laboratory conditions. Conclusions: Length and weight relationships, growth type, total time spent feeding of this species were explained in details for this region. It would be useful to sustainable management in the south-eastern Black Sea of Turkey. The results about the feeding behaviour of this species will contribute to the understanding of the role of this species within the ecosystem.

  1. Taxonomy of the early life stages of arrowtooth flounder (Atheresthes stomias) and Kamchatka flounder (A. evermanni) in the eastern Bering Sea, with notes on distribution and condition

    Science.gov (United States)

    De Forest, Lisa; Duffy-Anderson, J. T.; Heintz, R. A.; Matarese, A. C.; Siddon, E. C.; Smart, T. I.; Spies, I. B.

    2014-11-01

    Arrowtooth flounder (Atheresthes stomias) and Kamchatka flounder (A. evermanni) are closely related flatfish species that co-occur in the eastern Bering Sea. As adults, arrowtooth flounder can be distinguished from Kamchatka flounder; however, larvae and early juveniles can only be indentified to the genus level due to morphological similarities. This has precluded studies of ecology for the early life stages of both species in the eastern Bering Sea. In this study, we developed a genetic technique to identify the larvae and early juveniles of the two species using mtDNA cytochrome oxidase subunit I (COI). Genetically identified specimens were then examined to determine a visual identification method based on pigment patterns and morphology. Specimens 6.0-12.0 mm SL and≥18.0 mm SL can be identified to the species level, but species identification of individuals 12.1-17.9 mm SL by visual means alone remains elusive. The distribution of larvae (<25.0 mm SL) of both arrowtooth flounder and Kamchatka flounder is similar in the eastern Bering Sea; however, juvenile (≥25.0 mm SL) Kamchatka flounder occur closer to the shelf break and in deeper water than juvenile arrowtooth flounder. Condition was determined for larvae and juveniles of each species by analyzing lipid content (%) and energy density (kJ/g dry mass). Kamchatka flounder larvae on average had higher lipid content than arrowtooth flounder larvae, but were also larger on average than arrowtooth flounder larvae in the summer. When corrected for length, both species had similar lipid content in the larval and juvenile stages.

  2. An archaic ionian inscription in Huelva | Una inscripción jonia arcaica en Huelva

    OpenAIRE

    Jesús Fernández Jurado; Ricardo Olmos Romera

    1985-01-01

    We analyse in this paper a bowl fragment, probably Milesian, which comes from the excavations of Calle del Puerto, in the Tartessian settlement of Huelva. Along the outside lip runs an archaic Ionian inscription —middle of the 6th c. B .C.— whose interpretation is particularly difficult. It may be a dedication or offering made by a Greek for a local chief. But nothing can be said about it with certainty. | Se estudia en este artículo un fragmento de cuenco, probablemente milesio, que procede ...

  3. The Adriatic-Ionian Macroregion in the Eurasian Socio-economic Future

    Directory of Open Access Journals (Sweden)

    Carlo Carboni

    2014-12-01

    Full Text Available This paper discusses the economic and social potential enabled by the Adriatic Ionian Macroregion (AIMr, characterized by a diffuse industrial pattern based on small and mediumsized enterprises, located in a European periphery, logistics and politics. The analyses show a diverse environment, made up of territories and states that move between vitality, modernization, economic backwardness and social inadequacy of infrastructure networks. In reference to the pillars identified by the EU, the ability to develop investments agreements with strategic political partnership between the states are the main instruments to achieve the objectives of modernizing the infrastructure and technology of this new political and economic realities.

  4. Neogene Tectonics of Part of the Junction of Cyprus and Hellenic Arcs in the Eastern Mediterranean Sea

    Science.gov (United States)

    Küçük, H. M.; Dondurur, D.; ćifçi, G.; Gürçay, S.; Hall, J.; Yaltırak, C.; Aksu, A. E.

    2012-04-01

    the Finike Basin is puzzling and requires that the Finike Basin either remained above the depositional surface during the Messinian or was isolated from the eastern Mediterranean Sea.

  5. Reprint of - Deep-sea coral and hardbottom habitats on the west Florida slope, eastern Gulf of Mexico

    Science.gov (United States)

    Ross, Steve W.; Rhode, Mike; Brooke, Sandra

    2017-09-01

    Until recently, benthic habitats dominated by deep-sea corals (DSC) appeared to be less extensive on the slope of the Gulf of Mexico (GOM) than in the northeast Atlantic Ocean or off the southeastern US. There are relatively few bioherms (i.e., coral-built mounds) in the northern GOM, and most DSCs are attached to existing hard substrata (e.g., authigenically formed carbonate). The primary structure-forming, DSC in the GOM is Lophelia pertusa, but structure is also provided by other living and dead scleractinians, antipatharians (black corals), octocorals (gorgonians, soft corals), hydrocorals and sponges, as well as abundant rocky substrata. The best development of DSCs in the GOM was previously documented within Viosca Knoll oil and gas lease blocks 826 and 862/906 (north-central GOM) and on the Campeche Bank (southern GOM in Mexican waters). This paper documents extensive deep reef ecosystems composed of DSC and rocky hard-bottom recently surveyed on the West Florida Slope (WFS, eastern GOM) during six research cruises (2008-2012). Using multibeam sonar, CTD casts, and video from underwater vehicles, we describe the physical and oceanographic characteristics of these deep reefs and provide size or area estimates of deep coral and hardground habitats. The multibeam sonar analyses revealed hundreds of mounds and ridges, some of which were subsequently surveyed using underwater vehicles. Mounds and ridges in <525 m depths were usually capped with living coral colonies, dominated by L. pertusa. An extensive rocky scarp, running roughly north-south for at least 229 km, supported lower abundances of scleractinian corals than the mounds and ridges, despite an abundance of settlement substrata. Areal comparisons suggested that the WFS may exceed other parts of the GOM slope in extent of living deep coral coverage and other deep-reef habitat (dead coral and rock). The complex WFS region warrants additional studies to better understand the influences of oceanography and

  6. Eastern Baltic Sea Region

    DEFF Research Database (Denmark)

    Jakobsen, Johnny Grandjean Gøgsig

    2016-01-01

    Kort over den østlige Østersøregion i middelalderen med angivelse af lokaliteter omtalt i antologien, placeret på s.8 i bogen "Church and Belief in the Middle Ages", red. Kirsi Salonen & Sari Katajala-Peltomaa (Amsterdam, 2016).......Kort over den østlige Østersøregion i middelalderen med angivelse af lokaliteter omtalt i antologien, placeret på s.8 i bogen "Church and Belief in the Middle Ages", red. Kirsi Salonen & Sari Katajala-Peltomaa (Amsterdam, 2016)....

  7. Early-to-middle Holocene sea-level fluctuations, coastal progradation and the Neolithic occupations in Yaojiang valley of southern Hangzhou bay, eastern China

    Science.gov (United States)

    Liu, Y.; Sun, Q.; Fan, D.; Chen, Z.

    2017-12-01

    The formation of Holocene coast in eastern China provided material base for the development of Neolithic civilizations. The coastal Yaojiang valley of south Hangzhou bay was one of the examples where the well-known Neolithic Hemudu Culture (HC) of Eastern China initiated. Here, we studied the early-to-middle Holocene environment changes in relation to sea-level fluctuations on the basis of a serial of sediment cores based on a set of new Accelerator Mass Spectrometry radiocarbon (AMS 14C) chronology. The result indicated that relative sea-level rose rapidly in the Yaojiang valley at the early Holocene, reaching its maximum at ca. 8000-7800 cal yr BP and then decelerated at ca. 7800-7500 cal yr BP. The alluvial plain in Yaojiang valley began to form at the foothills first and then grew towards the valley center accompanying with the sea-level stabilization after ca. 7500 cal yr BP. This progressive progradation of alluvial plain would attract the early arrivals of foragers to dwell at the foothills to engaging in rice farming after ca.7000 cal yr BP and starting the epic Hemudu Culture. The HC people then move down to the valley center as more land became available thanks to sediment aggregation and progradation. The rise and development of HC were closely associated with the sea-level induced landscape changes in Yaojiang valley at the early-middle Holocene, and the unstable hydraulic condition in the valley after 5000 cal yr BP could be accountable for the cultural termination.

  8. Variability and connectivity of plaice populations from the Eastern North Sea to the Western Baltic Sea, and implications for assessment and management

    DEFF Research Database (Denmark)

    Ulrich, Clara; Boje, Jesper; Cardinale, Massimiliano

    2013-01-01

    and management. Plaice in Kattegat and Skagerrak have traditionally been considered as one stock unit. Current understanding indicates that several plaice components may exist in the transition area between the North Sea and the Baltic Sea. A comprehensive review of all available biological knowledge on plaice...

  9. Worst-Case Scenario Tsunami Hazard Assessment in Two Historically and Economically Important Districts in Eastern Sicily (Italy)

    Science.gov (United States)

    Armigliato, A.; Tinti, S.; Pagnoni, G.; Zaniboni, F.; Paparo, M. A.

    2015-12-01

    The portion of the eastern Sicily coastline (southern Italy), ranging from the southern part of the Catania Gulf (to the north) down to the southern-eastern end of the island, represents a very important geographical domain from the industrial, commercial, military, historical and cultural points of view. Here the two major cities of Augusta and Siracusa are found. In particular, the Augusta bay hosts one of the largest petrochemical poles in the Mediterranean, and Siracusa is listed among the UNESCO World Heritage Sites since 2005. This area was hit by at least seven tsunamis in the approximate time interval from 1600 BC to present, the most famous being the 365, 1169, 1693 and 1908 tsunamis. The choice of this area as one of the sites for the testing of innovative methods for tsunami hazard, vulnerability and risk assessment and reduction is then fully justified. This is being developed in the frame of the EU Project called ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe (Grant 603839, 7th FP, ENV.2013.6.4-3). We assess the tsunami hazard for the Augusta-Siracusa area through the worst-case credible scenario technique, which can be schematically divided into the following steps: 1) Selection of five main source areas, both in the near- and in the far-field (Hyblaean-Malta escarpment, Messina Straits, Ionian subduction zone, Calabria offshore, western Hellenic Trench); 2) Choice of potential and credible tsunamigenic faults in each area: 38 faults were selected, with properly assigned magnitude, geometry and focal mechanism; 3) Computation of the maximum tsunami wave elevations along the eastern Sicily coast on a coarse grid (by means of the in-house code UBO-TSUFD) and extraction of the 9 scenarios that produce the largest effects in the target areas of Augusta and Siracusa; 4) For each of the 9 scenarios we run numerical UBO-TSUFD simulations over a set of five nested grids, with grid cells size decreasing from 3 km in the open Ionian

  10. Evaluation of genetic diversity of cultivated tea clones (Camellia sinensis (L. Kuntze in the eastern black sea coast by inter-simple sequence repeats (ISSRS

    Directory of Open Access Journals (Sweden)

    Beris Fatih S.

    2016-01-01

    Full Text Available Tea is the most globally consumed drink after spring water and an important breeding plant with high economical value in Turkey. In half a century, various kinds of tea cultivars have been bred in Turkey to improve the quality and yield of tea plants. Since tea reproduces sexually, tea fields vary in quality. Thus, determining the genetic diversity and relationship of the plants to support breeding and cultivation is important. In this study we aimed to determine the genetic diversity of tea cultivars breeding in the Eastern Black Sea coast of Turkey and the genetic relationship between them, to verify whether the qualitative morphological designations of the clones are genetically true by the ISSR markers. Herein, the genetic diversity and relationships of 18 Turkish tea cultivars were determined using 15 ISSR markers with sizes ranging from 250 to 3000 base pairs. The similarity indices among these cultivars were between 0.456 and 0.743. Based on cluster analysis using UPGMA, some of tea cultivars originating from the same geographical position were found to be clustered closely. Our data provide valuable information and a useful basis to assist selection and cloning experiments of tea cultivars and also help farmers to find elite parental clones for tea breeding in the Eastern Black Sea coast of Turkey.

  11. Variability in the air–sea interaction patterns and timescales within the south-eastern Bay of Biscay, as observed by HF radar data

    Directory of Open Access Journals (Sweden)

    A. Fontán

    2013-04-01

    Full Text Available Two high-frequency (HF radar stations were installed on the coast of the south-eastern Bay of Biscay in 2009, providing high spatial and temporal resolution and large spatial coverage of currents in the area for the first time. This has made it possible to quantitatively assess the air–sea interaction patterns and timescales for the period 2009–2010. The analysis was conducted using the Barnett–Preisendorfer approach to canonical correlation analysis (CCA of reanalysis surface winds and HF radar-derived surface currents. The CCA yields two canonical patterns: the first wind–current interaction pattern corresponds to the classical Ekman drift at the sea surface, whilst the second describes an anticyclonic/cyclonic surface circulation. The results obtained demonstrate that local winds play an important role in driving the upper water circulation. The wind–current interaction timescales are mainly related to diurnal breezes and synoptic variability. In particular, the breezes force diurnal currents in waters of the continental shelf and slope of the south-eastern Bay. It is concluded that the breezes may force diurnal currents over considerably wider areas than that covered by the HF radar, considering that the northern and southern continental shelves of the Bay exhibit stronger diurnal than annual wind amplitudes.

  12. Unlocking the hydrocarbon potential of the eastern Black Sea basin. Prospectivity of middle Miocene submarine fan reservoirs by seismic sequence stratigraphy

    International Nuclear Information System (INIS)

    Gundogan, Coskun; Galip, Ozbek; Ali, Demirer

    2002-01-01

    Full text : The objective of this paper is to present present depositional characteristics and hydrocarbon prospectivity of the middle Miocene submarine basin floor fan deposits from the exploration stand point of view by using seismic data available in the offshore eastern Black Sea basin. This basin is a Tertiary trough formed as a continuation of the Mesozoic oceanic basin. The hydrocarbon potential of the basin is believed to be high in the Tertiary section because of the existence of the elements necessary for generation, migration and entrapment of hydrocarbon. A sequence stratigraphic study has been carried out by using 2-d seismic data in the Turkish portion of the eastern Black Sea basin. The objective of the study was to determine periods of major clastic sediment influxes which might lead to identify good reservoir intervals and their spatial distribution in this basin. All basic seismic sequence stratigraphic interpretation techniques and seismic facies analysis were used to identify times of these sand rich deposition periods. Sequence stratigraphy and seismic facies analysis indicate that the basinal areas of the middle Miocene sequences were dominated mainly by submarine fan complexes introduced in the lowstand stages and pelagic sediments deposited during the transgressive and highstand stages. It was proposed that Turkish portion of this basin which is one of the best frontier exploration area with its high potential left in the world, is glimpsing to those looking for good future exploration opportunities.

  13. 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.

  14. Hydrography and biogeochemistry of the north western Bay of Bengal and the north eastern Arabian Sea during winter monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Laluraj, C.M.; Jyothibabu, R.; Madhu, N.V.; Muraleedharan, K.R.; Vijay, J.G.; Maheswaran, P.A.; Ashraf, T.T.M.; Nair, K.K.C.; Achuthankutty, C.T.

    in the Arabian Sea is driven by net heat loss from the ocean, whereas the Bay of Bengal does not contribute to such large heat loss to the atmosphere. It appears that the subduction of high saline Arabian Sea water mass is the mechanism behind the formation of a...

  15. Changes in distributional patterns of plaice Pleuronectes platessa in the central and eastern North Sea; do declining nutrient loadings play a role?

    Science.gov (United States)

    Støttrup, Josianne G.; Munk, Peter; Kodama, Masashi; Stedmon, Colin

    2017-09-01

    Since the beginning of the 1990s, there has been a change in the relative distribution of smaller age-classes of plaice Pleuronectes platessa (age 1-3) in the North Sea. The abundances have increased in deeper, more offshore areas, while coastal abundances have been stagnant or declining. For the same time period available time series data on nutrient conditions in the coastal North Sea area show that the freshwater nitrogen loading has decreased by about 50%. While nutrient concentrations in the ambient environment have been shown to influence growth in juvenile plaice through influence on their prey, we here inspect the potential linkage between distributional changes in plaice and the decline in nutrient loading. We compare plaice observations in coastal areas in the eastern North Sea, which have experienced large changes in eutrophication, with observations for the Dogger Bank, a large sandbank in a shallow offshore area of the North Sea. The Dogger Bank, was used as a reference location assuming this area has been less influenced from coastal eutrophication but similar regional climate conditions, and here we found no changes in the abundances of juvenile plaice. The increase in the use of offshore habitats as nursery areas by juvenile plaice in the North Sea appears not related to water depth per se but driven by specific processes dominating in near-shore areas and may be related to changes in nutrient loadings. This point to the importance of separating more general depth-related factors from conditions specific for near-shore areas, such as nutrient loadings in coastal waters and export offshore. The concurrent changes in environment and in distribution of juvenile plaice may have implications for environmental and fisheries management.

  16. Rock-block configuration in Uppland and the Aalands-hav basin, the regional surroundings of the SKB site in Forsmark, Sea and land areas, eastern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Beckholmen, Monica; Tiren, Sven A. (GEOSIGMA AB (Sweden))

    2010-12-15

    The Forsmark SKB site lies at the west-northwest trending shoreline in northern Uppland, sheltered from the sea by one of the larger islands in the Uppland archipelago, Graesoe. To assess the structures around Forsmark also in the sea area, the bottom structures of the Aalands-hav basin were investigated by means of depth readings from sea charts. Two rock-block maps with rock blocks at different scales were constructed and analysed for their top surface elevation. The topography in Uppland is more broken in the sea area east and northeast of Forsmark than it is on land. The major structure in the Aalands-hav basin is a westnorth- westerly line that passes southwest of Aaland, with a very steep gradient from the Aaland archipelago down to an exceptionally low sea-floor valley. On its southern side it rises in steps to a low flat basin divided into a deeper western half and a somewhat shallower eastern half. The deep west-north-westerly zone can be traced on-land past Oeregrund and Forsmark. West of Oeregrund however, the main trough swings into a north-northwesterly direction, just west of Graesoe. The southern border south of Oeregrund and Forsmark, shows a major drop in elevation northern side down. Forsmark thus lies on a ribbon with lower ground on both its southern and northern boundaries. This west-north-westerly belt is cut in two by a major north-south lineament that cuts through the archipelago between Aaland and Graesoe with a very deep canyon. This structure was seismically active in June 2006. The southern part of this line constitutes the western border of the low basin and has a steep gradient on its western side up to the Uppland mainland. The deep basin is filled with Jotnian metasediments. South of this basin, the Uppland mainland continues under water towards the east. South of Aaland an east-north-easterly ridge separates the low basin to the north from an east-west trending trough which is the eastern continuation of a major onland structure

  17. Rock-block configuration in Uppland and the Aalands-hav basin, the regional surroundings of the SKB site in Forsmark, Sea and land areas, eastern Sweden

    International Nuclear Information System (INIS)

    Beckholmen, Monica; Tiren, Sven A.

    2010-12-01

    The Forsmark SKB site lies at the west-northwest trending shoreline in northern Uppland, sheltered from the sea by one of the larger islands in the Uppland archipelago, Graesoe. To assess the structures around Forsmark also in the sea area, the bottom structures of the Aalands-hav basin were investigated by means of depth readings from sea charts. Two rock-block maps with rock blocks at different scales were constructed and analysed for their top surface elevation. The topography in Uppland is more broken in the sea area east and northeast of Forsmark than it is on land. The major structure in the Aalands-hav basin is a westnorth- westerly line that passes southwest of Aaland, with a very steep gradient from the Aaland archipelago down to an exceptionally low sea-floor valley. On its southern side it rises in steps to a low flat basin divided into a deeper western half and a somewhat shallower eastern half. The deep west-north-westerly zone can be traced on-land past Oeregrund and Forsmark. West of Oeregrund however, the main trough swings into a north-northwesterly direction, just west of Graesoe. The southern border south of Oeregrund and Forsmark, shows a major drop in elevation northern side down. Forsmark thus lies on a ribbon with lower ground on both its southern and northern boundaries. This west-north-westerly belt is cut in two by a major north-south lineament that cuts through the archipelago between Aaland and Graesoe with a very deep canyon. This structure was seismically active in June 2006. The southern part of this line constitutes the western border of the low basin and has a steep gradient on its western side up to the Uppland mainland. The deep basin is filled with Jotnian metasediments. South of this basin, the Uppland mainland continues under water towards the east. South of Aaland an east-north-easterly ridge separates the low basin to the north from an east-west trending trough which is the eastern continuation of a major onland structure

  18. A characterisation of sea-breeze events in the eastern Cantabrian coast (Spain) from observational data and WRF simulations

    Science.gov (United States)

    Arrillaga, Jon A.; Yagüe, Carlos; Sastre, Mariano; Román-Cascón, Carlos

    2016-11-01

    The behaviour of the sea breeze along the north coast of Spain is investigated using observations of two topographically contrasting sites together with simulations from the Weather Research and Forecasting (WRF) model. An objective and systematic selection method is used to detect sea-breeze days from a database of two summer months. The direction and intensity of the sea breeze are significantly affected by the topography of the area; indeed, the estimated sea-breeze intensity shows an opposite relationship with the cross-shore temperature gradient for both sites. WRF simulations reproduce the onset of the sea breeze, but some characteristics are not adequately simulated: they generally overestimate the wind speed, smooth the temperature evolution and they do not represent the correct interaction with the terrain-induced flows. Additionally, four sensitivity experiments are performed with the WRF model varying the Planetary Boundary Layer (PBL) scheme, as well as the grid analysis nudging for an anomalous case study which is incorrectly filtered. As the two simulations considering nudging reproduce an unreal (not observed) sea breeze, this day turns out to be of great interest: it allows to evaluate the influence of the passage of the sea-breeze front (SBF) in other variables mainly related to turbulence. Furthermore, the best model scores are obtained for the PBL scheme that does not use a TKE closure.

  19. Long-Term Trends, Variability and Extremes of In Situ Sea Surface Temperature Measured Along the Eastern Adriatic Coast and its Relationship to Hemispheric Processes

    Science.gov (United States)

    Grbec, Branka; Matić, Frano; Beg Paklar, Gordana; Morović, Mira; Popović, Ružica; Vilibić, Ivica

    2018-02-01

    This paper examines long-term series of in situ sea surface temperature (SST) data measured at nine coastal and one open sea stations along the eastern Adriatic Sea for the period 1959-2015. Monthly and yearly averages were used to document SST trends and variability, while clustering and connections to hemispheric indices were achieved by applying the Principal Component Analysis (PCA) and Self-Organizing Maps (SOM) method. Both PCA and SOM revealed the dominance of temporal changes with respect to the effects of spatial differences in SST anomalies, indicating the prevalence of hemispheric processes over local dynamics, such as bora wind spatial inhomogeneity. SST extremes were connected with blocking atmospheric patterns. A substantial warming between 1979 and 2015, in total exceeding 1 °C, was preceded by a period with a negative SST trend, implying strong multidecadal variability in the Adriatic. The strongest connection was found between yearly SST and the East Atlantic (EA) pattern, while North Atlantic Oscillation (NAO) and East Atlantic/West Russia (EAWR) patterns were found to also affect February SST values. Quantification of the Adriatic SST and their connection to hemispheric indices allow for more precise projections of future SST, considered to be rather important for Adriatic thermohaline circulation, biogeochemistry and fisheries, and sensitive to ongoing climate change.

  20. Metabolite Profiling of Triterpene Glycosides of the Far Eastern Sea Cucumber Eupentacta fraudatrix and Their Distribution in Various Body Components Using LC-ESI QTOF-MS.

    Science.gov (United States)

    Popov, Roman S; Ivanchina, Natalia V; Silchenko, Alexandra S; Avilov, Sergey A; Kalinin, Vladimir I; Dolmatov, Igor Yu; Stonik, Valentin A; Dmitrenok, Pavel S

    2017-10-02

    The Far Eastern sea cucumber Eupentacta fraudatrix is an inhabitant of shallow waters of the south part of the Sea of Japan. This animal is an interesting and rich source of triterpene glycosides with unique chemical structures and various biological activities. The objective of this study was to investigate composition and distribution in various body components of triterpene glycosides of the sea cucumber E. fraudatrix . We applied LC-ESI MS (liquid chromatography-electrospray mass spectrometry) of whole body extract and extracts of various body components for metabolic profiling and structure elucidation of triterpene glycosides from the E. fraudatrix . Totally, 54 compounds, including 26 sulfated, 18 non-sulfated and 10 disulfated glycosides were detected and described. Triterpene glycosides from the body walls, gonads, aquapharyngeal bulbs, guts and respiratory trees were extracted separately and the distributions of the detected compounds in various body components were analyzed. Series of new glycosides with unusual structural features were described in E. fraudatrix , which allow clarifying the biosynthesis of these compounds. Comparison of the triterpene glycosides contents from the five different body components revealed that the profiles of triterpene glycosides were qualitatively similar, and only some quantitative variabilities for minor compounds were observed.

  1. Building Coastal Resilience to sea-level rise and storm hazards: supporting decisions in the NE USA, Gulf of Mexico, and eastern Caribbean

    Science.gov (United States)

    Shepard, C.; Beck, M. W.; Gilmer, B.; Ferdana, Z.; Raber, G.; Agostini, V.; Whelchel, A.; Stone, J.

    2012-12-01

    Coastal communities are increasingly vulnerable to coastal hazards including storm surge and sea level rise. We describe the use of Coastal Resilience, an approach to help support decisions to reduce socio-economic and ecological vulnerability to coastal hazards. We provide examples of this work from towns and cities around Long Island Sound (NY, CT) and the Gulf of Mexico (FL, AL, MS, LA, TX) in the USA and from the Eastern Caribbean (Grenada, St. Vincent and the Grenadines). All of these shores are densely populated and have significant coastal development only centimetres above the sea. This makes people and property very vulnerable and threatens coastal wetlands (marsh, mangrove) and reefs (oyster, coral) that provide habitat and natural buffers to storms while providing other ecosystem services. We describe this work specifically and then offer broader perspectives and recommendations for using ecological habitats to reduce vulnerability to coastal hazards. The Nature Conservancy's Coastal Resilience approach is driven by extensive community engagement and uses spatial information on storm surge, sea level rise, ecological and socio-economic variables to identify options for reducing the vulnerability of human and natural communities to coastal hazards (http://www.coastalresilience.org). We have worked with local communities to map current and future coastal hazards and to identify the vulnerable natural resources and human communities. Communities are able to visualize potential hazard impacts and identify options to reduce them within their existing planning and regulatory frameworks.

  2. A model study of the seasonality of sea surface temperature and circulation in the Atlantic North-Eastern Tropical Upwelling System.

    Directory of Open Access Journals (Sweden)

    Saliou eFaye

    2015-09-01

    Full Text Available The climatological seasonal cycle of the sea surface temperature (SST in the north-eastern tropical Atlantic (7-25°N, 26-12°W is studied using a mixed layer heat budget in a regional ocean general circulation model. The region, which experiences one of the larger SST cycle in the tropics, forms the main part of the Guinea Gyre. It is characterized by a seasonally varying open ocean and coastal upwelling system, driven by the movements of the intertropical convergence zone (ITCZ. The model annual mean heat budget has two regimes schematically. South of roughly 12°N, advection of equatorial waters, mostly warm, and warming by vertical mixing, is balanced by net air-sea flux. In the rest of the domain, a cooling by vertical mixing, reinforced by advection at the coast, is balanced by the air-sea fluxes. Regarding the seasonal cycle, within a narrow continental band, in zonal mean, the SST early decrease (from September, depending on latitude, until December is driven by upwelling dynamics off Senegal and Mauritania (15°-20°N, and instead by air-sea fluxes north and south of these latitudes. Paradoxically, the later peaks of upwelling intensity (from March to July, with increasing latitude essentially damp the warming phase, driven by air-sea fluxes. The open ocean cycle to the west, is entirely driven by the seasonal net air-sea fluxes. The oceanic processes significantly oppose it, but for winter north of ~18°N. Vertical mixing in summer-autumn tends to cool (warm the surface north (south of the ITCZ, and advective cooling or warming by the geostrophic Guinea Gyre currents and the Ekman drift. This analysis supports previous findings on the importance of air-sea fluxes offshore. It mainly offers quantitative elements on the modulation of the SST seasonal cycle by the ocean circulation, and particularly by the upwelling dynamics.Keywords: SST, upwelling, circulation, heat budget, observations, modeling

  3. Spatial variability in phytoplankton community structure along the eastern Arabian Sea during the onset of south-west monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Ahmed, A.; Kurian, S.; Gauns, M.; ChndrasekharaRao, A.V.; Mulla, A.; Naik, B.; Naik, H.; Naqvi, S.W.A.

    The Arabian Sea experiences moderate to weak upwelling along the south-west coast of India, which subsequently propagates towards the north. This causes variation in plankton community composition, which is addressed in the present study. Here we...

  4. Sedimentary pigments and nature of organic matter within the oxygen minimum zone (OMZ) of the Eastern Arabian Sea (Indian margin)

    Digital Repository Service at National Institute of Oceanography (India)

    Rasiq, K.T.; Kurian, S.; Karapurkar, S.G.; Naqvi, S.W.A.

    continental slope of India. Marine Geology, 111, 7-13. Qasim, S., 1982. Oceanography of the northern Arabian Sea. Deep Sea Research Part A, 29, 1041- 1068. Quiblier‐Llobéras, C., Bourdier, G., Amblard, C. and Pepin, D., 1996. A qualitative study..., but intact pigment quality was comparable. Qualitatively nine pigments were observed at the OMZ of Indian margin while nearly similar diversity of accessory pigments were reported at Pakistan margin (Woulds and Cowie., 2009), but only Chlorins degradation...

  5. Prevalence of immunoglobulin E-mediated food allergy in 6-9-year-old urban schoolchildren in the eastern Black Sea region of Turkey.

    Science.gov (United States)

    Orhan, F; Karakas, T; Cakir, M; Aksoy, A; Baki, A; Gedik, Y

    2009-07-01

    The prevalence of adverse reactions to food in childhood in Turkey is not known. We aimed to investigate the prevalence and characteristics of IgE-mediated food allergies (FAs) in 6-9-year-old urban schoolchildren. This cross-sectional study recruited 3500 of the randomly selected 6-9-year-old urban schoolchildren from the eastern Black Sea region of Turkey during 2006. Following a self-administered questionnaire completed by the parents and the child, consenting children were invited for skin prick tests (SPTs) and oral food challenges. Children with suspected IgE-mediated FA were skin prick tested with a predefined panel of food allergens (milk, hen's egg, soy, wheat, peanut, fish, and hazelnut), aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, dog, Alternaria, grass pollen mix, weed pollen mix, and tree pollen mix), and food allergens reported in the questionnaire. All children with a positive SPT to any food were invited for a double-blind, placebo-controlled food challenge (DBPCFC). The prevalence of IgE-mediated FA was established using DBPCFCs. The response rate to the questionnaire was 78.2% (2739/3500). The estimated prevalence of parental-reported IgE-mediated FA was 5.7% (156/2739) [95% confidence interval (CI), 4.83-6.57%]. The rate of sensitization to the food allergens was 33.1% (48/145) in the parental-reported group. The confirmed prevalence of IgE-mediated FA by means of DBPCFC in 6-9-year-old urban schoolchildren living in the eastern Black Sea region of Turkey was 0.80% (22/2739) (95% CI, 0.47-1.13%). The most common allergenic foods were beef (31.8%), cow's milk (18.1%), cocoa (18.1%), hen's egg (13.6%), and kiwi (13.6%). The rate of reported IgE-mediated FA was significantly higher than clinically confirmed FA by means of DBPCFC (odds ratio, 7.46; 95% CI, 4.67-12.01; Pfoods was different and somewhat unique to the eastern Black Sea region of Turkey when compared with western countries.

  6. Processes regulating pCO2 in the surface waters of the central eastern Gotland Sea: a model study

    Directory of Open Access Journals (Sweden)

    Bernd Schneider

    2011-09-01

    Full Text Available This work presents a one-dimensional simulation of the seasonal changes in CO2 partial pressure (pCO2. The results of the model were constrained using data from observations, which improved the model's ability to estimate nitrogen fixation in the central Baltic Sea and allowed the impact of nitrogen fixation on the ecological state of the Baltic Sea to be studied. The model used here is the public domain water-column model GOTM (General Ocean Turbulence Model, which in this study was coupled with a modifed Baltic Sea ecosystem model, ERGOM (The Baltic Sea Research Institute's ecosystem model. To estimate nitrogen fixation rates in the Gotland Sea, the ERGOM model was modified by including an additional cyanobacteria group able to fix nitrogen from March to June. Furthermore, the model was extended by a simple CO2 cycle. Variable C:P and N:P ratios, controlled by phosphate concentrations in ambient water, were used to represent cyanobacteria, detritus and sediment detritus. This approach improved the model's ability to reproduce sea-surface phosphate and pCO2 dynamics. The resulting nitrogen fixation rates in 2005 for the two simulations, with and without the additional cyanobacteria group, were 259 and 278 mmol N m-2 year-1respectively.

  7. Infectious disease control in the Ionian Islands during the British Protection (1815-1864).

    Science.gov (United States)

    Tsiamis, Costas; Thalassinou, E; Poulakou-Rebelakou, E; Anogiatis-Pelé, D; Hatzakis, A

    2013-09-01

    This review presents the medical and social role of British military doctors in the formation of the British sanitary campaign in the Ionian Islands during the period 1815-1864. They were the core of a health system based on the old sanitary model of the Venetian Republic, which was the former ruler of the region. The British innovation and reorganisation of the old lazarettos (a quarantine system for maritime travellers), the new marine sanitary procedures, the determination of quarantine duration for major infectious diseases along with the introduction of the vaccination system resulted in a satisfactory defence against epidemics in Greece during the 19th century. The British military physicians applied and established West European medical ideas, as well as the principles of preventive medicine, for the first time in the Greek territory and this is a historical example of a successful sanitary campaign based on the experience of military physicians and their collaboration with civilian physicians.

  8. Study of the seismic activity in central Ionian Islands via semi-Markov modelling

    Science.gov (United States)

    Pertsinidou, Christina Elisavet; Tsaklidis, George; Papadimitriou, Eleftheria

    2017-06-01

    The seismicity of the central Ionian Islands ( M ≥ 5.2, 1911-2014) is studied via a semi-Markov chain which is investigated in terms of the destination probabilities (occurrence probabilities). The interevent times are considered to follow geometric (in which case the semi-Markov model reduces to a Markov model) or Pareto distributions. The study of the destination probabilities is useful for forecasting purposes because they can provide the more probable earthquake magnitude and occurrence time. Using the first half of the data sample for the estimation procedure and the other half for forecasting purposes it is found that the time windows obtained by the destination probabilities include 72.9% of the observed earthquake occurrence times (for all magnitudes) and 71.4% for the larger ( M ≥ 6.0) ones.

  9. Glacial-interglacial vegetation dynamics in South Eastern Africa coupled to sea surface temperature variations in the Western Indian Ocean

    NARCIS (Netherlands)

    Dupont, L.M.; Caley, T.; Kim, J.H.; Castañeda, I.S; Malaize, B.; Giraudeau, J.

    2011-01-01

    Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a

  10. Late Holocene shorelines deduced from tidal notches on both sides of the Ionian Thrust (Greece): Fiscardo peninsula (Cephalonia) and Ithaca island

    Energy Technology Data Exchange (ETDEWEB)

    Evelpidou, N.; Karkani, A.; Kazmer, M.; Pirazzoli, P.

    2016-07-01

    Fossil shorelines produced by recent co-seismic movements were identified through a submarine survey along the coasts of Ithaca and Fiscardo (Greece). In both areas a tidal notch-slightly submerged below present Mean Sea Level (MSL) was observed at various sites. This “modern” notch is known to have been submerged by the global sea-level rise during the 19th and 20th centuries. The depth after tide and air-pressure correction of the vertex of the “modern” notch (that owes its submergence to the current rapid sea level rise) was measured between -20 and -30±5cm at Fiscardo and between -36 and -45±6cm at Ithaca. This “modern” notch at the same depth on east and west sides of the Ionian Thrust suggests that both areas were not affected by the co-seismic vertical movements that occurred in 1953 (in the wider area). On the other hand, a greater depth in Ithaca could be an effect of co-seismic subsidence. Over the long term, the tectonic behavior of Ithaca differs from Fiscardo. At Ithaca no evidence of emergence was found and Holocene vertical movements have been only of subsidence: submerged fossil tidal notches were distinguished below MSL at about -40 (modern), -60, -75, -95, -106, -126, -150 and -220±6cm. On the East coast of Fiscardo peninsula impacts of ancient earthquakes have left some marks of emergence at about +18 and +44±5cm, and of submergence at about -25 (modern), -45, -60, -75, -82, -100 and -230cm, with even some evidence of past uplift and subsidence at the same sites. (Author)

  11. Important aspects of Eastern Mediterranean large-scale variability revealed from data of three fixed observatories

    Science.gov (United States)

    Bensi, Manuel; Velaoras, Dimitris; Cardin, Vanessa; Perivoliotis, Leonidas; Pethiakis, George

    2015-04-01

    Long-term variations of temperature and salinity observed in the Adriatic and Aegean Seas seem to be regulated by larger-scale circulation modes of the Eastern Mediterranean (EMed) Sea, such as the recently discovered feedback mechanisms, namely the BiOS (Bimodal Oscillating System) and the internal thermohaline pump theories. These theories are the results of interpretation of many years' observations, highlighting possible interactions between two key regions of the EMed. Although repeated oceanographic cruises carried out in the past or planned for the future are a very useful tool for understanding the interaction between the two basins (e.g. alternating dense water formation, salt ingressions), recent long time-series of high frequency (up to 1h) sampling have added valuable information to the interpretation of internal mechanisms for both areas (i.e. mesoscale eddies, evolution of fast internal processes, etc.). During the last 10 years, three deep observatories were deployed and maintained in the Adriatic, Ionian, and Aegean Seas: they are respectively, the E2-M3A, the Pylos, and the E1-M3A. All are part of the largest European network of Fixed Point Open Ocean Observatories (FixO3, http://www.fixo3.eu/). Herein, from the analysis of temperature and salinity, and potential density time series collected at the three sites from the surface down to the intermediate and deep layers, we will discuss the almost perfect anti-correlated behavior between the Adriatic and the Aegean Seas. Our data, collected almost continuously since 2006, reveal that these observatories well represent the thermohaline variability of their own areas. Interestingly, temperature and salinity in the intermediate layer suddenly increased in the South Adriatic from the end of 2011, exactly when they started decreasing in the Aegean Sea. Moreover, Pylos data used together with additional ones (e.g. Absolute dynamic topography, temperature and salinity data from other platforms) collected

  12. Change in the intensity of low-salinity water inflow from the Bay of Bengal into the Eastern Arabian Sea from the Last Glacial Maximum to the Holocene: Implications for monsoon variations

    Digital Repository Service at National Institute of Oceanography (India)

    Mahesh, B.S.; Banakar, V.K.

    A 100–400 km wide region of the coastal Eastern Arabian Sea (EAS), off the west-coast of India, is characterized by a low-salinity tongue formed by the inflow of low-salinity surface water from the Bay of Bengal (BoB). This low-salinity tongue...

  13. A laboratory and field study of 210Po depuration by edible winkles (Littorina littorea L.) from the Cumbrian coast (north-eastern Irish Sea)

    International Nuclear Information System (INIS)

    Swift, D.J.; Smith, D.L.; Allington, D.J.; Winpenny, K.

    1995-01-01

    Edible winkles from Saltom Bay, Cumbria (north-eastern Irish Sea) had flesh 210 Po concentrations in excess of 200 Bq kg -1 (wet). This came from liquid waste discharged under authorisation from a chemical plant producing phosphoric acid. This labelling of the winkles under natural conditions was exploited to determine the 210 Po depuration rate and biological half-time. Winkles transferred to Lowestoft and depurated in flowing seawater had biological half-times ranging from 82 to 119 days depending on temperature. After the chemical plant was shut, changes in Saltom Bay winkle flesh contents of 210 Po, 210 Pb and cadmium were followed by monthly samples. The biological half-time in the environment for the decrease in 210 Po after the plant closed was estimated at about 92 days. (author)

  14. Quantitative estimation of massive gas hydrate in gas chimney structures, the eastern margin of Japan Sea, from the physical property anomalies obtained by LWD.

    Science.gov (United States)

    Tanahashi, M.; Morita, S.; Matsumoto, R.

    2017-12-01

    Two dedicated LWD (Logging While Drilling) cruises, GR14 and HR15, were conducted in summers of 2014 and 2015, respectively, by Meiji University and Geological Survey of Japan, AIST to explore the gas chimney structures, which are characterized by the columnar acoustic blanking below the topographic mound and/or pockmarks in eastern margin of Japan Sea. Shallow (33 to 172m-bsf, average 136m-bsf) 33 LWD drillings were carried out generally in and around gas chimney structures which are in Oki Trough, Off-Joetsu, and Mogami Trough areas, eastern margin of Japan Sea, during two cruises. Schlumberger LWD tools, GeoVISION (resistivity), TeleScope, ProVISION (NMR) and SonicVISION (sonic) were applied during GR14. NeoScope (neutron) was added and SonicScope was replaced for SonicVISION during HR15. The presence of thick highly-anomalous intervals within the LWD data at site J24L suggests the development of massive gas hydrate within Off-Joetsu, by very high resistivity ( 10,000 Ωm), high Vp ( 3,700 m/s) and Vs (370-1,839 m/s), high neutron porosity ( 1.2), low natural gamma ray intensity ( 0 API), low neutron gamma density ( 0.8 g/cm3), low NMR porosity ( 0.0), low permeability (10-2-10-4 mD), low formation neutron sigma (26-28). The extreme physical properties intervals suggest the development of the almost pure hydrate. Because of the clear contrast between pure hydrate and seawater saturated fine sediments, the hydrate amount can be estimated quantitatively based on the assumptions as the two component system of pure hydrate and the monotonous seawater saturated fine sediments. This study was conducted as a part of the methane hydrate research project funded by METI (the Ministry of Economy, Trade and Industry, Japan).

  15. The Tectonic Boundary Between Eastern Subbaisin and South-West Subbasin of the South China Sea Revealed from the Normalized Magnetic Source Strength

    Science.gov (United States)

    Guo, L.; Meng, X.

    2014-12-01

    The South China Sea (SCS), surrounded by the Eurasia, Pacific and India-Australia plates, is one of the largest marginal seas in the Western Pacific. It was formed by the interaction of the three plates and the seafloor spreading during Late Oligocene time to Early Miocene time. The boundary between Eastern Subbaisin and South-west Subbasin of the SCS has long been debated in the literature. Refining the boundary is one of the crucial tasks for correctly understanding the seafloor spreading model of the SCS. Due to few drills on the deep ocean basin of the SCS, magnetic data become important information for refining the boundary. However, the interpretation of magnetic data in the SCS suffers from the remanent magnetization of ocean crust as well as igneous rock and seamounts. The conventional reduction-to-pole anomalies at low latitudes usually neglect the remanent magnetization, making the interpretation incorrect. Here, we assembled high-resolution total magnetic intensity (TMI) data around the ocean basin of the SCS, and then did a special transformation of the TMI anomalies with a varying magnetic inclinations algorithm to obtain the normalized source strength (NSS). The NSS has advantage of insensitivity to remanent magnetization, benefitting correct interpretation. The NSS presents discriminative features from east to west in the ocean basin. The boundary of the discriminative features is clear and just ranges from the northeastern edge of the Zhongsha Islands running in the southeast direction to the northeastern edge of the Reed Bank. These imply that magnetic structure and tectonic features in the crust are discriminative between both sides of this boundary. It can be deduced that this boundary is the tectonic boundary between Eastern Subbaisin and South-west Subbasin. We acknowledge the financial support of the National Natural Science Foundation of China (41374093) and the SinoProbe-01-05 project.

  16. Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

    Directory of Open Access Journals (Sweden)

    John M Maniscalco

    Full Text Available Steller sea lion (Eumetopias jubatus numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

  17. Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus) in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

    Science.gov (United States)

    Maniscalco, John M; Springer, Alan M; Adkison, Milo D; Parker, Pamela

    2015-01-01

    Steller sea lion (Eumetopias jubatus) numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population) in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ) was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

  18. Testing sea-level markers observed in ground-penetrating radar data from Feddet, south-eastern Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Nielsen, Lars; Clemmensen, Lars B

    2012-01-01

    a number of profile lines across less than c. 60 years old berm, beach ridge and swale structures at the Feddet peninsula. The GPR images allow us to interpret internal sedimentary architecture, and here we focus especially on the identification of downlapping reflections, which are interpreted to mark...... fluctuations in past sea level due to variations in tidal effects and meteorological conditions (isostatic rebound is expected to have a minimal effect on Feddet (Hansen et al., 2011)). Comparison with existing time series of measurements of actual sea level from the Danish Maritime Safety Administration (from...

  19. Geological and Structural evolution of the Eurasia Africa plate boundary in the Gulf of Cadiz Central Eastern Atlantic Sea.

    OpenAIRE

    D’Oriano, Filippo

    2010-01-01

    Iberia Africa plate boundary, cross, roughly W-E, connecting the eastern Atlantic Ocean from Azores triple junction to the Continental margin of Morocco. Relative movement between the two plate change along the boundary, from transtensive near the Azores archipelago, through trascurrent movement in the middle at the Gloria Fracture Zone, to transpressive in the Gulf of Cadiz area. This study presents the results of geophysical and geological analysis on the plate boundary area offshore Gibral...

  20. Assessment of fish populations and habitat on Oculina Bank, a deep-sea coral marine protected area off eastern Florida

    OpenAIRE

    Harter , Stacey L.; Ribera, Marta M.; Shepard, Andrew N.; Reed, John K.

    2009-01-01

    A portion of the Oculina Bank located off eastern Florida is a marine protected area (MPA) preserved for its dense populations of the ivory tree coral (Oculina varicosa), which provides important habitat for fish. Surveys of fish assemblages and benthic habitat were conducted inside and outside the MPA in 2003 and 2005 by using remotely operated vehicle video transects and digital still imagery. Fish species composition, biodiversity, and grouper densities were used to determine w...

  1. Sustainability Organic Agriculture and Livestock Production with Respect to European Union in Eastern Anatolia and East Black Sea Regions

    Directory of Open Access Journals (Sweden)

    Vecihi Aksakal

    2016-11-01

    Full Text Available The majority of farm households in Turkey and especially the Eastern Anatolia are still based on low-input semi subsistence agriculture and livestock production. Despite a slow decline in recent years, agriculture and livestock production remains a major employer in Turkey and it is a significant contributor to the country’s gross domestic product, GDP. Whist Turkey is one of the EU candidate countries, is self sufficient in food production and Turkish agriculture is poorly structured inefficient, with farming in the Eastern Anatolia being mainly subsistence farming. Yet, these traditional rural structures combined with poor access to low level of education and low level of off-farm unemployment problem makes the situation more complicated and unsustainable. The best way to promote sustainability, better and higher production of Eastern Anatolian and rural Turkey is to invest in the local people, villages through improved, continuing and effective agricultural and livestock programs in particular. Investment in human capital especially in the rural areas leads to more employment opportunities through entrepreneurship and innovation in organic agriculture and livestock production. A holistic approach to developing and improving supply chains could unlock the potential for sophisticated, state-of-the-art organic agriculture and livestock producers and businesses in the region to become EU and global players. Eastern Anatolian livestock producers and the farmers have the ambitions to take part in future progress because the region is naturally organic not by design but default. It is for sure that present potential of the region has not been fully determined and utilized. EU has greatly benefited from previous enlargements economically, politically and socially. When European Union (EU and Turkish Government relations considered and accession of Turkey to EU would be the logical consequence of the previous accessions. The screening on chapter 11

  2. Relationships between fish, sea urchins and macroalgae: The structure of shallow rocky sublittoral communities in the Cyclades, Eastern Mediterranean

    Science.gov (United States)

    Giakoumi, Sylvaine; Cebrian, Emma; Kokkoris, Giorgos D.; Ballesteros, Enric; Sala, Enric

    2012-08-01

    Historical overfishing is the most likely explanation for the depletion of the shallow sublittoral communities in many areas not least in the Cyclades Archipelago, Greece. The present study is the first quantitative study of the shallow rocky sublittoral of the Cyclades based on in situ underwater surveys of algal cover, and fish and sea urchin abundance at 181 sampling sites in 25 islands to provide a baseline and investigate the relationship between these communities. Algal turf was the most abundant algal functional group, and canopy algae of the genus Cystoseira were more abundant at the northern islands. A range in fish biomass of almost two orders of magnitude was found across islands, but overall the Cyclades displayed much lower values than fished areas of the Western Mediterranean. We observed apex predators only in 25% of our sampling sites, and their biomass was uncorrelated to total fish biomass, indicating a depleted ecosystem. Sea urchin biomass was also low but similar to values found in other Mediterranean islands and was positively correlated with barrens. We observed a gradient of benthic community complexity from sea urchin barrens to communities dominated by Cystoseira spp. There was no correlation between sea urchins and their predators Diplodus spp., which presented extremely low densities.

  3. The bloom of the dinoflagellate (Noctiluca miliaris) in the North Eastern Arabian Sea: Ship and Satellite study

    Digital Repository Service at National Institute of Oceanography (India)

    Matondkar, S.G.P.; Basu, S.; Parab, S.G.; Pednekar, S.; Dwivedi, R.M.; Raman, M.; Goes, J.I.; Gomes, H.

    The bloom of Noctiluca miliaris (a dinoflagellate) which appears in the form of a green tide was studied from 2003-2011. This bloom covered a large area of the Arabian Sea from the west coast of India to the coast of Oman. The bloom was easily...

  4. Altimeter-derived flow field over a newly identified coastal ocean boundary in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Somayajulu, Y.K.; Swamy, G.N.

    part, tapers off towards north and bulges towards south. In the present communication, the T/P-derived flow pattern over this new boundary is presented. The derived flow pattern shows the general dominance of meso-scale eddies in the Arabian Sea...

  5. Quantification of the early small-scale fishery in the north-eastern Baltic Sea in the late 17th century.

    Science.gov (United States)

    Verliin, Aare; Ojaveer, Henn; Kaju, Katre; Tammiksaar, Erki

    2013-01-01

    Historical perspectives on fisheries and related human behaviour provide valuable information on fishery resources and their exploitation, helping to more appropriately set management targets and determine relevant reference levels. In this study we analyse historical fisheries and fish trade at the north-eastern Baltic Sea coast in the late 17th century. Local consumption and export together amounted to the annual removal of about 200 tonnes of fish from the nearby sea and freshwater bodies. The fishery was very diverse and exploited altogether one cyclostome and 17 fish species with over 90% of the catch being consumed locally. The exported fish consisted almost entirely of high-valued species with Stockholm (Sweden) being the most important export destination. Due to rich political history and natural features of the region, we suggest that the documented evidence of this small-scale fishery should be considered as the first quantitative summary of exploitation of aquatic living resources in the region and can provide a background for future analyses.

  6. Quantification of the early small-scale fishery in the north-eastern Baltic Sea in the late 17th century.

    Directory of Open Access Journals (Sweden)

    Aare Verliin

    Full Text Available Historical perspectives on fisheries and related human behaviour provide valuable information on fishery resources and their exploitation, helping to more appropriately set management targets and determine relevant reference levels. In this study we analyse historical fisheries and fish trade at the north-eastern Baltic Sea coast in the late 17th century. Local consumption and export together amounted to the annual removal of about 200 tonnes of fish from the nearby sea and freshwater bodies. The fishery was very diverse and exploited altogether one cyclostome and 17 fish species with over 90% of the catch being consumed locally. The exported fish consisted almost entirely of high-valued species with Stockholm (Sweden being the most important export destination. Due to rich political history and natural features of the region, we suggest that the documented evidence of this small-scale fishery should be considered as the first quantitative summary of exploitation of aquatic living resources in the region and can provide a background for future analyses.

  7. Removing Regional Trends in Microgravity in Complex Environments: Testing on 3D Model and Field Investigations in the Eastern Dead Sea Coast (Jordan

    Directory of Open Access Journals (Sweden)

    A. Al-Zoubi

    2013-01-01

    Full Text Available Microgravity investigations are now recognized as a powerful tool for subsurface imaging and especially for the localization of underground karsts. However numerous natural (geological, technical, and environmental factors interfere with microgravity survey processing and interpretation. One of natural factors that causes the most disturbance in complex geological environments is the influence of regional trends. In the Dead Sea coastal areas the influence of regional trends can exceed residual gravity effects by some tenfold. Many widely applied methods are unable to remove regional trends with sufficient accuracy. We tested number of transformation methods (including computing gravity field derivatives, self-adjusting and adaptive filtering, Fourier series, wavelet, and other procedures on a 3D model (complicated by randomly distributed noise, and field investigations were carried out in Ghor Al-Haditha (the eastern side of the Dead Sea in Jordan. We show that the most effective methods for regional trend removal (at least for the theoretical and field cases here are the bilinear saddle and local polynomial regressions. Application of these methods made it possible to detect the anomalous gravity effect from buried targets in the theoretical model and to extract the local gravity anomaly at the Ghor Al-Haditha site. The local anomaly was utilized for 3D gravity modeling to construct a physical-geological model (PGM.

  8. Age, growth and utility of otolith morphometrics as a predictor of age in the wrasse Coris julis (Labridae from the eastern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Frane Škeljo

    2012-09-01

    Full Text Available Age and growth of Coris julis were determined by examining sagittal otoliths belonging to fish sampled between November 2008 and October 2009 in the eastern Adriatic Sea (north-central Mediterranean Sea. A total of 1102 specimens (528 males, 487 females and 87 individuals of indeterminate sex, ranging from 48 to 222 mm total length were analysed. Ninety-two per cent of the otoliths were readable and 68% of the specimens had two readings in agreement. Counting of daily rings revealed that the second opaque ring represents the first annulus (315.1±27.8 daily rings. The maximum observed age was 7 years for males and 5 years for females, with males dominating in higher age classes ( > 3 years and females in age classes 1+ and 2+. Growth was described by the von Bertalanffy growth curves and significant differences were found between males (L∞=29.10 cm, k=0.12 and t0=–1.48 and females (L∞=21.27 cm, k=0.21 and t0=–1.08. Otolith mass, length, width and thickness were determined for the otoliths belonging to 465 fish and the utility of these morphometrics as a predictor of age was evaluated. The most precise age estimations were obtained from the otolith length data, followed by the otolith mass.

  9. Lead in blood and eggs of the sea turtle, Lepidochelys olivacea, from the Eastern Pacific: Concentration, isotopic composition and maternal transfer

    International Nuclear Information System (INIS)

    Paez-Osuna, F.; Calderon-Campuzano, M.F.; Soto-Jimenez, M.F.; Ruelas-Inzunza, J.R.

    2010-01-01

    Concentrations of lead were assessed in the sea turtle, Lepidochelys olivacea, from a nesting colony of the Eastern Pacific. Twenty-five female turtles were sampled and a total of 250 eggs were collected during the 'arribada' event of the 2005-2006 season. Considering the nesting season, the maternal transfer of lead (Pb) via egg-laying, in terms of metal burden in whole body, was 0.5%. Pb concentrations (in dry weight) in blood (0.95 ± 0.18 μg g -1 ) and egg samples (yolk, 0.80 ± 0.10 μg g -1 ; albumen, 1.08 ± 0.20 μg g -1 ; eggshell, 1.05 ± 0.20 μg g -1 ) were comparable or even lower than those found in other sea turtles. The isotope ratios ( 206 Pb/ 207 Pb and 206 Pb/ 208 Pb) in blood (1.183 ± 0.0006 and 2.452 ± 0.0006, respectively) were comparable to that of natural Pb-bearing bedrock in Mexico (1.188 ± 0.005 and 2.455 ± 0.008, respectively). According to international norms of Pb, the health of this population and its habitats is acceptable for Pb and corresponds to basic levels of a nearly pristine environment.

  10. A Perspective on Sea Level Rise and Coastal Storm Surge from Southern and Eastern Africa: A Case Study Near Durban, South Africa

    Directory of Open Access Journals (Sweden)

    Derek D. Stretch

    2012-03-01

    Full Text Available Recent coastal storms in southern Africa have highlighted the need for more proactive management of the coastline. Within the southern and eastern African region the availability of coastal information is poor. The greatest gap in information is the likely effects of a combination of severe sea storms and future sea level rise (SLR on the shoreline. This lack of information creates a barrier to informed decision making. This research outlines a practical localized approach to this problem, which can be applied as a first order assessment within the region. In so doing it provides a cost effective and simple decision support tool for the built environment and disaster professionals in development and disaster assessments. In a South African context the newly promulgated Integrated Coastal Management Act requires that all proposed coastal developments take into consideration future SLR, however such information currently does not exist, despite it being vital for informed planning in the coastal zone. This practical approach has been applied to the coastline of Durban, South Africa as a case study. The outputs are presented in a Geographic Information System (GIS based freeware viewer tool enabling ease of access to both professionals and laypersons. This demonstrates that a simple approach can provide valuable information about the current and future risk of flooding and coastal erosion under climate change to buildings, infrastructure as well as natural features along the coast.

  11. Predicting the impacts of Mississippi River diversions and sea-level rise on spatial patterns of eastern oyster growth rate and production

    Science.gov (United States)

    Wang, Hongqing; Chen, Qin; La Peyre, Megan K.; Hu, Kelin; La Peyre, Jerome F.

    2017-01-01

    There remains much debate regarding the perceived tradeoffs of using freshwater and sediment diversions for coastal restoration in terms of balancing the need for wetland restoration versus preserving eastern oyster (Crassostrea virginica) production. Further complicating the issue, climate change-induced sea-level rise (SLR) and land subsidence are also expected to affect estuarine water quality. In this study, we developed a process-based numerical modeling system that couples hydrodynamic, water quality, and oyster population dynamics. We selected Breton Sound Estuary (BSE) (∼2740 km2) in the eastern Mississippi River Deltaic Plain since it is home to several of the largest public oyster seed grounds and private leases for the Gulf coast. The coupled oyster population model was calibrated and validated against field observed oyster growth data. We predicted the responses of oyster population in BSE to small- (142 m3 s−1) and large-scale (7080 m3 s−1) river diversions at the Caernarvon Freshwater Diversion structure planned in the 2012 Coastal Master Plan (Louisiana) under low (0.38 m) and high (1.44 m) relative sea-level rise (RSLR = eustatic SLR + subsidence) compared to a baseline condition (Year 2009). Model results showed that the large-scale diversion had a stronger negative impact on oyster population dynamics via freshening of the entire estuary, resulting in reduced oyster growth rate and production than RSLR. Under the large-scale diversion, areas with optimal oyster growth rates (>15 mg ash-free dry weight (AFDW) oyster−1 wk−1) and production (>500 g AFDW m−2 yr−1) would shift seaward to the southeastern edge of the estuary, turning the estuary into a very low oyster production system. RSLR however played a greater role than the small-scale diversion on the magnitude and spatial pattern of oyster growth rate and production. RSLR would result in an overall estuary-wide decrease in oyster growth rate and production as a

  12. Early to Middle Holocene sea level fluctuation, coastal progradation and the Neolithic occupation in the Yaojiang Valley of southern Hangzhou Bay, Eastern China

    Science.gov (United States)

    Liu, Yan; Sun, Qianli; Fan, Daidu; Dai, Bin; Ma, Fuwei; Xu, Lichen; Chen, Jing; Chen, Zhongyuan

    2018-06-01

    The Yaojiang Valley (YJV) of southern Hangzhou Bay was the birthplace of the well-known Hemudu Culture (HC), one of the representatives of Neolithic civilization in eastern China. To explore the magnitude of natural environmental effects on the HC trajectory, the palaeo-embayment setting of the YJV was studied in detail for the first time in terms of 3D Holocene strata supported by a series of new radiocarbon-dated cores. The results indicated that the local relative sea level rose rapidly during the Early Holocene in the YJV, reached its maximum flooding surface ca. 7900 cal yr BP, and then remained stable ca. 7900-7600 cal yr BP. Thereupon, an estuary stretching inland was first formed by marine transgression, and then, it was transformed to an alluvial-coastal plain by regressive progradation. The alluvial plain was initiated in the foothills and then spread towards the valley centre after sea level stabilization ca. 7600 cal yr BP. Accompanying these natural environmental changes, the earliest arrivals of foragers in the valley occurred no later than ca. 7000 cal yr BP. They engaged in rice farming and fostered the HC for approximately two millennia from ca. 7000-5000 cal yr BP as more lands developed from coastal progradation. The rise and development of the HC are closely associated with the sea level-induced landscape changes in the YJV in the Early-Middle Holocene, but the enigmatic exodus of the HC people after ca. 5000 cal yr BP is still contentious and possibly linked with the rapid waterlogging and deterioration of this setting in such a low-lying coastal plain as well as with associated social reasons.

  13. Evolutionary melting pots: a biodiversity hotspot shaped by ring diversifications around the Black Sea in the Eastern tree frog (Hyla orientalis).

    Science.gov (United States)

    Dufresnes, Christophe; Litvinchuk, Spartak N; Leuenberger, Julien; Ghali, Karim; Zinenko, Oleksandr; Stöck, Matthias; Perrin, Nicolas

    2016-09-01

    Hotspots of intraspecific genetic diversity, which are of primary importance for the conservation of species, have been associated with glacial refugia, that is areas where species survived the Quaternary climatic oscillations. However, the proximate mechanisms generating these hotspots remain an open issue. Hotspots may reflect the long-term persistence of large refugial populations; alternatively, they may result from allopatric differentiation between small and isolated populations, that later admixed. Here, we test these two scenarios in a widely distributed species of tree frog, Hyla orientalis, which inhabits Asia Minor and southeastern Europe. We apply a fine-scale phylogeographic survey, combining fast-evolving mitochondrial and nuclear markers, with a dense sampling throughout the range, as well as ecological niche modelling, to understand what shaped the genetic variation of this species. We documented an important diversity centre around the Black Sea, composed of multiple allopatric and/or parapatric diversifications, likely driven by a combination of Pleistocene climatic fluctuations and complex regional topography. Remarkably, this diversification forms a ring around the Black Sea, from the Caucasus through Anatolia and eastern Europe, with terminal forms coming into contact and partially admixing in Crimea. Our results support the view that glacial refugia generate rather than host genetic diversity and can also function as evolutionary melting pots of biodiversity. Moreover, we report a new case of ring diversification, triggered by a large, yet cohesive dispersal barrier, a very rare situation in nature. Finally, we emphasize the Black Sea region as an important centre of intraspecific diversity in the Palearctic with implications for conservation. © 2016 John Wiley & Sons Ltd.

  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. Incidence of lesions on Fungiidae corals in the eastern Red Sea is related to water temperature and coastal pollution

    KAUST Repository

    Furby, K.A.

    2014-07-01

    As sea surface temperatures rise and the global human population increases, large-scale field observations of marine organism health and water quality are increasingly necessary. We investigated the health of corals from the family Fungiidae using visual observations in relation to water quality and microbial biogeochemistry parameters along 1300 km of the Red Sea coast of Saudi Arabia. At large scales, incidence of lesions caused by unidentified etiology showed consistent signs, increasing significantly from the northern to southern coast and positively correlated to annual mean seawater temperatures. Lesion abundance also increased to a maximum of 96% near the populous city of Jeddah. The presence of lesioned corals in the region surrounding Jeddah was strongly correlated with elevated concentrations of ammonium and changes in microbial communities that are linked to decreased water quality. This study suggests that both high seawater temperatures and nutrient pollution may play an indirect role in the formation of lesions on corals. © 2014 Elsevier Ltd.

  16. Incidence of lesions on Fungiidae corals in the eastern Red Sea is related to water temperature and coastal pollution

    KAUST Repository

    Furby, K.A.; Apprill, A.; Cervino, J.M.; Ossolinski, J.E.; Hughen, K.A.

    2014-01-01

    As sea surface temperatures rise and the global human population increases, large-scale field observations of marine organism health and water quality are increasingly necessary. We investigated the health of corals from the family Fungiidae using visual observations in relation to water quality and microbial biogeochemistry parameters along 1300 km of the Red Sea coast of Saudi Arabia. At large scales, incidence of lesions caused by unidentified etiology showed consistent signs, increasing significantly from the northern to southern coast and positively correlated to annual mean seawater temperatures. Lesion abundance also increased to a maximum of 96% near the populous city of Jeddah. The presence of lesioned corals in the region surrounding Jeddah was strongly correlated with elevated concentrations of ammonium and changes in microbial communities that are linked to decreased water quality. This study suggests that both high seawater temperatures and nutrient pollution may play an indirect role in the formation of lesions on corals. © 2014 Elsevier Ltd.

  17. Sulina and Danube-Black Sea Channels: Competitors or Allies on Cargo Transport in South-Eastern Europe?

    Directory of Open Access Journals (Sweden)

    Ionica Soare

    2015-10-01

    Full Text Available The two river channels which connect the Black Sea to the inland Romanian area, have constituted since the beginning of their building two very important transport routes for the cargo and passenger traffic (Sulina that have connected Black Sea to the internal ports of Romania, thus representing ”transport highways” of the Romanian economy. The present study tries to present the chronological evolution of these two shipping routes, regarding their importance to the cargo traffic, as well as the financial policy imposed by the administration of these channels. We will present and analyze retrospectively the major elements regarding the administration of these channels, a comparative analysis of the role of these two channels in the river cargo transport, consequently trying to predict a future evolution of these two river communication routes.

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

    Directory of Open Access Journals (Sweden)

    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. Seasonal and geographic distribution of luminous bacteria in the eastern mediterranean sea and the gulf of elat.

    Science.gov (United States)

    Yetinson, T; Shilo, M

    1979-06-01

    Luminous bacteria in the Mediterranean Sea and the Gulf of Aqaba-Elat have different distribution patterns. In the Mediterranean Sea, Beneckea harveyi is present all year round, with different subtypes alternating in summer and winter; Photobacterium fischeri was only present during the winter. In the Gulf of Elat, P. leiognathi is present throughout the water column in similar densities during the entire year. This constancy in distribution is presumably due to the near-constancy in water temperature. In summer, Photobacterium leiognathi is replaced by B. harveyi in coastal surface waters. In the hypersaline Bardawil lagoon, only B. harveyi types are present. P. fischeri, a major component of the Mediterranean Sea winter communities, is absent from the lagoon. Luminous Beneckea strains show a great diversity in properties, e.g. temperature range for growth, sensitivity to infection by phages, sensitivity to attack by Bdellovibrio strains, and differences in tolerance to high-salinity shock. Therefore, subdivision of the taxonomic cluster of B. harveyi into subtypes is indicated. The composition of the luminous bacteria communities may serve as indicators of different marine water bodies. The symbiotic luminous bacteria of the light organ of the common Gulf of Elat fish, Photoblepharon palbebratus steinitzi, is different from any of the types described.

  20. 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 Report (AR5) of the Intergovernmental Panel on Climate change (IPCC) - a storm-induced sea level rise of 0.6 m is projected to result in a complete erosion of between 31 and 88 % of all beaches (29-87 % of beaches are currently fronting coastal infrastructure and assets), at least temporarily. Our results suggest a very considerable risk which will require significant effort, financial resources and policies/regulation in order to protect/maintain the critical economic resource of the Aegean archipelago.

  1. Quantity and biochemical composition of particulate organic matter in a highly trawled area (Thermaikos Gulf, Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Antonio Pusceddu

    2015-11-01

    Full Text Available Bottom trawling represents nowadays one of the most severe anthropogenic disturbances at sea, and determines large impacts on benthic communities and processes. Bottom trawling determines also local sediment resuspension and the effects of the injection of large amounts of surface sediments into the water column have been repeatedly investigated. Few studies have assessed the consequences of sediment resuspension caused by bottom trawling on the quantity, biochemical composition and bioavailability of suspended organic particles and how these eventually rival those exerted by natural storms. To provide insights on this poorly addressed issue, we investigated concentrations and biochemical composition of total and enzymatically digestible pools of particulate organic matter (POM in the Thermaikos Gulf (Mediterranean Sea under calm sea conditions, during intensive trawling activities, and after a severe storm. We show here that sediment resuspension caused by trawling can cause large effects on POM quantity, biochemical composition and bioavailability. Both during trawling and after the storm, the relative importance of the carbohydrate pools increased (in the upper water column and the total lipid concentrations decreased (in the intermediate and bottom layers when compared to values measured during calm conditions. These results would suggest that bottom trawling could inject in the upper water column POM pools more refractory in nature (e.g., carbohydrates than those present in calm or after-storm conditions. By contrast, we show also that the bioavailable fraction of biopolymeric C increased significantly during trawling in the upper water column of the shallowest stations and in the bottom water column layer of the deepest ones. These results provide evidence that bottom trawling can influence the overall trophic status of coastal waters, exerting effects similar or stronger than those caused by natural storms, though of variable amplitude

  2. Prevalence of skeletal tissue growth anomalies in a scleractinian coral: Turbinaria mesenterina of Malvan Marine Sanctuary, eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Hussain, A.; De, K.; Thomas, L.; Nagesh, R.; Mote, S.; Ingole, B.S.

    (1998), ultra- violet radiation-induced cell damage is a potential mechanism leading to growth anomalies in corals. The severity may be related to exposure to environ- mental stressors such as light, high levels of sedimen- tation (Riegl et al. 1996... west coast of India. The patch reef, located in the core area of the MMS’s MPA harbours 74 species of fishes, 73 species of sea weeds and 9 coral species, as well as 181 other associated flora and fauna species (Parulekar 1981). Two sites were selected...

  3. Application of a linked stress release model in Corinth Gulf and Central Ionian Islands (Greece)

    Science.gov (United States)

    Mangira, Ourania; Vasiliadis, Georgios; Papadimitriou, Eleftheria

    2017-06-01

    Spatio-temporal stress changes and interactions between adjacent fault segments consist of the most important component in seismic hazard assessment, as they can alter the occurrence probability of strong earthquake onto these segments. The investigation of the interactions between adjacent areas by means of the linked stress release model is attempted for moderate earthquakes ( M ≥ 5.2) in the Corinth Gulf and the Central Ionian Islands (Greece). The study areas were divided in two subareas, based on seismotectonic criteria. The seismicity of each subarea is investigated by means of a stochastic point process and its behavior is determined by the conditional intensity function, which usually gets an exponential form. A conditional intensity function of Weibull form is used for identifying the most appropriate among the models (simple, independent and linked stress release model) for the interpretation of the earthquake generation process. The appropriateness of the models was decided after evaluation via the Akaike information criterion. Despite the fact that the curves of the conditional intensity functions exhibit similar behavior, the use of the exponential-type conditional intensity function seems to fit better the data.

  4. Age, Growth, Reproduction and Feeding of the Spurdog ( Squalus acanthias Linnaeus, 1758) in the South-eastern Black Sea

    Science.gov (United States)

    Avsar, D.

    2001-02-01

    Life-history parameters and diet of spurdog ( Squalus acanthias) sampled from the SE Black Sea were studied. Spurdog from age classes I to XIV were identified, with a dominance of age class VIII for both sexes. The length-weight relationship was W=0·0040*L 2·95and the mean annual growth rates in length and weight were 7·2 cm and 540·1 g, respectively. The estimated von Bertalanffy growth parameters were: W ∞=12021 (g), L ∞=157 (cm), K=0·12 (year -1) and t 0=-1·30 (year). The size at first maturity was 82 cm for males and 88 cm for females. Mean biennial fecundity was also found to be 8 pups/female. The relationships between fecundity-length, fecundity-weight and fecundity-age were found to be: F=-17·0842+0·2369*L (R=0·93), F=0·3780+0·0018*W (R=0·89) and F =-0·7859+1·1609*A (R=0·94) respectively. The spurdog can be considered an opportunistic feeder. Their natural diet was composed mainly of teleost fishes, followed by Crustaceans, Nematodes and Actinarians (=sea anemones). Whiting ( Merlangius merlangus euxinus) was the predominant prey item among their fish prey. Demersal teleosts formed the majority of the diet, and there was no difference ( P>0·05) among the food items of immature, maturing and mature individuals of both sexes.

  5. The distribution and remobilisation of plutonium and americium in estuaries of the eastern Irish Sea: a review

    International Nuclear Information System (INIS)

    Toole, J.

    1993-01-01

    The plutonium and americium components in the authorised discharges from BNFL Sellafield are rapidly removed from Irish Sea seawater onto the particulate phase. These actinides tend to be concentrated in fine sediment deposits on the Irish Sea bed and in estuaries where fine sediment accumulates. This paper focuses on these estuarine areas and brings together the available data on the levels and distributions of Pu and Am within the estuarine sediments. The results from field and laboratory experiments which have been undertaken in order to determine the degree of Pu and Am remobilisation, and the mechanism responsible, are also reviewed. These sediment-associated actinides may undergo both chemical and physical remobilisation, leading to increased dissolved concentrations in low-salinity waters and to apparent losses from the estuary on the sediment phase under certain conditions. Saltmarsh sediments are demonstrated to be the most important reservoirs for Pu and Am. The radiological significance of the levels of Pu and Am found in these and in other sediments is summarised, by comparison with GDLs. The appropriateness of GDLs for assessing the radiological significance of Pu and Am in these saltmarsh sediments is discussed. A more site-specific assessment methodology is recommended. (author)

  6. Lionfishes Pterois miles and Pterois volitans in the North-eastern Mediterranean Sea: Distribution, Habitation, Predation and Predators

    Directory of Open Access Journals (Sweden)

    Cemal Turan

    2017-02-01

    Full Text Available The lionfish Pterois miles was first recorded in the Iskenderun Bay on 2014 in Turkish Marine waters, and then its distribution was extended to Mersin and Antalya Bays in 2014 in the Mediterranean part of Turkey. The first observation of P. miles in the Aegean Sea was from Fethiye region in July 2015. The extension of P. miles in Turkish marine waters seems to be fast even though it’s slow moving feature. Second species of the lionfish, red lionfish Pterois volitans, was also recorded from Turkish Marine waters on May 2016 by a commercial purse seine at 30 m depth at İskenderun Bay and underwater observation was also recorded on October 2016 at Antakya Bay. Therefore, the number of Pterois species in the Mediterranean Sea has reached to two, P. miles and P. volitans. Based on underwater observations, P. miles and P. volitans are usually observed in rocky and cave habitats and prefer 10-40 meters for feeding that may cause the reduction of populations of vanikoro sweeper (Pemperis spp., cardinal fish (Apagon spp. and red coat (Holocentrus rubrum species. P. miles and P. volitans also show cohabitation and gathering usually with 2-5 individuals. Grouper species such as dusky gruper Ephinephelus marginatus and goldblotch grouper Ephinephelus costae are the main predators of the lionfishes.

  7. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. How a collaborative integrated taxonomic effort has trained new spongiologists and improved knowledge of Martinique Island (French Antilles, eastern Caribbean Sea marine biodiversity.

    Directory of Open Access Journals (Sweden)

    Thierry Pérez

    Full Text Available Although sponges are important components of benthic ecosystems of the Caribbean Sea, their diversity remained poorly investigated in the Lesser Antilles. By organizing a training course in Martinique, we wanted both to promote taxonomy and to provide a first inventory of the sponge diversity on this island. The course was like a naturalist expedition, with a field laboratory and a classroom nearby. Early-career scientists and environmental managers were trained in sponge taxonomy. We gathered unpublished data and conducted an inventory at 13 coastal sites. We explored only shallow water habitats (0-30 m, such as mangroves, reefs or rocky bottoms and underwater caves. According to this study, the sponge fauna of Martinique is currently represented by a minimum of 191 species, 134 of which we could assign species names. One third of the remaining non-identified sponge species we consider to be new to science. Martinique appears very remarkable because of its littoral marine fauna harboring sponge aggregations with high biomass and species diversity dominating over coral species. In mangroves, sponges cover about 10% of the surface of subtidal roots. Several submarine caves are true reservoirs of hidden and insufficiently described sponge diversity. Thanks to this new collaborative effort, the Eastern Caribbean has gained a significant increase of knowledge, with sponge diversity of this area potentially representing 40% of the total in the Caribbean Sea. We thus demonstrated the importance of developing exploratory and educational research in areas historically devoid of biodiversity inventories and systematics studies. Finally, we believe in the necessity to consider not only the number of species but their distribution in space to evaluate their putative contribution to ecosystem services and our willingness to preserve them.

  9. Sinkholes, subsidence and subrosion on the eastern shore of the Dead Sea as revealed by a close-range photogrammetric survey

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Saberi, Leila; Alrshdan, Hussam; Sawarieh, Ali; Closson, Damien; Walter, Thomas R.; Dahm, Torsten

    2017-05-01

    Ground subsidence and sinkhole collapse are phenomena affecting regions of karst geology worldwide. The rapid development of such phenomena around the Dead Sea in the last four decades poses a major geological hazard to the local population, agriculture and industry. Nonetheless many aspects of this hazard are still incompletely described and understood, especially on the eastern Dead Sea shore. In this work, we present a first low altitude (sinkhole area of Ghor Al-Haditha, Jordan. We provide a detailed qualitative and quantitative analysis of a new, high resolution digital surface model (5 cm px-1) and orthophoto of this area (2.1 km2). We also outline the factors affecting the quality and accuracy of this approach. Our analysis reveals a kilometer-scale sinuous depression bound partly by flexure and partly by non-tectonic faults. The estimated minimum volume loss of this subsided zone is 1.83 ṡ 106 m3 with an average subsidence rate of 0.21 m yr-1 over the last 25 years. Sinkholes in the surveyed area are localized mainly within this depression. The sinkholes are commonly elliptically shaped (mean eccentricity 1.31) and clustered (nearest neighbor ratio 0.69). Their morphologies and orientations depend on the type of sediment they form in: in mud, sinkholes have a low depth to diameter ratio (0.14) and a long-axis azimuth of NNE-NE. In alluvium, sinkholes have a higher ratio (0.4) and are orientated NNW-N. From field work, we identify actively evolving artesian springs and channelized, sediment-laden groundwater flows that appear locally in the main depression. Consequently, subrosion, i.e. subsurface mechanical erosion, is identified as a key physical process, in addition to dissolution, behind the subsidence and sinkhole hazard. Furthermore, satellite image analysis links the development of the sinuous depression and sinkhole formation at Ghor Al-Haditha to preferential groundwater flow paths along ancient and current wadi riverbeds.

  10. The cycling and sea-air exchange of mercury in the waters of the Eastern Mediterranean during the 2010 MED-OCEANOR cruise campaign.

    Science.gov (United States)

    Fantozzi, L; Manca, G; Ammoscato, I; Pirrone, N; Sprovieri, F

    2013-03-15

    An oceanographic cruise campaign on-board the Italian research vessel Urania was carried out from the 26th of August to the 13th of September 2010 in the Eastern Mediterranean. The campaign sought to investigate the mercury cycle at coastal and offshore locations in different weather conditions. The experimental activity focused on measuring mercury speciation in both seawater and in air, and using meteorological parameters to estimate elemental mercury exchange at the sea-atmosphere interface. Dissolved gaseous mercury (DGM), unfiltered total mercury (UTHg) and filtered total mercury (FTHg) surface concentrations ranged from 16 to 114, 300 to 18,760, and 230 to 10,990pgL(-1), respectively. The highest DGM, UTHg and FTHg values were observed close to Augusta (Sicily), a highly industrialized area of the Mediterranean region, while the lowest values were recorded at offshore stations. DGM vertical profiles partially followed the distribution of sunlight, as a result of the photoinduced transformations of elemental mercury in the surface layers of the water column. However, at some stations, we observed higher DGM concentrations in samples taken from the bottom of the water column, suggesting biological mercury production processes or the presence of tectonic activity. Moreover, two days of continuous measurement at one location demonstrated that surface DGM concentration is affected by solar radiation and atmospheric turbulence intensity. Atmospheric measurements of gaseous elemental mercury (GEM) showed an average concentration (1.6ngm(-3)) close to the background level for the northern hemisphere. For the first time this study used a numerical scheme based on a two-thin film model with a specific parameterization for mercury to estimate elemental mercury flux. The calculated average mercury flux during the entire cruise was 2.2±1.5ngm(-2)h(-1). The analysis of flux data highlights the importance of the wind speed on the mercury evasion from sea surfaces

  11. Sea-surface temperatures for the last 7200 years from the eastern Sunda Shelf, South China Sea: Climatic inferences from planktonic foraminiferal Mg/Ca ratios

    Science.gov (United States)

    Woodson, Anna Lee; Leorri, Eduardo; Culver, Stephen J.; Mallinson, David J.; Parham, Peter R.; Thunell, Robert C.; Vijayan, V. R.; Curtis, Scott

    2017-06-01

    To test whether low latitude shallow shelf deposits can provide high resolution paleoclimatic records, we utilized two cores from the Holocene sedimentary fill of incised valleys on the Sunda Shelf off Sarawak, Malaysia. We developed a new sea-surface temperature (SST) record based on planktonic foraminiferal Mg/Ca for the last 7200 years. This record reveals several significant shifts between warmer and colder conditions. Temperatures averaged 27.5 °C ca. 7200 cal. years BP, then climbed to 28.2 °C from 6500 to 5500 cal. years BP. At 5500-4500 cal. years BP we identified the coldest period (26.8 °C) of the analyzed period. For the last 4500 years SST again averaged 27.5 °C but the profile is rather variable. The last ca. 1000 years recorded the warmest SST averaging 28.5 °C. We record, for the first time in this region, a cool interval, ca. 1000 years in duration, centered on 5000 cal years BP concomitant with a wet period recorded in Borneo. The record also reflects a warm interval from ca. 1000 to 500 cal years BP that may represent the Medieval Climate Anomaly. Variations in the East Asian Monsoon (EAM) and solar activity are considered as potential drivers of SST trends. However, hydrology changes related to the El Niño-Southern Oscillation (ENSO) variability, shifts of the Western Pacific Warm Pool and migration of the Intertropical Convergence Zone are more likely to have impacted our SST temporal trend. Our findings indicate that climatic patterns in the region might be in phase with ENSO and out of phase with the EAM.

  12. Temperature profiles from mechanical bathythermograph (MBT) casts from the USS WARBLER in the Eastern China Sea and other locations in support of the Fleet Observations of Oceanographic Data (FLOOD) project from 1966-09-19 to 1966-09-27 (NODC Accession 6600396)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MBT data were collected from the USS WARBLER in support of the Fleet Observations of Oceanographic Data (FLOOD) project. Data were collected in the Eastern China Sea...

  13. A STUDY ON THE HENDIADYOINS IN THE EASTERN BLACK-SEA REGION DIALECTS / ORTA VE DOĞU KARADENIZ AĞIZLARINDA GÖRÜLEN IKILEMELER ÜZERINE BIR DEĞERLENDIRME

    Directory of Open Access Journals (Sweden)

    Dr. Ercan ALKAYA

    2008-08-01

    Full Text Available In this study, the hendiadyoins of the dialects of the Central andEastern Black-Sea Region such as Ordu, Giresun, Rize and Trabzon whichcan be observed as non-literary usages are dealt with. The hendiadyoins takenfrom the dialect studies on the afore-mentioned dialects and from theDerleme Sözlüğü are assessed in respect with their origins, structures andmeanings.

  14. Light microscopic study of four plagiorchiid trematodes infecting marine fish in the south-eastern Mediterranean Sea, Alexandria City, with descriptions of two new species.

    Science.gov (United States)

    Abdel-Gaber, Rewaida; Abdel-Ghaffar, Fathy; Mehlhorn, Heinz; Al Quraishy, Saleh; Morsy, Kareem; Maher, Sherein

    2018-05-01

    During the present investigation, a total of 220 fish specimens belonging to three different species, namely, little tunny Euthynnus alletteratus, African snook Lates niloticus, and striped red mullet Mullus surmuletus, were collected from January-November 2016 from the coasts off Abu Qir landing site, Alexandria City, south-eastern Mediterranean Sea, Egypt. The collected fish samples were dissected and examined for the presence of helminth parasites. Twenty-three out of 220 (10.45%) fish specimens were found to be naturally infected with four species of trematode parasites belonging to three different families of the order Plagiorchiida. The recovered parasite species were collected and identified by applying light microscopic examinations. The present study recorded two new parasite species, namely, Stephanostomum alletterani sp. nov. and Bathycreadium mulli sp. nov., belonging to the families Acanthocolpidae and Opecoelidae and infecting E. alletteratus and M. surmuletus, respectively and re-descriptions of the two remaining species, namely, Acanthostomum spiniceps and Aponurus mulli of the families Acanthostomatidae and Opecoelidae, respectively, to clarify the measurements of some body parts. Morphological and morphometric characterizations revealed some differences between the present species and other related species detected previously. Future studies are recommended to include advanced molecular characteristics for these species.

  15. Marine pollution risk in a coastal city: use of an eco-genotoxic tool as a stress indicator in mussels from the Eastern Aegean Sea.

    Science.gov (United States)

    Kacar, Asli; Pazi, Idil; Gonul, Tolga; Kucuksezgin, Filiz

    2016-08-01

    Coastal areas, such as bays, estuaries, and harbors, are heavily polluted since these areas are the settlements to which toxic chemicals from industrial and domestic wastes are discharged. The genetic damage was evaluated using bioindicator mussel Mytilus galloprovincialis caused by toxic chemicals (metals and polycyclic aromatic hydrocarbons) in İzmir and Çandarlı Bays (the Eastern Aegean Sea) through comet assay. Three sampling sites from the two bays were selected and the study was conducted during the spring and autumn periods. The highest levels of DNA damage expressed as %Tail-DNA were observed in İzmir Bay (34.60 % Tail-DNA) in the spring. Analysis of the correlation between PAHs and metals in mussels and %T-DNA in the hemolymph and gill cells showed a statistically significant positive correlation between %T-DNA and ∑PAH, chromium (p llution level of the İzmir and Çandarlı Bays by using the DNA damage to the mussel, which can identify the effects of environmental pollutants at the cellular levels. These results confirm that comet assay can be used to determine the temporal and spatial differences of DNA damage, and as a suitable tool for the measurement of genotoxicity in regions with low pollutant concentrations.

  16. A Study of the Distribution of Natural Radionuclides and their Environmental Impacts in Halayeb Triangle Area, along the South Eastern Coast of the Red Sea, Egypt

    International Nuclear Information System (INIS)

    Salama, M.H.M.; Khedr, R.F.E.

    2017-01-01

    Thirty samples (14 surficial soil, 3 Sea water-3 desalinated water, and 10 plant) were collected from halayeb triangle are a along the south eastern Coast of the Red Sea, Egypt . Distributions of natural radionuclides of "2"2"6 Ra, "2"3"2 Th, "4"0 K and "1"3"7Cs in these samples were determined using γ-ray spectrometry. The average activities of natural radionuclides in all samples in the study are a are 19.38 (3.35-61.09) Bq kg"-"1 for "2"2"6 Ra, 10.87 (1.39-24.28) Bq kg"-"1 for "2"3"2 Th, 245.25 (132.46-531.19) Bq kg"-"1 for "40 K, and 1.48 (0.67 - 2.52) Bq kg"-"1 "1"3"7 Cs for surficial soil samples . These values were 8.59 (1.48-21.57) Bq kg"-"1 for 226 Ra, 11.34 (2. 64-25.44) Bq kg"-"1 for "2"3"2Th, and 254.66(69.73-450.58) Bq kg"-"1 for "4"0K, for plant samples. For sea water samples, the average activity for "2"2"6 Ra is 3.20 (1.99-3.91) Bq kg"-"1, for "2"3"2Th is 1.73(1.24-2.45) Bq kg"-"1, and 15.10 (8.67-23.25) Bq kg"-"1 for "4"0 K. For desalinised water the average activity is under detection limits for "2"2"6Ra, "2"3"2Th, and 13.49 (8.67-17.85) Bq kg"-"1 for "4"0K. A comparison of radionuclide activities in the study area and in other coastal and aquatic environments is given. The radiation hazard parameters (absorbed dose rate, radium equivalent activity, internal hazard index, external hazard index ,annual gonadal dose equivalent); and transfer factor of elements from soil to plant were calculated. The results of measurements will serve as base line data and background reference level for south Egyptian coastlines

  17. Mesostructural observations along the Western coast of Bel'kovsky Island: preliminary results (North-Eastern Laptev Sea region, Russian Arctic)

    Science.gov (United States)

    Verzhbitsky, V. E.

    2003-04-01

    This study is based on the field works carried out by the Institute of the Lithosphere of Marginal Seas RAS in the central part of the Bel'kovsky island during 2002 August-September. In the tectonic sense the Bel'kovsky island is located in the eastern part of the Late Cretaceous (?) - Cenozoic Laptev Sea rift system and also is a part of extended Bel’kov horst, dividing Bel’kov Svyatoi Nos (in the east) and Anisin (in the west) rifts (e.g. Drachev et al, 1998). Mesostructural investigations included statistical measurments of kinematic indicators (cleavage planes, extensional veins, slickensides, axes of folds and bedding plains) in Devonian and Carboniferous sedimentary formations and also slickensides in diabase magmatic complex (presumably of Late Paleozoic age). It is supposed, that this studies will allow to characterize the stages of regional tectonic processes: synsedimentary (slump) folds formation (1), NE-SW compression (2), which corresponds to the general (NW-SE trending) structural pattern of the island, E-W compression (3), expressed in N-S trending subvertical cleavage and associated strike-slips and thrust faults, NW-SE (4) and ENE-WSW - NE-SW (5) extension, expressed in strike-slip faults with different strike-slip component, and also, probably to specify the character of the recent tectonic processes near to the area of conjunction between the Eurasian and American plates. It is likely, that synsedimentary (slump) folds, identified in the Carboniferous clastic formation marks the paleoslope setting of New Siberian Islands Chukotka platform (block). Presumably, second of the determined stages corresponds to closing of the South Anyui Lyakhov paleooceanic basin in Neocomian; the last stage, expressed in wide-developed submeridional normal faults with sinistral strike-slip component along the western coast of the island, reflects the modern regional stress-field in area of conjunction between the Eurasian and American plates (e.g. Avetisov, 1999

  18. Comparison of CDOM EEMs Characteristics along F and PN section in Eastern China Sea: significance for sources tracing

    Science.gov (United States)

    Du, Yong; Zhang, Xiaoyu; Jiang, Binbin; Huang, Dasong; Yao, Lingling

    2015-04-01

    In this paper, a total of 28 water samples were collected mainly from three sections(C section in the Yangtze river inner estuary, PN section and F section on the spindle of Changjiang diluted water influenced by different hydrodynamic processes),which taken on two cruises in spring and summer of 2011. Absorption and fluorescence spectroscopy were measured along with dissolved organic carbon(DOC) concentrations and temperature, salinity and another environmental parameters to characterize the material sources and environmental implications of dissolved organic matter(DOM). Two protein-like components(tyrosine-like peak B and tryptophan-like peak T1), and two humic-like components(marine humic-like peak M and ultraviolet region humic-like peak A ) were identified by PARAFAC. We discussed CDOM distribution characteristic, material composition, and influence factors during the slowly dilution process of Changjiang diluted water into the east China sea by comparing the correlation of the CDOM absorption, fluorescence intensity, and fluorescence peak with DOC, in order to provide the based biogeochemistry theory basis for building DOC implications using CDOM fluorescence properties. The results revealed that:1) the Yangtze river and its inner estuary (upstream of the river mouth) were detected a higher amount of humic-like components. With the rapid dilution (or settlement) at the inner estuary, the humic-like components would further spread and dilute slowly on PN section and F section. On PN section, the terrigenous material is the main source material, and the main mechanism of CDOM distribution characteristics is controlled by dilution diffusion. Affected by the water mass convergence, marine dissolved organic matter in local waters had obvious input. However, due to the complexed hydrodynamic environment on F section, the input of terrigenous material has many ways. The influence of marine dissolved organic matter increased with the offshore distance increases.2

  19. Assemblages of deep-sea fishes on the middle slope off Northwest Africa (26°-33° N, eastern Atlantic)

    Science.gov (United States)

    Pajuelo, J. G.; Seoane, J.; Biscoito, M.; Freitas, M.; González, J. A.

    2016-12-01

    The structure and composition of deep-sea fish assemblages living on the middle slope off NW Africa (26-33° N) were investigated. Data were collected by six commercial trawlers during experimental fishing (1027 hauls) at depths between 800 and 1515 m. A total of 1,115,727 fish specimens, belonging to 37 families and 96 species (24 Elasmobranchii, 5 Holocephali, and 67 Actinopteri) were collected with bottom trawls. The deep-sea demersal fish fauna off NW Africa is dominated by fishes of the family Macrouridae, followed by the Moridae and Alepocephalidae families. The main abundant species were Trachyrincus scabrus, Bathygadus favosus, Mora moro, Alepocephalus productus, Nezumia aequalis and Bathygadus melanobranchus. PERMANOVA analysis showed differences in demersal fish assemblages among bottom types, depth strata and between areas (north and south of parallel 30° N), with the area being the most influential factor followed by the type of substrate. PERMANOVAs computed separately for each area showed significant differences among the bottom types and depths in both areas. SIMPER analysis revealed that B. melanobranchus and B. favosus, which occurred at higher abundances in the area ≥30° N, were the species that were best discriminated between areas; whilst T. scabrus and M. moro occurred at higher abundances in the area <30° N. N. aequalis, B. favosus, B. melanobranchus, Deania hystricosa, Aphanopus intermedius, Coelorinchus labiatus and Halosaurus johnsonianus were restricted or more abundant in the area ≥30° N, and functioned as the discriminating species that most contributed to the average dissimilarity between areas. T. scabrus, M. moro, Alepocephalus productus and Alepocephalus bairdii were more abundant in the area <30° N. The standardized mean abundance (in number of individuals/km2) showed a decreasing pattern: i) with depth in both areas, north and south of parallel 30° N, and ii) with depth on each type of substrate, except on cold coral

  20. Absorption and fluorescence properties of chromophoric dissolved organic matter of the eastern Bering Sea in the summer with special reference to the influence of a cold pool

    Science.gov (United States)

    D'Sa, E. J.; Goes, J. I.; Gomes, H.; Mouw, C.

    2014-06-01

    The absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) are reported for the inner shelf, slope waters and outer shelf regions of the eastern Bering Sea during the summer of 2008, when a warm, thermally stratified surface mixed layer lay over a cold pool (CDOM absorption at 355 nm (ag355) and its spectral slope (S) in conjunction with excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) revealed large variability in the characteristics of CDOM in different regions of the Bering Sea. PARAFAC analysis aided in the identification of three humic-like (components one, two and five) and two protein-like (a tyrosine-like component three, and a tryptophan-like component four) components. In the extensive shelf region, average absorption coefficients at 355 nm (ag355, m-1) and DOC concentrations (μM) were highest in the inner shelf (0.342 ± 0.11 m-1, 92.67 ± 14.60 μM) and lower in the middle (0.226 ± 0.05 m-1, 78.38 ± 10.64 μM) and outer (0.185 ± 0.05 m-1, 79.24 ± 18.01 μM) shelves, respectively. DOC concentrations, however were not significantly different, suggesting CDOM sources and sinks to be uncoupled from DOC. Mean spectral slopes S were elevated in the middle shelf (24.38 ± 2.25 μm-1) especially in the surface waters (26.87 ± 2.39 μm-1) indicating high rates of photodegradation in the highly stratified surface mixed layer, which intensified northwards in the northern middle shelf likely contributing to greater light penetration and to phytoplankton blooms at deeper depths. The fluorescent humic-like components one, two, and five were most elevated in the inner shelf most likely from riverine inputs. Along the productive "green belt" in the outer shelf/slope region, absorption and fluorescence properties indicated the presence of fresh and degraded autochthonous DOM. Near the Unimak Pass region of the Aleutian Islands, low DOC and ag355 (mean 66.99 ± 7.94 μM; 0.182 ± 0.05 m-1) and a

  1. An integrated multi-parameter monitoring approach for the quantification and mitigation of the climate change impact on the coasts of Eastern Crete, S. Aegean Sea (Project AKTAIA)

    Science.gov (United States)

    Ghionis, George; Alexandrakis, George; Karditsa, Aikaterini; Sifnioti, Dafni; Vousdoukas, Michalis; Andreadis, Olympos; Petrakis, Stelios; Poulos, Serafim; Velegrakis, Adonis; Kampanis, Nikolaos; Lipakis, Michalis

    2014-05-01

    The AKTAIA project aims at the production of new knowledge regarding the forms of manifestation of the climate change and its influence on the stability and evolution of the coastal landforms along the shoreline of eastern Crete (approximate length: 757 km), taking into account the various aspects of human intervention. Aerial photographs, satellite images and orthophotomaps have been used to produce a detailed coastline map and to study the morphological characteristics of the coastal zone of Eastern Crete. More than 100 beach zones have been visited during three field campaigns, which included geomorphological and human intervention mapping, topographic, meteorological and oceanographic measurements and sedimentological sampling and observations. In addition, two pilot sites (one in the north and one in the south part of Crete) are being monitored, via the installation of coastal video monitoring systems, shore-based meteorological stations and wave-tide recorders installed in the nearshore zone. Detailed seafloor mapping with the use of side scan sonar and scuba diving and bathymetric surveys were conducted in the two pilot sites. Meteorological and oceanographic data from all existing land-based meteorological stations, oceanographic buoys and the ERA-interim dataset are used to determine the wind and wave climate of each beach. The collected climatic, sedimentological and coastal environmental data are being integrated in a GIS database that will be used to forecast the climatic trends in the area of Crete for the next decades and to model the impact of the climatic change on the future evolution of the coastal zone. New methodologies for the continuous monitoring of land-sea interaction and for the quantification of the loss of sensitive coastal zones due to sea-level rise and a modified Coastal Vulnerability Index for a comparative evaluation of the vulnerability of the coasts are being developed. Numerical modelling of the nearshore hydrodynamics and the

  2. Metazoan parasites of deep-sea fishes from the South Eastern Pacific: Exploring the role of ecology and host phylogeny

    Science.gov (United States)

    Ñacari, Luis A.; Oliva, Marcelo E.

    2016-09-01

    We studied the parasite fauna of five deep-sea fish species (>1000 m depth), Three members of Macrouridae (Macrourus holotrachys, Coryphaenoides ariommus and Coelorhynchus sp.), the Morid Antimora rostrata and the Synaphobranchidae Diaptobranchus capensis caught as by-catch of the Patagonian toothfish (Dissostichus eleginoides) from central and northern Chile at depths between 1000 and 2000 m. The parasite fauna of M. holotrachys was the most diverse, with 32 species (The higher reported for Macrourus spp.) and the lower occur in the basketwork eel D. capensis (one species). Trophically transmitted parasites, mainly Digenea and Nematoda explain 59.1% of the total number of species obtained (44 species) and the 81.1% of the 1020 specimens collected. Similarity analysis based on prevalence as well as a Correspondence analysis shows that higher similitude in parasite fauna occurs in members of Macrouridae. The importance of diet and phylogeny is discussed as forces behind the characteristics of the endoparasite and ectoparasite communities found in the studied fish species.

  3. Bio-concentration of Polycyclic Aromatic Hydrocarbons in the grey Mangrove (Avicennia marina along eastern coast of the Red Sea

    Directory of Open Access Journals (Sweden)

    El-Amin Bashir M.

    2017-12-01

    Full Text Available There are numerous sources of chemical pollutants which can impact the mangrove ecosystem through adjacent waters, industrial and sewage discharges and air depositions. Polycyclic aromatic hydrocarbons (PAHs are semi volatile ubiquitous anthropogenic pollutants detected in all environmental compartments. In the monitoring framework for the mangrove ecosystem along the Red Sea coast of Saudi Arabia, nine mangrove stands were examined for the accumulation of PAHs. Polycyclic aromatic hydrocarbons were measured using Gas Chromatography-Mass Spectrometry (GC-MS. The mean values detected for total PAHs in sediments, roots and leaf were 2.98, 8.57 and 23.43 ng/g respectively. The trend of the total PAHs concentration in all sites showed the descending order: leaf > roots > sediments. Beside the sandy nature of the sediments, the presences of all stands in remote areas fare from the direct anthropogenic effects lead to these relative low values. PAH bio-concentration factors for leaf are two to three magnitudes higher than that in roots, suggesting atmosphere deposition /leaf uptake mechanism in addition to the sediment/root mechanism. The diagnostic ratios revealed that the sources of PAHs are mainly pyrogenic.

  4. Distribution of tributyltin in surface sediments from transitional marine-lagoon system of the south-eastern Baltic Sea, Lithuania.

    Science.gov (United States)

    Suzdalev, Sergej; Gulbinskas, Saulius; Blažauskas, Nerijus

    2015-02-01

    The current research paper presents the results of contamination by tributyltin (TBT) compounds in Klaipėda Port, which is situated in a unique marine-lagoon water interaction zone. One hundred fifty-four surface sediment samples have been taken along the whole transition path from lagoon to the sea and analysed in order to quantify the contamination rate in specific environment of high anthropogenic pressure. The detected TBT concentrations ranged from 1 to 5,200 ng Sn g(-1) of dry weight of sediment. The back-trace of horizontal distribution of TBT-contaminated sediments show obvious increase of tributyltin concentrations closer to port areas dealing with ship repair and places of dry-docking facilities. This is a clear indication that those activities are the main source of contamination in the study area. The estimated correlation of TBT concentration in sediments with total organic carbon and the amount of fine fraction (tributyltin is related to potential contamination source areas (ship repairing, dockyards) due to direct input of hazardous substances into the water.

  5. Potential risk assessment of metals in edible fish species for human consumption from the Eastern Aegean Sea.

    Science.gov (United States)

    Pazi, Idil; Gonul, L Tolga; Kucuksezgin, Filiz; Avaz, Gulsen; Tolun, Leyla; Unluoglu, Aydın; Karaaslan, Yakup; Gucver, S Mine; Koc Orhon, Aybala; Siltu, Esra; Olmez, Gulnur

    2017-07-15

    The levels of Hg, Cd, Pb, Cr, Cu and Zn were measured in the tissues of four edible fish species namely: Diplodus annularis, Pagellus erythrinus, Merluccius merluccius and Mullus barbatus, collected from the Turkish Coast of the Aegean Sea. Except for D. annularis, the levels of Cd and Pb in all fish tissues sampled in Aliaga Bay in 2009 were above the tolerable limits according to the Food and Agriculture Organization of the United Nations (FAO). Hg in P. erythrinus and M. barbatus were higher than the maximum permitted limits (FAO), while D. annularis and M. merluccius were lower than the limit for biota in the district of Aliaga. Although the Target Hazard Quotient (THQ) values for Cd, Pb, Cu, Cr, Zn in all fish samples were lower than 1.0, the THQ for Hg levels were higher than 1.0 for most of the samples. According to the THQ values, M. merluccius may be consumed in moderation from Aliaga Bay, while the consumption of M. barbatus and P. erythrinus collected from Aliaga Bay are potentially hazardous to human health due to the Hg concentrations. Fish collected from Izmir Bay can be consumed safely. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Temporal and spatial responses of the bioindicator Fucus to discharges of 99Tc in the eastern Irish Sea

    International Nuclear Information System (INIS)

    McDonald, P.; Busby, R.G.; McCartney, M.

    1999-01-01

    Technetium-99 is a radioactive isotope discharged under authorisation to the Irish Sea from the British Nuclear Fuels plc Sellafield reprocessing plant in Cumbria via a marine pipeline. An increase in 99 Tc discharges from Sellafield in recent years has provided an ideal opportunity to undertake a more detailed investigation of its environmental behaviour. Here, the temporal and spatial response of Fucus sp. to the increased discharges has been investigated and its role as a bioindicator assessed. Initial investigations in 1995, have confirmed the expectation that Fucus does act as an effective bioindicator of 99 Tc, with easily detectable 99 Tc concentrations (1 - 15 kBq kg -1 wet weight) being encountered, providing a time integrated signal of 99 Tc discharges. Analysis of subsequent samples collected during 1996, however, have shown significant short-term peaks in Fucus 99 Tc concentrations close to Sellafield (up to 90 kBq kg -1 wet weight) and this can be related to peaks in 99 Tc seawater concentrations. This type of response suggests that Fucus has a means of rapidly accumulating 99 Tc, although the rate at which this accumulated component may be eliminated remains unclear. This effect was only observed at sites close to Sellafield (within 15 km). Relatively constant 99 Tc concentrations in Fucus were found at more distant sites (50 - 150 km). (author)

  7. THE CURRENT DYNAMICS OF THE SUBMARINE PERMAFROST AND METHANE EMISSION ON THE SHELF OF THE EASTERN ARCTIC SEAS

    Directory of Open Access Journals (Sweden)

    O. A. Anisimov

    2012-01-01

    Full Text Available We study the methane emission over the East Siberian Arctic Shelf (ESAS under the changing sub-aquatic permafrost conditions from the time of inundation 9–6 thousand years BP to present and further until the end of the millennium. The study is based on the full-physics model of hydrothermal regime of soil. Our results indicate that the current elevated methane emission from ESAS is responsible for 0.01 ºС global air temperature rise. Even under the hypothetic climate scenario that overestimates the range of near-bottom water temperature rise, projected by the end of the millennium thawing of the bottom sediments is likely to be about90 mand will thus not reach the upper limit of the methane hydrate stability zone that is located 100–140 munderneath the sea bottom. The results of the study do not support the so called «methane bomb» hypothesis that is widely discussed in the scientific literature and in the media.

  8. Insight into the Pacific Sea Surface Temperature- North American Hydroclimate Connection from an Eastern Tropical North Pacific Coral Record

    Science.gov (United States)

    Sanchez, S. C.; Charles, C. D.; Carriquiry, J. D.

    2015-12-01

    The last few years of record-breaking climate anomalies across North America--a resilient atmospheric ridge and extreme drought over the West Coast, and severe winters across the Midwest and East Coast regions--have been linked to anomalous Pacific sea surface temperatures (Seager et al. 2014, Wang et al. 2014, Hartmann 2015). The synoptic associations prompt important questions on the relation between these unusual phenomena and extreme expressions of known Pacific decadal modes, such as the North Pacific Gyre Oscillation (NPGO). These questions motivate our pursuit to document multiple realizations of decadal variability in the Pacific-North American region through periods of varied radiative forcing. Here we introduce a 178 year, seasonally resolved Porites coral record from Clarion Island (18N, 115W), the westernmost island of the Revillagigedo Archipelago, a region both highly influenced by NPGO SST and SSS variability and critical for NPGO tropical-extratropical communication via the Seasonal Footprinting Mechanism (Vimont et al. 2003). When coupled with tree ring records from the western United States (Griffin and Anchukaitis 2014, MacDonald and Case 2005) and coral records from the central tropical Pacific (Cobb et al. 2001), the δ18O signal from the Clarion coral offers an extended framework of coherent continental hydroclimate and oceanic variability across the Pacific basin beyond the instrumental record. Over the last 200 years, we find clear commonality in the timing, magnitude and spatial expression of variability (illustrated through the NADA Atlas, Cook et al. 2004) amongst the proxy records. The strong relationship between Northeastern Pacific Clarion and the Central Pacific Palmyra record with the North American hydroclimate records can be viewed within the mechanistic framework of the NPGO; this framework is then explored over the last millennium across intervals of varied radiative forcing.

  9. Disintegration of a marine-based ice stream - evidence from the Norwegian Channel, north-eastern North Sea

    Science.gov (United States)

    Morén, Björn M.; Petter Sejrup, Hans; Hjelstuen, Berit O.; Haflidason, Haflidi; Schäuble, Cathrina; Borge, Marianne

    2014-05-01

    The Norwegian Channel Ice Stream repeatedly drained large part of the Fennoscandian Ice Sheet through Mid and Late Pleistocene glacial stages. During parts of Marine Isotope Stages 2 and 3, glacial ice from Fennoscandia and the British Isles coalesced in the central North Sea and the Norwegian Channel Ice Stream reached the shelf edge on multiple occasions. Through the last decades a large amount of acoustic and sediment core data have been collected from the Norwegian Channel, providing a good background for studies focussing on stability- and development-controlling parameters for marine-based ice streams, the retreat rate of the Norwegian Channel Ice Stream, and the behaviour of the Fennoscandian Ice Sheet. Further, this improved understanding can be used to develop more accurate numerical climate models and models which can be used to model ice-sheet behaviour of the past as well as the future. This study presents new acoustic records and data from sediment cores which contribute to a better understanding of the retreat pattern and the retreat rate of the last ice stream that occupied the Norwegian Channel. From bathymetric and TOPAS seismic data, mega-scale glacial lineations, grounding-zone wedges, and end moraines have been mapped, thereby allowing us to reconstruct the pro- and subglacial conditions at the time of the creation of these landforms. It is concluded that the whole Norwegian Channel was deglaciated in just over 1 000 years and that for most of this time the ice margin was located at positions reflected by depositional grounding-zone wedges. Further work will explore the influence of channel shape and feeding of ice from western Norwegian fjords on this retreat pattern through numerical modelling.

  10. Mean temperature of the catch (MTC in the Greek Seas based on landings and survey data

    Directory of Open Access Journals (Sweden)

    Athanassios C. Tsikliras

    2015-04-01

    Full Text Available The mean temperature of the catch (MTC, which is the average inferred temperature preference of the exploited species weighted by their annual catch, is an index that has been used for evaluating the effect of sea warming on marine ecosystems. In the present work, we examined the effect of sea surface temperature on the catch composition of the Greek Seas using the MTC applied on the official catch statistics (landings for the period 1970-2010 (Aegean and Ionian Seas and on experimental bottom trawl survey data for 1997-2014 (southern Aegean Sea. The MTC of the landings for the study period increased from 11.8 οC to 16.2 οC in the Aegean Sea and from 10.0 οC to 14.7 οC in the Ionian Sea. Overall, the rate of MTC increase was 1.01 οC per decade for the Aegean and 1.17 οC per decade for the Ionian Sea and was positively related to sea surface temperature anomalies in both areas. For the survey data, the increase of the MTC of the bottom trawl catch in the southern Aegean Sea was lower (0.51 οC per decade but referred to a shorter time frame and included only demersal species. The change in MTC of official and survey catches indicates that the relative catch proportions of species preferring warmer waters and those preferring colder waters have changed in favour of the former and that this change is linked to sea surface temperature increase, both internally (through the Atlantic Multidecadal Oscillation or externally (warming trend driven.

  11. The lithosphere-asthenosphere system in the Calabrian Arc and surrounding seas

    Energy Technology Data Exchange (ETDEWEB)

    Panza, G F [Department of Earth Sciences, University of Trieste, Trieste (Italy); [Abdus Salam International Centre for Theoretical Physics, SAND Group, Trieste (Italy)]. E-mail: panza@dst.univ.trieste.it; Pontevivo, A [Department of Earth Sciences, University of Trieste, Trieste (Italy)

    2002-10-01

    Through the non-linear inversion of Surface-Wave Tomography data, using as a priori constraints seismic data from literature, it has been possible to define a fairly detailed structural model of the lithosphere-asthenosphere system (thickness, S-wave and P-wave velocities of the crust and of the upper mantle layers) in the Calabrian Arc region (Southern Tyrrhenian Sea, Calabria and the Northern-Western part of the Ionian Sea). The main features identified by our study are: (1) a very shallow (less then 10 km deep) crust-mantle transition in the Southern Tyrrhenian Sea and very low S-wave velocities just below a very thin lid in correspondence of the submarine volcanic bodies in the study area; (2) a shallow and very low S-wave velocity layer in the mantle in the areas of Aeolian islands, of Vesuvius, Ischia and Phlegraean Fields, representing their shallow-mantle magma source; (3) a thickened continental crust and lithospheric doubling in Calabria; (4) a crust about 25 km thick and a mantle velocity profile versus depth consistent with the presence of a continental rifled, now thermally relaxed, lithosphere in the investigated part of the Ionian Sea; (5) the subduction of the Ionian lithosphere towards NW below the Tyrrhenian Basin; (6) the subduction of the Adriatic lithosphere underneath the Vesuvius and Phlegraean Fields. (author)

  12. Functional composition of epifauna in the south-eastern North Sea in relation to habitat characteristics and fishing effort

    Science.gov (United States)

    Neumann, Hermann; Diekmann, Rabea; Kröncke, Ingrid

    2016-02-01

    Analysis of ecosystem functioning is essential to describe the ecological status of ecosystems and is therefore directly requested in international directives. There is a lack of knowledge regarding functional aspects of benthic communities and their environmental and anthropogenic driving forces in the southern North Sea. This study linked functional composition of epibenthic communities to environmental conditions and fishing effort and investigated spatial correlations between habitat characteristics to gain insight into potential synergistic and/or cumulative effects. Functional composition of epifauna was assessed by using biological trait analysis (BTA), which considered 15 ecological traits of 54 species. Functional composition was related to ten predictor variables derived from sediment composition, bottom temperature and salinity, hydrodynamics, annual primary production and fishing effort. Our results revealed significantly different functional composition between the Dogger Bank, the Oyster Ground, the West and North Frisian coast. Mobility, feeding type, size and adult longevity were the most important traits differentiating the communities. A high proportion of trait modalities related to an opportunistic life mode were obvious in coastal areas especially at the West Frisian coast and in the area of the Frisian Front indicating disturbed communities. In contrast, functional composition in the Dogger Bank area indicated undisturbed communities with prevalence of large, long-lived and permanently attached species being sensitive towards disturbance such as fishing. Tidal stress, mud content of sediments, salinity, stratification and fishing effort were found to be the most important habitat characteristics shaping functional composition. Strong correlations were found between variables, especially between those which changed gradually from the coast to offshore areas including fishing effort. Unfavourable extremes of these factors in coastal areas

  13. 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.

  14. Regional intensity-duration-frequency analysis in the Eastern Black Sea Basin, Turkey, by using L-moments and regression analysis

    Science.gov (United States)

    Ghiaei, Farhad; Kankal, Murat; Anilan, Tugce; Yuksek, Omer

    2018-01-01

    The analysis of rainfall frequency is an important step in hydrology and water resources engineering. However, a lack of measuring stations, short duration of statistical periods, and unreliable outliers are among the most important problems when designing hydrology projects. In this study, regional rainfall analysis based on L-moments was used to overcome these problems in the Eastern Black Sea Basin (EBSB) of Turkey. The L-moments technique was applied at all stages of the regional analysis, including determining homogeneous regions, in addition to fitting and estimating parameters from appropriate distribution functions in each homogeneous region. We studied annual maximum rainfall height values of various durations (5 min to 24 h) from seven rain gauge stations located in the EBSB in Turkey, which have gauging periods of 39 to 70 years. Homogeneity of the region was evaluated by using L-moments. The goodness-of-fit criterion for each distribution was defined as the ZDIST statistics, depending on various distributions, including generalized logistic (GLO), generalized extreme value (GEV), generalized normal (GNO), Pearson type 3 (PE3), and generalized Pareto (GPA). GLO and GEV determined the best distributions for short (5 to 30 min) and long (1 to 24 h) period data, respectively. Based on the distribution functions, the governing equations were extracted for calculation of intensities of 2, 5, 25, 50, 100, 250, and 500 years return periods (T). Subsequently, the T values for different rainfall intensities were estimated using data quantifying maximum amount of rainfall at different times. Using these T values, duration, altitude, latitude, and longitude values were used as independent variables in a regression model of the data. The determination coefficient ( R 2) value indicated that the model yields suitable results for the regional relationship of intensity-duration-frequency (IDF), which is necessary for the design of hydraulic structures in small and

  15. Plasma levels of pollutants are much higher in loggerhead turtle populations from the Adriatic Sea than in those from open waters (Eastern Atlantic Ocean).

    Science.gov (United States)

    Bucchia, Matteo; Camacho, María; Santos, Marcelo R D; Boada, Luis D; Roncada, Paola; Mateo, Rafael; Ortiz-Santaliestra, Manuel E; Rodríguez-Estival, Jaime; Zumbado, Manuel; Orós, Jorge; Henríquez-Hernández, Luis A; García-Álvarez, Natalia; Luzardo, Octavio P

    2015-08-01

    In this paper we determined the levels of 63 environmental contaminants, including organic (PCBs, organochlorine pesticides, and PAHs) and inorganic (As, Cd, Cu, Pb, Hg and Zn) compounds in the blood of loggerhead turtles (Caretta caretta) from two comparable populations that inhabit distinct geographic areas: the Adriatic Sea (Mediterranean basin) and the Canary Islands (Eastern Atlantic Ocean). All animals were sampled at the end of a period of rehabilitation in centers of wildlife recovery, before being released back into the wild, so they can be considered to be in good health condition. The dual purpose of this paper is to provide reliable data on the current levels of contamination of this species in these geographic areas, and secondly to compare the results of both populations, as it has been reported that marine biota inhabiting the Mediterranean basin is exposed to much higher pollution levels than that which inhabit in other areas of the planet. According to our results it is found that current levels of contamination by organic compounds are considerably higher in Adriatic turtles than in the Atlantic ones (∑PCBs, 28.45 vs. 1.12ng/ml; ∑OCPs, 1.63 vs. 0.19ng/ml; ∑PAHs, 13.39 vs. 4.91ng/ml; pmercury (5.74 vs. 7.59μg/ml, p<0.01). The results of this study confirm that the concentrations are larger in turtles from the Mediterranean, probably related to the high degree of anthropogenic pressure in this basin, and thus they are more likely to suffer adverse effects related to contaminants. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. 137Cs, 239+24Pu and 24Pu/239Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas

    International Nuclear Information System (INIS)

    Yamada, Masatoshi; Zheng Jian; Wang Zhongliang

    2006-01-01

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The 137 Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The 137 Cs activities showed a wide variation with values ranging from 1.1 Bq m -3 in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m -3 in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of 137 Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of 137 Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of 137 Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr -1 in the Sulu and Indonesian Seas, 0.033 yr -1 in the Bay of Bengal and Andaman Sea, and 0.029 yr -1 in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. 239+24 Pu activities and 24 Pu/ 239 Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The 24 Pu / 239 Pu atom ratios ranged from 0.199 ± 0.026 to 0.248 ± 0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by using the two end-member mixing model. The higher 24 Pu / 239 Pu atom ratios

  17. Parapatric genetic divergence among deep evolutionary lineages in the Mediterranean green crab, Carcinus aestuarii (Brachyura, Portunoidea, Carcinidae), accounts for a sharp phylogeographic break in the Eastern Mediterranean.

    Science.gov (United States)

    Deli, Temim; Kalkan, Evrim; Karhan, Selahattin Ünsal; Uzunova, Sonya; Keikhosravi, Alireza; Bilgin, Raşit; Schubart, Christoph D

    2018-04-11

    Recently, population genetic studies of Mediterranean marine species highlighted patterns of genetic divergence and phylogeographic breaks, due to the interplay between impacts of Pleistocene climate shifts and contemporary hydrographical barriers. These factors markedly shaped the distribution of marine organisms and their genetic makeup. The present study is part of an ongoing effort to understand the phylogeography and evolutionary history of the highly dispersive Mediterranean green crab, Carcinus aestuarii (Nardo, 1847), across the Mediterranean Sea. Recently, marked divergence between two highly separated haplogroups (genetic types I and II) of C. aestuarii was discerned across the Siculo-Tunisian Strait, suggesting an Early Pleistocene vicariant event. In order to better identify phylogeographic patterns in this species, a total of 263 individuals from 22 Mediterranean locations were analysed by comparing a 587 basepair region of the mitochondrial gene Cox1 (cytochrome oxidase subunit 1). The examined dataset is composed of both newly generated sequences (76) and previously investigated ones (187). Our results unveiled the occurrence of a highly divergent haplogroup (genetic type III) in the most north-eastern part of the Mediterranean Sea. Divergence between the most distinct type III and the common ancestor of both types I and II corresponds to the Early Pleistocene and coincides with the historical episode of separation between types I and II. Our results also revealed strong genetic divergence among adjacent regions (separating the Aegean and Marmara seas from the remaining distribution zone) and confirmed a sharp phylogeographic break across the Eastern Mediterranean. The recorded parapatric genetic divergence, with the potential existence of a contact zone between both groups in the Ionian Sea and notable differences in the demographic history, suggest the likely impact of paleoclimatic events, as well as past and contemporary oceanographic processes

  18. Organic-carbon deposition in the Cretaceous of the Ionian Basin, NW-Greece : The Paquier Event (OAE 1b) re-visited

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Tsikos, H.; Karakitsios, V.; Breugel, Y. van; Walsworth-Bell, B.; Petrizzo, M.R.; Bombardiere, L.; Schouten, S.; Erba, E.; Premoli Silva, I.; Farrimond, P.; Tyson, R.V.; Jenkyns, H.C.

    2004-01-01

    We present new stable (C, O) isotopic, biostratigraphic and organic geochemical data for the Vigla Shale Member of the Ionian Zone in NW Greece, in order to characterize organic carbon-rich strata that potentially record the impact of Cretaceous Oceanic Anoxic Events (OAEs). In a section exposed

  19. 16S rRNA-based bacterial diversity in the organic-rich sediments underlying oxygen-deficient waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Divya, B.; Parvathi, A.; LokaBharathi, P.A.; Nair, S.

    ). Bootstrap analysis was carried out using 1000 iterations. Diversity analysis The clone library of AS-OMZ was compared with those of other anoxic sediments from Gulf of Mexico, North Sea and South China Sea (28, 60 and 87 sequences, respectively.... Figure 2d Bacterial diversity and richness To understand the bacterial diversity and richness of the AS-OMZ sediment clone library, comparisons were made with suboxic sediment clone libraries from South China Sea, North Sea and Gulf of Mexico...

  20. Climate to fish: Synthesizing field work, data and models in a 39-year retrospective analysis of seasonal processes on the eastern Bering Sea shelf and slope

    Science.gov (United States)

    Ortiz, Ivonne; Aydin, Kerim; Hermann, Albert J.; Gibson, Georgina A.; Punt, André E.; Wiese, Francis K.; Eisner, Lisa B.; Ferm, Nissa; Buckley, Troy W.; Moffitt, Elizabeth A.; Ianelli, James N.; Murphy, James; Dalton, Michael; Cheng, Wei; Wang, Muyin; Hedstrom, Kate; Bond, Nicholas A.; Curchitser, Enrique N.; Boyd, Charlotte

    2016-12-01

    We combined field data and the output from a climate-to-fish coupled biophysical model to calculate weekly climatologies and 1971-2009 time series of physical and biological drivers for 16 distinct regions of the eastern Bering Sea shelf and slope. We focus on spatial trends and physical-biological interactions as a framework to compare model output to localized or season-specific observations. Data on pollock (≥8 cm) diet were used to evaluate energy flows and zooplankton dynamics predicted by the model. Model validation shows good agreement to sea-ice cover albeit with a one month delay in ice retreat. Likewise, the timing of spring phytoplankton blooms in the model were delayed approximately one month in the south and extend further into summer, but the relative timing between the spring and fall bloom peaks was consistent with observations. Ice-related primary producers may shift the timing of the spring bloom maximum biomass earlier in years when sea ice was still present after mid-March in the southern regions. Including the effects of explicit, dynamic fish predation on zooplankton in the model shifts the seasonal spring peak and distribution of zooplankton later in the year relative to simulations with implicit predation dependent only on zooplankton biomass and temperature; the former capturing the dynamic demand on zooplankton prey by fish. Pollock diets based on stomach samples collected in late fall and winter from 1982-2013 show overwintering euphausiids and small pollock as key prey items in the outer and southern Bering Sea shelf; a characteristic not currently present in the model. The model captured two large-scale gradients, supported by field data, characterizing the overall dynamics: 1) inshore to off-shelf physical and biological differences with a gradient in inter-annual variability from higher frequency inshore to lower frequency offshore; and 2) latitudinal gradients in the timing of events. The combined effects of length of day

  1. Tsunami hazard for the city of Catania, eastern Sicily, Italy, assessed by means of Worst-case Credible Tsunami Scenario Analysis (WCTSA

    Directory of Open Access Journals (Sweden)

    R. Tonini

    2011-05-01

    Full Text Available Eastern Sicily is one of the coastal areas most exposed to earthquakes and tsunamis in Italy. The city of Catania that developed between the eastern base of Etna volcano and the Ionian Sea is, together with the neighbour coastal belt, under the strong menace of tsunamis. This paper addresses the estimation of the tsunami hazard for the city of Catania by using the technique of the Worst-case Credible Tsunami Scenario Analysis (WCTSA and is focused on a target area including the Catania harbour and the beach called La Plaia where many human activities develop and many important structures are present. The aim of the work is to provide a detailed tsunami hazard analysis, firstly by building scenarios that are proposed on the basis of tectonic considerations and of the largest historical events that hit the city in the past, and then by combining all the information deriving from single scenarios into a unique aggregated scenario that can be viewed as the worst virtual scenario. Scenarios have been calculated by means of numerical simulations on computational grids of different resolutions, passing from 3 km on a regional scale to 40 m in the target area. La Plaia beach results to be the area most exposed to tsunami inundation, with inland penetration up to hundreds of meters. The harbour turns out to be more exposed to tsunami waves with low frequencies: in particular, it is found that the major contribution to the hazard in the harbour is due to a tsunami from a remote source, which propagates with much longer periods than tsunamis from local sources. This work has been performed in the framework of the EU-funded project SCHEMA.

  2. Proposals for the conservation of otters Lutra lutra L. on Corfu island (Ionian Sea, Greece

    Directory of Open Access Journals (Sweden)

    Xavier Grémillet

    1995-12-01

    Full Text Available Abstract Suggested measures for the conservation of otters (Lutra lutra on Corfu include: 1 a nature sanctuary ("Otter Haven" for some little remote lagoons near Aghios Stephanos in the north-east; 2 a lagoon restoration scheme including restoration of traditional fishing with joint nature tourism for the large reedbeds and lagoons: Antinioti (100 ha in the north, Chalkiopoulou (380 ha in the suburbs of Kerkyra, Korission (500 ha in the south-west; 3 the stopping of raw sewage discharge, illegal infilling, building and waste dumping in the wetlands; 4 the limitation of intensive fish farming schemes. Such a policy is reconcilable with economic activities (tourism, fishing, trade or administration. Riassunto Proposte per la conservazione della lontra Lutra lutra L. nell'isola di Corfù (Mare Jonio, Grecia - Per la conservazione della lontra (Lutra lutra nell'Isola di Corfù sono suggeriti i seguenti interventi: 1 creazione di "santuari naturali" per la specie comprendenti le piccole lagune vicino a Aghios Stephanos nella parte nord-est dell'isola; 2 riqualificazione degli ambienti a canneto e delle lagune, abbinata a1 ripristino della pesca tradizionale e allo sviluppo del turismo ecologico: Antinioti (100 ha nella parte settentrionale, Chalkiopoulou (380 ha nell'area suburbana di Kerkyra, Korission (500 ha nella parte sud-ovest; 3 divieto di scarichi fognari e abusivi, divieto di costruzione di insediamenti abitativi e eliminazione di discariche nelle zone umide; 4 limitazioni allo sviluppo degli allevamenti ittici intensivi. Gli interventi prospettati si inquadrano in una politica di gestione ambientale compatibile con le attività economiche presenti (turismo, pesca, commercio.

  3. Holocene sedimentology and coastal geomorphology of Zakynthos Island, Ionian Sea : A history of a divided Mediterranean island

    NARCIS (Netherlands)

    Avramidis, P.; Iliopoulos, G.; Nikolaou, K; Kontopoulos, N.; Koutsodendris, A.; van Wijngaarden, G.J.

    2017-01-01

    The island of Zakynthos is one of the most seismically active areas in the Mediterranean region because it is located very close to the convergent boundary between the African and Eurasian plates. Its evolution during the Holocene has been influenced by tectonic activity, catastrophic events and

  4. Managing Disaster in the Ionian Sea: Planning and Optimizing Logistics for Disaster Relief Operations for the Island of Kefalonia

    Science.gov (United States)

    2010-06-01

    the last similar event. The BPT distribution is named after the Scottish botanist Robert Brown (1866), who observed the seemingly random movement of...ports of the island. The communities (towns or villages) are connected with each other and their capital by narrow rural roads that are shown in

  5. The Ionian and Alfeo-Etna fault zones : New segments of an evolving plate boundary in the central Mediterranean Sea?

    NARCIS (Netherlands)

    Polonia, A.; Torelli, L.; Artoni, A.; Carlini, M.; Faccenna, C.; Ferranti, L.; Gasperini, L.; Govers, R.|info:eu-repo/dai/nl/108173836; Klaeschen, D.; Monaco, C.; Neri, G.; Nijholt, N.|info:eu-repo/dai/nl/413306674; Orecchio, B.; Wortel, R.|info:eu-repo/dai/nl/068439202

    2016-01-01

    The Calabrian Arc is a narrow subduction-rollback system resulting from Africa/Eurasia plate convergence. While crustal shortening is taken up in the accretionary wedge, transtensive deformation accounts for margin segmentation along transverse lithospheric faults. One of these structures is the

  6. Late Neogene Orbitally-Forced Sea Surface Temperature Variability in the Eastern Equatorial Pacific as Measured by Uk'37 and TEX86

    Science.gov (United States)

    Lawrence, K. T.; Pearson, A.; Castañeda, I. S.; Peterson, L.

    2017-12-01

    Key features of late Neogene climate remain uncertain due to conflicting records derived from different sea surface temperature (SST) proxies. To resolve these disputes, it is necessary to explore both the consistencies and differences between paleotemperature estimates from critical oceanographic regimes. Here, we report orbital-scale climate variability at ODP Site 846 in the Eastern Equatorial Pacific (EEP) in the interval from 5-6 Ma using alkenone and TEX86 temperature estimates. Results from both proxies are very similar in their secular trends and magnitude of long-term temperature change; and spectral analysis demonstrates that the records are coherent and in-phase or nearly in-phase in both the obliquity and precession bands. However, we find that the temperatures reconstructed by TEX86 are consistently offset towards colder values by 2ºC with orbital-scale variations approximately twice the amplitude of the Uk'37 derived estimates. Both temperature records are antiphased - i.e. "colder" - at higher sediment alkenone concentrations, a qualitative indicator of increased glacial productivity. Temperature differences between the proxies are accentuated during glacial intervals in contrasts to modern observations of EEP surface and subsurface temperatures, which show that thermocline temperatures are fairly stable, and thus by analogy, glacial cooling and/or enhanced upwelling should have reduced rather than accentuated temperature gradients in the upper water column. Therefore, arguments that Uk'37 corresponds to temperature variability in the surface, while TEX86 responds to the subsurface, may be too simplistic. Instead, it appears generally true that high-productivity environments, including the EEP, tend to have negative TEX86 anomalies. This may reflect a dual dependence of TEX86 records on both water column temperature and local productivity. Overall, our data suggest that in the EEP and likely in other upwelling zones, paleotemperature data derived

  7. Paleoclimatic changes occurred during the last two centuries in the Gulf of Gaeta (central-eastern Tyrrhenian Sea): a contribution of NEXTDATA project

    Science.gov (United States)

    Lirer, Fabrizio; Vallefuoco, Mattia; Albertazzi, Sonia; Anzalone, Erlisiana; Bellucci, Luca; Bonomo, Sergio; Capotondi, Lucilla; Cascella, Antonio; Di Rita, Federico; Ferraro, Luciana; Florindo, Fabio; Giuliani, Silvia; Domenica Insinga, Donatella; Lurcock, Pont; Magri, Donatella; Margaritelli, Giulia; Marsella, Ennio; Petrosino, Paola; Sprovieri, Mario; Sorgato, Stefania

    2014-05-01

    A high-resolution integrated study, which includes tephrochronology (tefra layer associated to 1906 AD Vesuvius event) and radionuclide dating method (210Pb and 137Cs), has been performed in a super-expanded marine record (sedimentation rate of 0.47 cm/yr) from the continental shelf of the Gulf of Gaeta (central eastern Tyrrhenian Sea). Planktonic foraminifera, calcareous nannofossils, pollens and oxygen stable isotope data performed on Globigerinoides ruber, revealed environmental changes occurred during the last two centuries. In detail we recognise four paleoclimatic changes. From ca. 1800 to ca. 1865 AD, d18O G. ruber signal combined with evidences of abundance increase of planktonic foraminifera Globoratialia inflata and G. truncatulinoides and of calcareous nannofossils Emiliana huxley document cold-temperate phase. Between ca. 1865 and ca. 1882 AD, d18O G. ruber record document a short warm interval associated with a turnover from carnivorous to herbivorous-opportunistic planktonic foraminiferal species and an increase in abundance of calcareous nannofossil Florisphaera profunda. At ca. 1935 AD, d18O G. ruber data indicate a gradually warming, concomitant an evident turnover from carnivorous to herbivorous-opportunistic planktonic foraminiferal species, and associated to the increase of calcareous nannofossil F. profunda. From ca. 1950 AD to the present day the warm phase documents a further strong increase in G. ruber alba, G. quadrilobatus and F. profunda abundances. The pollen analysis carried out on the same core revealed a two-step increase in arboreal vegetation, this is mostly related to a rise of Olea, Quercus evergreen and riparian trees (Alnus and Salix) from ca. 1882 AD, and increase in conifers (Pinus and Cupressaceae) from ca. 1980 AD. The short lived warm interval documented by d18O between ca. 1865 and ca. 1882 AD may triggered the increase in Olea and the coeval general decrease in deciduous trees. Among herbs, Cyperaceae, along with ferns

  8. An overview of the ecological half-life of the 137Cs radioisotope and a determination of radioactivity levels in sediment samples after Chernobyl in the Eastern Black Sea, Turkey

    Science.gov (United States)

    Baltas, Hasan; Sirin, Murat; Dalgic, Goktug; Cevik, Ugur

    2018-01-01

    A study which determined the activity concentration of 137Cs in sediments contaminated by effluents from the Chernobyl accident which had collected along the coast of the Eastern Black Sea region in Turkey was carried out in 1993. Marine sediment samples were collected in 2015 from the same fifteen sampling points, and the activity concentrations of 226Ra, 232Th, 40K and 137Cs were determined for the sediment samples. The activity concentrations ranged from 10.94-25.95, 12.14-33.05, 265.74-459.89 and 2.08-37.45 Bq kg- 1 for 226Ra, 232Th, 40K and 137Cs respectively. The results showed that there was a steep decline in 137Cs within the sediment at most of the sampling sites from the Eastern Black Sea region during the 22-year period, except for two sites at which the measured levels were much higher. This may be the result of the combined effects of radioactive contaminant entry into this area from rivers, environmental changes and nuclear testing between 1993 and 2015. Furthermore, the ecological half-life (EHL) of the 137Cs radionuclide was estimated for the sediment samples, and radiological hazard parameters such as the absorbed dose rate in air (D), the annual effective dose equivalent (AEDE) and the excess lifetime cancer risk (ELCR) were calculated and compared with the international recommended values. It was shown that these sediments do not present any significant health risk for humans in this area.

  9. Temporal variations in the wind and wave climate at a location in the eastern Arabian Sea based on ERA-Interim reanalysis data.

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.

    –597, 2011. Dube, S. K., Rao, A. D., Sinha, P. C., Murty, T. S., and Bahulayan, N.: Numerical modelling of storm surges in the Arabian Sea, Appl. Math. Model., 9, 289–294, 1997. Evan, A. T. and Camargo S. J.: A Climatology of Arabian Sea Cy- clonic Storms, J...

  10. Growth of gas hydrate mounds and gas chimneys of the eastern margin of Japan Sea as revealed by MBES, SSS and SBP of AUV

    Science.gov (United States)

    Matsumoto, R.; Satoh, M.; Hiromatsu, M.; Tomaru, H.; Machiyama, H.

    2010-12-01

    A series of PC, ROV and SCS surveys to study the origin and evolution of gas hydrate systems along the eastern margin of Japan Sea have identified a number of shallow GH accumulations on the mounds, 300m to 500m in diameter and 30m to 40m high, on the Umitaka spur and Joetsu knoll in Joetsu basin with the WD of 880m to 1200m (Matsumoto et al., 2005; 2009). All of the hydrate mounds develop on gas chimneys as recognized by seismic profiles, and some are associated with gigantic methane plumes, 600m to 700m high. Multi Beam Echo Sounder (MBES), Side Scan Sonar (SSS) and Sub-Bottom Profiler (SBP) of AUV Urashima have revealed ultra-high resolution topographic features and subsurface structures of the mounds and adjacent areas during the JAMSTEC YK10-08 cruise, July 2010. AUV Urashima ran over the spur and knoll at 50m to 80m above seafloor at a cruising speed of 2.4 knots. MBES and SSS mosaics demonstrate two types of mounds. One is a low swell with smooth surface and weak reflectance, while the other is characterized by rough and uneven topographic features with strong SSS images due to incrustation by methane-induced carbonate concretions and gas hydrates. SBP provides clear stratigraphic and structural relations down to 50mbsf to 80mbsf and recognizes three stratigraphic units as I: upper massive unit (5-10m thick), II: middle evenly bedded unit (15-25m thick) and III: lower slightly bedded unit (> 15-25m thick). Gas chimneys grow up toward the seafloor through Units III, II, and I. When the ceiling of gas chimney stays within Unit III or II, the mound above the chimney is either low swell or nearly flat, while the swell grows up higher when the ceiling reaches to Unit I or the seafloor. Eventually, the ceiling breaks through the seafloor and protrudes to form GH mound up to 40m to 50m high, and then start to decay probably due to mechanical collapse and chemical dissolution of gas hydrates. The ceiling of gas chimneys is often represented by high amplitude, uneven

  11. The study of genetic diversity and population structure of Vimba vimba persa (Pallas, 1814 populations in the Eastern and Western coastline of the Caspian sea (Havigh River and GorganRoud River using microsatellite markers

    Directory of Open Access Journals (Sweden)

    Samira Mohamadian

    2011-01-01

    Full Text Available Genetic diversity of Vimba vimba persa was investigated using microsatellite markers from two regions of the Iranian coastline of southern Caspian sea (Havigh River in Guilan province, GorganRoud River in Golestan province. The purpose of this research was the study of Vimba vimba persa’s possible populations related to genetic diversity and population structure in the Caspian sea and introducing the useful genetic markers. To investigate the genetic structure of Vimba vimba persa populations, we sampled 50 specimens of Vimba vimba persa caught by beach seine from GorganRoud River in Golestan Province (30 specimens and Havigh River in the Guilan Province (20 specimens. Genomic DNA was extracted from fin tissue by phenol-Chlorophorm method and PCR reaction was accomplished with 17 microsatellite primers 10 of which were amplified with reasonable polymorphism. Means of alleles were on 6.75 averages, observed and expected heterozygosity averages were 0.817 and 0.735, respectively. Most cases, significantly deviated from Hardy-Weinberg equilibrium (p≤0.01. According to the Fst values, there are two significant populations of Vimba vimba persa in the eastern and western coasts of the Caspian Sea which restocking of these species should be considered. Based on the survey revealed, since the population of this species is decreasing with its high genetic diversity, the Caspian Vimba had an enormous diversity in the past.

  12. Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: A tracer for mixing and nitrogen cycles

    Digital Repository Service at National Institute of Oceanography (India)

    Brandes, J.A.; Devol, A.H.; Yoshinari, T.; Jayakumar, D.A.; Naqvi, S.W.A.

    Trench. Ph.D. Thesis, Univ. of Cali- fornia, Los Angeles. -. AND I. R. KAPLAN. 1975. Isotopic fractionation of dissolved nitrate during denitrification in the eastern tropical North Pa- cific. Mar. Chem. 3: 271-299. CODISPOTI, L. A., AND J. P....-K. 1979. Geochemistry of inorganic nitrogen compounds in two marine environments: The Santa Barbara basin and the ocean off Peru. Ph.D. Thesis, Univ. of California, Los Angeles. -, AND I. R. KAPLAN. 1989. The eastern tropical Pacific as a source of 15N...

  13. Intraseasonal meridional current variability in the eastern equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Ogata, T.; Sasaki, H.; Murty, V.S.N.; Sarma, M.S.S.; Masumoto, Y.

    . [2007] demonstrate the possibility of the air-sea interac- tion in the eastern Indian Ocean at the intraseasonal time- scale by analyzing observed and simulated data. Recent studies also reveal that multiscale air-sea interactions be- tween intraseasonal...

  14. AFSC/RACE/SAP/Pathobiology: 2015 Bitter crab disease prevalence in immature Chionoecetes spp. at 6 index sites in eastern Bering Sea

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains crab data from a field survey of Chionoecetes bairdi and C. opilio collected at six designated index sites in the Bering Sea during the 2015...

  15. AFSC/RACE/SAP/Pathobiology: 2016 Bitter crab disease prevalence in immature Chionoecetes spp. at 6 index sites in eastern Bering Sea

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains crab data from a field survey of Chionoecetes bairdi and C. opilio collected at six designated index sites in the Bering Sea during the 2016...

  16. AFSC/RACE/SAP/Pathobiology: 2014 Bitter crab disease prevalence in immature Chionoecetes spp. at 6 index sites in eastern Bering Sea

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains crab data from a field survey of Chionoecetes bairdi and C. opilio collected at six designated index sites in the Bering Sea during the 2014...

  17. Provenance of Neoproterozoic to upper Cretaceous sedimentary rocks, eastern Greenland: Implications for recognizing the sources of sediments in the Norwegian Sea

    Czech Academy of Sciences Publication Activity Database

    Sláma, Jiří; Walderhaug, O.; Fonneland, H.; Kosler, J.; Pederson, R. B.

    2011-01-01

    Roč. 238, 3/4 (2011), s. 254-267 ISSN 0037-0738 Institutional research plan: CEZ:AV0Z30130516 Keywords : sedimentary * Eastern Greenland * provenance * U-Pb and Lu-Hf * zircon * Jan Mayen Island * North Atlantic Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.537, year: 2011

  18. Expedition surveys of the sea water and atmospheric air radioactive contamination in the Russian Far Eastern coastal areas and in the North- Western Pacific in connection with accident at the 'Fukushima-1' NPP

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Aleksandr; Shershakov, Viacheslav; Artemev, Georgii [Research and Production Association ' Typhoon' (RPA ' Typhoon' ), Obninsk, Kaluga Region (Russian Federation); Ramzaev, Valery [Ramzaev Saint-Petersburg Research Institute of Radiation Hygiene, Saint-Petersburg (Russian Federation); Osokin, Vladimir [V.G.Khlopin Radium institute, Saint-Petersburg (Russian Federation); Sevastianov, Aleksandr [Far Eastern Regional Hydrometeorological Research Institute, Vladivostok (Russian Federation)

    2014-07-01

    In accordance with decision of the Russian Federation Federal Service on Hydro-meteorology and Environmental Monitoring (Roshydromet) on assessment of the sea water and atmospheric air radioactive contamination in the Russian coastal areas of the Far East in connection with accident at the 'Fukushima-1' NPP in Japan, two radioecological expedition surveys were conducted onboard of research vessels of the Far Eastern Regional Hydro-meteorological Research Institute (FERHRI) of Roshydromet in the Sea of Japan and in the North-Western Pacific (in the area adjacent to Kurile Islands and in the Kuroshio current selected area (coordinates 36 deg. 00'- 39 deg. 33' n., 146 deg. 33'- 150 deg. 00' e.): first survey in April-May 2011, onboard R/V 'Pavel Gordienko', second survey in August-September 2012, onboard R/V 'Akademik Shokalsky'. Both surveys were conducted under the Russian Geographical Society patronage. The leading Russian institutions dealing with ensuring of population radiation safety and protection of environment from radioactive contamination were enlisted to investigations. The following main observations were performed during the surveys: constant measurement of gamma-radiation dose rate above the sea surface; twenty-four hour sampling of atmospheric aerosols, sea water sampling from the surface and deep water horizons with preliminary concentrating of radionuclides for onboard gamma-spectrometry and for subsequent transportation to the shore laboratories for further analysis. During the expeditions, a real-time data were received onboard of research vessels which characterize impact of input of radioactive products of the 'Fukushima-1' NPP accident on radioactive contamination of environment existed on that period (these are onboard estimates of {sup 137}Cs and {sup 134}Cs concentrations in the sea water samples and {sup 131}I, {sup 137}Cs, {sup 134}Cs content in atmospheric aerosol samples, data

  19. Fore-arc Deformation in the Paola Basin Segment (Offshore Western Calabria) of the Tyrrhenian-Ionian Subduction System

    Science.gov (United States)

    Pepe, F.; Corradino, M.; Nicolich, R.; Barreca, G.; Bertotti, G.; Ferranti, L.; Monaco, C.

    2017-12-01

    The 3D stratigraphic architecture and Late Neogene to Recent tectonic evolution of the Paola Basin (offshore western Calabria), a segment in the fore-arc of the Tyrrhenian-Ionian subduction system, is reconstructed by using a grid of high-penetration reflection seismics. Oligocene to Messinian deposits are interpreted all along the profile. They tend to fossilize preexisting topography and reach the largest thicknesses between (fault controlled) basement highs. Plio-Quaternary deposits are found over the entire area and display variations in thickness and tectonic style. They are thicken up to 4.5 km in the depocenter of the basin, and decrease both in the east and west termination of the lines. The Paola Basin can be partitioned into two sectors with different tectonic deformation, separated by a NNW-SSE elongated area that coincides with the basin depocenter. Tectonic features associated with strike-slip restraining and releasing bends are widely spread over the western sector of the basin. Overall, they form an approximately NS-trending and geomorphically prominent ridge separating the Paola Basin from the Marsili abyssal plain. A high-angle, NNE-trending, normal fault system develops on the south-west tip of the basin, where the faults offset the Messinian horizon of ca. 500 m. Data suggest that limited vertical slip occurs along reverse faults detected at the border and inside the sedimentary infilling of the Paola Basin, reaching thickness of more than 3.8s two way travel time. The reflection sequence pattern can be interpreted as a result of the infilling of the thrust-top basin related to a prograding system, located between a growth ramp-anticline to the west and a culmination of basement-thrust sheets to the East. We propose that the Paola Basin developed near the northern edge of the Ionian slab where tearing of the lithosphere is expected. Also, the strike-slip fault system is a kinematic consequence of obliquely convergent subduction settings, where

  20. Chronology and stratigraphy of the Magdalen Islands archipelago from the last glaciation to the early Holocene: new insights into the glacial and sea-level history of eastern Canada

    DEFF Research Database (Denmark)

    Rémillard, Audrey M.; St-Onge, Guillaume; Bernatchez, Pascal

    2016-01-01

    of the deposits and the establishment of a precise chronological framework. This study provides a detailed description of 21 stratigraphical sequences located throughout the archipelago, as well as the first comprehensive luminescence chronology from the Last Glacial Maximum (LGM) to c. 10 ka. In addition......The Magdalen Islands (Québec, Canada) are a key location for unravelling the glacial and sea-level history of the Maritime Provinces of eastern Canada. Although many sedimentary sequences have been described in the literature, absolute ages are lacking, impeding an accurate interpretation...... to the five samples collected for age control purposes, 34 luminescence samples were taken from 17 different sites in glacial, periglacial and coastal deposits. The stratigraphical and chronological data reveal that the islands were at the crossroads of two icecaps during the LGM; the southern islands were...

  1. Determination of sedimentation, diffusion, and mixing rates in coastal sediments of the eastern Red Sea via natural and anthropogenic fallout radionuclides.

    Science.gov (United States)

    Al-Mur, Bandar A; Quicksall, Andrew N; Kaste, James M

    2017-09-15

    The Red Sea is a unique ecosystem with high biodiversity in one of the warmest regions of the world. In the last five decades, Red Sea coastal development has rapidly increased. Sediments from continental margins are delivered to depths by advection and diffusion-like processes which are difficult to quantify yet provide invaluable data to researchers. Beryllium-7, lead-210 and ceseium-137 were analyzed from sediment cores from the near-coast Red Sea near Jeddah, Saudi Arabia. The results of this work are the first estimates of diffusion, mixing, and sedimentation rates of the Red Sea coastal sediments. Maximum chemical diffusion and particle mixing rates range from 69.1 to 380cm -2 y -1 and 2.54 to 6.80cm -2 y -1 , respectively. Sedimentation rate is constrained to approximately 0.6cm/yr via multiple methods. These data provide baselines for tracking changes in various environmental problems including erosion, marine benthic ecosystem silting, and particle-bound contaminant delivery to the seafloor. Copyright © 2017. Published by Elsevier Ltd.

  2. 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; Mapelli, Francesca; Chouaia, Bessem; Crotti, Elena; Daffonchio, Daniele; Borin, Sara

    2015-01-01

    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.

  3. 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.

  4. Influence of winds on temporally varying short and long period gravity waves in the near shore regions of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Glejin, J.; SanilKumar, V.; Nair, T.M.B.; Singh, J.

    pro- vided by the NOAA-CIRES (Cooperative Institute for Re- search in the Environmental Sciences) Climate Diagnostics Center in Boulder, Colorado (http://www.cdc.noaa.gov/). To determine the sea/land breeze system at Ratnagiri during the study period...

  5. 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.

  6. Aerial Surveys of Endangered Whales in the Northern Bering, Eastern Chukchi, and Alaskan Beaufort Seas, 1984: with a Six Year Review, 1979-1984.

    Science.gov (United States)

    1985-06-01

    I- * I 4 ?2 7- /’PT L0~ *70 BATRIS. K ERSCHIE I 158 158 154 152 1SO 148 146 144 142 140 138 9EAUFORT SEA 72 D 71 70 - -BRE i" isI ISO 154 152... ISO 146 146 144 142 140 136 Figure 19. (Continued). 51 Sp In October, 99 bowheads were sighted in the Beaufort Sea along and seaward of the 20-m isobath...04501T 51% 2% 43% 3% 27001 09001 27001 09001 21% 19% 4% 22501 9% 13501 22501 4% 3% 13501 18001 18001 n 47, R :226 0T n - 10, R 211 IT z2740,pɘD01 z -39.86

  7. Radiocarbon in particulate matter from the eastern sub-arctic Pacific Ocean: evidence of source of terrestrial carbon to the deep sea

    International Nuclear Information System (INIS)

    Druffel, E.R.M.; Honjo, S.; Griffin, S.; Wong, C.S.

    1986-01-01

    Carbon isotope ratios were measured in organic and inorganic carbon of settling particulate matter collected with a sediment trap at Ocean Station P in the Gulf of Alaska from March to October, 1983. Dissolved inorganic carbon (DIC) in surface sea water collected during two different seasons in 1984 were analyzed using large gas proportional counters and revealed a minimum seasonal Δ 14 C variation of 14 per thousand. Results show that the Δ 14 C of calcium carbonate sedimenting to the deep sea is the same as that measured in surface water DIC. In contrast, particulate organic carbon (POC) had significantly higher Δ 14 C values (by 25-70 per thousand) than that in surface water DIC. Also, the Δ 13 C of the POC was markedly lower than previously reported values from other trap stations and marine particulate matter in general. Results from this study suggest that a significant amount of the POC settling to the deep sea at this pelagic station is of terrestrial origin, not strictly of marine origin as had previously been believed

  8. Magnetic signature of river sediments drained into the southern and eastern part of the South China Sea (Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan)

    Science.gov (United States)

    Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

    2017-01-01

    Magnetic properties of 22 river samples collected in the Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan have been investigated in order to magnetically characterize the sediments drained and deposited into the South China Sea. The geological formations as well as the present climatic conditions are different from one region to another. Laboratory analyses include low-field magnetic susceptibility, anhysteretic (ARM) and isothermal (IRM) remanent magnetizations acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis cycles and low-temperature magnetic measurements. The magnetic properties indicate that the sediments are a mixture of hematite, magnetite and pyrrhotite in different proportions depending on the region. Combined with results previously reported for the three main Asian rivers (Pearl, Red and Mekong rivers), the new data indicate that, in general, hematite-rich sediments are delivered to the southern basin of the South China Sea while the northern basin is fed with magnetite and pyrrhotite-rich sediments. In addition to this general picture, some variability is observed at smaller geographic scales. Indeed, the magnetic assemblages are closely related to the geology of the various catchments while clay minerals, previously reported for the same samples, are more representative of the climatic conditions under which the parent rocks have evolved within each catchment. The magnetic fraction, now well characterized in the main river sediments drained into the South China Sea, can be used as a tracer for changes in precipitation on land and in oceanic water mass transport and exchange.

  9. Ichthyophonus-infected walleye pollock Theragra chalcogramma (Pallas) in the eastern Bering Sea: a potential reservoir of infections in the North Pacific.

    Science.gov (United States)

    White, V C; Morado, J F; Friedman, C S

    2014-07-01

    In 2003, the Alaska walleye pollock industry reported product quality issues attributed to an unspecified parasite in fish muscle. Using molecular and histological methods, we identified the parasite in Bering Sea pollock as Ichthyophonus. Infected pollock were identified throughout the study area, and prevalence was greater in adults than in juveniles. This study not only provides the first documented report of Ichthyophonus in any fish species captured in the Bering Sea, but also reveals that the parasite has been present in this region for nearly 20 years and is not a recent introduction. Sequence analysis of 18S rDNA from Ichthyophonus in pollock revealed that consensus sequences were identical to published parasite sequences from Pacific herring and Yukon River Chinook salmon. Results from this study suggest potential for Ichthyophonus exposures from infected pollock via two trophic pathways; feeding on whole fish as prey and scavenging on industry-discharged offal. Considering the notable Ichthyophonus levels in pollock, the low host specificity of the parasite and the role of this host as a central prey item in the Bering Sea, pollock likely serve as a key Ichthyophonus reservoir for other susceptible hosts in the North Pacific. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  10. Climatology of sea breezes along the Red Sea coast of Saudi Arabia

    KAUST Repository

    Khan, Basit; Abualnaja, Yasser; Al-Subhi, Abdullah M.; Nellayaputhenpeedika, Mohammedali; Nellikkattu Thody, Manoj; Sturman, Andrew P.

    2018-01-01

    and Atmospheric Administration (NOAA) are used to investigate the climatology of sea breezes over the eastern side of the Red Sea region. Results show existence of separate sea breeze systems along different segments of the Red Sea coastline. Based on the physical

  11. Eastern Europe

    International Nuclear Information System (INIS)

    Baret, J.P.; Corcuff, A.; Jousten, M.; Cherie, J.B.; Gorge, X.; Augustin, X.; Belime, F.

    1999-01-01

    By its economical and political impact, nuclear energy has an important contribution the countries of Eastern Europe that goes beyond simple energy source. The most important challenge is to gain a safety culture. Improvements have been noted but the reactors safety must stay a priority of the international cooperation in Eastern Europe. The plan for the completion and improvement of Mochovce nuclear plant is described, the situation of Chernobyl and how to make the sarcophagus in safe is discussed, the experience of a french P.M.E. ( small and medium size firm) called Corys Tess that has chosen to position itself on the Eastern Europe nuclear market is related. (N.C.)

  12. Twenty two years of sewage sludge marine disposal monitoring in the Eastern Mediterranean Sea: Impact on sediment quality and infauna and the response to load reduction.

    Science.gov (United States)

    Kress, N; Shoham-Frider, E; Galil, B S

    2016-09-15

    Effects of sewage sludge disposal on sediments and infauna are presented in a unique long-term (22years) data set from the Eastern Mediterranean. While organic carbon (Corg) and metals affected sediment quality in an area which size varied seasonally, the infauna exhibited seasonal "boom and bust" cycle. Metal concentrations declined following load reduction. However, Corg did not decrease and infaunal abundance, closely related to Corg, varied with changes in environmental forcing. Mild winters affected the infaunal populations at the heavily impacted stations, due to anoxic conditions. Planned cessation of disposal is estimated to reduce Corg and metal concentrations to pre-discharge levels. Yet the resettling biota is expected to differ significantly from the pre-discharge one and consist in large part of Erythraean non indigenous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Detection of Trichodesmium bloom patches along the eastern Arabian Sea by IRS-P4/OCM ocean color sensor and by in-situ measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Suresh, T.; Matondkar, S.G.P.; Desa, E.; Goes, J; Mascarenhas, A.A.M.Q.; Parab, S.G.; Shaikh, N.; Fernandes, C

    for the SeaWiFS sensor channels are slightly different from the OCM sensor) Criteria I and II represent absolute and relative magnitudes of nLw radiance, and the III depends on the shape of the spectrum emitted by Trichodesmium. The inequalities... was seen on 21 st March at 11:20 hrs, and also smaller patches on the 19 th March. The normalized water leaving spectra at different stations are shown plotted in Fig. 6. All spectra exhibit shapes that show enhanced (or maximum) values of n...

  14. Black Sea aerosols

    International Nuclear Information System (INIS)

    Hacisalihoglu, G.; Eliyakut, F.; Anwari, M.A.; Ataman, O.Y.; Balkas, T.I.; Tuncel, G.; Olmez, I.

    1991-01-01

    Shipboard, high volume air particulate samples were collected from the Black Sea atmosphere and analyzed by instrumental neutron activation analysis, atomic absorption spectrophotometry and ion chromatography for about 40 elements and ions. Concentrations of elements in the eastern and western parts of the Black Sea are different at the 95% confidence level, with lower concentrations in the eastern Black Sea. Back-trajectories and concentrations of elements in trajectory groups show that Europe accounts for more than 70% of the anthropogenic elements in the atmosphere. The average sulfate concentration was 7 μg/m 3 , which is comparable with rural sulfate levels in western Europe. Fluxes of elements from the atmosphere to the Black Sea are in good agreement with the results of similar flux calculations for other regions

  15. Acanthocotyle gurgesiella n. sp. (Monogenea: Acanthocotylidae) from the deep-sea skate Gurgesiella furvescens (Rajidae) in the south-eastern Pacific.

    Science.gov (United States)

    Ñacari, L A; Sepulveda, F A; Escribano, R; Oliva, M E

    2018-03-01

    Little is known about the diversity of parasites of the deep-sea fish of the world's oceans. Here, a new species of monogenean parasite of the deep-sea skate Gurgesiella furvescens is described. Specimens of parasites were obtained from the skin of two specimens of the dusky finless skate, G. furvescens (Rajidae), in the vicinity of Valparaiso (33°S, 72°W), central Chile, from midwater trawl fishing at depths of 350-450 m. Both morphological and molecular analyses were conducted to provide a full description of the new species, named Acanthocotyle gurgesiella. For the molecular analyses, nuclear large subunit (LSU) rDNA and the mitochondrial gene cytochrome c oxidase 1 (COI) were used. From the morphological analysis and a comparison with the known species of the genus, A. gurgesiella can be identified by a combination of morphological characteristics, including the number of testes, number of radial rows of sclerites in the pseudohaptor, aperture of the genital pore and shape of the vitelline follicles. The results from the DNA analysis indicated that A. gurgesiella has a genetic divergence of 3.2-3.7% (LSU rDNA gene) from A. urolophi, the only congener species for which molecular data are available.

  16. Survey on germination and species composition of dinoflagellates from ballast tanks and recent sediments in ports on the South Coast of Finland, North-Eastern Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Pertola, Sari [Finnish Institute of Marine Research, Department of Biological Research, P.O. Box 2, FI-00561 Helsinki (Finland)]. E-mail sari.pertola@fimr.fi; Faust, Maria A. [Department of Botany, US National Herbarium, Smithsonian Institution, 4210 Silver Hill Road, Suitland, Maryland 20746 (United States); Kuosa, Harri [Tvaerminne Zoological Station, University of Helsinki, FI-10900 Hanko (Finland)

    2006-08-15

    Cyst beds in ships and ports in Finland have previously been unstudied. Therefore, sediments from ships' ballast water tanks and four Finnish ports were sampled for dinoflagellate cysts and other phytoplankton. Untreated sediments were incubated at 10 {sup o}C and 20 {sup o}C in the local 6 psu salinity for 1, 4 and 7 days, and vegetative cells were examined with light and scanning electron microscope. Sediments were inhabited by various dinoflagellates, diatoms, chlorophytes, cyanophytes and small flagellates. Germinated dinoflagellates were found in 90% of ballast tanks and in all ports. Gymnodiniales spp. and Heterocapsa rotundata formed a major proportion of the proliferating dinoflagellate cells. One species, Peridinium quinquecorne, not previously reported from the Baltic Sea, was identified with SEM. The study emphasises that ships are potential transport vehicles for dinoflagellate cysts even in the low salinity Finnish waters, and small-sized dinoflagellates should be focused upon in ballast water studies.

  17. Survey on germination and species composition of dinoflagellates from ballast tanks and recent sediments in ports on the South Coast of Finland, North-Eastern Baltic Sea

    International Nuclear Information System (INIS)

    Pertola, Sari . E-mail sari.pertola@fimr.fi; Faust, Maria A.; Kuosa, Harri

    2006-01-01

    Cyst beds in ships and ports in Finland have previously been unstudied. Therefore, sediments from ships' ballast water tanks and four Finnish ports were sampled for dinoflagellate cysts and other phytoplankton. Untreated sediments were incubated at 10 o C and 20 o C in the local 6 psu salinity for 1, 4 and 7 days, and vegetative cells were examined with light and scanning electron microscope. Sediments were inhabited by various dinoflagellates, diatoms, chlorophytes, cyanophytes and small flagellates. Germinated dinoflagellates were found in 90% of ballast tanks and in all ports. Gymnodiniales spp. and Heterocapsa rotundata formed a major proportion of the proliferating dinoflagellate cells. One species, Peridinium quinquecorne, not previously reported from the Baltic Sea, was identified with SEM. The study emphasises that ships are potential transport vehicles for dinoflagellate cysts even in the low salinity Finnish waters, and small-sized dinoflagellates should be focused upon in ballast water studies

  18. Contrasting Effects of Historical Sea Level Rise and Contemporary Ocean Currents on Regional Gene Flow of Rhizophora racemosa in Eastern Atlantic Mangroves.

    Directory of Open Access Journals (Sweden)

    Magdalene N Ngeve

    Full Text Available Mangroves are seafaring taxa through their hydrochorous propagules that have the potential to disperse over long distances. Therefore, investigating their patterns of gene flow provides insights on the processes involved in the spatial genetic structuring of populations. The coastline of Cameroon has a particular geomorphological history and coastal hydrology with complex contemporary patterns of ocean currents, which we hypothesize to have effects on the spatial configuration and composition of present-day mangroves within its spans. A total of 982 trees were sampled from 33 transects (11 sites in 4 estuaries. Using 11 polymorphic SSR markers, we investigated genetic diversity and structure of Rhizophora racemosa, a widespread species in the region. Genetic diversity was low to moderate and genetic differentiation between nearly all population pairs was significant. Bayesian clustering analysis, PCoA, estimates of contemporary migration rates and identification of barriers to gene flow were used and complemented with estimated dispersal trajectories of hourly released virtual propagules, using high-resolution surface current from a mesoscale and tide-resolving ocean simulation. These indicate that the Cameroon Volcanic Line (CVL is not a present-day barrier to gene flow. Rather, the Inter-Bioko-Cameroon (IBC corridor, formed due to sea level rise, allows for connectivity between two mangrove areas that were isolated during glacial times by the CVL. Genetic data and numerical ocean simulations indicated that an oceanic convergence zone near the Cameroon Estuary complex (CEC presents a strong barrier to gene flow, resulting in genetic discontinuities between the mangrove areas on either side. This convergence did not result in higher genetic diversity at the CEC as we had hypothesized. In conclusion, the genetic structure of Rhizophora racemosa is maintained by the contrasting effects of the contemporary oceanic convergence and historical climate

  19. Sea level variability in the eastern tropical Pacific as observed by TOPEX and Tropical Ocean-Global Atmosphere Tropical Atmosphere-Ocean Experiment

    Science.gov (United States)

    Giese, Benjamin S.; Carton, James A.; Holl, Lydia J.

    1994-01-01

    Sea surface height measurements from the TOPEX altimeter and dynamic height from Tropical Ocean-Global Atmosphere Tropical Atmosphere-Ocean (TOGA TAO) moorings are used to explore sea level variability in the northeastern tropical Pacific Ocean. Afetr the annual harmonic is removed, there are two distinct bands of variability: one band is centered at 5 deg N to 7 deg N and extends from 165 deg W to 110 deg W, and the other band is centered at 10 deg N to 12 deg N and extends from 120 deg W to the coast of Central America. The correspondence between the two independent observation data sets at 5 deg N is excellent with correlations of about 90%. The variability at 5 deg-7 deg N is identified as instability waves formed just south of the North Equatorial Countercurrent during the months of July and March. Wave amplitudes are largest in the range of longitudes 160 deg-140 deg W, where they can exceed 10 cm. The waves disappear when the equatorial current system weakens, during the months of March and May. The variability at 11 deg N in 1993 has the form of anticyclone eddies. These eddies propagate westward at a speed of about 17 cm/s, consistent with the dispersion characteristics of free Rossby waves. The eddies are shown to have their origin near the coast of central America during northern fall and winter. Their formation seems to result from intense wind bursts across the Gulfs of Tehuantepec and Papagayo which generate strong anticyclonic ocean eddies. The disappearance of the eddies in the summer of 1993 coincidences with the seasonal intensification of equatorial currents. Thus the variability at 11 deg N has very little overlap in time with the variability at 5 deg N.

  20. The tropospheric biennial oscillation defined by a biennial mode of sea surface temperature and its impact on the atmospheric circulation and precipitation in the tropical eastern Indo-western Pacific region

    Science.gov (United States)

    Kim, Jinju; Kim, Kwang-Yul

    2016-10-01

    Temporal and spatial patterns of anomalous atmospheric circulation and precipitation over the Indo-Pacific region are analyzed in conjunction with the Tropospheric Biennial Oscillation as represented by the biennial mode of sea surface temperature anomalies (SSTA). The biennial components of key variables are identified independently of other variability via CSEOF analysis. Then, its impact on the Asian-Australian monsoon is examined. The biennial mode exhibits a seasonally distinctive atmospheric response over the tropical eastern Indo-western Pacific (EIWP) region (90°-150°E, 20°S-20°N). In boreal summer, local meridional circulation is a distinguishing characteristic over the tropical EIWP region, whereas a meridionally expanded branch of intensified zonal circulation develops in austral summer. Temporally varying evolution and distinct timing of SSTA phase transition in the Indian and Pacific Oceans is considered a main factor for this variation of circulation in the tropical EIWP region. The impact of the biennial mode is not the same between the two seasons, with different impacts over ocean areas in Asian monsoon and Australian monsoon regions.

  1. Cumulative impacts from multiple human activities on seagrass meadows in eastern Mediterranean waters: the case of Saronikos Gulf (Aegean Sea, Greece).

    Science.gov (United States)

    Brodersen, Maren Myrto; Pantazi, Maria; Kokkali, Athina; Panayotidis, Panayotis; Gerakaris, Vasilis; Maina, Irida; Kavadas, Stefanos; Kaberi, Helen; Vassilopoulou, Vassiliki

    2017-12-05

    Ecosystem-based management (EBM) addresses the fundamental need to account for cumulative impacts of human activities with the aim of sustainably delivering ecosystem services. The Saronikos Gulf, a large embayment of the Aegean Sea, provides a wide range of ecosystem services that are impacted by multiple human activities, deriving from the metropolitan area of Athens (situated at the northeast part of the Gulf). The anthropogenic impacts affect the status of several marine ecosystem components, e.g., seagrass meadows. Cymodocea nodosa meadows are only present at the most confined western part of the Gulf, whereas Posidonia oceanica meadows are mainly distributed in the inner and outer part of the Gulf. The aim of this study is to assess the cumulative impacts from multiple human activities on the seagrass meadows in the Gulf. The main results indicated that most impacted meadows are P. oceanica in the inner part of the Gulf, adjacent to the most urbanized coastal areas, and near port infrastructures. Land-based pollution, as well as physical damage and loss seem to be the main pressures exerted on the meadows. Understanding cumulative impacts is crucial for informing policy decisions under an EBM approach.

  2. Mesoscale changes in the water column in response to fish farming zones in three coastal areas in the Eastern Mediterranean Sea

    Science.gov (United States)

    Pitta, P.; Apostolaki, E. T.; Giannoulaki, M.; Karakassis, I.

    2005-11-01

    The hypothesis that the presence of fish farming zones affects the water quality and plankton communities at large spatial scales was investigated through sampling carried out in three regions of the Aegean Sea during May and September. In each region, two sub-areas were sampled: one with fish farming zones (within 2-3 nm) and one without fish farms ('reference site', more than 20 nm). Replicated water samples at different depths were taken in each sub-area for each of the investigated regions. Samples were analysed for nutrients, chlorophyll a, phaeopigments, POC and PON as well as for heterotrophic bacteria, cyanobacteria, flagellates and ciliates. Statistically significant changes in some nutrient species were found during September, which is in the period of maximal supply of feed to caged fish and nutrient loss to a highly stratified oligotrophic environment. Most of the significant changes of nutrients as well as chlorophyll a or PON were found at the deepest layer of the water column below the thermocline, indicating that it is related to the remineralization of benthic organic material. The data support previously published results in this area indicating that there is a rapid transfer of nutrients up the food web. This study also showed the need for studying the effects of fish farms on water quality at larger spatial scales.

  3. Ice Draft and Ice Velocity Data in the Beaufort Sea, 1990-2003, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides measurement of sea ice draft (m) and the movement of sea ice (cm/s) over the continental shelf of the Eastern Beaufort Sea. The data set spans...

  4. Paleotsunamis in Eastern Taiwan

    Science.gov (United States)

    Yen, Jiun-Yee; Yu, Neng-Ti; Hirakawa, Kazuomi; Chyi, Shyh-Jeng; Huang, Shao-Yi

    2017-04-01

    Although Taiwan is located in the active collision zone between Eurasian and the Philippine Sea plate with very high seismicity in and surrounding the island, and supposedly highly susceptible to tsunami hazard. However, there is no record of tsunami hazard in the past one hundred years, and only very few historical records show some possible extreme event occurred. Therefore study of tsunami was scarce in Taiwan. Although historical records do show possible tsunami events, the records were too sparse and incomplete to confidently reconstruct the paleotsunami events. In the past few years, numerical simulations based on possible tsunami-genic zones near Taiwan show that the island could be affected by the correctly directed tsunami. Nevertheless, there is no detail, scientific research of paleotsunami records yet in Taiwan. Our field survey in eastern Taiwan (facing the western Pacific Ocean) along the coast uncovered several outcrops contain gravels embedded in well-developed soil layers. The rounded meta-sandstone gravels are clearly beach-origin and were brought to their current location upon extreme wave events, which is composed of either volcanic-clastic deposits from nearby hills or organic soil layers formed locally. Our investigation indicates that there are at least 3 events in the northern half of eastern Taiwan and at least 2 events in southern part of eastern Taiwan. Although these outcrops are next to the shoreline and Taiwan is susceptible from typhoons, these gravels could be farther away from the beach at the time of their deposition due to current high retreat rate of the sea cliff. Further investigations are needed to delineate possible sources of tsunamis that caused the deposits.

  5. 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

  6. Spatial match-mismatch between juvenile fish and prey provides a mechanism for recruitment variability across contrasting climate conditions in the eastern Bering Sea.

    Science.gov (United States)

    Siddon, Elizabeth Calvert; Kristiansen, Trond; Mueter, Franz J; Holsman, Kirstin K; Heintz, Ron A; Farley, Edward V

    2013-01-01

    Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma) support the largest single-species commercial fishery in the United States and represent an ecologically important component of the Bering Sea ecosystem. Variability in walleye pollock growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches, informed by observations, to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1) a bioenergetics model that included local predator and prey energy densities, and (2) an individual-based model that included a mechanistic feeding component dependent on larval development and behavior, local prey densities and size, and physical oceanographic conditions. Prey composition in late-summer shifted from predominantly smaller copepod species in the warmer 2005 season to larger species in the cooler 2010 season, reflecting differences in zooplankton composition between years. In 2010, the main prey of juvenile walleye pollock were more abundant, had greater biomass, and higher mean energy density, resulting in better growth conditions. Moreover, spatial patterns in prey composition and water temperature lead to areas of enhanced growth, or growth 'hot spots', for juvenile walleye pollock and survival may be enhanced when fish overlap with these areas. This study provides evidence that a spatial mismatch between juvenile walleye pollock and growth 'hot spots' in 2005 contributed to poor recruitment while a higher degree of overlap in 2010 resulted in improved recruitment. Our results indicate that climate-driven changes in prey quality and composition can impact growth of juvenile walleye pollock, potentially severely affecting recruitment variability.

  7. Coastal fisheries in the Eastern Baltic Sea (Gulf of Finland and its basin from the 15 to the Early 20th centuries.

    Directory of Open Access Journals (Sweden)

    Julia Lajus

    Full Text Available The paper describes and analyzes original data, extracted from historical documents and scientific surveys, related to Russian fisheries in the southeastern part of the Gulf of Finland and its inflowing rivers during the 15- early 20(th centuries. The data allow tracing key trends in fisheries development and in the abundance of major commercial species. In particular, results showed that, over time, the main fishing areas moved from the middle part of rivers downstream towards and onto the coastal sea. Changes in fishing patterns were closely interrelated with changes in the abundance of exploited fish. Anadromous species, such as Atlantic sturgeon, Atlantic salmon, brown trout, whitefish, vimba bream, smelt, lamprey, and catadromous eel were the most important commercial fish in the area because they were abundant, had high commercial value and were easily available for fishing in rivers. Due to intensive exploitation and other human-induced factors, populations of most of these species had declined notably by the early 20(th century and have now lost commercial significance. The last sturgeon was caught in 1996, and today only smelt and lamprey support small commercial fisheries. According to historical sources, catches of freshwater species such as roach, ide, pike, perch, ruffe and burbot regularly occurred, in some areas exceeding half of the total catch, but they were not as important as migrating fish and no clear trends in abundance are apparent. Of documented marine catch, Baltic herring appeared in the 16(th century, but did not become commercially significant until the 19(th century. From then until now herring have been the dominant catch.

  8. Dactylogyrids (Monogenoidea: Polyonchoinea parasitizing the gills of snappers (Perciformes: Lutjanidae: revision of Euryhaliotrema with new and previously described species from the Red Sea, Persian Gulf, the eastern and Indo-west Pacific Ocean, and the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Delane C. Kritsky

    2012-06-01

    Full Text Available Twenty one of 29 species of snappers (Lutjanidae, examined for dactylogyrids (Monogenoidea from the Red Sea, Persian Gulf, the Indo-west and eastern Pacific Ocean, the Gulf of Mexico, and Caribbean Sea were parasitized by 16 new and 11 previously described species of Euryhaliotrema: Euryhaliotrema adelpha sp. nov., Euryhaliotrema anecorhizion sp. nov., Euryhaliotrema cardinale sp. nov., Euryhaliotrema chrysotaeniae, Euryhaliotrema cognatus sp. nov., Euryhaliotrema cryptophallus sp. nov., Euryhaliotrema diplops sp. nov., Euryhaliotrema distinctum sp. nov., Euryhaliotrema fajeravilae sp. nov., Euryhaliotrema fastigatum, Euryhaliotrema fatuum sp. nov., Euryhaliotrema ferocis sp. nov., Euryhaliotrema hainanense, Euryhaliotrema longibaculum, Euryhaliotrema mehen comb. nov., Euryhaliotrema paracanthi, Euryhaliotrema paululum sp. nov., Euryhaliotrema perezponcei, Euryhaliotrema ramulum sp. nov., Euryhaliotrema seyi sp. nov., Euryhaliotrema simplicis sp. nov., Euryhaliotrema spirotubiforum, Euryhaliotrema tormocleithrum sp. nov., Euryhaliotrema torquecirrus, Euryhaliotrema tubocirrus, Euryhaliotrema xinyingense, and Euryhaliotrema youngi sp. nov. Six species of Euryhaliotrema, previously reported from lutjanid hosts, were not collected: Euryhaliotrema anguiformis comb. nov., Euryhaliotrema guangdongense, Euryhaliotrema johni, Euryhaliotrema lutiani, Euryhaliotrema lutjani, and Euryhaliotrema nanaoense comb. nov. The diagnosis of Euryhaliotrema was emended to include species having tandem or slightly overlapping gonads, a pretesticular germarium, a globose haptor with morphologically similar anchors and hooks, a coiled or meandering male copulatory organ, a dextral vaginal pore, and hooks with upright acute thumbs and slender shanks comprised of one subunit. A bulbous base of the MCO and presence of an accessory piece in the copulatory complex were no longer considered features defining the genus. As a result, Euryhaliotrematoides and Aliatrema were

  9. Evidence of extensional and strike-slip deformation in the offshore Gökova-Kos area affected by the July 2017 Mw6.6 Bodrum-Kos earthquake, eastern Aegean Sea

    Science.gov (United States)

    Ocakoğlu, Neslihan; Nomikou, Paraskevi; İşcan, Yeliz; Loreto, Maria Filomena; Lampridou, Danai

    2018-01-01

    The interpretation of new multichannel seismic profiles and previously published high-resolution swath and seismic reflection data from the Gökova Gulf and southeast of Kos Island in the eastern Aegean Sea revealed new morphotectonic features related to the July 20, 2017 Mw6.6 Bodrum-Kos earthquake offshore between Kos Island and the Bodrum Peninsula. The seafloor morphology in the northern part of the gulf is characterized by south-dipping E-W-oriented listric normal faults. These faults bend to a ENE-WSW direction towards Kos Island, and then extend parallel to the southern coastline. A left-lateral SW-NE strike-slip fault zone is mapped with segments crossing the Gökova Gulf from its northern part to south of Kos Island. This fault zone intersects and displaces the deep basins in the gulf. The basins are thus interpreted as the youngest deformed features in the study area. The strike-slip faults also produce E-W-oriented ridges between the basin segments, and the ridge-related vertical faults are interpreted as reverse faults. This offshore study reveals that the normal and strike-slip faults are well correlated with the focal mechanism solutions of the recent earthquake and general seismicity of the Gökova Gulf. Although the complex morphotectonic features could suggest that the area is under a transtensional regime, kinematic elements normally associated with a transtensional system are missing. At present, the Gökova Gulf is experiencing strike-slip motion with dominant extensional deformation, rather than transtensional deformation.

  10. Evidence of extensional and strike-slip deformation in the offshore Gökova-Kos area affected by the July 2017 Mw6.6 Bodrum-Kos earthquake, eastern Aegean Sea

    Science.gov (United States)

    Ocakoğlu, Neslihan; Nomikou, Paraskevi; İşcan, Yeliz; Loreto, Maria Filomena; Lampridou, Danai

    2018-06-01

    The interpretation of new multichannel seismic profiles and previously published high-resolution swath and seismic reflection data from the Gökova Gulf and southeast of Kos Island in the eastern Aegean Sea revealed new morphotectonic features related to the July 20, 2017 Mw6.6 Bodrum-Kos earthquake offshore between Kos Island and the Bodrum Peninsula. The seafloor morphology in the northern part of the gulf is characterized by south-dipping E-W-oriented listric normal faults. These faults bend to a ENE-WSW direction towards Kos Island, and then extend parallel to the southern coastline. A left-lateral SW-NE strike-slip fault zone is mapped with segments crossing the Gökova Gulf from its northern part to south of Kos Island. This fault zone intersects and displaces the deep basins in the gulf. The basins are thus interpreted as the youngest deformed features in the study area. The strike-slip faults also produce E-W-oriented ridges between the basin segments, and the ridge-related vertical faults are interpreted as reverse faults. This offshore study reveals that the normal and strike-slip faults are well correlated with the focal mechanism solutions of the recent earthquake and general seismicity of the Gökova Gulf. Although the complex morphotectonic features could suggest that the area is under a transtensional regime, kinematic elements normally associated with a transtensional system are missing. At present, the Gökova Gulf is experiencing strike-slip motion with dominant extensional deformation, rather than transtensional deformation.

  11. The Messinian/Early Pliocene transition in Eastern Mediterranean: New palaeoenvironmental data from the Kalamaki section (Zakynthos Island, Greece)

    Science.gov (United States)

    Drinia, Hara; Antonarakou, Assimina; Tsourou, Theodora; Tzortzaki, Evi; Filippidi, Amalia; Nikolaou, Konstantinos

    2010-05-01

    foraminiferal facies distribution in the studied part of the Kalamaki section is in accordance with isotope oxygen data from basins in the central and eastern Mediterranean basin which indicates the existence of a salinity gradient during this time span. Ostracod fauna is characterised by low diversity and abundance. It is consisting mainly of Bythocypris and Cytherella species, which confirm the bathyal depositional environment. The study of the late Messinian-Early Pliocene sediments in Zakynthos island (Kalamaki section) correlated with time equivalent sections in Crete (e.g. Drinia et al., 2007) and the comparison with the offshore coeval deposits drilled in the ODP Leg 160 boreholes, illustrate the environmental changes which occurred in the Eastern Mediterranean at the end of the salinity crisis. References Dermitzakis, M.D., 1978. Stratigraphy and sedimentary history of the Miocene of Zakynthos (Ionian Islands, Greece). Ann. Geol. Pays Hell., 29:47 186. Drinia, H., Antonarakou, A., Kontakiotis, G., 2007. On the occurrence of Early Pliocene marine deposits in the Ierapetra Basin, Eastern Crete, Greece. Bulletin of Geosciences, 83 (1), 63-78. Jorissen, F.J., 1988. Benthic foraminifera from the Adriatic Sea: principles of phenotypic variation. Utrecht Micropaleontological Bulletins, 37, 1-174. Murray, J., 2006. Ecology and applications of Benthic foraminifera. Cambridge University press, 426pp. Nikolaou, K.A., 1986. Contribution to the knowledge of the Neogene , the geology and the limits of the Ionian and Preapulian zones, in relation to the petroleum exploration , observations in Strofades , Zakynthos and Kefallinia islands. The doct. University of Athens. Pierre, C., Caruso, A., Blanc-Valleron, M., Rouchy, J. M., Orzsag-Sperber, F., 2006. Reconstruction of the paleoenvironmental changes around the Miocene-Pliocene boundary along a West-East transect across the Mediterranean. Sedimentary Geology 188-189, 319-340. The Messinian Salinity Crisis Revisited. Pujos, M., 1976

  12. Contemporary Arctic Sea Level

    Science.gov (United States)

    Cazenave, A. A.

    2017-12-01

    During recent decades, the Arctic region has warmed at a rate about twice the rest of the globe. Sea ice melting is increasing and the Greenland ice sheet is losing mass at an accelerated rate. Arctic warming, decrease in the sea ice cover and fresh water input to the Arctic ocean may eventually impact the Arctic sea level. In this presentation, we review our current knowledge of contemporary Arctic sea level changes. Until the beginning of the 1990s, Arctic sea level variations were essentially deduced from tide gauges located along the Russian and Norwegian coastlines. Since then, high inclination satellite altimetry missions have allowed measuring sea level over a large portion of the Arctic Ocean (up to 80 degree north). Measuring sea level in the Arctic by satellite altimetry is challenging because the presence of sea ice cover limits the full capacity of this technique. However adapted processing of raw altimetric measurements significantly increases the number of valid data, hence the data coverage, from which regional sea level variations can be extracted. Over the altimetry era, positive trend patterns are observed over the Beaufort Gyre and along the east coast of Greenland, while negative trends are reported along the Siberian shelf. On average over the Arctic region covered by satellite altimetry, the rate of sea level rise since 1992 is slightly less than the global mea sea level rate (of about 3 mm per year). On the other hand, the interannual variability is quite significant. Space gravimetry data from the GRACE mission and ocean reanalyses provide information on the mass and steric contributions to sea level, hence on the sea level budget. Budget studies show that regional sea level trends over the Beaufort Gyre and along the eastern coast of Greenland, are essentially due to salinity changes. However, in terms of regional average, the net steric component contributes little to the observed sea level trend. The sea level budget in the Arctic

  13. Formation and ridging of flaw leads in the eastern Canadian Beaufort Sea. Special Session C06 on: “Physical, biological and biogeochemical processes associated with young thin ice types”

    Science.gov (United States)

    Prinsenberg, S. J.

    2009-12-01

    Formation and ridging of flaw leads in the eastern Canadian Beaufort Sea. Simon Prinsenberg1 and Yves Graton2 1Bedford Inst. of Oceanography, Fisheries and Oceans Canada P.O. Box1006, Dartmouth, Nova Scotia, B2Y 4A2, Canada prinsenbergs@mar.dfo-mpo.gc.ca 2Inst. National de la Recherche Scientifique-Eau, INRS-ETE University of Quebec at Quebec City, Quebec yvesgratton@eteinrs.ca During the winter of 2008, the flaw lead south of Banks Island repeatedly opened and closed representing an elongated region where periodically the large ice growth stimulates the densification of the surface layer due to salt rejection and instigates a local circulation pattern that will affect the biological processes of the region. Helicopter-borne sensors were available to monitor the aftermath of one of the rapid closing of the flaw lead into extensive elongated rubble field using a Canadian Ice breaker, CCGS Amundsen, as a logistic base. After the wind reversed a new open flaw lead 20km wide restarting a new flaw lead formation cycle. Ice thickness and surface roughness data were collected from the rubble field and adjacent open flaw lead with an Electromagnetic-Laser system. The strong wind event of April 4-5 2009 generated a large linear 1.5km wide ice rubble field up to 8-10m thick when the 60cm thick, 18km wide flaw lead was crunched into land-fast by the 1.5m thick offshore pack ice. It is expected that during rapid ice growth in a flaw lead, salt rejection increase the density of the surface water layer producing a surface depression (Low) and cyclonic circulation. In contrast at depth, the extra surface dense water produces a high in the horizontal pressure field and anti-cyclonic circulation which remains after the rapid ice growth within the flaw lead stops. One of such remnants may have been observed during the CFL-IPY winter survey.

  14. Searching for a stock structure in Sardina pilchardus from the Adriatic and Ionian seas using a microsatellite DNA-based approach

    DEFF Research Database (Denmark)

    Ruggeri, Paolo; Splendiani, Andrea; Bonanomi, Sara

    2013-01-01

    of homozygote individuals higher than expected at Hardy-Weinberg equilibrium. The inter-population differentiation level estimated by AMOVA, qST and rRST and Bayesian descriptors detected no signs of population differentiation between the samples analysed. These results are consistent with previous studies...

  15. Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea.

    Science.gov (United States)

    Detlef, H; Belt, S T; Sosdian, S M; Smik, L; Lear, C H; Hall, I R; Cabedo-Sanz, P; Husum, K; Kender, S

    2018-03-05

    Sea ice and associated feedback mechanisms play an important role for both long- and short-term climate change. Our ability to predict future sea ice extent, however, hinges on a greater understanding of past sea ice dynamics. Here we investigate sea ice changes in the eastern Bering Sea prior to, across, and after the Mid-Pleistocene transition (MPT). The sea ice record, based on the Arctic sea ice biomarker IP 25 and related open water proxies from the International Ocean Discovery Program Site U1343, shows a substantial increase in sea ice extent across the MPT. The occurrence of late-glacial/deglacial sea ice maxima are consistent with sea ice/land ice hysteresis and land-glacier retreat via the temperature-precipitation feedback. We also identify interactions of sea ice with phytoplankton growth and ocean circulation patterns, which have important implications for glacial North Pacific Intermediate Water formation and potentially North Pacific abyssal carbon storage.

  16. 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

  17. The radioactivity of the sea

    International Nuclear Information System (INIS)

    Walker, M.I.; Rose, K.S.B.

    1990-01-01

    The radioactivity in the world's surface sea water averages 13.6 Bq/kg of water. Over 88% of this activity arises from a single natural radionuclide, 40 K, and 7% of the remainder results from nuclear weapon test fallout. Variations in the radioactivity occur due to changes in salinity, weapon test fallout and discharges of artificial radionuclides, and are examined here on the basis of published measurements. The most radioactive sea identified by these measurements is the Dead Sea, which averages 178 Bq/kg due to its high salinity. Other enclosed, highly saline waters can be expected to have similar levels. The radioactivity in open seas varies within a much narrower range, generally within 20% of the world average. The highest averages are found in the Persian Gulf (22 Bq/kg), the Red Sea (15 Bq/kg) and the Eastern Mediterranean (14.6 Bq/kg). The Irish Sea averaged 13.7 Bq/kg in 1987, with the effect of the Sellafield discharges being partly offset by lower than average salinity. Although higher levels occurred in the Irish Sea during the 1970s when the Sellafield discharges were higher, the average level has always been much less than that in the Dead Sea, so that the Irish Sea has never been the most radioactive sea in the world. Exceptionally low levels of radioactivity (4 Bq/kg) occur in the Baltic Sea due to dilution by fresh water. (author)

  18. Source of Aegean Sea harbour porpoises

    DEFF Research Database (Denmark)

    Lockyer, Christina; Rosel, P. E.; Frantzis, A.

    2003-01-01

    Documented sightings of harbour porpoises in the Mediterranean are rare, although the species is common in the neighbouring North Atlantic and Black Sea. However, in the past 2 decades, 4 harbour porpoises Phocoena phocoena have been recorded in the northern Aegean Sea in the eastern Mediterranea...

  19. Climatology of sea breezes along the Red Sea coast of Saudi Arabia

    KAUST Repository

    Khan, Basit

    2018-04-25

    Long-term near-surface observations from five coastal stations, high-resolution model data from Modern Era Retrospective-Analysis for Research and Applications (MERRA) and high-resolution daily sea surface temperature (SST) from National Ocean and Atmospheric Administration (NOAA) are used to investigate the climatology of sea breezes over the eastern side of the Red Sea region. Results show existence of separate sea breeze systems along different segments of the Red Sea coastline. Based on the physical character and synoptic influences, sea breezes in the Red Sea are broadly divided into three regions: the north and the middle Red Sea (NMRS), the Red Sea convergence zone (RSCZ) and the southern Red Sea (SRS) regions. On average, sea breezes developed on 67% of days of the 10-year study period. Although sea breezes occur almost all year, this mesoscale phenomenon is most frequent from May to October (78% of the total sea breeze days). The sea breeze frequency increases from north to south (equatorwards), and sea breeze characteristics appear to vary both temporally and spatially. In addition to land-sea thermal differential, coastline shape, latitude and topography, the prevailing northwesterly at NMRS region, the convergence of northwesterly and southeasterly wind system at RSCZ region and the northeast and southwest monsoon at SRS region play an important role in defining the sea breeze characteristics over the Red Sea.

  20. Steric and mass-induced Mediterranean sea level trends from 14 years of altimetry data

    Science.gov (United States)

    Criado-Aldeanueva, Francisco; Del Río Vera, Jorge; García-Lafuente, Jesús

    2008-02-01

    Long-term series of almost 14 years of altimetry data (1992-2005) have been analysed along with Sea Surface Temperature (SST) and temperature and salinity profiles to investigate sea level trends over the Mediterranean Sea. Although sea level variations are mainly driven by the steric contribution, the mass-induced component plays some role in modulating its oscillation. A spatially averaged positive trend of 2.1 ± 0.6 mm/year has been observed, but a change in sign in 2001 seems to appear. Steric effects (mainly on thermal origin) account for ˜ 55% of sea level trend. Although Mediterranean Sea is a semi-enclosed basin, this value is comparable to that reported for the global ocean. Sea level rise is particularly important in the Levantine basin south of Crete with values up to 10 ± 1 mm/year. Other areas of sea level rise are localised throughout the Levantine basin and in the Adriatic and Alboran Seas, with more moderate values. Sea level drop areas are localised in the Algerian basin, between the Balearic Islands and the African coasts and, particularly, in the Ionian basin. In this area, negative trends as high as - 10 ± 0.8 mm/year are detected mainly due to the mass-induced contribution, which suggests decadal changes of surface circulation. The inferred sea level trends have been correlated with North Atlantic Oscillation (NAO) indices and a low but significant correlation has been detected between sea level in the Levantine and Balearic basins and NAO index.

  1. 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,...

  2. Observations of carbon dioxide in the surface waters of the Eastern North Pacific Ocean and the Bering Sea from 21 July 1968 to 03 September 1968 (NODC Accession 7100114)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of the equilibrium concentration of carbon dioxide in the air and surface waters of the North Pacific Ocean and the Bering Sea are presented....

  3. 75 FR 77602 - Endangered and Threatened Species; 90-Day Finding on Petitions To Delist the Eastern Distinct...

    Science.gov (United States)

    2010-12-13

    ... the Eastern Distinct Population Segment of the Steller Sea Lion AGENCY: National Marine Fisheries... delist the eastern Distinct Population Segment (DPS) of the Steller Sea Lion (Eumetopias jubatus) under...-implementing regulations issued by NMFS and the U.S. Fish and Wildlife Service (FWS) also establish procedures...

  4. Le plateau Cyrénien : promontoire africain sur la marge Ionienne The Cyrenian Plateau: African Promontory on the Ionian Margin

    Directory of Open Access Journals (Sweden)

    Groupe Escarmed

    2006-11-01

    Full Text Available Le Comité d'Études Pétrolières Marines (CEPM et le Centre National pour l'Exploration des Océans (CNEXO ont mené une série d'études sous-marines des escarpements Ioniens pour en définir l'origine, l'âge et l'évolution. Les résultats présentés ici concernent le plateau Cyrénien, au sud du bassin Ionien profond. Ils comprennent : les données bathymétriques sous forme d'une carte à 1/100 000e hors texte, l'analyse morphologique des reliefs, les déterminations stratigraphiques effectuées sur les échantillons récoltés en dragages ou en plongées, la description sommaire des cinq plongées réalisées sur les escarpements. Les conclusions font ressortir : - l'existence de séries carbonatées de plate-forme d'âge Crétacé inférieur, affectées d'une subsidence rapide; - un changement paléogéographique majeur, post-Albien, qui correspondrait sans doute à la première individualisation du plateau sous-marin; - la distinction d'une série litée, probablement lithologiquement diversifiée, d'âge Crétacé supérieur; - la distinction d'une série supérieure massive, non datée, probablement entièrement carbonatée; - une évolution récente marquée par la formation de figures de dissolution sur les parois rocheuses, la diagenèse d'encroûtements carbonatés sur les pentes envasées. The Comité d'Études Pétrolières Marines (CEPM and the Centre National pour l'Exploitation des Océans (CNEXO have conducted a series of subsea surveys of the Ionian escarpments to determine their origin, age and evolution. The results presented here concern the Cyrenian Shelf, south of the deep Ionian basin. They include the bathymetric data in the form of a map at 1:100,000 (inset, the morphological analysis of the reliefs, the stratigraphic determinations carried out on samples taken by dredging and diving, and the brief description of the five dives carried out on the escarpments. The conclusions reveal the following:(a the existence

  5. Reconstruction and outlook of the radionuclide transport in the Mediterranean seas chain

    International Nuclear Information System (INIS)

    Maderich, M.

    1999-01-01

    A set of models was developed to reconstruct and predict in 1960-2010 the 137 Cs contamination in the system of Mediterranean seas that was result of the testing of nuclear weapons and the Chernobyl accident. It incorporates the submodels of the Black Sea, Azov Sea, Marmara Sea, Western and Eastern Mediterranean

  6. Determination of trace metals in sea waters of the albanian coast by energy-dispersive x-ray fluorescence

    International Nuclear Information System (INIS)

    Civici, N.

    1994-01-01

    Preconcentration of trace transition and heavy metal ions by precipitation with APDC has been combined with energy-dispersive X-ray fluorescence for environmental sea water analysis. The preconcentration procedure implies adding of 500 μg Mo ion and 10 ml of 1 % water solution of APDC to a 500 ml water sample at pH 4, filtering off on a Millipore filter and analyzing after drying. Realistic detection limits are at 1 μg * l -1 level and precision varies between 10 - 25% at about 5 μg * l -1 level, depending on the element. Eleven sea water samples, covering Albanian Adriatic and Ionian coast, are analyzed for trace metal ions. (author) 8 refs.; 2 figs.; 5 tabs

  7. Nitrogen and oxygen isotopic composition of N sub(2)O from suboxic waters of the eastern tropical North Pacific and the Arabian Sea - measurement by continuous-flow isotope-ratio monitoring

    Digital Repository Service at National Institute of Oceanography (India)

    Yoshinari, T.; Altabet, M.A.; Naqvi, S.W.A.; Codispoti, L.; Jayakumar, D.A.; Kuhland, M.; Devol, A.

    of the correlation between apparent oxygen utilization and N,O con- centration found in many portions of the ocean. However, such a correlation is not sufficient evi- dence to conclude that nitrification is the dominant source (Pierotti and Rasmussen, 1980...,O is also significantly affected by denitrification (Yoshinari and Koike, 1994). In the eastern tropical North Pa- cific, nitrate deficits (an estimate of the NO; con- verted to N, by denitrification) are relatively large in the water mass that contains...

  8. The Ross Sea Dipole - temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

    Science.gov (United States)

    Bertler, Nancy A. N.; Conway, Howard; Dahl-Jensen, Dorthe; Emanuelsson, Daniel B.; Winstrup, Mai; Vallelonga, Paul T.; Lee, James E.; Brook, Ed J.; Severinghaus, Jeffrey P.; Fudge, Taylor J.; Keller, Elizabeth D.; Baisden, W. Troy; Hindmarsh, Richard C. A.; Neff, Peter D.; Blunier, Thomas; Edwards, Ross; Mayewski, Paul A.; Kipfstuhl, Sepp; Buizert, Christo; Canessa, Silvia; Dadic, Ruzica; Kjær, Helle A.; Kurbatov, Andrei; Zhang, Dongqi; Waddington, Edwin D.; Baccolo, Giovanni; Beers, Thomas; Brightley, Hannah J.; Carter, Lionel; Clemens-Sewall, David; Ciobanu, Viorela G.; Delmonte, Barbara; Eling, Lukas; Ellis, Aja; Ganesh, Shruthi; Golledge, Nicholas R.; Haines, Skylar; Handley, Michael; Hawley, Robert L.; Hogan, Chad M.; Johnson, Katelyn M.; Korotkikh, Elena; Lowry, Daniel P.; Mandeno, Darcy; McKay, Robert M.; Menking, James A.; Naish, Timothy R.; Noerling, Caroline; Ollive, Agathe; Orsi, Anaïs; Proemse, Bernadette C.; Pyne, Alexander R.; Pyne, Rebecca L.; Renwick, James; Scherer, Reed P.; Semper, Stefanie; Simonsen, Marius; Sneed, Sharon B.; Steig, Eric J.; Tuohy, Andrea; Ulayottil Venugopal, Abhijith; Valero-Delgado, Fernando; Venkatesh, Janani; Wang, Feitang; Wang, Shimeng; Winski, Dominic A.; Winton, V. Holly L.; Whiteford, Arran; Xiao, Cunde; Yang, Jiao; Zhang, Xin

    2018-02-01

    High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979-2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.

  9. The Ross Sea Dipole – temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

    Directory of Open Access Journals (Sweden)

    N. A. N. Bertler

    2018-02-01

    Full Text Available High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE ice core. Comparison of this record with climate reanalysis data for the 1979–2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons, with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.

  10. Seasonal and interannual variations in pigments in the Adriatic Sea

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    30m), depends on the freshwater inflow as well ... The Adriatic Sea (Northern Mediterranean) and location of satellite pigment data (cross marks) ..... landings of small pelagic fish in the eastern Adriatic– ... and North America (1858–1980).

  11. Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover and fast ice decay

    Directory of Open Access Journals (Sweden)

    P. Itkin

    2017-10-01

    Full Text Available Ice retreat in the eastern Eurasian Arctic is a consequence of atmospheric and oceanic processes and regional feedback mechanisms acting on the ice cover, both in winter and summer. A correct representation of these processes in numerical models is important, since it will improve predictions of sea ice anomalies along the Northeast Passage and beyond. In this study, we highlight the importance of winter ice dynamics for local summer sea ice anomalies in thickness, volume and extent. By means of airborne sea ice thickness surveys made over pack ice areas in the south-eastern Laptev Sea, we show that years of offshore-directed sea ice transport have a thinning effect on the late-winter sea ice cover. To confirm the preconditioning effect of enhanced offshore advection in late winter on the summer sea ice cover, we perform a sensitivity study using a numerical model. Results verify that the preconditioning effect plays a bigger role for the regional ice extent. Furthermore, they indicate an increase in volume export from the Laptev Sea as a consequence of enhanced offshore advection, which has far-reaching consequences for the entire Arctic sea ice mass balance. Moreover we show that ice dynamics in winter not only preconditions local summer ice extent, but also accelerate fast-ice decay.

  12. Proliferation and demise of deep-sea corals in the Mediterranean during the Younger Dryas

    International Nuclear Information System (INIS)

    McCulloch, Malcolm; Taviani, Marco; Lopez Correa, Matthias; Remia, Alessandro; Montagna, Paolo; Mortimer, Graham

    2010-01-01

    Uranium-series and radiocarbon ages are reported for deep-sea corals Madrepora oculata, Desmophyllum dianthus, Lophelia pertusa and Caryophyllia smithii from the Mediterranean Sea. U-series dating indicates that deep-sea corals have persisted in the Mediterranean for over 480, 000 years, especially during cool inter-stadial periods. The most prolific period of growth however appears to have occurred within the Younger Dryas (YD) period from 12, 900 to 11, 700 years BP followed by a short (∼ 330 years) phase of post-YD coral growth from 11, 230 to 10, 900 years BP. This indicates that deep-sea corals were prolific in the Mediterranean not only during the return to the more glacial-like conditions of the YD, but also following the rapid deglaciation and transition to warmer conditions that followed the end of the YD. Surprisingly, there is a paucity Last Glacial Maximum (LGM) coral ages, implying they were largely absent during this period when cold-water conditions were more prevalent. Radiocarbon ages show that the intermediate depth waters of the Mediterranean generally had Δ 14 C compositions similar to surface waters, indicating that these waters were extremely well ventilated. The only exception is a narrow period in the YD (12, 500 ± 100 years BP) when several samples of Lophelia pertusa from the Ionian Sea had Δ 14 C values falling significantly below the marine curve. Using a refined approach, isolation ages (T isol ) of 300 years to 500 years are estimated for these intermediate (800-1000 m) depth waters relative to surface marine waters, indicating a reduction or absence of deep-water formation in the Ionian and adjacent Adriatic Seas during the YD. Contrary to previous findings, we find no evidence for widespread intrusion of low Δ 14 C Atlantic waters into the Mediterranean. Prolific growth of deep-sea corals in the Mediterranean ended abruptly at ∼ 10, 900 years BP, with many of the coral-bearing mounds on the continental slopes being draped in

  13. Proliferation and demise of deep-sea corals in the Mediterranean during the Younger Dryas

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, Malcolm [ARC Centre of Excellence for Coral Reef Studies, School of Earth and Environment, The University of Western Australian, Crawley, 6009, Western Australia (Australia); Research School of Earth Sciences, Australian National University, Canberra, 0200 (Australia); Taviani, Marco; Lopez Correa, Matthias; Remia, Alessandro [ISMAR-CNR, via Gobetti 101, I-40129 Bologna (Italy); Montagna, Paolo [LSCE, Av. de la Terrasse, 91198 Gif-sur-Yvette, France, ISMAR-CNR, via Gobetti 101, I-40129 Bologna (Italy); Mortimer, Graham [Research School of Earth Sciences, Australian National University, Canberra, 0200 (Australia)

    2010-07-01

    Uranium-series and radiocarbon ages are reported for deep-sea corals Madrepora oculata, Desmophyllum dianthus, Lophelia pertusa and Caryophyllia smithii from the Mediterranean Sea. U-series dating indicates that deep-sea corals have persisted in the Mediterranean for over 480, 000 years, especially during cool inter-stadial periods. The most prolific period of growth however appears to have occurred within the Younger Dryas (YD) period from 12, 900 to 11, 700 years BP followed by a short ({approx} 330 years) phase of post-YD coral growth from 11, 230 to 10, 900 years BP. This indicates that deep-sea corals were prolific in the Mediterranean not only during the return to the more glacial-like conditions of the YD, but also following the rapid deglaciation and transition to warmer conditions that followed the end of the YD. Surprisingly, there is a paucity Last Glacial Maximum (LGM) coral ages, implying they were largely absent during this period when cold-water conditions were more prevalent. Radiocarbon ages show that the intermediate depth waters of the Mediterranean generally had {Delta}{sup 14}C compositions similar to surface waters, indicating that these waters were extremely well ventilated. The only exception is a narrow period in the YD (12, 500 {+-} 100 years BP) when several samples of Lophelia pertusa from the Ionian Sea had {Delta}{sup 14}C values falling significantly below the marine curve. Using a refined approach, isolation ages (T{sub isol}) of 300 years to 500 years are estimated for these intermediate (800-1000 m) depth waters relative to surface marine waters, indicating a reduction or absence of deep-water formation in the Ionian and adjacent Adriatic Seas during the YD. Contrary to previous findings, we find no evidence for widespread intrusion of low {Delta}{sup 14}C Atlantic waters into the Mediterranean. Prolific growth of deep-sea corals in the Mediterranean ended abruptly at {approx} 10, 900 years BP, with many of the coral-bearing mounds

  14. Valorisation of vernacular farm buildings for the sustainable development of rural tourism in mountain areas of the Adriatic-Ionian macro-region

    Directory of Open Access Journals (Sweden)

    Dina Statuto

    2017-08-01

    Full Text Available Rural buildings play a central role on the environmental characteristics of the extra-urban land. They accompanied in the centuries the development of agricultural activities by humans, who was so able to breed cattle, to grow and yield crops, and to store, transform and process agricultural products in a functional and efficient way, working into intensive conditions, so being unaffected by the external climate. On the other hand, constructions built by the farmer-man marked the territory, influencing and steering the spontaneous development of nature, while leading to production that enabled humanity to get food. Vernacular farm buildings, often used as seasonal settlements, are in some cases organised in areas of mountain pasture for summer cattle grazing. Even if in most case they were abandoned during recent years - since people living there moved to more comfortable residences within urban settlements - their contemporary potential for preserving traditional cattle-raising procedures and dairy products, rich cultural-historical heritage and perspectives of organised tourism activities, appears a very intriguing task to be approached. Rural tourism - including agro-, eco- and cultural tourism - offers indeed new opportunities for enjoying the extra-urban land in close contact with naturally untouched landscapes. It enables to appreciate some traditional aspects that the new industrialised modern society may have forgotten. The opportunities offered by rural tourism could help in the development of environmentally friendly tourism, which is growing three times faster than those choosing mainstream trips. With the aim to valorise the vernacular rural buildings in some mountain areas of the Adriatic-Ionian macro-region, in the present paper a first approach was proposed, through the implementation of a geographical information system aimed to survey the current situation into two different mountain areas within this macro-region, located in

  15. Black Sea coastal forecasting system

    Directory of Open Access Journals (Sweden)

    A. I. Kubryakov

    2012-03-01

    Full Text Available The Black Sea coastal nowcasting and forecasting system was built within the framework of EU FP6 ECOOP (European COastalshelf sea OPerational observing and forecasting system project for five regions: the south-western basin along the coasts of Bulgaria and Turkey, the north-western shelf along the Romanian and Ukrainian coasts, coastal zone around of the Crimea peninsula, the north-eastern Russian coastal zone and the coastal zone of Georgia. The system operates in the real-time mode during the ECOOP project and afterwards. The forecasts include temperature, salinity and current velocity fields. Ecosystem model operates in the off-line mode near the Crimea coast.

  16. Sensitivity analysis of the model for estimation of the Adriatic sea turnover time using fallout 90Sr as a radioactive tracer

    International Nuclear Information System (INIS)

    Franic, Z.

    2005-01-01

    Reliable data on the turnover time of water in the Adriatic Sea (approximately 35000 cubic kilometres) is extremely important for any risk analysis involving various economic activities, tourism, etc. Water exchange through the Strait of Otranto between the Adriatic and the Ionian seas has been the subject of a series of experimental investigations and more recently, of some numerical studies, is extensively presented by Cushman-Roisin et al. [1]. The turnover time of the Adriatic sea water can be easily calculated from the data on water fluxes through the Strait by calculating annual water mass flowing through the Strait and dividing it by the total volume of the Adriatic sea. Literature data on the Adriatic Sea water turnover time range from minimal 0.7 to maximal 5.0 years. Using a model describing the rate of change of 9 0S r activity concentrations in the Adriatic Sea water by function minimisation to long-term experimental data, the turnover time for 9 0S r in the Adriatic was calculated to be 3.3±0.4 years. The uncertainty was estimated by Monte Carlo analysis. As 9 0S r is a reliable radiotracer for seawater, this value also reflects the sea water turnover time. Sensitivity analysis of the model, applied by varying critical parameters over their nominal values, showed that ±25% uncertainty in the estimation of the Adriatic sea water activity results in approximately ±10% change in 9 0S r mean residence time. On the other hand, a larger input of 9 0S r, either by fallout or water influx from the Ionian Sea may lead to a shorter mean residence time.Direct proportionality between 9 0S r input into the Adriatic sea and its mean residence time in the sea water suggests that 3.3 years is the upper limit of the Adriatic sea water turnover time. Namely, re-suspension from sediments could affect 9 0S r activity concentrations, acting as additional input, especially in the northern, relatively shallow part of the Adriatic.(author)

  17. Eastern Redcedar Seedling Assessment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Eastern redcedar tree seedling growth in response to various soil, nitrogen, and photosynthetic radiation characteristics. This dataset is associated with the...

  18. Sea surface temperature mapping using a thermal infrared scanner

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R; Pandya, R; Mathur, K.M.; Charyulu, R; Rao, L.V.G.

    1 metre water column below the sea surface. A thermal infrared scanner developed by the Space Applications Centre (ISRO), Ahmedabad was operated on board R.V. Gaveshani in April/May 1984 for mapping SST over the eastern Arabian Sea. SST values...

  19. Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Kornilios, S.; Drakopoulos, P.G.; Dounas, C. [Institute of Marine Biology of Crete, Iraklio (Greece). Environmental Dept.

    1998-12-01

    During the first cruise of R/V `Philia` in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 {mu}g/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1-4280 and 0-1160 {mu}g/m{sup 2}, respectively. Mean pelagic tar concentration was 318 {mu}g/m{sup 2}, more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea. (author)

  20. Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Kornilios, S.; Drakopoulos, P.G.; Dounas, C. [Institute of Marine Biology of Crete, Iraklio (Greece). Environmental Dept.

    1998-12-01

    During the first cruise of R/V 'Philia' in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 {mu}g/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1-4280 and 0-1160 {mu}g/m{sup 2}, respectively. Mean pelagic tar concentration was 318 {mu}g/m{sup 2}, more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea. (author)

  1. Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

    International Nuclear Information System (INIS)

    Kornilios, S.; Drakopoulos, P.G.; Dounas, C.

    1998-01-01

    During the first cruise of R/V 'Philia' in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 μg/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1-4280 and 0-1160 μg/m 2 , respectively. Mean pelagic tar concentration was 318 μg/m 2 , more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea. (author)

  2. Rationale for restocking the Eastern Baltic cod stock

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Overton, Julia Lynne; Paulsen, Helge

    2008-01-01

    The Danish Institute for Fisheries Research and Bornholm's Salmon Hatchery examined the potential for restocking Baltic cod (Gadus morhua callarias L.) in the eastern Baltic Sea. This cod population has adapted to the unique brackish water conditions where successful spawning depends on regular i...

  3. Gas in Eastern Europe

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    West European gas companies have long recognised the potential for lucrative business within eastern Europe. But they recognise that the region's integration into the west European system will be far from straightforward, with deals between east European gas companies and their western counterparts invariably containing financial mechanisms, such as barter trade, that are designed to cope with the easterners' shortage of hard currency. (author)

  4. Middle Eastern rhinoplasty.

    Science.gov (United States)

    Azizzadeh, Babak; Mashkevich, Grigoriy

    2010-02-01

    The ethnic appearance of the Middle Eastern nose is defined by several unique visual features, particularly a high radix, wide overprojecting dorsum, and an amorphous hanging nasal tip. These external characteristics reflect distinct structural properties of the osseo-cartilaginous nasal framework and skin-soft tissue envelope in patients of Middle Eastern extraction. The goal, and the ultimate challenge, of rhinoplasty on Middle Eastern patients is to achieve balanced aesthetic refinement, while avoiding surgical westernization. Detailed understanding of the ethnic visual harmony in a Middle Eastern nose greatly assists in preserving native nasal-facial relationships during rhinoplasty on Middle Eastern patients. Esthetic alteration of a Middle Eastern nose follows a different set of goals and principles compared with rhinoplasties on white or other ethnic patients. This article highlights the inherent nasal features of the Middle Eastern nose and reviews pertinent concepts of rhinoplasty on Middle Eastern patients. Essential considerations in the process spanning the consultation and surgery are reviewed. Reliable operative techniques that achieve a successful aesthetic outcome are discussed in detail. Copyright 2010 Elsevier Inc. All rights reserved.

  5. The Ionian Renaissance and Alexandria

    DEFF Research Database (Denmark)

    Pedersen, Poul

    2008-01-01

    Ved hjælp af kunstneriske og tekniske særehenheder, som f.eks det særlige karisk-ioniske løftehul, er det muligt at definere en overset hovedepoke i den antikke græske arkitektur med kerneområde i det vestlige Lillesaien i senklassisk og hellenistisk tid. Der argumenteres i artiklen for at denne ...

  6. Sea Dragon

    National Research Council Canada - National Science Library

    1997-01-01

    .... In preparation for these changes, the Navy is exploring new command and control relationships, and the Marine Corps established Sea Dragon to experiment with emerging technologies, operational...

  7. Lack of P-limitation of phytoplankton and heterotrophic prokaryotes in surface waters of three anticyclonic eddies in the stratified Mediterranean Sea

    Science.gov (United States)

    Tanaka, T.; Thingstad, T. F.; Christaki, U.; Colombet, J.; Cornet-Barthaux, V.; Courties, C.; Grattepanche, J.-D.; Lagaria, A.; Nedoma, J.; Oriol, L.; Psarra, S.; Pujo-Pay, M.; van Wambeke, F.

    2011-02-01

    We investigated the identity of the limiting nutrient of the pelagic microbial food web in the Mediterranean Sea using nutrient manipulated microcosms during summer 2008. Experiments were carried out with surface waters at the center of anticyclonic eddies in the Western Basin, the Ionian Basin, and the Levantine Basin. In situ, the ratio of N to P was always higher in both dissolved and particulate organic fractions compared to the Redfield ratio, suggesting a relative P-starvation. In each experiment, four different treatments in triplicates (addition of ammonium, phosphate, a combination of both, and the unamended control) were employed and chemical and biological parameters monitored throughout a 3-4 day incubation. Temporal changes of turnover time of phosphate and ATP, and alkaline phosphatase activity during the incubation suggested that the phytoplankton and heterotrophic prokaryotes (Hprok) communities were not P-limited at the sites. Furthermore, statistical comparison among treatments at the end of the incubation did not support a hypothesis of P-limitation at the three study sites. In contrast, primary production was consistently limited by N, and Hprok growth was not limited by N nor P in the Western Basin, but N-limited in the Ionian Basin, and N and P co-limited in the Levantine Basin. Our results demonstrated the gap between biogeochemical features (an apparent P-starved status) and biological responses (no apparent P-limitation). We question the general notion that Mediterranean surface waters are limited by P alone during the stratified period.

  8. Ice Draft and Ice Velocity Data in the Beaufort Sea, 1990-2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set provides measurement of sea ice draft (m) and the movement of sea ice (cm/s) over the continental shelf of the Eastern Beaufort Sea. The data set spans...

  9. Copepod distribution and biodiversity patterns from the surface to the deep sea along a latitudinal transect in the eastern Atlantic Ocean (24°N to 21°S)

    Science.gov (United States)

    Bode, Maya; Hagen, Wilhelm; Cornils, Astrid; Kaiser, Patricia; Auel, Holger

    2018-02-01

    Vertical distribution, community structure and diversity of calanoid copepods were studied at six stations along a latitudinal transect from 24°N to 21°S in the eastern Atlantic Ocean, resolving nine discrete depth layers to 2000 m. Total copepod abundances integrated from 0 to 2000 m ranged from 148,000 to 197,000 ind m-2. Usually, abundance and biomass were highest in the upper 100 m, exponentially decreasing with increasing depth. Only at the northern- and southernmost stations, a deeper biomass maximum was observed at 100-200 m and 200-400 m, respectively. In total, 26 families, 79 genera and at least 172 species were identified among calanoid copepods. Although there were certain regional differences in species composition between tropical and subtropical stations from north to south, depth had the strongest impact on the community structure of calanoids, resulting in statistically distinct communities in different depth zones. Maximum diversity of calanoids was observed between 100-200 m in the tropical zone and between 400-700 m in subtropical regions. Various interacting mechanisms such as vast spatial extent of the ecosystem, physical stability, avoidance from predators under dim light, small population sizes and high biologically generated heterogeneity possibly contribute to the biodiversity maxima in the twilight zone.

  10. Crust Structure Data of Seas Surrounding Turkey

    International Nuclear Information System (INIS)

    Maden, N.; Gelisli, K.

    2007-01-01

    Black Sea, Aegean, Mediterranean and Marmara Sea, which surround the Turkey, have not been examined with respect to the Geological, Geophysical and other natural sciences sufficiently. In fact, it is not attach importance the Turkish seas adequately and abandoned with respect to the scientific researches. The most important reason of this situation is the lack of the education of the Marine Sciences in the Turkish Universities. In this study, it is tried to construct a crustal structure data base of the surrounding seas of the Turkey by collecting crustal structure data sets done by different authors in different times so far. The data acquired in the base are collected from different data base sources by dragging. The Moho depth in the eastern and western basin of the Black sea is 22 km and 19 km, respectively. In the Marmara Sea the Moho depth is 24 km. The moho value in the southern Aegean is 20 km, in the northern Aegean the moho depth is 30 km. on the other hand, the moho depth value in the eastern and western basin of the Mediterranean Sea are 15-20 km and 25-30 km, respectively

  11. A cold pool south of Indo-Sri Lanka channel and its intrus on into the southeastern Arabian Sea during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, R.R.; GirishKumar, M.S.; Ravichandran, M.; Gopalakrishna, V.V.; Pankajakshan, T.

    northwestward by the Maldives Island Chain. The resultant near-surface circulation also appears to strengthen the amplitude of the near-surface thermal inversions observed in the SouthEastern Arabian Sea (SEAS)...

  12. Effect of Ocean Interannual Variability on Acoustic Propagation in the Philippine Sea and South China Sea

    Science.gov (United States)

    2017-06-01

    depth in order to analyze the Deep Water (Figure 12). The maximum values are found in the Philippine Sea, eastern part of the Mindanao Island in May...the water column stability. The seasonal variability is modulated by interannual and decadal modes of variability. The same effects were found ...ABSTRACT (maximum 200 words ) Effect of interannual variability of temperature and salinity on acoustic propagation in the Philippine Sea and South

  13. Indo-Pacific sea level variability during recent decades

    Science.gov (United States)

    Yamanaka, G.; Tsujino, H.; Nakano, H.; Urakawa, S. L.; Sakamoto, K.

    2016-12-01

    Decadal variability of sea level in the Indo-Pacific region is investigated using a historical OGCM simulation. The OGCM driven by the atmospheric forcing removing long-term trends clearly exhibits decadal sea level variability in the Pacific Ocean, which is associated with eastern tropical Pacific thermal anomalies. During the period of 1977-1987, the sea level anomalies are positive in the eastern equatorial Pacific and show deviations from a north-south symmetric distribution, with strongly negative anomalies in the western tropical South Pacific. During the period of 1996-2006, in contrast, the sea level anomalies are negative in the eastern equatorial Pacific and show a nearly north-south symmetric pattern, with positive anomalies in both hemispheres. Concurrently, sea level anomalies in the south-eastern Indian Ocean vary with those in the western tropical Pacific. These sea level variations are closely related to large-scale wind fields. Indo-Pacific sea level distributions are basically determined by wind anomalies over the equatorial region as well as wind stress curl anomalies over the off-equatorial region.

  14. New Mediterranean Marine biodiversity records (December, 2013

    Directory of Open Access Journals (Sweden)

    M. BILECENOGLU

    2013-10-01

    Full Text Available Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters; the nemertean Amphiporus allucens (Iberian Peninsula, Spain; the salp Salpa maxima (Syria; the opistobranchs Felimida britoi and Berghia coerulescens (Aegean Sea, Greece; the dusky shark Carcharhinus obscurus (central-west Mediterranean and Ionian Sea, Italy; Randall’s threadfin bream Nemipterus randalli, the broadbanded cardinalfish Apogon fasciatus and the goby Gobius kolombatovici (Aegean Sea, Turkey; the reticulated leatherjack Stephanolepis diaspros and the halacarid Agaue chevreuxi (Sea of Marmara, Turkey; the slimy liagora Ganonema farinosum, the yellowstripe barracuda Sphyraena chrysotaenia, the rayed pearl oyster Pinctada imbricata radiata and the Persian conch Conomurex persicus (south-eastern Crete, Greece; the blenny Microlipophrys dalmatinus and the bastard grunt Pomadasys incisus (Ionian Sea, Italy; the brown shrimp Farfantepenaeus aztecus (north-eastern Levant, Turkey; the blue-crab Callinectes sapidus (Corfu, Ionian Sea, Greece. In addition, the findings of the following rare species improve currently available biogeographical knowledge: the oceanic pufferfish Lagocephalus lagocephalus (Malta; the yellow sea chub Kyphosus incisor (Almuñécar coast of Spain; the basking shark Cetorhinus maximus and the shortfin mako Isurus oxyrinchus (north-eastern Levant, Turkey.

  15. Paleogene magnetic isochrons and palaeo-propagators in the Arabian and Eastern Somali basins, NW Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A.K.; Dyment, J.; Bhattacharya, G.C.; Royer, J.-Y.; Srinivas, K.; Yatheesh, V.

    A revised magnetic isochron map of the conjugate Arabian and Eastern Somali basins based on an up-to-date compilation of Indian, French, and other available sea-surface magnetic data are presented. The magnetic anomaly and the modulus...

  16. AFSC/RACE/EcoFOCI - Fish diet analyses performed in support of FOCI assessment surveys and ecosystem observations in the Bering Sea and the Gulf of Alaska. 1990's - 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set focuses on the diets of young of the year Gadus chalcogrammus from the Eastern Gulf of Alaska and the South Eastern Bering Sea. Diet data is available...

  17. Sea Legs

    Science.gov (United States)

    Macdonald, Kenneth C.

    Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

  18. Changes in Sea Salt Emissions Enhance ENSO Variability

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Russell, Lynn M.; Lou, Sijia; Lamjiri, Maryam A.; Liu, Ying; Singh, Balwinder; Ghan, Steven J.

    2016-11-15

    Two 150-year pre-industrial simulations with and without interactive sea salt emissions from the Community Earth System Model (CESM) are performed to quantify the interactions between sea salt emissions and El Niño–Southern Oscillation (ENSO). Variations in sea salt emissions over the tropical Pacific Ocean are affected by changing wind speed associated with ENSO variability. ENSO-induced interannual variations in sea salt emissions result in decreasing (increasing) aerosol optical depth (AOD) by 0.03 over the equatorial central-eastern (western) Pacific Ocean during El Niño events compared to those during La Niña events. These changes in AOD further increase (decrease) radiative fluxes into the atmosphere by +0.2 W m-2 (-0.4 W m-2) over the tropical eastern (western) Pacific. Thereby, sea surface temperature increases (decreases) by 0.2–0.4 K over the tropical eastern (western) Pacific Ocean during El Niño compared to La Niña events and enhances ENSO variability by 10%. The increase in ENSO amplitude is a result of systematic heating (cooling) during the warm (cold) phase, of ENSO in the eastern Pacific. Interannual variations in sea salt emissions then produce the anomalous ascent (subsidence) over the equatorial eastern (western) Pacific between El Niño and La Niña events, which is a result of heating anomalies. Due to variations in sea salt emissions, the convective precipitation is enhanced by 0.6–1.2 mm day-1 over the tropical central-eastern Pacific Ocean and weakened by 0.9–1.5 mm day-1 over the Maritime Continent during El Niño compared to La Niña events, enhancing the precipitation variability over the tropical Pacific.

  19. Relação entre a precipitação no setor leste do nordeste do Brasil e a temperatura da superfície nos oceanos Atlântico e Pacífico Relationship between the rainfall in eastern Northeast Brazil and the sea surface temperature in the Atlantic and Pacific oceans

    Directory of Open Access Journals (Sweden)

    Geber Barbosa de A. Moura

    2000-01-01

    Full Text Available Objetivou-se, com este estudo, relacionar a precipitação no setor leste do Nordeste do Brasil (NEB com a Temperatura da Superfície do Mar (TSM nos oceanos Atlântico (área do Dipolo e Pacífico, no período de 1945 a 1985. Através dessa análise pode-se ter uma idéia de como os episódios com anomalias de TSM influenciam na pluviometria da costa leste do NEB (que se estende do Rio Grande do Norte à Bahia. Os resultados mais significativos foram os seguintes: em anos com gradiente de temperatura negativo no Atlântico, aqui também chamado gradiente desfavorável, as chuvas ocorreram abaixo da média de longo período nos estados do Rio Grande do Norte (84% e Paraíba (74%; em anos com gradiente de temperatura neutro, as chuvas foram normais ou acima do normal na Paraíba (73%; em anos com gradiente de temperatura positivo no Atlântico, aqui também chamado gradiente favorável, as chuvas ocorreram na média e acima da média de longo período, nos Estados de Alagoas (73%, Sergipe (73% e Bahia (73%.The main purpose of this study was to relate the rainfall in eastern Northeast Brazil (NEB with the sea surface temperature (SST in the Atlantic (Dipole area and Pacific oceans during the 1945-1985 period. This analysis shows how anomalous SST events influence precipitation in the eastern part of NEB, from the states of Rio Grande do Norte through to Bahia. The main significant results were: in years with a negative temperature gradient in the Atlantic, the rainfall was below the long term mean in Rio Grande do Norte (84% and Paraíba (74%; in years with neutral gradient, the rainfall was normal or above normal in Paraíba (73%; in years with positive temperature gradient (south minus north, hereby called favorable gradient, the rainfall was above the long term mean, in Alagoas (73%, Sergipe (73% and Bahia (73%.

  20. Biotechnological studies in the Far-Eastern Region of Russia.

    Science.gov (United States)

    Stonik, Valentin A; Mikhailov, Valery V; Bulgakov, Victor P; Zhuravlev, Yuri N

    2007-07-01

    Achievements and problems in both the studies on natural bioactive compounds from the Far-Eastern higher plants and marine invertebrates and development of the corresponding biotechnologies concerning new drugs and food supplements, as well as pharmaceutical leads are discussed. Special emphasis is made on recent results from the Far-eastern Institutions belonging to the Russian Academy of Sciences, and their application in both medicine and the food industry, as well as on peculiarities of biological and chemical diversity in the North-Western part of Asia and adjoining seas.