The Experts below are selected from a list of 16236 Experts worldwide ranked by ideXlab platform

Okan Akyol - One of the best experts on this subject based on the ideXlab platform.

Halit Filiz - One of the best experts on this subject based on the ideXlab platform.

Athanasios Koukouras - One of the best experts on this subject based on the ideXlab platform.

  • the echinoderm deuterostomia fauna of the Aegean Sea and comparison with those of the neighbouring Seas
    Journal of Biological Research, 2007
    Co-Authors: Athanasios Koukouras, A Sinis, Savas Kazantzidis, Dimitra Bobori, Miltiadisspyridon Kitsos
    Abstract:

    Earlier and recent sampling carried out in the Aegean Sea revealed the presence of 20 asteroid, 14 ophiuroid, 21 echinoid, and 1 holothuroid species. The ophiuroid Monaphiura apicula, and the echinoids Arbaciella elegans, Echinus melo and Hemiaster expergitus are recorded for the first time in the Eastern Mediterranean; the latter has previously been known only from the Western Mediterranean. The ophiuroid Amphiura (Acrocnida) brachiata is recorded for the first time in the Aegean Sea. For all species, information on their distribution and habitat is given. A checklist of the Mediterranean and Black Sea echinoderms, as well as their distribution in the Mediterranean territorial areas and the Black Sea are also presented. Furthermore, the faunas of the Mediterranean territorial areas are compared. According to the considered data, the number of species decreases as follows: Western Mediterranean, Aegean Sea, Adriatic Sea, Central Mediterranean, Levantine Sea and Black Sea. Species with an Atlanto-Mediterranean distribution dominate in all areas and are followed in numbers by the Mediterranean endemics and cosmopolitans. Four species of Indo-Pacific origin are located in the Levantine and SE Aegean Seas.

  • contribution to the knowledge of keratose sponges dictyoceratida dendroceratida verongida demospongiae porifera of the Aegean Sea
    Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie (Berlin), 1993
    Co-Authors: Eleni Voultsiadoukoukoura, Athanasios Koukouras
    Abstract:

    Samplings carried out in the North Aegean Sea revealed the presence of 24 Keratose sponge species belonging to the orders Dictyoceratida, Dendroceratida and Verongida. Eight of these species are new records for the Eastern Mediterranean, 1 for the Aegean Sea and 5 for the North Aegean Sea. For the 24 species found, geographical distribution, as well as ecological and other information is given. A check list of the Keratose species found up to the present in the Eastern Mediterranean is presented and discussed. Finally, the Keratose fauna of the Aegean is compared to that of other Mediterranean areas on the basis of their common species.

  • contribution to the knowledge of keratose sponges dictyoceratida dendroceratida verongida demospongiae porifera of the Aegean Sea
    Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie (Berlin), 1993
    Co-Authors: Eleni Voultsiadoukoukoura, Athanasios Koukouras
    Abstract:

    Samplings carried out in the North Aegean Sea revealed the presence of 24 Keratose sponge species belonging to the orders Dictyoceratida, Dendroceratida and Verongida. Eight of these species are new records for the Eastern Mediterranean, 1 for the Aegean Sea and 5 for the North Aegean Sea. For the 24 species found, geographical distribution, as well as ecological and other information is given. A check list of the Keratose species found up to the present in the Eastern Mediterranean is presented and discussed. Finally, the Keratose fauna of the Aegean is compared to that of other Mediterranean areas on the basis of their common species.

Maria Triantaphyllou - One of the best experts on this subject based on the ideXlab platform.

  • live and dead benthic foraminiferal assemblages from coastal environments of the Aegean Sea greece distribution and diversity
    Revue de Micropaléontologie, 2016
    Co-Authors: Margarita D Dimiza, Olga Koukousioura, Maria Triantaphyllou, Michael Dermitzakis
    Abstract:

    Abstract Benthic foraminiferal composition assemblages and their temporal changes, ecological indices and foraminiferal densities are used to compare three coastal environments with different physicogeographical features in the Aegean Sea (coastal environment of Avdira–Vistonikos Gulf and Kitros–Thermaikos Gulf and open lagoonal environment of Vravron–South Evoikos Gulf). Three main foraminiferal assemblages have been recognized: a) “Assemblage A”; high degree of similarity between living and dead foraminiferal species, dominated by Ammonia beccarii, Elphidium spp. and relatively abundant and diverse miliolids, b) “Assemblage B1”; intermediate degree of similarity between live and dead assemblages, characterized by highly-abundant and well-diversified foraminiferal assemblages including the algal symbiont bearing Peneroplis pertusus together with Ammonia tepida and several small epiphytic rotaliids and miliolids, and c) “Assemblage B2”; absence of living individuals, strongly dominated by the opportunistic species A. tepida. Our results suggest a good comparison between living and dead assemblages from different coastal environments in the Aegean Sea, however the prevailing environmental conditions (vegetation cover, hydrodynamics, fresh water influx) have a strong impact on the taphonomic processes.

  • alien foraminifers from greek coastal areas Aegean Sea eastern mediterranean
    Mediterranean Marine Science, 2010
    Co-Authors: Olga Koukousioura, Margarita D Dimiza, Maria Triantaphyllou
    Abstract:

    The present study provides additional data on the distributional range of six alien foraminiferal species in living assemblages from Greek coastal areas (Aegean Sea, Eastern Mediterranean). Amphistegina lobifera LARSEN 1976, Sorites orbiculus (FORSK L 1775) and Coscinospira hemprichii EHRENBERG 1839 are well established in Greek coastal areas, whereas Triloculina fichteliana D'ORBIGNY 1839, Planogypsina acervalis (BRADY 1884) and Cymbaloporetta plana (CUSHMAN 1924), are recorded for the first time in this paper. The occurrence of these species in a number of sites in the Aegean Sea establishes their presence in the Eastern Mediterranean.

  • Seasonal variation in emiliania huxleyi coccolith morphology and calcification in the Aegean Sea eastern mediterranean
    Geobios, 2010
    Co-Authors: Maria Triantaphyllou, Margarita D Dimiza, Eva Krasakopoulou, Elisa Malinverno, Valia Lianou, Ekaterini Souvermezoglou
    Abstract:

    Abstract A Seasonal morphological variability is observed in Emiliania huxleyi var. huxleyi specimens, collected from discrete water samples in the Aegean Sea. Biometric analyses reveal a consistent pattern of increase in the size of coccoliths and coccospheres, including the thickness of the inner tube elements (INT), in winter/spring time low Sea surface temperature and moderate productivity samples when compared with summer time high temperature–low productivity samples. The small range of salinity change in the Aegean Sea and the absence of Seasonal pattern in nutrient content do not support any association with the observed increase in E. huxleyi coccolith size. A relatively increased [HCO 3 - ] content is observed during spring-time interval related with the increase in the coccolith size, however it remains unclear which parameter of the carbonate system causes the observed effects.

  • late glacial holocene climate variability at the south eastern margin of the Aegean Sea
    Marine Geology, 2009
    Co-Authors: Maria Triantaphyllou, Katerina Kouli, Patrizia Ziveri, Alexandra Gogou, Gianluca Marino, Vasilios Lykousis, Ioanna Bouloubassi, Kaychristian Emeis, M Dimiza, Antoni Rosellmele
    Abstract:

    Abstract New micropaleontological, palynological, and geochemical results from a relatively shallow (∼ 500 m) sediment core (NS-14) in the south-eastern Aegean Sea provide a detailed picture of the regional expression of sapropel S1 formation in this sub-basin of the eastern Mediterranean Sea. Specifically, freshwater input during ∼ 10.6–10.0 ka BP has preceded the deposition of S1. Further decrease in surface water salinity is evidenced between 10.0 and 8.5 ka BP at the lower part of S1a, which in respect to S1b, is featured by warmer (∼ 19.5 °C) and more productive surface waters associated with dysoxic bottom conditions. A series of coolings detected within the S1 depositional interval, may be linked to outbursts of cold northerly air masses and relevant pulses in the deep-intermediate water ventilation that caused the S1 interruption between 7.9 and 7.3 ka BP and culminated during the deposition of S1b, with the decline of deep chlorophyll maximum (DCM) at ∼ 6.5 ka BP. The climate instability and the relevant absence of anoxia weakened the organic matter preservation in the shallow south-eastern Aegean margin during the S1 times. NS-14 record provides evidence for a distinct mid Holocene warm (up to ∼ 25 °C) and wet phase associated with the deposition of the sapropel-like layer SMH (Sapropel Mid Holocene), between 5.4 and 4.3 ka BP. The SMH layer could represent evidence of on-going, albeit weak, African monsoon forcing, only expressed at the south-eastern edge of the Aegean Sea. Its end is associated with the 4.2 ka BP Northern Hemisphere mega-drought event and the termination of the African Humid Period at 3.8 ka BP.

  • late glacial holocene ecostratigraphy of the south eastern Aegean Sea based on plankton and pollen assemblages
    Geo-marine Letters, 2009
    Co-Authors: Maria Triantaphyllou, Margarita D Dimiza, Assimina Antonarakou, Katerina Kouli, George Kontakiotis, M Papanikolaou, Patrizia Ziveri, P G Mortyn, V Lianou
    Abstract:

    Quantitative analyses of coccolithophores, planktonic foraminifers, dinoflagellate cysts and pollen assemblages were carried out on shallow (NS-14) and deeper (NS-40) sediment cores from the south-eastern Aegean Sea. Nine coccolithophore (ACE 1–9) and nine planktonic foraminifer (APFE 1–9) ecozones, correlated with dinoflagellate cyst evidence, have been defined for the last ~14.5 cal. ka. Additionally, eight pollen assemblage zones (PAZ 1–8) have been recognised and correlated with the plankton ecozones. Although generally consistent with existing schemes for the central and eastern Mediterranean, the established high-resolution ecostratigraphy has led to an expanded palaeoecological reconstruction of the Late Glacial–Holocene archive in the south-eastern Aegean Sea, defining two warm and humid phases at 9.3–8.6 and 7.6–6.4 cal. ka b.p., associated with the deposition of the early Holocene sapropel S1, and a third one between 5.2 and 4.2 cal. ka b.p. The high sedimentation rates which characterise the study area enabled the detection of even minor and brief climatic events in the Aegean Sea during S1 deposition times.

Vengatesan Venugopal - One of the best experts on this subject based on the ideXlab platform.

  • a 35 year high resolution wave atlas for nearshore energy production and economics at the Aegean Sea
    Renewable Energy, 2017
    Co-Authors: George Lavidas, Vengatesan Venugopal
    Abstract:

    The study enhances the coastal resource knowledge and discusses opportunities for wave energy in the Aegean Sea. A fine-resolution numerical wave model is utilised to provide results for the Greek coastal regions. The model ran for 35 years (1980–2014) estimating wave characteristics, and quantifying the wave energy potential in coastal areas. The results deliver the energy potential, variability, and site characterisation for the Aegean Sea.

  • a 35 year high resolution wave atlas for nearshore energy production and economics at the Aegean Sea
    Renewable Energy, 2017
    Co-Authors: George Lavidas, Vengatesan Venugopal
    Abstract:

    Abstract The study enhances the coastal resource knowledge and discusses opportunities for wave energy in the Aegean Sea. A fine-resolution numerical wave model is utilised to provide results for the Greek coastal regions. The model ran for 35 years (1980–2014) estimating wave characteristics, and quantifying the wave energy potential in coastal areas. The results deliver the energy potential, variability, and site characterisation for the Aegean Sea. The dataset is coupled with wave energy converters power matrices to provide for the first time a long-term analysis of expected power production. Performance of devices is highly dependent on matching the power matrix to the local resource, suitable devices can obtain capacity factor up to 20% and favour operation for low wave heights and high frequencies. Based on energy analysis data, an economic performance and payback period of a hypothetical wave farm is examined. With little information on wave energy in the region, this preliminary cost-to-benefit analysis shows the viability of wave converters. Even with high capital expenditure associated with novel technologies, certain scenarios achieve amortization periods at 7.5 years for a properly selected converter. Results are comparable with previous renewable schemes aimed at increasing the cumulative installation of other early stage technologies.