35 research outputs found

    Recovery of the commercial sponges in the central and southeastern Aegean Sea (NE Mediterranean) after an outbreak of sponge disease

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    The distribution and biometry of commercial sponges (Porifera) in coastal areas of the central and southeastern Aegean Sea was investigated to estimate the recovery progress of the populations eight years after the first appearance of sponge disease. Signs of the disease were detected only in 1.6% of the harvested sponges. Multivariate analysis on the percentage abundance of sponges showed two distinct groups among the sixteen fishing grounds studied: the eight deep (50-110 m) and the eight shallow ones (<40 m). The group from the deep depths consisted of Spongia officinalis adriatica, S. agaricina and S. zimocca. The infralittoral zone was characterized by the presence of Hippospongia communis, S. officinalis adriatica and S. officinalis mollissima. These bath sponges showed an enhanced abundance in the eastern Cretan Sea (S. Aegean Sea). In addition, their dimensions, particularly height, increased with increasing depth. It is indicated that the hydrographic conditions prevailing in the eastern Cretan Sea affected the repopulating processes of sponge banks. In each species, the biometric characteristics of the experimental specimens were similar to those of the sponges found in the market and harvested at respective depths prior to the appearance of sponge disease

    Mortality and Effect on Growth of Artemia franciscana Exposed to Two Common Organic Pollutants

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    Acute toxicity and inhibition on growth of Artemia franciscana nauplii (Instar I-II) after exposure to the reference toxicants bisphenol a (BPA) and sodium dodecyl sulfate (SDS) were studied. LC50 values were calculated and differences in body growth were recorded after 24, 48, and 72 h of exposure to the toxicants. The results indicated that BPA had lower toxicity than SDS. Development of the nauplii was clearly influenced by duration of exposure. Growth inhibition was detected for both toxicants. Abnormal growth of the central eye of several Artemia nauplii after 72 h of exposure to BPA was also detected. Our results indicate that growth inhibition could be used as a valid endpoint for toxicity studies

    Neue linguistische Methoden und arbeitstechnische Verfahren in der Erschliessung der ägyptischen Grammatik

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    15 páginas, 1 tabla, 6 figuras.Does diversity beget diversity? Diversity includes a diversity of concepts because it is linked to variability in and of life and can be applied to multiple levels. The connections between multiple levels of diversity are poorly understood. Here, we investigated the relationships between genetic, bacterial, and chemical diversity of the endangered Atlanto-Mediterranean sponge Spongia lamella. These levels of diversity are intrinsically related to sponge evolution and could have strong conservation implications. We used microsatellite markers, denaturing gel gradient electrophoresis and quantitative polymerase chain reaction, and high performance liquid chromatography to quantify genetic, bacterial, and chemical diversity of nine sponge populations. We then used correlations to test whether these diversity levels covaried. We found that sponge populations differed significantly in genetic, bacterial, and chemical diversity. We also found a strong geographic pattern of increasing genetic, bacterial, and chemical dissimilarity with increasing geographic distance between populations. However, we failed to detect significant correlations between the three levels of diversity investigated in our study. Our results suggest that diversity fails to beget diversity within a single species and indicates that a diversity of factors regulates a diversity of diversities, which highlights the complex nature of the mechanisms behind diversityResearch funded by grants from the Agence Nationale de la Recherche (ECIMAR), from the Spanish Ministry of Science and Technology SOLID (CTM2010-17755) and Benthomics (CTM2010-22218-C02-01) and the BIOCAPITAL project (MRTN-CT-2004-512301) of the European Union. This is a contribution of the Consolidated Research Group ‘‘Grupo de Ecologı´a Bento´nica,’’ SGR2009-655.Peer reviewe

    Patterns of Chemical Diversity in the Mediterranean Sponge Spongia lamella

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    The intra-specific diversity in secondary metabolites can provide crucial information for understanding species ecology and evolution but has received limited attention in marine chemical ecology. The complex nature of diversity is partially responsible for the lack of studies, which often target a narrow number of major compounds. Here, we investigated the intra-specific chemical diversity of the Mediterranean sponge Spongia lamella. The chemical profiles of seven populations spreading over 1200 km in the Western Mediterranean were obtained by a straightforward SPE-HPLC-DAD-ELSD process whereas the identity of compounds was assessed by comparison between HPLC-MS spectra and literature data. Chemical diversity calculated by richness and Shannon indexes differed significantly between sponge populations but not at a larger regional scale. We used factor analysis, analysis of variance, and regression analysis to examine the chemical variability of this sponge at local and regional scales, to establish general patterns of variation in chemical diversity. The abundance of some metabolites varied significantly between sponge populations. Despite these significant differences between populations, we found a clear pattern of increasing chemical dissimilarity with increasing geographic distance. Additional large spatial scale studies on the chemical diversity of marine organisms will validate the universality or exclusivity of this pattern

    The common agricultural policy's effects on the agricultural sector in Greece and its environmental impacts

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    The Common Agricultural Policy (CAP) has been many times quoted as one of the most important drivers for the agricultural sector in the European countries and its adverse effects on the environment. Various approaches have been used to investigate the actual links between the two. In this research effort the use of datamining techniques have been used in order to determine what are the links, if any, between the funding provided by the CAP to Greece during the 2nd Programming Period (1994-1999) and the changes in the agricultural sector during that period and in particular the environmental effects of the programs. The results indicate that the three larger financial programs were having some impact to agricultural production. These programs were the Less Favored Areas program, the Farming Investment Plans program and the New Farmers' program. All this programs were funded in Greece by Measure 1.1 of the 2nd Community Support Framework (CSF) for Greece. The main field of environmental investment for the Farming Investment Plans was drop irrigation but this amounted only to 2% of the total investment plans for the whole of the country. On the other hand, no direct linkage with the agricultural production of the three Accompanying Measures of the EU CAP was observed. These Measures were the Organic production program, the Rare Animal Breeds Preservation program and the Reduction of Nitrates Pollution program. Although these programs are more directed towards environmental protection, their limited impact is hardly surprising since these three programs have a narrow scope with regard to areas affected as well as funds provided. The results confirm that the link between the CAP and the agricultural sector size exists but the actual impact of the environmental reform of the CAP during the 90s had hardly any effect in Greece since it was largely underfunded. © 2012 by Nova Science Publishers, Inc. All rights reserved

    A simple bioassay with Artemia larvae to determine the acute toxicity of antifouling paints

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    The toxic effects on mollusc cultures, of chemicals leaching from coatings on ship hulls of pleasure craft, has triggered substantial research on the hazard of antifouling paints for non-target biota. Conventional laboratory bioassays are mostly carried out on individual (pure) toxicants incorporated in such paints and thus do not simulate the leaching of the toxic-compounds from the antifouling coatings. In order to simulate such conditions, an attempt has been made to determine the toxicity of coated test panels, to nauplii of the brine shrimp Artemia as test-species. The &quot;surface-to-volume ratio&quot; (S/V = coated surface of test panel to volume of seawater in the test-vessel) has been used as a criterion for determination of the S/V-LC50, which may be a useful approach for toxicity ranking of antifouling paints. This preliminary study explains the principles for a rapid and cost-effective bioassay for direct determination of the toxicity of surfaces coated with potentially hazardous compounds. © 1989

    Acute toxicity effects of tributyltin chloride and triphenyltin chloride on gilthead seabream, Sparus aurata L., embryos

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    Acute toxicity studies, using two organotin compounds, tributyltin chloride (TBTCl) and triphenyltin chloride (TPhTCl), were performed on gilthead seabream, Sparus aurata, fertilized eggs. The tests were static and run for 24h (temperature = 19±1°C, salinity = 39.5g/L). Three replicate egg groups were incubated in solutions containing different concentrations of the toxicants. The (24h)LC50 value for TBTCl was 28.3μg/L and for TPhTCl was 34.2μg/L, when the embryos were at the morula and late blastula stage at the start of the experiment. The value for TBTCl was 38.6μg/L, when the embryos were at the gastrula stage at the start of the experiment. The results reconfirm the expected toxicity of TBT to this euryhaline fish species and introduce TPhT as a toxicant of potentially similar impact on teleosts. © 2002 Elsevier Science (USA). All rights reserved

    Depiction of the role of women on the Island of Evia (Greece): A significant fishing area

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    The role of women (and specifically those involved in the fisheries) on the island of Evia (Central Greece), the second biggest island in the country, was depicted through an extended survey. Evia is a significant fishing area, in terms of fishing fleets and number of fish farms. The field research was based on semi-structured interviews and on the usage of proper questionnaires. These were addressed to professional fishermen, owners of fish farms and conversion plants, women occupied in fish farms, local associations and local cooperatives. The data collected refers to the economic situation of the family, the structure of the family, the social status and the educational level. Care was taken that the interviewed were covering a minimum of 5% in each category. Data was also used from the last National (Greek) census. The women on the island of Evia play a secondary role, in relation to males, in all fields of activity. The majority of fishermen's wives is not employed, but belongs to the category of assisting spouses. They have a lower educational level than their husbands, and their participation in public affairs is very limited. The women who are working do so, mainly in the primary sector (most commonly in the fisheries), and secondarily in the tertiary sector, usually in tourism or in the service field (in the urban areas). In fish farming, women are working independently from their husband's involvement in the field. Most of the women (59%) are workers, 27% are clerks in the offices and 14% are technological or scientific staff. In the cooperatives, the role of women is also secondary: they do not participate in the administration, being mainly involved in the production and marketing of the products. © 2012 by Nova Science Publishers, Inc. All rights reserved

    Taxonomy of some sponges (Porifera: Demospongiae) collected from the Aegean Sea and description of a new species

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    A systematic survey of the sponge fauna of the Aegean Sea has been carried out. Twenty-eight stations located in the Aegean Sea were explored and 59 species of Demospongiae were collected from this particular area, which covers a broader geographical area of the Aegean and Cretan Seas. Some of the species found are poorly known for the Mediterranean fauna, like Cerbaris curvispiculifera and Spongosorites flavens, which are reported for the first time in the Aegean Sea and generally in the eastern Mediterranean. The species Axinyssa michaelis sp. nov. (Halichondriidae: Halichondrida) is new to science. In this paper, a description of the new species is presented along with the description of the first recorded species in the Aegean Sea. In addition to the taxonomic description of the species, some ecological data and a distribution pattern are also presented
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