20 research outputs found

    Large-scale testing of phytoplankton diversity indices for environmental assessment in Mediterranean sub-regions (Adriatic, Ionian and Aegean Seas)

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    Abstract According to the methodological standards established by Marine Strategy Framework Directive, the assessment for the pelagic habitat under the Biodiversity Descriptor should be carried out at the regional or sub-regional level. In the case of Mediterranean Sea, the sub-regional assessment seems optimal to take into account biogeographic differences in species composition and functional characteristics. Previous research has shown that phytoplankton diversity indicators are efficient for reliable environmental assessments, although more effort has been recommended to test these indicators on a wide spatial scale to cover wider gradients of natural and anthropogenic pressures. In this work, a set of eight diversity indices was tested against the pressure levels within a common data set of the structure and abundance of phytoplankton communities from the Adriatic, Ionian and Aegean Seas. Expert knowledge was used to define four categories of impacts that take into account partial pressures, such as point and non-point pollution, industry, ports and fisheries. At the level of the common data set, most of the diversity, evenness and dominance indices could only distinguish between the highest level of impact and the rest of impact categories. These indices maintained the distinction between two levels of subsequently dichotomised impacts (no to low impact vs. high impact) across latitudinal and longitudinal gradients. On average, the indices were less sensitive to impacts in the northernmost and westernmost areas than in the southernmost and easternmost areas, although they still showed a significant response. The results also suggest that phytoplankton communities become more uniform and less dominated by a single taxon as sampling depth increases at sites with low impact, while evenness and dominance at impacted sites remain similar at all depths. In order to establish meaningful definitions of good environmental status and targets for pelagic habitats in the Mediterranean Sea, it is necessary to establish spatially specific thresholds by additional examination of indices of good performance

    Probiotics Supplementation during Pregnancy: Can They Exert Potential Beneficial Effects against Adverse Pregnancy Outcomes beyond Gestational Diabetes Mellitus?

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    Background: Probiotics, as supplements or food ingredients, are considered to exert promising healthy effects when administered in adequate quantity. Probiotics’ healthy effects are related with the prevention of many diseases, as well as decreasing symptom severity. Currently, the most available data concerning their potential health effects are associated with metabolic disorders, including gestational diabetes mellitus. There is also clinical evidence supporting that they may exert beneficial effects against diverse adverse pregnancy outcomes. The purpose of the current narrative study is to extensively review and analyze the current existing clinical studies concerning the probable positive impacts of probiotics supplementation during pregnancy as a protective agent against adverse pregnancy outcomes beyond gestational diabetes mellitus. Methods: a comprehensive and thorough literature search was conducted in the most precise scientific databases, such as PubMed, Scopus, and Web of Sciences, utilizing efficient, representative, and appropriate keywords. Results: in the last few years, recent research has been conducted concerning the potential beneficial effects against several adverse pregnancy outcomes such as lipid metabolism dysregulation, gestational hypertensive disorders, preterm birth, excessive gestational weight gain, caesarean risk section, vaginal microbiota impairment, mental health disturbances, and others. Conclusion: up to the present day, there is only preliminary clinical data and not conclusive results for probiotics’ healthy effects during pregnancy, and it remains questionable whether they could be used as supplementary treatment against adverse pregnancy outcomes beyond gestational diabetes mellitus

    Circulation and nutrient modeling of Thermaikos Gulf, Greece

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    Summarization: Thermaikos Gulf is considered to be one of the most polluted coastal zones in Greece. It is the final receptor of both municipal and industrial wastewaters from the city of Thessaloniki and of two heavily polluted rivers, Axios and Aliakmon. Nutrient enrichment and consequent eutrophication is the primary water quality issue of Thermaikos. The mathematical model WASP 6.0 was used to simulate the hydrodynamics, nutrient dynamics and phytoplakton evolution in the gulf. The model is a physical-based model that compartmentalizes the water body into high dispersivity, uniform concentration compartments. It then performs mass balances on water quantity and quality. In addition to the hydrodynamics, the model can simulate the carbon, oxygen, nitrogen, phosphorous and plankton concentrations in the water body. Monthly hydrologic and water quality fluxes from 1997 to 1998, inputs to the gulf and seasonal nutrient surveys in the gulf were used to calibrate nutrient dynamics. The gulf was compartmentalized into 12 compartments, six were horizontal and two were vertical. Salinity data were used to calibrate the hydrodynamic variables of the model. Model calibration was conducted by minimizing the root mean square error between field observations and model simulation. The model was able to capture the variation of salinity and nutrient concentrations. The results showed the importance of Thessaloniki effluents to the Thessaloniki Bay and Gulf and the Axios and Aliakmon River loads to the degree of eutrophication of the entire gulf. The model can be used to assess management scenarios to improve the water quality of the gulf.Presented on: Journal of Marine System

    One Step forward: Benthic Pelagic Coupling and Indicators for Environmental Status

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    <div><p>A large data set from the Eastern Mediterranean was analyzed to explore the relationship between seawater column variables and benthic community status. Our results showed a strong quantitative link between the seawater column variables (Chlorophyll <i>a</i> and Eutrophication Index) and various indicators describing benthic diversity and community composition. The percentage of benthic opportunistic species increased significantly in the stations with high trophic status of the seawater column and so did the strength of the coupling between values of seawater column and benthic indicators. The Eutrophication Index threshold level of 0.85, separating the “Bad and Poor” from “Moderate to High” conditions could serve as an acceptable critical value above which there is a readily observable change in benthic community composition.</p></div
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