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Ifigenia Kagalou Georgios Economidis Ioannis Leonardos Constantinos Papaloukas 《Limnologica》2006,36(4):269-278
Macroinvertebrates play a key role in freshwater lentic and lotic ecosystems. The macroinvertebrate benthic community of a shallow Mediterranean lake (Lake Pamvotis, NW Greece) was studied. The benthic assemblage was sampled monthly at five sites during a period of 1 year (Apr. 1998–Mar. 1999). In addition hypolimnetic water quality variables were monitored over the same period at each site.
The aim of the study was (a) to describe the intra-annual and spatial variability in benthic communities, (b) to relate possible community changes to environmental conditions and (c) to evaluate the responses of the lake's ecological status on community indices.
The benthic fauna of Lake Pamvotis was found to be very limited with a total of 10 species belonging to five taxonomic groups. The oligochaete community comprised 80% of the total benthic fauna with Potamothrix bavaricus as a new record for the Lake Pamvotis and Potamothrix hammoniensis, being the dominant benthic species represented more than 61% of the total benthic fauna. Chironomus plumosus was the most abundant chironomid species contributing with about 6% of the total benthic fauna, and Chaoborus flavicans with 19% was the important dipteran. Almost all benthic species showed the same intra-annual seasonal pattern, with peak population densities during spring and early summer except P. hammoniensis which predominated during the whole sampling period. Dissolved oxygen and temperature seemed to be the main environmental factors affecting community indices.
Benthic communities are affected by human disturbances in Lake Pamvotis shifting their composition to more tolerant taxa, reflecting also the eutrophic to hypertophic character of the lake. 相似文献
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Maria Economou-Eliopoulos Ifigenia Megremi Charalampos Vasilatos 《Chemie der Erde / Geochemistry》2011,(1):39-52
The effective influence of industry or ultramafic rocks by natural processes to soil, plants and groundwater contamination by chromium, which is often a subject of debate, was investigated for the case of the Assopos basin, Greece. The Neogene Assopos basin, is mainly composed by Tertiary and Quaternary sediments of more than 400 m thick and is characterized by brittle type deformation (fault zones, faults). Chromium in soil, ranging from 67 to 204 ppm, is mostly hosted in chromite, Fe-chromite, Cr-bearing goethite and silicates.Special attention was given to the plants, which are a major source of organic matter that serves as the driving force for Cr(VI) reduction. The increase of the Fe, Mn and Ni contents, with the increasing Cr content in the plant-roots, in particular at the external parts of roots and those of bulb-type plants, suggest reduction and immobilization of Cr(VI) and that redox reactions play a significant role to the translocation processes from root to shoot.Groundwater samples from the Assopos aquifer showed a wide spatial variability, ranging from <2 to 180 ppb Crtotal content [almost same to the Cr(VI)-values] despite their spatial association. The presence of Cr(VI)-contaminated groundwater at depths >200 m is attributed to a direct injection of Cr(VI)-rich industrial wastes at depth rather than that Cr(VI) is derived from the Assopos river or by the interaction between water and Cr-bearing rocks. The heterogeneous distribution of Cr in groundwater may be related with the intense neotectonic deformation, as is exemplified by several sharp tectonic contacts between sediment types, while the Cr content in soil is mostly depend on the transported chromite grains. 相似文献
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Evanthia Lekka Ifigenia Kagalou Maria Lazaridou‐Dimitriadou Triantafilos Albanis Vasileios Dakos Dimitra Lambropoulou Vasilis Sakkas 《洁净——土壤、空气、水》2004,32(3):175-188
In the present study, the water quality of Kalamas river (NW Greece) was evaluated using physicochemical and hydromorphological parameters and benthic macroinvertebrates. Statistical analyses (Cluster and FUZZY analyses) were performed and two biotic scores (BMWP' and HS) were used in order to classify the sites according to water quality. Kalamas river appeared to have excellent tomoderate water quality at all sampling sites except one (close to the delta area) which was ”fairly or significantly polluted”. During the low flow season water quality appeared poorer than during the high flow season. The ecological parameters (hydromorphological, chemical, and biological) used for this integrated approach are the ones proposed by the New Water Directive 2000/60 EC for an efficient surveying monitoring of running waters. 相似文献
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The objective of this study is the assessment of the typology and the trophic relevant water quality parameters in two Mediterranean lakes (Lake Ziros and Lake Kastoria) under the view of the WFD. Lake types were identified based on characteristics specified in Annex II of the WFD, while trophic indexes (OECD, TSI Carlson) were used in order to assess their trophic status. A modified TSI index appropriate for warmer lakes was also applied. According to our results, Lake Kastoria is classified as eutrophic lake with a tendency to hypertrophication while Lake Ziros is a mesotrophic ecosystem with clear signals of eutrophication. Both ecosystems are considered “at risk” of not fulfilling the WFD environmental objectives due to the existence of certain anthropogenic pressures. 相似文献
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Assessment of pressures and impacts on surface water bodies of the Mediterranean. Case study: Pamvotis Lake, Greece 总被引：1，自引：1，他引：0
The aim of the study presented in this article is to assess the ecological status of a surface water body in the Mediterranean using the methodological approach of Driver-Pressure-State-Impact-Response. Based on this approach for the case study analyzed (Pamvotis Lake, Greece), it is concluded that the main drivers, which lead to pressures in the study area are: intensive agricultural activities, alteration of hydrological regime, contamination from point sources and changes in the land-use and fish stocking. The ecological status is assessed by analysing data series of physical, chemical and biological elements that are available from early ’80s. Findings suggest elevated nutrient concentrations sufficient for maintaining eutrophic conditions while their seasonal variability is mostly driven by factors as water level fluctuation, catchment runoff and in-lake biological processes. Subsequently, concerning biotic factors, the poor biodiversity mainly represented by the dominance of the most tolerant species, confirm the previous profile. Since, reference conditions have only recently been established in Greece, the ECOFRAME scheme and the guidelines proposed by the “Intercalibration Group for Mediterranean Lakes” were applied. In terms of the above elements; the water quality status could be characterized as “High”, “High to Good” and “High to Bad”, respectively, whereas the overall ecological status tends to shift in poor conditions. Finally, the major response actions needed should be in the direction of reduced application of fertilizers and chemicals in the cultivated land of the catchment, removal of the point-contamination sources from the catchment, appropriate land-use management and biomanipulation. 相似文献
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The present study was undertaken to investigate the accumulation of microcystins (MCYST) in the various tissues of an endemic and protected fish species (Rutilus panosi). We also tried to identify any differences in sensitivity and accumulation of MCYST, for various specimens of the same fish species related to body length. MCYST concentrations in lake water and fish tissues were determined by a commercial Microcystin ELISA kit. Results showed that considerable amount of toxins were found to be accumulated in tissues of R. panosi throughout the year. Among them, liver had the highest MCYST concentrations (407.97 ± 32.43 ng/g). This study confirmed the accumulation of high MCYST concentrations in fish brain (308.75 ± 26.49 ng/g). Our results suggest, that MCYST accumulation in R. panosi tissues is size depended. High MCYST concentration in the muscle of the fish increases the risk of unsafe consumption, thus threatening human health. 相似文献
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