Affiner votre recherche
Résultats 1-10 de 100
Oligochaetes community as an indicator of accelerated eutrophication process in the second oxidation lake Palic [Serbia, Yugoslavia]
1998
Djukic, N. (Poljoprivredni fakultet, Novi Sad (Yugoslavia)) | Maletin, S. | Miljanovic, B. | Tepavcevic, D. | Teodorovic, I.
During the 1981-1996 period, qualitative and quantitative structure of oligachaeta communities as indicator of the eutrophication process was investigated in the lake Palic (the 2nd oxidation lake), Serbia (Yugoslavia). The mean annual number of oligochaetes was related to nutrient concentration (total nitrogen and total phosphorus). The analysed data for both oligochaete community and nutrients, leads to the conclusion that the second oxidation lake Palic can be classified as an highly eutrophic environment, with tendency towards dystrophic, particularly in past two years.
Afficher plus [+] Moins [-]Oligochaeta community of "Kapetanski rit" fish pond [Serbia, Yugoslavia]
2001
Mrkic, B. | Dulic, S. (Zavod za zastitu zdravlja, Subotica (Yugoslavia))
During the period May - September 2000, the structure of quality and quantity of Oligochaeta community was investigated on three locations of "Kapetanski rit" fish pond (Serbia, Yugoslavia). At same time were determined some physical and chemical parameters of water temperature, pH value and concentration of dissolved oxygen. In that period of time, the location of Divlje jezero there was no presence of Oligochaeta community. The location of Novo jezero was characterized by 6 species from two families - Naididae and Tubificidae, and the location of Veliko jezero was characterized by only three species. The results from Veliko and Novo jezero show differences in proportional presence and quantity characteristics.
Afficher plus [+] Moins [-][Oligochaeta community as indicator of water quality in the Bajski canal [Serbia, Yugoslavia]]
1997
Djukic, N. | Miljanovic, B. | Maletin, S. | Ivanc, A. (Prirodno-matematicki fakultet, Novi Sad (Yugoslavia). Institut za biologiju)
During the period 1977-1996, Oligochaeta have been studied as indicator of water quality in the Bajski canal, Serbia (Yugoslavia). The locality was characterized by the 13 species from nine genera and two families - Naididae and Tubificidae. Species in genera Limnodrilus, Potamothrix and Branchiura were dominant, defining the environment as natural eutrophic.
Afficher plus [+] Moins [-]Toxicity of a chromium-enriched superfood, Spirulina platensis, assessed by taxonomic and morpho-functional diversity of marine meiofauna
2020
Essid, Naceur | Gharbi, Rifka | Harrath, Abdel Halim | Mansour, Lamjed | Mahmoudi, Ezzeddine | Beyrem, Hamouda | Ansari, Kapuli Gani Mohamed Thameemul | Boufahja, Fehmi
A laboratory bioassay was conducted to investigate the ecotoxicity of a chromium-enriched superfood, Spirulina platensis, on the meiofauna collected from the Ghar El Melh lagoon, Tunisia. After 1 month of exposure, the abundances of meiobenthic taxa and the taxonomic and morpho-functional diversity of nematodes showed significant differences between the Spirulina and Spirulina + chromium groups. The nematodes were more tolerant of all types of stressors compared to harpacticoids, polychaetes, and oligochaetes, and the lowest taxonomic and morpho-functional diversity of nematodes was observed in the highest sedimentary concentration of S. platensis (50% DW). The mixed treatments may have been richer in micro-habitats and subject to low selective pressure, thereby hosting nematodes with a wide range of adaptations. The responses of the nematode species differed depending on their functional traits. Spirulina enriched with chromium induced two responses for the same feeding group: high toxicity for Daptonema fallax and low toxicity for two Theristus species (T. flevensis and T. modicus). The ecotoxicity of the Spirulina/chromium mixtures were lower than that of Spirulina alone, suggesting mutual neutralization between these two elements. The association between functional traits and taxonomic diversity showed that the effects of the mixtures were not additive and that one of the stressors camouflaged the effect of the other. Our findings should encourage the commercialization of chromium-enriched S. platensis owing to its lower ecotoxicity than Spirulina alone.
Afficher plus [+] Moins [-]Bioturbation effects on metal release from contaminated sediments are metal-dependent
2019
Xie, Minwei | Simpson, Stuart L. | Wang, Wen-Xiong
Metal flux measurements inform the mobility, potential bioavailability and risk of toxicity for metals in contaminated sediments and therefore is an important approach for sediment quality assessment. The binding and release of metals that contribute to the net flux is strongly influenced by the presence and behaviors of benthic organisms. Here we studied the effects of bioturbation on the mobility and efflux of metals from multi-metal contaminated sediments that inhabited by oligochaete worms or both worms and bivalves. Presence of bivalves enhanced the release of Mn, Co, Ni and Zn but not for copper and chromium, which is likely due to the high affinities of copper and chromium for the solid phase. Metals in the overlying water were primarily associated with fractions smaller than 10 kDa, and the fractionation of all metals were not affected by the presence of the bivalve. Metal fluxes attributed to different processes were also distinguished, and the bioturbation induced effluxes were substantially higher than the diffusive effluxes. Temporal variabilities in the total net effluxes of Mn, Co, Ni and Zn were also observed and were attributed to the biological activities of the bivalves. Overall, the present study demonstrated that the response of different metals to the same bioturbation behavior was different, resulting in distinct mobility and fate of the metal contaminants.
Afficher plus [+] Moins [-]Assessing ecotoxicity and uptake of metals and metalloids in relation to two different earthworm species (Eiseina hortensis and Lumbricus terrestris)
2013
Leveque, Thibaut | Capowiez, Yvan | Schreck, Eva | Mazzia, Christophe | Auffan, Mélanie | Foucault, Yann | Austruy, Annabelle | Dumat, Camille
Due to diffuse atmospheric fallouts of process particles enriched by metals and metalloids, polluted soils concern large areas at the global scale. Useful tools to assess ecotoxicity induced by these polluted soils are therefore needed. Earthworms are currently used as biotest, however the influence of specie and earthworm behaviour, soil characteristics are poorly highlighted. Our aim was therefore to assess the toxicity of various polluted soils with process particles enriches by metals and metalloids (Pb, Cd, Cu, Zn, As and Sb) collected from a lead recycling facility on two earthworm species belonging to different ecological types and thus likely to have contrasted behavioural responses (Eiseina hortensis and Lumbricus terrestris).The combination of behavioural factors measurements (cast production and biomass) and physico-chemical parameters such as metal absorption, bioaccumulation by earthworms and their localization in invertebrate tissues provided a valuable indication of pollutant bioavailability and ecotoxicity. Soil characteristics influenced ecotoxicity and metal uptake by earthworms, as well as their soil bioturbation.
Afficher plus [+] Moins [-]Supercritical fluid extraction of persistent organic pollutants from natural and artificial soils and comparison with bioaccumulation in earthworms
2013
Bielská, Lucie | Šmídová, Klára | Hofman, Jakub
Selective supercritical fluid extraction (SSFE) was used as a measurement of compound chemical accessibility and as a predictor of compound bioavailability from three natural soils and artificial analogues prepared to have comparable total organic carbon content. Soils spiked with phenanthrene, pyrene, PCB 153, lindane, and p,p′-DDT were aged for 0, 14, 28, or 56 days and then selectively extracted by supercritical fluid extraction. Compounds exhibited decreasing extractability with increasing pollutant–soil contact time and increasing total organic carbon content in tested soils. However, the different extractability of compounds from artificial and natural pairs having comparable TOC indicates the limitations of using TOC as an extrapolation basis between various soils. The comparison of extractability with bioaccumulation by earthworms (Eisenia fetida) previously published by Vlčková and Hofman (2012) showed that only for PAHs it was possible to predict their bioaccumulation by means of selective SFE.
Afficher plus [+] Moins [-]Life-history effects of arsenic toxicity in clades of the earthworm Lumbricus rubellus
2013
Anderson, C.J. | Kille, P. | Lawlor, A.J. | Spurgeon, D.J.
Exposures of Lumbricus rubellus to a series of arsenic concentrations in soil were used to assess life-stage (juvenile, adult) and genotype specific sensitivities, to calculate population growth rate (λ) and to assess patterns of As accumulation. Significant mortality was seen in juveniles at 125 mg/kg As, while growth and maturation was affected from 36 mg/kg and above. In adults, cocoon production at the highest concentration (125 mg/kg) was significantly reduced. Phylogenetic analysis was performed by comparison of mitochondrial sequences to establish genotypic variation among juveniles. Three clades with more than 7.5% divergent were described, with 70% of earthworms belonging to a single clade. Date of and mass at maturation was significantly different between clades, but clades were not differentially As sensitive. Parameter λ was reduced at 36 mg/kg As and was negative at 125 mg/kg As, suggesting impacts and population stability and potential extinction at environmentally relevant concentrations.
Afficher plus [+] Moins [-]In situ application of activated carbon and biochar to PCB-contaminated soil and the effects of mixing regime
2013
Denyes, Mackenzie J. | Rutter, Allison | Zeeb, Barbara A.
The in situ use of carbon amendments such as activated carbon (AC) and biochar to minimize the bioavailability of organic contaminants is gaining in popularity. In the first in situ experiment conducted at a Canadian PCB-contaminated Brownfield site, GAC and two types of biochar were statistically equal at reducing PCB uptake into plants. PCB concentrations in Cucurbita pepo root tissue were reduced by 74%, 72% and 64%, with the addition of 2.8% GAC, Burt's biochar and BlueLeaf biochar, respectively. A complementary greenhouse study which included a bioaccumulation study of Eisenia fetida (earthworm), found mechanically mixing carbon amendments with PCB-contaminated soil (i.e. 24 h at 30 rpm) resulted in shoot, root and worm PCB concentrations 66%, 59% and 39% lower than in the manually mixed treatments (i.e. with a spade and bucket). Therefore, studies which mechanically mix carbon amendments with contaminated soil may over-estimate the short-term potential to reduce PCB bioavailability.
Afficher plus [+] Moins [-]1-D and 2-D NMR-based metabolomics of earthworms exposed to endosulfan and endosulfan sulfate in soil
2013
Yuk, Jimmy | Simpson, Myrna J. | Simpson, Andre J.
One-dimensional (1-D) and two-dimensional (2-D) nuclear magnetic resonance (NMR)-based metabolomics was used to investigate the toxic mode of action (MOA) of endosulfan, an organochlorine pesticide, and its degradation product, endosulfan sulfate, to Eisenia fetida earthworms in soil. Three soil concentrations (0.1, 1.0 and 10.0 mg/kg) were used for both endosulfan and endosulfan sulfate. Both earthworm coelomic fluid (CF) and tissues were extracted and then analyzed using 1H and 1H–13C NMR techniques. A similar separation trajectory was observed for endosulfan and endosulfan sulfate-exposed earthworms in the mean principal component analysis (PCA) scores plot for both the earthworm CF and tissue extracts.A neurotoxic and apoptotic MOA was postulated for both endosulfan and endosulfan sulfate exposed earthworms as significant fluctuations in glutamine/GABA–glutamate cycle metabolites and spermidine were detected respectively. This study highlights the application of NMR-based metabolomics to understand molecular-level toxicity of persistent organochlorine pesticides and their degradation products directly in soil.
Afficher plus [+] Moins [-]