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Geochemical and ecological changes within Moira Lake (Ontario, Canada): A legacy of industrial contamination and remediation
Abstract not provided
Ecological and human exposure assessment to PBDEs in Adige River
Highlights: • Exposure assessment of aquatic species in Adige river to PBDEs Population exposure to PBDEs due to contaminated freshwater fish ingestion. • Use of MERLIN-Expo model for integrated exposure assessment. • Comparability between simulated and real PBDEs concentrations in aquatic species. • Different exposure trends to PBDEs were observed for children, adolescent, adult and elderly. The interest for environmental issues and the concern resulting from the potential exposure to contaminants were the starting point to develop methodologies in order to evaluate the consequences that those might have over both the environment and human health. Considering the feature of POPs, including PBDEs, such as bioaccumulation, biomagnification, long-range transport and adverse effects even long time after exposure, risk assessment of POPs requires specific approaches and tools. In this particular context, the MERLIN-Expo tool was used to assess the aquatic environmental exposure of Adige River to PBDEs and the accumulation of PBDEs in humans through the consumption of possible contaminated local aquatic food. The aquatic food web models provided as output of the deterministic simulation the time trend of concentrations for twenty years of BDE-47 and total PBDEs, expressed using the physico-chemical properties of BDE-47, in aquatic organisms of the food web of Adige River. For BDE-47, the highest accumulated concentrations were detected for two benthic species: Thymallus thymallus and Squalius cephalus whereas the lowest concentrations were obtained for the pelagic specie Salmo trutta marmoratus. The trend obtained for the total PBDEs, calculated using the physico-chemical properties of BDE-47, follows the one of BDE-47. For human exposure, different BDE-47 and total PBDEs concentration trends between children, adolescent, adults and elderly were observed, probably correlated with the human intake of fish products in the daily diet and the ability to metabolize these contaminants. In detail, for the adolescents, adults and elderly a continuous accumulation of the target contaminants during the simulation's years was observed, whereas for children a plateau at the end of the simulation period was perceived.
The developing relationship between the study of fungal communities and community ecology theory
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Agricultural Risk Factors Influence Microbial Ecology in Honghu Lake
Agricultural activities, including stock-farming, planting industry, and fish aquaculture, can affect the physicochemical and biological characters of freshwater lakes. However, the effects of pollution producing by agricultural activities on microbial ecosystem of lakes remain unclear. Hence, in this work, we selected Honghu Lake as a typical lake that is influenced by agriculture activities. We collected water and sediment samples from 18 sites, which span a wide range of areas from impacted and less-impacted areas. We performed a geospatial analysis on the composition of microbial communities associated with physicochemical properties and antibiotic pollution of samples. The co-occurrence networks of water and sediment were also built and analyzed. Our results showed that the microbial communities of impacted and less-impacted samples of water were largely driven by the concentrations of TN, TP, NO3--N, and NO2--N, while those of sediment were affected by the concentrations of Sed-OM and Sed-TN. Antibiotics have also played important roles in shaping these microbial communities: the concentrations of oxytetracycline and tetracycline clearly reflected the variance in taxonomic diversity and predicted functional diversity between impacted and less-impacted sites in water and sediment samples, respectively. Furthermore, for samples from both water and sediment, large differences of network topology structures between impacted and less-impacted were also observed. Our results provide compelling evidence that the microbial community can be used as a sentinel of eutrophication and antibiotics pollution risk associated with agricultural activity; and that proper monitoring of this environment is vital to maintain a sustainable environment in Honghu Lake.
The effect of malathion on the activity, performance, and microbial ecology of activated sludge
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Hydro-ecological processes of hyporheic zone in a karst spring-fed pool: Effects of groundwater decline and river backflow
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Synthetic Ecology of Microbes: Mathematical Models and Applications
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Community variability and ecological functioning: 40 years of change in the North Sea benthos
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Ecological zonation of benthic foraminifera in the lower Guadiana Estuary (southeastern Portugal)
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Methodology for assessing the individual role of fish, oyster, phytoplankton and macroalgae in the ecology of integrated production in earthen ponds
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Ecological patterns of seed microbiome diversity, transmission, and assembly
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Assessing the fidelity of marine vertebrate microfossil δ18O signatures and their potential for palaeo-ecological and -climatic reconstructions
Conodont biogenic apatite has become a preferred analytical target for oxygen isotope studies investigating ocean temperature and palaeoclimate change in the Palaeozoic. Despite the growing application in geochemical based palaeoenvironmental reconstructions, the paucity or absence of conodont fossils in certain facies necessitates greater flexibility in selection of robust oxygen bearing compounds for analysis. Microvertebrates offer a potential substitute for conodonts from the middle Palaeozoic. Microvertebrate bioapatite is particularly advantageous given a fossil record extending to the present with representatives across freshwater to fully marine environments, thus widening the scope of oxygen isotope studies on bioapatite. However, significant tissue heterogeneity within vertebrates and differential susceptibility of these tissues to diagenetic alteration have been raised as potential problems affecting the reliability of the oxygen isotope ratios as palaeoclimate proxies. Pristine microvertebrate and co-occurring conodont fossils from the Late Devonian and Early Carboniferous of the Lennard Shelf, Canning Basin, Western Australia, were analysed using bulk (gas isotope ratio mass spectrometry) and in-situ (secondary ion mass spectrometry) methodologies, with the latter technique allowing investigation of specific tissues within vertebrate elements. The δ18Oconodont results may be interpreted in terms of palaeolatitudinally and environmentally sensible palaeotemperatures and provide a baseline standard for comparison against δ18Omicrovertebrate values. Despite an absence of obvious diagenetic influences, GIRMS of microvertebrate denticles yielded δ18O values depleted by 2-4 ‰ relative to co-occurring conodonts. SIMS analysis of hypermineralised tissues in both scales and teeth produced δ18O values comparable with those of associated conodonts. The susceptibility of porous phosphatic fossil tissues to microbial activity, fluid interaction and introduction of mineral precipitates post-formation is demonstrated in microvertebrate dentine, which showed significant heterogeneity and consistent depletion in 18O. The hypermineralised tissues present in both teeth and scales appear resistant to many diagenetic processes and indicate potential for palaeoclimatic reconstructions and palaeoecological investigations.