Water management and aquatic ecosystem services of a tropical reservoir (Itaparica,São Francisco,Brazil)

Reservoirs have a wide variety of uses that have led to frequent conflicts over ecological conservation and contamination, especially as land management has intensified. Oligotrophication must be implemented in numerous tropical reservoirs that experience advanced eutrophication to maintain aquatic ecosystem functions. To quantify impacts on ecosystem functions and to develop an adaptive management policy, multiple studies have been conducted on the Itaparica Reservoir, São Francisco River, in the semi-arid north-eastern region of Brazil. Here, we add to that existing body of knowledge through investigating how nutrient accumulation is affected by water exchange between the main river flow and Icó-Mandantes Bay. Operational water-level fluctuations in the reservoir create large desiccated littoral areas that release high amounts of nutrients when they are rewetted. In particular, water-level variation promotes proliferation of Egeria densa, a noxious weed, thus elevating trophic levels of the Itaparica Reservoir and Icó-Mandantes Bay. Analysis with a P efficiency model determined 25 μg P L^?1 to be the critical concentration and further indicated that the critical load in both bodies of water have been exceeded. Moreover, intensive fish aquaculture using net cages has led to further overtaxing of the reservoir. We conclude that an effective ecological reservoir management policy must involve oligotrophication, harvesting of noxious water weeds for use as soil amendment in agriculture or biogas production, “blue” aquaculture, and limiting hydroelectric power production based on current water availability.     

The causal impact of material productivity on microeconomic competitiveness and environmental performance in the European Union

Environmental Economics and Policy Studies - Interdisciplinary scholars and policymakers in the European Union (EU) claim that increasing material productivity improves the competitiveness of...     

Cadmium concentration in tobacco (Nicotiana tabacum L.) from different countries and its relationship with other elements

Cadmium accumulation in crop plants, such as tobacco (Nicotiana tabacum L.), can lead to human exposure to this carcinogenic metal. To better define actual Cd distribution in cured or processed tobacco leaves from chief tobacco-producing regions, we analyzed 755 leaf samples of three major types (Flue-cured, Burley, and Oriental) obtained from 13 countries during 2001-2003. This survey may help identify regions with low- or high-Cd concentrations in tobacco to obtain insight into the cause of the concentration extremes and to assist in defining strategies to reduce Cd in tobacco. Cadmium concentrations in the samples ranged from 0 to 6.78 microg g(-1), as determined by ICP-MS. Significant differences were found among types and among countries, but significant interactions between type and country were found. Variations in Cd concentrations were also found in all countries. Our results suggest an important contribution of the field (e.g., bioavailable Cd in soil, other soil characteristics) to the Cd concentration in tobacco. Finally, the correlation between the concentration of Cd and that of other elements differed among the types, which could be effectively discriminated based on the concentrations of 20 elements.     

Impact of climate change on vulnerability of forests and ecosystem service supply in Western Rhodopes Mountains

The vulnerability of forest ecosystem services to climate change is expected to depend on landscape characteristic and management history, but may also be influenced by the proximity to the southern range limit of constituent tree species. In the Western Rhodopes in South Bulgaria, Norway spruce is an important commercial species, but is approaching its current southern limit. Using climate sensitive forest models, we projected the impact of climate change on timber production, carbon storage, biodiversity and soil retention in two representative landscapes in the Western Rhodopes; a lower elevation landscape (1000–1450 m a.s.l) dominated by mixed species forests, and a higher elevation landscape (1550–2100 m a.s.l.) currently dominated by spruce. In both landscapes climate change is projected to induce a shift in forest composition, with drought-sensitive species, such as Norway spruce, being replaced by more drought-tolerant species such as Scots pine and black pine at lower elevations. In the higher elevation landscape a reduction in spruce growth is projected, particularly under the more severe climate change scenarios. Under most climate scenarios a reduction in growing stock is projected to occur, but under some scenarios a moderate increase in higher elevation stands (>1500 m a.s.l.) is expected. Climate change is projected to negatively influence carbon storage potential across landscapes with the magnitude depending on the severity of the climate change scenario. The impact of climate change on forest diversity and habitat availability is projected to differ considerably between the two landscapes, with diversity and habitat quality generally increasing at higher elevations, and being reduced at lower elevations. Our results suggest that if currently management practices are maintained the sensitivity of forests and forest ecosystem services in the Western Rhodopes to climate change will differ between low and higher elevation sites and will depend strongly on current forest composition.     

Breccias of the Adnet Formation: indicators of a Mid-Liassic tectonic event in the Northern Calcareous Alps (Salzburg/Austria)

Stratigraphy, lithology and depositional structures of Liassic red limestone-breccias of the Adnet Formation, including the 'Adnet Scheck', were studied at several outcrops of the Northern Calcareous Alps (NCA) south-east of Salzburg. A four-fold lithostratigraphic division is proposed for the Adnet Formation of the Osterhorn Mountains: the hemipelagic Schmiedwirt (Sinemurian) and Kehlbach (Carixian) members are separated from the pelagic Saubach Member (Toarcian) by a layer of amalgamated breccias (Scheck Member, probably Domerian to early Toarcian). Several other breccia beds occur locally from the base of the Kehlbach Member up to the lower Saubach Member. Although the sediments overlying the Scheck Member breccias are of coeval age, the ages of the underlying strata are very different. This can be explained by submarine Liassic erosion during a period of resedimentation from the middle Carixian until the early Toarcian. At least 10–15?m of partly lithified sediments were eroded by gravity flows. The entire Kehlbach Member and up to two-thirds of the Schmiedwirt Member were removed at Adnet. The breccias originated from submarine debris flows. Repeated flows over a long period and the depositional setting exclude a triggering by sea-level fluctuations. Most probably they arose from tectonically triggered slumps and slides of superficial sediments. The 'Scheck' was initiated on the steep upper slope of the drowned Triassic Adnet reef and flowed to the north-east.The Pliensbachian to early Toarcian period of tectonic activity indicated by the breccias was the most important during the Liassic in the Osterhorn Mountains and other parts of the NCA. From the large-scale regional distribution of the breccias and in accord with published data, a roughly north-east trending strike-slip fault zone is proposed, crossing the NCA south of the Osterhorn block, with a peaking activity during the Pliensbachian to early Toarcian as the cause of the tectonic movements.     

Correlation of six anthropogenic markers in wastewater, surface water, bank filtrate, and soil aquifer treatment

Six trace contaminants (acesulfame (ACE), sucralose (SUC), carbamazepine (CBZ), diatrizoic acid (DTA), 1H-benzotriazole (BTZ) and its 4-methyl analogue (4-TTri)) were traced from wastewater treatment plants (WWTPs) to receiving waters and further to riverbank filtration (RBF) wells to evaluate their prediction power as potential wastewater markers. Furthermore, the persistence of some compounds was investigated in advanced wastewater treatment by soil aquifer treatment (SAT). During wastewater treatment in four conventional activated sludge WWTPs ACE, SUC, and CBZ showed a pronounced stability expressed by stable concentration ratios in influent (in) and effluent (out) (ACE/CBZ: in45, out40; SUC/CBZ: in1.8, out1.7; and ACE/SUC: in24, out24). In a fifth WWTP, additional treatment with powdered activated carbon led to a strong elimination of CBZ, BTZ, and 4-TTri of about 80% and consequently to a distinctive shift of their ratios with unaffected compounds. Data from a seven month monitoring program at seven sampling locations at the rivers Rhine and Main in Germany revealed the best concentration correlation for ACE and CBZ (r(2) = 0.94) and also a good correlation of ACE and CBZ concentrations to BTZ and 4-TTri levels (r(2) = 0.66 to 0.82). The comparison of ratios at different sampling sites allowed for the identification of a CBZ point source. Furthermore, in Switzerland a higher consumption of SUC compared to Germany can be assumed, as a steadily increasing ACE/SUC ratio along the river Rhine was observed. In RBF wells a good correlation (r(2) = 0.85) was again observed for ACE and CBZ. Both also showed the highest stability at a prolonged residence time in the subsurface of a SAT field. In the most peripheral wells ACE and CBZ were still detected with mean values higher than 36 μg L(-1) and 1.3 μg L(-1), respectively. Although SUC concentrations in wastewater used for SAT decreased by more than 80% from about 18 μg L(-1) to 2.1 μg L(-1) and 3.5 μg L(-1) in these outlying wells, the compound was still adequate to indicate a wastewater impact in a qualitative way.     

The silvering process of European eel (Anguilla anguilla) influences PAH metabolite concentrations in bile fluid: consequences for monitoring

The stock of the catadromous European eel (Anguilla anguilla L.) continues to decline and there is growing evidence that poor health status due to contaminants might be a key element in this decrease. Organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) belong to the major threats to yellow eel in their growth habitat and their metabolites are detectable in the bile. Starting the silvering process eels undergo physiological and morphological changes including cessation of feeding and downstream migration back to their spawning grounds. Reduced feed intake results in a diminishment of bile production and induces accumulation of e.g. PAH-metabolites in bile. Therefore, the aim of the present study was to demonstrate the impact of silvering on biliary PAH metabolite concentrations and to utilize normalization procedures to overcome silvering related accumulation effects of PAH-metabolites in eel bile. We investigated the hydroxyl-metabolites of pyrene (1-OH Pyr) and phenantrene (1-OH Phen) in the bile of different maturation stages of eels (silvering index I-V) from nine German rivers. We detected increasing absolute PAH metabolite levels in bile during the silvering process. The highest rise could be observed at the transition from pre migration stage III to the migrating stage IV, suggesting the onset of cessation of feeding at this stage. A cessation bias in PAH metabolite measurement could be diminished by normalization of absolute values against bile pigments (A₃₈₀, biliverdin). In conclusion, we demonstrated the impact of silvering on PAH metabolite concentrations in eel bile and present suitable normalization procedures to overcome silvering related accumulation effects. Thus, for a future eel monitoring we recommend (1) to regularly monitor PAH metabolites in bile, (2) to determine silvering index of eel and (3) to normalize PAH metabolite values in bile based on maturation/silvering stages. The knowledge of the silvering stage is mandatory for an unbiased evaluation of PAH contamination of European eel towards an international harmonized eel monitoring program.     

Antibiotic resistant bacteria/genes dissemination in lacustrine sediments highly increased following cultural eutrophication of Lake Geneva (Switzerland)

This study investigates faecal indicator bacteria (FIB), multiple antibiotic resistant (MAR), and antibiotic resistance genes (ARGs), of sediment profiles from different parts of Lake Geneva (Switzerland) over the last decades. MARs consist to expose culturable Escherichia coli (EC) and Enterococcus (ENT) to mixed five antibiotics including Ampicillin, Tetracycline, Amoxicillin, Chloramphenicol and Erythromycin. Culture-independent is performed to assess the distribution of ARGs responsible for, β-lactams (blaTEM; Amoxicillin/Ampicillin), Streptomycin/Spectinomycin (aadA), Tetracycline (tet) Chloramphenicol (cmlA) and Vancomycin (van). Bacterial cultures reveal that in the sediments deposited following eutrophication of Lake Geneva in the 1970s, the percentage of MARs to five antibiotics varied from 0.12% to 4.6% and 0.016% to 11.6% of total culturable EC and ENT, respectively. In these organic-rich bacteria-contaminated sediments, the blaTEM resistant of FIB varied from 22% to 48% and 16% to 37% for EC and ENT respectively, whereas the positive PCR assays responsible for tested ARGs were observed for EC, ENT, and total DNA from all samples. The aadA resistance gene was amplified for all the sediment samples, including those not influenced by WWTP effluent water. Our results demonstrate that bacteria MARs and ARGs highly increased in the sediments contaminated with WWTP effluent following the cultural eutrophication of Lake Geneva. Hence, the human-induced changing limnological conditions highly enhanced the sediment microbial activity, and therein the spreading of antibiotic resistant bacteria and genes in this aquatic environment used to supply drinking water in a highly populated area. Furthermore, the presence of the antibiotic resistance gene aadA in all the studied samples points out a regional dissemination of this emerging contaminant in freshwater sediments since at least the late nineteenth century.     

Aerogels and metal–organic frameworks for environmental remediation and energy production

Environmental pollution and climate change are requiring new methods to clean pollutants and produce sustainable energy. Aerogels and metal organic frameworks are emerging as advanced porous materials with higher functionality, high surface area, high porosity and flexible chemistry. Aerogels are dried gels prepared using the sol–gel procedure, whereas metal organic frameworks are networks of organic ligands and metal ions connected by coordination bonds. Applications of aerogels include the removal of heavy metals, CO₂ capture and reduction, photodegradation of pollutants, air cleanup and water splitting. This article reviews the synthesis and types of aerogels and metal organic frameworks, and the application to pollutant removal, energy production including hydrogen, methane reforming, CO₂ conversion and NOx removal.