- Harmful effects of cocaine byproduct in the reproduction of sea urchin in different ocean acidification scenarios. [Journal Article]
- CChemosphere 2019 Jul 02; 236:124284
- This study has as main objective assessing the toxicity of crack-cocaine combined with different scenarios of ocean acidification on fertilization rate and embryo-larval development of Echinometra lu…
This study has as main objective assessing the toxicity of crack-cocaine combined with different scenarios of ocean acidification on fertilization rate and embryo-larval development of Echinometra lucunter sea urchin. Effects on early life stages were assessed at five different concentrations (6,25 mg.L-1; 12,5 mg.L-1; 25 mg.L-1; 50 mg.L-1 and 100 mg.L-1) of crack-cocaine at four different pH values (8.5; 8.0; 7.5; 7.0). The pH values were achieved using two different methodologies: adding hydrochloric acid (HCl) and injecting carbon dioxide (CO2). The fertilization test did not show significant differences (p ≤ 0.05) compared with control sample at pH values 8.5; 8.0 and 7.5. Results of embryo-larval assays showed a half maximal effective concentration (EC50) of crack-cocaine at pH values tested (8.5, 8.0, 7.5) as 58.83, 10.67 and 11.58 mg/L-1 for HCl acidification and 58.83, 23.28 and 12.57 mg/L-1 for CO2 enrichment. At pH 7.0 the effects observed in fertilization rate and embryo development were associated with the acidification. This study is the first ecotoxicological assessment of illicit drug toxicity in aquatic ecosystems at different ocean acidification scenarios.
- Integrated biomarker response index to assess toxic effects of environmentally relevant concentrations of paracetamol in a neotropical catfish (Rhamdia quelen). [Journal Article]
- EEEcotoxicol Environ Saf 2019 Jul 12; 182:109438
- The nonsteroidal anti-inflammatory drugs (NSAIDs) are amongst the most commonly detected classes of pharmaceuticals in freshwater environments, with paracetamol being the most abundant. The aim of th…
The nonsteroidal anti-inflammatory drugs (NSAIDs) are amongst the most commonly detected classes of pharmaceuticals in freshwater environments, with paracetamol being the most abundant. The aim of this study was to evaluate the possible toxic effects of environmentally relevant concentrations (0.25, 2.5 and 25 μg.L-1) of paracetamol in Rhamdia quelen fish exposed for 14 days using different biomarkers. The total count of leukocytes and thrombocytes was reduced at the highest concentration. In the gills, all concentrations of paracetamol reduced the glutathione S-transferase (GST) activity and the reduced glutathione (GSH) levels compared to the control group. The activity of catalase (CAT) was not altered and glutathione peroxidase (GPx) activity increased at the highest concentrations. The superoxide dismutase (SOD) activity decreased at 25 μg.L-1 and the LPO levels increased at 2.5 μg.L-1 when compared to the control group. The concentration of ROS was not different among the groups. In the posterior kidney the activities of GST (2.5 μg.L-1), CAT (2.5 μg.L-1 and at 25 μg. L-1) and GPx and GSH levels increased at all concentrations when compared to the control group. The SOD activity and LPO levels did not change. Paracetamol caused genotoxicity in the blood and gills at concentrations of 2.5 μg.L-1 and in the posterior kidney at 2.5 and 25 μg.L-1. An osmoregulatory imbalance in plasma ions and a reduction in the carbonic anhydrase activity in the gills at 0.25 μg.L-1 were observed. Histopathological alterations occurred in the gills of fish exposed to 25 μg.L-1 and in the posterior kidney at 0.25 and 25 μg.L-1 of paracetamol. The integrated biomarker index showed that the stress caused by the concentration of 25 μg.L-1 was the highest one. These results demonstrated toxic effects of paracetamol on the gills and posterior kidneys of fish, compromising their physiological functions and evidencing the need for monitoring the residues of pharmaceuticals released into aquatic environment.
- Process optimization of anammox-driven hydroxyapatite crystallization for simultaneous nitrogen removal and phosphorus recovery. [Journal Article]
- BTBioresour Technol 2019 Jul 09; 290:121779
- Based on the requirements for advanced treatment and resource recovery of nitrogen and phosphorus pollutants in wastewater, the coupled anammox and hydroxyapatite crystallization (anammox-HAP) proces…
Based on the requirements for advanced treatment and resource recovery of nitrogen and phosphorus pollutants in wastewater, the coupled anammox and hydroxyapatite crystallization (anammox-HAP) process was studied with an aim of achieving high efficiency and low energy consumption during simultaneous nitrogen and phosphorus removal. In the long-term experiments and batch tests, the effects of substrate conditions (nitrogen and phosphorus load, calcium concentration, etc.) on the nitrogen removal and phosphorus recovery efficiencies were investigated. The granular structure and crystal properties were analyzed together with microscopic characterization methods, and the formation mechanism of coupled anammox-HAP granules was verified. Based on these experiments, a theoretical model and technical method for realizing the coupled process were established, and a reference for practical engineering application was provided.
- Stoichiometry and daily rhythms: experimental evidence shows nutrient limitation decouples N uptake from photosynthesis. [Journal Article]
- EEcology 2019 Jul 16
- Diel variability in nutrient concentrations is common but not universal in aquatic ecosystems. Theoretical models of photoautotrophic systems attribute the absence of diel uptake variation to nutrien…
Diel variability in nutrient concentrations is common but not universal in aquatic ecosystems. Theoretical models of photoautotrophic systems attribute the absence of diel uptake variation to nutrient scarcity, such that diel variability in nutrient uptake disappears as nutrients becomes limiting. We tested this prediction in a mesocosm experiment, by exposing benthic algal communities to a range of nitrogen (N) and phosphorus concentrations and recording the rates of uptake during both day and night. We found that higher concentrations of N produced diel variability in uptake, and that the difference between the day and night total mass uptakes approximately equaled N demand for observed primary production as seen in other studies. At lower concentrations of N, uptake rates during the day and night were indistinguishable. These results are the first empirical evidence to imply that diel nitrate patterns in streams and rivers indicate a release from N limitation and offer a new way to assess nutrient limitation. This article is protected by copyright. All rights reserved.
- Structure, Development, and Functional Morphology of the Cement Gland of the Giant Danio, Devario malabaricus. [Journal Article]
- DDDev Dyn 2019 Jul 16
- CONCLUSIONS: Taken together, our studies provide the first documentation of the embryonic development, structure and function of the adhesive apparatus of a danioninae. To our knowledge this is also the first report of a cement gland arising from convergence of two bilateral fields. This article is protected by copyright. All rights reserved.
- Recovery and confirmation of Edwardsiella piscicida from a black crappie Pomoxis nigromaculatus (Lesueur, 1829). [Journal Article]
- JFJ Fish Dis 2019 Jul 15
- Biodegradation of diuron by endophytic Bacillus licheniformis strain SDS12 and its application in reducing diuron toxicity for green algae. [Journal Article]
- ESEnviron Sci Pollut Res Int 2019 Jul 15
- The endophytic bacteria live in close nuptial relationship with the host plant. The stress experienced by the plant is expected to be transferred to the endophytes. Thus, plants thriving at polluted …
The endophytic bacteria live in close nuptial relationship with the host plant. The stress experienced by the plant is expected to be transferred to the endophytes. Thus, plants thriving at polluted sites are likely to harbor pollutant-degrading endophytes. The present study reports the isolation of phenylurea herbicides assimilating Bacillus sps. from Parthenium weed growing at diuron-contaminated site. The isolated endophytes exhibited plant growth-promoting (PGP) activities. Among five isolated diuron-degrading endophytes, the most efficient isolate Bacillus licheniformis strain SDS12 degraded 85.60 ± 1.36% of 50 ppm diuron to benign form via formation of degradation intermediate 3, 4-dichloroaniline (3,4-DCA). Cell-free supernatant (CFS) obtained after diuron degradation by strain SDS12 supported algal growth comparable with the pond water. The chlorophyll content and photosynthetic efficiency of green algae decreased significantly in the presence of diuron-contaminated water; however, no such change was observed in CFS of strain SDS12, thus, suggesting that strain SDS12 can be applied in aquatic bodies for degrading diuron and reducing diuron toxicity for primary producers. Further, the use of PGP and diuron-degrading bacteria in agriculture fields will not only help in remediating the soil but also support plant growth.
- Population Dynamics of Bank Voles Predicts Human Puumala Hantavirus Risk. [Journal Article]
- EEcohealth 2019 Jul 15
- Predicting risk of zoonotic diseases, i.e., diseases shared by humans and animals, is often complicated by the population ecology of wildlife host(s). We here demonstrate how ecological knowledge of …
Predicting risk of zoonotic diseases, i.e., diseases shared by humans and animals, is often complicated by the population ecology of wildlife host(s). We here demonstrate how ecological knowledge of a disease system can be used for early prediction of human risk using Puumala hantavirus (PUUV) in bank voles (Myodes glareolus), which causes Nephropathia epidemica (NE) in humans, as a model system. Bank vole populations at northern latitudes exhibit multiannual fluctuations in density and spatial distribution, a phenomenon that has been studied extensively. Nevertheless, existing studies predict NE incidence only a few months before an outbreak. We used a time series on cyclic bank vole population density (1972-2013), their PUUV infection rates (1979-1986; 2003-2013), and NE incidence in Sweden (1990-2013). Depending on the relationship between vole density and infection prevalence (proportion of infected animals), either overall density of bank voles or the density of infected bank voles may be used to predict seasonal NE incidence. The density and spatial distribution of voles at density minima of a population cycle contribute to the early warning of NE risk later at its cyclic peak. When bank voles remain relatively widespread in the landscape during cyclic minima, PUUV can spread from a high baseline during a cycle, culminating in high prevalence in bank voles and potentially high NE risk during peak densities.
- Spatial Distribution and Congener Profiles of Polybrominated Diphenyl Ethers in Surface Sediment from Sanmen Bay and Xiamen Bay, Southeast China. [Journal Article]
- BEBull Environ Contam Toxicol 2019 Jul 15
- Coastal areas are influenced by anthropogenic input of a variety of organic pollutants, among which polybrominated diphenyl ethers (PBDEs) represent an important group. In the present study, we inves…
Coastal areas are influenced by anthropogenic input of a variety of organic pollutants, among which polybrominated diphenyl ethers (PBDEs) represent an important group. In the present study, we investigated the contamination status of PBDEs in surface sediment from two economically important Bays in Southeast China, Sanmen Bay (SMB; n = 29) and Xiamen Bay (XMB; n = 10). Concentrations of ∑PBDEs ranged from 2.2 to 78.5 ng/g dw (median 5.7 ng/g dw) in SMB and 7.9-276.0 ng/g dw (median 43.5 ng/g dw) in XMB, respectively. A nearshore-offshore decreasing trend was observed for both ∑PBDEs and BDE-209 concentrations, indicating strong urban influences. Although the current levels would not produce any significant impact on benthos and aquatic ecosystems of the studied regions, continuous monitoring is needed to understand the temporal trends of contamination in the important coastal waters and whether sediment-associated PBDEs constitute a potential source to aquatic ecosystems.
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- Slow-moving soil organisms on a water highway: aquatic dispersal and survival potential of Oribatida and Collembola in running water. [Journal Article]
- MEMov Ecol 2019; 7:20
- CONCLUSIONS: This is the first study to demonstrate successful passive dispersal with running water for two groups of terrestrial soil microarthropods, including subsequent colonisation of new soil. We show that submersion survival, as well as floating abilities, and therefore dispersal capability, are not only high in oribatid mites, but also species-specific. Running waters obviously serve as long-distance dispersal highways for many of these less mobile soil-living animals.