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Berlin Brandenburg

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  • 11
    Language: English
    In: Chemosphere, 2000, Vol.41(10), pp.1511-1517
    Description: Episodic pollution events such as runoff or spraydrift can lead to a short-term (few hours) contamination of aquatic ecosystems with pesticides. So far, different short-term exposures with respect to long-term effects have not been studied. In the present study, caddisfly larvae, typical for agricultural streams (Limnephilus lunatus Curtis, 2nd and 3rd instar) were exposed for 1- vs 10-h to three different equivalent doses ( mu g h) of fenvalerate. After transfer into an artificial stream microcosm with pesticide-free water, chronic effects were observed over 240 days. Comparison of 1- and 10-h exposure revealed that 1-h contamination leads to stronger effects. The differences were significant for the sublethal endpoints emergence pattern and dry weight of adults (ANOVA, Fisher's PLSD; P 〈 0.05). In terms of exposure dose, the difference between 1- and 10-h exposure equals a factor of 6 as a mean of all endpoints studied. The following significant effect levels for the 1-h exposure were obtained for the different endpoints investigated: reduced emergence success and production at 0.1 mu g l super(-1), temporal pattern of emergence at 0.001 mu g l super(-1), dry weight of adults at 0.01 mu g l super(-1).
    Keywords: Acute ; Production ; Pyrethroid ; Runoff ; Short-Term Exposure ; Spraydrift ; Trichoptera ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 12
    Language: English
    In: Aquatic Toxicology, 2011, Vol.104(1), pp.32-37
    Description: The energy stored in coarse particulate organic matter, e.g. leaf litter, is released to aquatic ecosystems by breakdown processes involving microorganisms and leaf shredding invertebrates. The palatability of leaves and thus the feeding of shredders on leaf material are highly influenced by microorganisms. However, implications in the colonization of leaves by microorganisms (=conditioning) caused by chemical stressors are rarely studied. Our laboratory experiments, therefore, investigated for the first time effects of a fungicide on the conditioning process of leaf material by means of food-choice experiments using (Crustacea: Amphipoda). Additionally, microbial analyses were conducted to facilitate the mechanistic understanding of the observed behavior. Gammarids significantly preferred control leaf discs over those conditioned in presence of the fungicide tebuconazole at concentrations of 50 and 500 μg/L. Besides the decrease of fungal biomass with increasing fungicide concentration, also the leaf associated fungal community composition showed that species preferred by gammarids, such as , , or , were more frequent in the control. , however, which is rejected by gammarids, was abundant in all treatments suggesting an increasing importance of this species for the lower leaf palatability – as other more palatable fungal species were almost absent – in the fungicide treatments. Hence, the food-choice behavior of seems to be a suitable indicator for alterations in leaf associated microbial communities, especially fungal species composition, caused by chemical stressors. Finally, this or similar test systems may be a reasonable supplement to the environmental risk assessment of chemicals in order to achieve its protection goals, as on the one hand, indirect effects may occur far below concentrations known to affect gammarids directly, and on the other hand, the observed shifts in leaf associated microbial communities may have perpetuating implications in leaf shredding invertebrates.
    Keywords: Fungal Community ; Leaf Litter Decomposition ; Confidence Interval Testing ; Aquatic Hyphomycetes ; Azole Fungicide ; Bacteria ; Chemistry ; Ecology
    ISSN: 0166-445X
    E-ISSN: 1879-1514
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  • 13
    In: Rapid Communications in Mass Spectrometry, 15 October 2015, Vol.29(19), pp.1789-1794
    Description: RATIONALE: Dietary sterol deficiencies can have severe life history consequences for consumers. Compound-specific stable isotope analysis (CSIA) was applied to the exploration of the sterol metabolic constraints and bioconversion capacities of the amphipod Gammarus roeselii. Evaluating structural sterol requirements has great potential to improve our understanding of the ecological relevance of sterols as limiting nutrients.METHODS: Juvenile G. roeselii were reared on food mixtures consisting of different ratios of the two algae Scenedesmus obliquus (cultivated with (13)C-labeled NaHCO3) and Nannochloropsis limnetica (unlabeled), which have been shown previously to differ in food quality. We measured the sterol content and composition using a gas chromatograph equipped with a flame ionization detector and the δ(13)C values of sterols using compound-specific isotope ratio mass spectrometry to examine potential sterol-mediated nutritional constraints of G. roeselii.RESULTS: In the food mixtures, δ(13)C values of cholesterol, synthesized by N. limnetica, were -25‰ and those of the Δ(7)-phytosterols, chondrillasterol and fungisterol, synthesized by S. obliquus, were 7 and 18‰, respectively. Although the cholesterol concentrations in G. roeselii decreased with increasing proportion of dietary S. obliquus, the δ(13)C values remained constant at -25‰. Lathosterol, which appeared in G. roeselii at high dietary proportions of S. obliquus, had a δ(13)C value of 35‰.CONCLUSIONS: We provide evidence that the the Δ(7)-phytosterols present in S. obliquus cannot be metabolized to cholesterol in G. roeselii, resulting in the accumulation of lathosterol in the animals and potentially in sterol-limited growth. These findings emphasize the advantage of CSIA in revealing the physiological mechanisms associated with nutritional constraints.
    Keywords: Chemistry;
    ISSN: 0951-4198
    E-ISSN: 1097-0231
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  • 14
    Language: English
    In: Aquatic Toxicology, December 2016, Vol.181, pp.94-103
    Description: For in situ remediation of groundwater contaminated by halogenated hydrocarbons Carbo-Iron , a composite of microscale activated carbon and nano Fe , was developed. Against the background of intended release of Carbo-Iron into the environment in concentrations in the g/L-range, potential ecotoxicological consequences were evaluated in the present study. The nano Fei in Carbo-Iron acts as reducing agent and is oxidized in aqueous systems by chlorinated solvents, groundwater constituents (e.g. dissolved oxygen) and anaerobic corrosion. As Carbo-Iron is generally oxidized rapidly after application into the environment, the oxidized state is environmentally most relevant, and Carbo-Iron was used in its oxidized form in the ecotoxicological tests. The amphipod was selected as a surrogate test species for functionally important groundwater crustaceans. Effects of Carbo-Iron on were determined in a 10-d acute test, a 7-d feeding activity test and a 42-d chronic test. Additionally, a 56-d life cycle test was performed with a modified design to further evaluate effects of Carbo-Iron on adult and their offspring. The size of Carbo-Iron particles in stock and test suspensions was determined via dynamic light scattering. Potential uptake of particles into test organisms was investigated using transmission and scanning electron microscopy. At the termination of the feeding and acute toxicity test (i.e. after 7 and 10 d of exposure, respectively), Carbo-Iron had a significant effect on the weight, length and feeding rate of at the highest test concentration of 100 mg/L. While an uptake of Carbo-Iron into the gut was observed, no passage into the surrounding tissue was detected. In both chronic tests, the number of offspring was the most sensitive endpoint and significant effects were recorded at concentrations ≥50 mg/L (42-d experiment) and ≥12.5 mg/L (56-d experiment). Parental exposure to oxidized Carbo-Iron significantly exacerbated the acute effects of the nanocomposite on the subsequent generation of by a factor 〉10. The present study indicates risks for groundwater species at concentrations in the mg/L range. Carbo-Iron may exceed these effect concentrations in treated aquifers, but the presence of the pollutant has most likely impaired the quality of this habitat already. The benefit of remediation has to be regarded against the risk of ecological consequences with special consideration of the observed increasing sensitivity of juvenile .
    Keywords: Iron-Based Nanomaterial ; Nanocomposite ; Groundwater Remediation ; Environmental Risk ; Chemistry ; Ecology
    ISSN: 0166-445X
    E-ISSN: 1879-1514
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  • 15
    Language: English
    In: International Journal of Environmental Analytical Chemistry, 15 June 2011, Vol.91(7-8), pp.768-785
    Description: Salt tracers (sodium bromide/sodium chloride) and two different fluorescent tracers, uranine (UR) and sulforhodamine-B (SRB), were injected as a pulse into six different surface flow wetlands (SFWs). Salt tracers documented wetland hydraulics. The fluorescent tracers were used as a reference...
    Keywords: Surface Flow Wetlands ; Residence Time Distribution ; Fluorescent Tracers ; Reference Tracer ; Contaminant Mitigation ; Sorption ; Pesticides ; Environmental Sciences ; Chemistry
    ISSN: 0306-7319
    E-ISSN: 1029-0397
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  • 16
    Language: English
    In: Chemosphere, 2003, Vol.51(6), pp.509-513
    Description: A water-sampling device to monitor the quality of water periodically and temporarily flowing out of concrete tubes, sewers or channels is described. It inexpensively and easily enables a qualitative characterization of contamination via these point-source entry routes. The water sampler can be reverse engineered with different sizes and materials, once installed needs no maintenance, passively samples the first surge, and the emptying procedure is short. In an agricultural catchment area in Germany we monitored an emergency overflow of a sewage sewer, an outlet of a rainwater sewer and two small drainage channels as input sources to a small stream. Seven inflow events were analysed for 20 pesticide agents (insecticides, fungicides and herbicides). All three entry routes were remarkably contaminated. We found parathion-ethyl concentrations of 0.3 mu g l super(-1), diuron up to 17.3 mu g l super(-1), ethofumesate up to 51.1 mu g l super(-1), metamitron up to 92 mu g l super(-1) and prosulfocarb up to 130 mu g l super(-1).
    Keywords: Herbicides ; Fungicides ; Insecticides ; Small Streams ; Point Sources ; Sewage Plant ; Rainwater Sewer ; Pipes ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 17
    Language: English
    In: Chemosphere, February 2019, Vol.216, pp.587-594
    Description: Understanding fate and transport of plant protection products (PPPs) that enter vegetated streams from agricultural fields is important for both exposure assessment and risk attenuation, yet limited knowledge is available. The present laboratory study investigated sorption processes governing mass transfer of three common PPPs between water and aquatic plant phases at flow-through exposure conditions (transient aqueous-phase PPP-peak of 4 h 25 min) using three temperature regimes. The exposure produced rapid sorption of PPPs to plants, followed by a gradual depuration from plants. Dynamic sorption kinetics depended on temperature, plant species, and physicochemical properties of the PPPs. Sorption to plants contributed to a 10% reduction of the water-phase peak concentrations of the PPPs. However, being reversible, the attenuation effect was limited to the residence time of the PPPs in the systems. Results of the present study highlight that effectivity of aquatic plants in the attenuation of PPP loads may vary greatly depending on hydrodynamic properties of aquatic systems.
    Keywords: Dynamic Sorption ; Plant Protection Product ; Pesticide ; Specific Surface Area ; Risk Attenuation ; Aquatic Plants ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 18
    Language: English
    In: Chemosphere, 1996, Vol.32(10), pp.1963-1969
    Description: The suspended particle sampler (SPS) for monitoring pesticide concentrations in small streams is described. The sampler was evaluated in a small headwater stream in northern Germany which was contaminated with the insecticide fenvalerate during rainfall in June 1994. The amount retained by the SPS decreased with increasing flow rate. The results obtained with the SPS were compared with those obtained using a runoff-triggered sampler and with those obtained by analysis of bottom sediment. Concentrations obtained using the SPS, runoff-triggered sampler and analysis of bottom sediment were 71, 302 and 10.9 ug fenvalerate per kg. Suspended particles were more heavily contaminated than the stream bed. Temporal dynamics of contamination of suspended particles with fenvalerate and parathion were studied.
    Keywords: Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 19
    Language: English
    In: Chemosphere, 2007, Vol.68(4), pp.605-612
    Description: Spraydrift and edge-of-field runoff are important routes of pesticide entry into streams. Pesticide contamination originating from spraydrift usually resides in the water phase, while pesticides in contaminated runoff are to a large extent associated with suspended particles (SPs). The effects of two organophosphorous insecticides (OPs), chloropyrifos (CPF) and azinphos-methyl (AZP), on acetylcholinesterase (AChE) activity in rainbow trout were compared between two exposure scenarios, simulating spraydrift- and runoff-borne contamination events in the Lourens River (LR), Western Cape, South Africa. NOECs of brain AChE inhibition, determined after 1 h of exposure followed by 24 h of recovery, were 0.33 μg l for aqueous CPF, 200 mg kg for SP-associated CPF and 20 mg kg for SP-associated AZP (at 0.5 g l SP). The highest aqueous AZP concentration tested (3.3 μg l ) was without significant effects. Previously reported peak levels of aqueous CPF in the LR (∼0.2 μg l ) are close to its NOEC (this study), suggesting a significant toxicological risk to fish in the LR. By contrast, reported levels of SP-associated OPs in the LR are 20–200-fold lower than their NOECs (this study). In a comparative in situ study, trout were exposed for seven days at agricultural (LR2, LR3) and upstream reference (LR1) sites. No runoff occurred during the study. Brain AChE was significantly inhibited at LR3. However, OP levels at LR3 (CPF 0.01 μg l ; AZP 0.14 μg l ) were minor compared to concentrations having effects in the laboratory (see above). Additionally, muscle AChE activity was significantly higher in caged trout from LR1 than in animals maintained in laboratory tanks.
    Keywords: Biomonitoring ; Fish ; Biomarker ; Spraydrift ; Runoff ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 20
    Language: English
    In: Aquatic Toxicology, August 2015, Vol.165, pp.154-159
    Description: In aquatic ecosystems, titanium dioxide nanoparticles (nano-TiO ) may adsorb co-occurring chemical stressors, such as copper (Cu). This interaction has the potential to reduce the concentration of dissolved Cu due to surface binding to the nanoparticles. The subsequent sedimentation of nano-TiO agglomerates may increase the exposure of benthic species towards the associated Cu. This scenario was assessed by employing the amphipod as model species and taking advantage of a 2 × 2-factorial design investigating absence and presence of 2 mg nano-TiO /L and 40 μg Cu/L ( = 45; = 24 d) in darkness, respectively. Nano-TiO alone did not affect mortality and leaf consumption, whereas Cu alone caused high mortality (〉70%), reduced leaf consumption (25%) and feces production (30%) relative to the control. In presence of nano-TiO , Cu-induced toxicity was largely eliminated. However, independent of Cu, nano-TiO decreased the gammarids’ assimilation and weight. Hence, nano-TiO may be applicable as Cu-remediation agent, while its potential long-term effects need further attention.
    Keywords: Heavy Metal ; Benthic Invertebrates ; Energy Processing ; Remediation ; Combined Toxicity ; Chemistry ; Ecology
    ISSN: 0166-445X
    E-ISSN: 1879-1514
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