| 31. |
- Bundschuh, Mirco
(author)
-
Impacts of invasive plants on resident animals across ecosystems, taxa, and feeding types: a global assessment
- 2016
-
In: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 22, s. 594-603
-
Journal article (peer-reviewed)abstract
- As drivers of global change, biological invasions have fundamental ecological consequences. However, it remains unclear how invasive plant effects on resident animals vary across ecosystems, animal classes, and functional groups. We performed a comprehensive meta-analysis covering 198 field and laboratory studies reporting a total of 3624 observations of invasive plant effects on animals. Invasive plants had reducing (56%) or neutral (44%) effects on animal abundance, diversity, fitness, and ecosystem function across different ecosystems, animal classes, and feeding types while we could not find any increasing effect. Most importantly, we found that invasive plants reduced overall animal abundance, diversity and fitness. However, this significant overall effect was contingent on ecosystems, taxa, and feeding types of animals. Decreasing effects of invasive plants were most evident in riparian ecosystems, possibly because frequent disturbance facilitates more intense plant invasions compared to other ecosystem types. In accordance with their immediate reliance on plants for food, invasive plant effects were strongest on herbivores. Regarding taxonomic groups, birds and insects were most strongly affected. In insects, this may be explained by their high frequency of herbivory, while birds demonstrate that invasive plant effects can also cascade up to secondary consumers. Since data on impacts of invasive plants are rather limited for many animal groups in most ecosystems, we argue for overcoming gaps in knowledge and for a more differentiated discussion on effects of invasive plant on native fauna.
|
|
| 32. |
- Bundschuh, Mirco
(author)
-
Mitigation of fungicide pollution in detention ponds and vegetated ditches within a vine-growing area in Germany
- 2016
-
In: Ecological Engineering. - : Elsevier BV. - 0925-8574 .- 1872-6992. ; 89, s. 121-130
-
Journal article (peer-reviewed)abstract
- Large amounts of fungicides are commonly applied to agricultural fields, particularly vineyards. Following their application, fungicides may accidentally be introduced into agricultural surface waters posing a potential risk for the integrity of aquatic ecosystems. In this context, the present study characterized the aquatic fungicide exposure at base flow and during rainfall-related runoff events in viticulture in Southern Palatinate (SW-Germany) between 2006 and 2009. The mitigation performance of three vegetated ditches (VD) and five vegetated detention ponds (DP) was assessed. The measurements uncovered the presence of 4 to 11 different fungicide compounds in each of the 81 samples. During runoff events, the ecotoxicological potential-expressed as the sum of toxic units calculated based on the acute toxicity towards algae, Daphnia and fish-of some of the mixtures detected at the inlet of the VD or DP exceeded the Uniform Principle threshold set by the European Union. Both the VD and the DP systems reduced the median fungicide concentrations and thus their associated ecotoxicological potential by 56% and 38%, respectively. This fungicide mitigation efficiency was mainly explained by the plant density and size-related properties of the vegetated systems. Although VP and DP are promising tools to mitigate fungicide exposure, a better mechanistic understanding of the factors triggering the remediation potential finally feeding back into policy decision making is required. (C) 2015 Elsevier B.V. All rights reserved.
|
|
| 33. |
- Bundschuh, Mirco
(author)
-
Modeling Remobilization of Neonicotinoid Residues from Tree Foliage in Streams-A Relevant Exposure Pathway in Risk Assessment?
- 2017
-
In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51, s. 1785-1794
-
Journal article (peer-reviewed)abstract
- Systemic neonicotinoid insecticides are increasingly used as a crop protection measure to suppress insect pests on trees. However, senescent foliage falling from treated trees represents a rarely studied pathway through which neonicotinoids may enter nontarget environments, e.g., surface waters. To estimate risk posed by this pathway, neonicotinoid residues were analyzed in foliage from black alder trees treated with one of three neonicotinoid insecticides (imidacloprid, thiacloprid, or acetamiprid) at five concentrations, each ranging from 0.0375-9.6 g active ingredient/cm trunk diameter at breast height (n = 3). Foliar residues measured at the time of leaf fall were used as input parameters for a model predicting imidacloprid water concentrations over a 100-m-long stream stretch as a consequence of remobilization from introduced foliage (input: 600 g foliage/m(2) containing 80 mu g imidacloprid/g). The water concentration (up to,similar to 250 mu g/L) predicted by the model exceeded the recently proposed Maximum Permissible Concentration of 8.3 mu g/L for 15.5 days. Moreover, dietary uptake was identified as an additional exposure route for aquatic organisms. The alternative pathway (i.e., introduction via leaf fall) and exposure route (i.e., dietary uptake) associated with the systemic nature of neonicotinoids should be accounted for during their registration process in order to safeguard ecosystem integrity.
|
|
| 34. |
- Bundschuh, Mirco
(author)
-
Monitoring the Fate and Transformation of Silver Nanoparticles in Natural Waters
- 2016
-
In: Bulletin of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0007-4861 .- 1432-0800. ; 97, s. 449-455
-
Research review (peer-reviewed)abstract
- There is potential for silver nanoparticles (AgNPs) to be released into surface waters and thus affect aquatic organisms. However, agglomeration, dissolution, surface modifications and chemical speciation are important transformation processes that control the toxicity of AgNPs. Analytical methods are needed to determine the size distribution, mass and form of AgNPs and other silver species in natural waters. Cloud point extraction, single particle inductively coupled plasma mass spectrometry (spICP-MS) and asymmetric flow field flow fractionation with on-line ICP-MS (AF4-ICP-MS) are analytical techniques that show potential for quantitative analysis of AgNPs in aquatic matrices at environmentally relevant concentrations. In this review, we discuss the fate processes for AgNPs in natural waters and the analytical methods that can be used to determine the distribution of AgNPs and their transformation products.
|
|
| 35. |
- Bundschuh, Mirco
(author)
-
Multiple exposure routes of a pesticide exacerbate effects on a grazing mayfly
- 2016
-
In: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 178, s. 190-196
-
Journal article (peer-reviewed)abstract
- Hydrophobic pesticides such as pyrethroid insecticides tend to occur in their soluble form mainly as transient pulses in streams. In addition, they are regularly detected in significant quantities adsorbed to stream sediments and other organic in-stream structures. Consequently, stream biota is likely subjected to pesticide exposure via multiple routes. In this study we aimed at investigating the influence of exposure routes for the pyrethroid insecticide lambda-cyhalothrin on the grazing mayfly Heptagenia sulphurea. Therefore, H. sulphurea was exposed to lambda-cyhalothrin via single- (water or biofilm) or biphasic exposure (water and biofilm) at environmentally realistic concentrations (0, 0.1, 1 mu g L-1) and exposure duration (2 h) in a full factorial design (n = 5). Mortality, moulting frequency, and biofilm accrual (proxy for feeding rate) were recorded subsequent to a 7 d post exposure period. Mortality significantly increased and moulting frequency significantly decreased with increasing concentrations of lambda-cyhalothrin in the water phase whereas exposure via biofilm prompted no significant effects on these endpoints (alpha=0.05). Effect predictions systematically underestimated and overestimated effects for mortality and moulting frequency, respectively. Similarly, mayfly feeding rate was significantly reduced by water phase exposure whereas pre-exposed biofilm did not significantly affect this variable. However, we found a significant but non-systematic interaction between water phase and biofilm exposure on mayfly feeding rate. Our results show that exposure to the same pesticide via multiple exposure routes may increase the magnitude of effects beyond the level predicted from single phase exposures which has clear implications for the aquatic risk assessment of hydrophobic pesticides. However, our results additionally reveal that interactions between pesticide exposure routes may vary between selected dependent variables. We emphasize that unravelling the underlying mechanisms causing these discrepancies in interactive effects between exposure routes is a major aspect that should receive further attention in future research. (C) 2016 Elsevier B.V. All rights reserved.
|
|
| 36. |
- Bundschuh, Mirco
(author)
-
Nanosized titanium dioxide influences copper-induced toxicity during aging as a function of environmental conditions
- 2016
-
In: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 35, s. 1766-1774
-
Journal article (peer-reviewed)abstract
- Titanium dioxide nanoparticles (TiO2-NPs) adsorb co-occurring heavy metals in surface waters, modulating their toxicity for freshwater invertebrates. The processes triggering this interaction may be influenced by several environmental parameters; however, their relative importance remains unclear. The present study assessed the implications of aging on the joint acute toxicity of copper (Cu) and TiO2-NPs for Daphnia magna over a duration of up to 72h. The influences of aging duration as well as ionic strength, pH, and presence of different qualities of organic matter during aging were assessed. The results indicated that the presence of TiO2-NPs often reduced the Cu-induced toxicity for daphnids after aging (albeit with varying extent), which was displayed by up to 3-fold higher EC50 (50% effective concentration) values compared to the absence of TiO2-NPs. Moreover, the Cu speciation, influenced by the ionic composition and the pH as well as the presence of organic additives in the medium, strongly modulated the processes during aging, with partly limited implications of the aging duration on the ecotoxicological response of D. magna. Nonetheless, the present study underpins the potential of TiO2-NPs to modify toxicity induced by heavy metals in freshwater ecosystems under various environmental conditions. This pattern, however, needs further verification using heavy metal ions with differing properties in combination with further environmental factors, such as ultraviolet irradiation. Environ Toxicol Chem 2016;35:1766-1774. (c) 2015 SETAC
|
|
| 37. |
- Bundschuh, Mirco
(author)
-
Narrow pH Range of Surface Water Bodies Receiving Pesticide Input in Europe
- 2016
-
In: Bulletin of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0007-4861 .- 1432-0800. ; 96, s. 3-8
-
Journal article (peer-reviewed)abstract
- Fate and toxicity of the active ingredients (AI's) of plant protection products in surface waters is often influenced by pH. Although a general range of pH values is reported in literature, an evaluation targeting aquatic ecosystems with documented AI inputs is lacking at the larger scale. Results show 95 % of European surface waters (n = 3075) with a documented history of AI exposure fall within a rather narrow pH range, between 7.0 and 8.5. Spatial and temporal variability in the data may at least be partly explained by the calcareous characteristics of parental rock material, the affiliation of the sampling site to a freshwater ecoregion, and the photosynthetic activity of macrophytes (i.e., higher pH values with photosynthesis). Nonetheless, the documented pH range fits well with the standard pH of most ecotoxicological test guidelines, confirming the fate and ecotoxicity of AIs are usually adequately addressed.
|
|
| 38. |
- Bundschuh, Mirco
(author)
-
Oxidized Carbo-Iron causes reduced reproduction and lower tolerance of juveniles in the amphipod Hyalella azteca
- 2016
-
In: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 181, s. 94-103
-
Journal article (peer-reviewed)abstract
- 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(0) 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 Hyalella azteca was selected as a surrogate test species for functionally important groundwater crustaceans. Effects of Carbo-Iron on H. azteca 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 H. azteca 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 H. azteca 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 H. azteca 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 H. azteca. (C) 2016 Elsevier B.V. All rights reserved.
|
|
| 39. |
- Bundschuh, Mirco
(author)
-
Prioritizing stream types according to their potential risk to receive crop plant material - A GIS-based procedure to assist in the risk assessment of genetically modified crops and systemic insecticide residues
- 2016
-
In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 547, s. 226-233
-
Journal article (peer-reviewed)abstract
- Crop plant residues may enter aquatic ecosystems via wind deposition or surface runoff. In the case of genetically modified crops or crops treated with systemic pesticides, these materials may contain insecticidal Bt toxins or pesticides that potentially affect aquatic life. However, the particular exposure pattern of aquatic ecosystems (i.e., via plant material) is not properly reflected in current risk assessment schemes, which primarily focus on waterborne toxicity and not on plant material as the route of uptake. To assist in risk assessment, the present study proposes a prioritization procedure of stream types based on the freshwater network and crop-specific cultivation data using maize in Germany as a model system. To identify stream types with a high probability of receiving crop materials, we developed a formalized, criteria-based and thus transparent procedure that considers the exposure-related parameters, ecological status - an estimate of the diversity and potential vulnerability of local communities towards anthropogenic stress - and availability of uncontaminated reference sections. By applying the procedure to maize, ten stream types out of 38 are expected to be the most relevant if the ecological effects from plant-incorporated pesticides need to be evaluated. This information is an important first step to identifying habitats within these stream types with a high probability of receiving crop plant material at a more local scale, including accumulation areas. Moreover, the prioritization procedure developed in the present study may support the selection of aquatic species for ecotoxicological testing based on their probability of occurrence in stream types having a higher chance of exposure. Finally, this procedure can be adapted to any geographical region or crop of interest and is, therefore, a valuable tool for a site-specific risk assessment of crop plants carrying systemic pesticides or novel proteins, such as insecticidal Bt toxins, expressed in genetically modified crops. (C) 2015 Elsevier B.V. All rights reserved.
|
|
| 40. |
- Bundschuh, Mirco
(author)
-
Procedure to select test organisms for environmental risk assessment of genetically modified crops in aquatic systems
- 2017
-
In: Integrated Environmental Assessment and Management. - : Wiley. - 1551-3777 .- 1551-3793. ; 13, s. 974-979
-
Journal article (peer-reviewed)abstract
- For a long time, the environmental risk assessment (ERA) of genetically modified (GM) crops focused mainly on terrestrial ecosystems. This changed when it was scientifically established that aquatic ecosystems are exposed to GM crop residues that may negatively affect aquatic species. To assist the risk assessment process, we present a tool to identify ecologically relevant species usable in tiered testing prior to authorization or for biological monitoring in the field. The tool is derived from a selection procedure for terrestrial ecosystems with substantial but necessary changes to adequately consider the differences in the type of ecosystems. By using available information from the Water Framework Directive (2000/60/EC), the procedure can draw upon existing biological data on aquatic systems. The proposed procedure for aquatic ecosystems was tested for the first time during an expert workshop in 2013, using the cultivation of Bacillus thuringiensis (Bt) maize as the GM crop and 1 stream type as the receiving environment in the model system. During this workshop, species executing important ecological functions in aquatic environments were identified in a stepwise procedure according to predefined ecological criteria. By doing so, we demonstrated that the procedure is practicable with regard to its goal: From the initial long list of 141 potentially exposed aquatic species, 7 species and 1 genus were identified as the most suitable candidates for nontarget testing programs. Integr Environ Assess Manag 2017;13:974-979. (c) 2017 SETAC
|
|
