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.
Microplastic (plastic particles measuring <5mm) pollution is ubiquitous. Unlike in other well‐studied ecosystems, for example, marine and freshwater environments, microplastics in terrestrial systems ...are relatively understudied. Their potential impacts on terrestrial environments, in particular the risk of causing ecological surprise, must be better understood and quantified. Ecological surprise occurs when ecosystem behavior deviates radically from expectations and generally has negative consequences for ecosystem services. The properties and behavior of microplastics within terrestrial environments may increase their likelihood of causing ecological surprises as they (a) are highly persistent global pollutants that will last for centuries, (b) can interact with the abiotic environment in a complex manner, (c) can impact terrestrial organisms directly or indirectly and (d) interact with other contaminants and can facilitate their transport. Here, we compiled findings of previous research on microplastics in terrestrial environments. We systematically focused on studies addressing different facets of microplastics related to their distribution, dispersion, impact on soil characteristics and functions, levels of biological organization of tested terrestrial biota (single species vs. assemblages), scale of experimental study and corresponding ecotoxicological effects. Our systematic assessment of previous microplastic research revealed that most studies have been conducted on single species under laboratory conditions with short‐term exposures; few studies were conducted under more realistic long‐term field conditions and/or with multi‐species assemblages. Studies targeting multi‐species assemblages primarily considered soil bacterial communities and showed that microplastics can alter essential nutrient cycling functions. More ecologically meaningful studies of terrestrial microplastics encompassing multi‐species assemblages, critical ecological processes (e.g., biogeochemical cycles and pollination) and interactions with other anthropogenic stressors must be conducted. Addressing these knowledge gaps will provide a better understanding of microplastics as emerging global stressors and should lower the risk of ecological surprise in terrestrial ecosystems.
Our systematic assessment of previous microplastic research revealed that most studies have been conducted on single species (50%) compared to studies targeting exclusively multi‐species assemblages (36%). The results of single species testing showed that microplastics are rarely lethal for terrestrial organisms, but rather induce sub‐lethal effects including oxidative stress, reproductive impairment and physical changes. Studies targeting multi‐species assemblages primarily considered soil microbial communities and showed that microplastics can alter essential nutrient cycling functions. More ecologically meaningful studies of terrestrial microplastics encompassing multi‐species assemblages and/or critical ecological processes (e.g., biogeochemical cycles and pollination) must be conducted.
This paper presents the ecotoxicological assessment and environmental risk evaluation of complex pesticide mixtures occurring in freshwater ecosystems in southern Sweden. The evaluation is based on ...exposure data collected between 2002 and 2013 by the Swedish pesticide monitoring program and includes 1308 individual samples, detecting mixtures of up to 53 pesticides (modal=8). Pesticide mixture risks were evaluated using three different scenarios for non-detects (best-case, worst-case and using the Kaplan-Meier method). The risk of each scenario was analyzed using Swedish Water Quality Objectives (WQO) and trophic-level specific environmental thresholds.
Using the Kaplan-Meier method the environmental risk of 73% of the samples exceeded acceptable levels, based on an assessment using Concentration-Addition and WQOs for the individual pesticides. Algae were the most sensitive organism group. However, analytical detection limits, especially for insecticides, were insufficient to analyze concentrations at or near their WQO's. Thus, the risk of the analyzed pesticide mixtures to crustaceans and fish is systematically underestimated. Treating non-detects as being present at their individual limit of detection increased the estimated risk by a factor 100 or more, compared to the best-case or the Kaplan-Meier scenario.
Pesticide mixture risks are often driven by only 1–3 compounds. However, the risk-drivers (i.e., individual pesticides explaining the largest share of potential effects) differ substantially between sites and samples, and 83 of the 141 monitored pesticides need to be included in the assessment to account for 95% of the risk at all sites and years.
Single-substance oriented risk mitigation measures that would ensure that each individual pesticide is present at a maximum of 95% of its individual WQO, would also reduce the mixture risk, but only from a median risk quotient of 2.1 to a median risk quotient of 1.8. Also, acceptable total risk levels would still be exceeded in more than 70% of the samples.
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•Detected pesticide mixtures regularly exceed the Swedish threshold concentrations.•Analytical detection-limits for insecticides often exceeds concentration thresholds.•83 of 141 pesticides are needed to explain 95% of estimated risk across all samples.•No change in risk from pesticide mixtures can be seen between 2002 and 2013.•Single substance risk mitigation will not lower mixture risks to acceptable levels.
This paper presents the ecotoxicological assessment and environmental risk evaluation of complex pesticide mixtures occurring in freshwater ecosystems in southern Sweden. The evaluation is based on ...exposure data collected between 2002 and 2013 by the Swedish pesticide monitoring program and includes 1308 individual samples, detecting mixtures of up to 53 pesticides (modal = 8). Pesticide mixture risks were evaluated using three different scenarios for non-detects (best-case, worst-case and using the Kaplan-Meier method). The risk of each scenario was analyzed using Swedish Water Quality Objectives (WQO) and trophic-level specific environmental thresholds.Using the Kaplan-Meier method the environmental risk of 73% of the samples exceeded acceptable levels, based on an assessment using Concentration-Addition and WQOs for the individual pesticides. Algae were the most sensitive organism group. However, analytical detection limits, especially for insecticides, were insufficient to analyze concentrations at or near their WQO's. Thus, the risk of the analyzed pesticide mixtures to crustaceans and fish is systematically underestimated. Treating non-detects as being present at their individual limit of detection increased the estimated risk by a factor 100 or more, compared to the best-case or the Kaplan-Meier scenario. Pesticide mixture risks are often driven by only 1-3 compounds. However, the risk-drivers (i.e., individual pesticides explaining the largest share of potential effects) differ substantially between sites and samples, and 83 of the 141 monitored pesticides need to be included in the assessment to account for 95% of the risk at all sites and years. Single-substance oriented risk mitigation measures that would ensure that each individual pesticide is present at a maximum of 95% of its individual WQO, would also reduce the mixture risk, but only from a median risk quotient of 2.1 to a median risk quotient of 1.8. Also, acceptable total risk levels would still be exceeded in more than 70% of the samples. (C) 2017 Elsevier B.V. All rights reserved.
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.
Summary
Fine particulate organic matter (FPOM) provides a key longitudinal link within stream networks, and is the predominant food source for filter‐ and deposit‐feeding invertebrates, collectively ...classified as ‘collectors’.
Organisms involved in producing and using FPOM are sensitive to chemical and other anthropogenic stressors, but information on such impacts, and on FPOM dynamics in general, is limited.
Here, we review information on the ecological role of FPOM in streams, and discuss potential impacts on FPOM dynamics of organic and inorganic chemical stressors, including metals and pesticides. Emphasis is placed on faecal particles produced within the leaf‐litter processing chain.
Key biological factors controlling the resource quality of FPOM for collectors include the identity of the invertebrates producing FPOM, and the nutritional quality of their food resources. FPOM nutrient content is also strongly influenced by microbial colonisation and activity, and FPOM processing rates are thus likely to be sensitive to the impacts of stressors affecting microbes, including nutrients and antimicrobial chemicals.
The potential for FPOM to bind and subsequently transport chemical stressors is high, particularly for hydrophobic compounds, but the extent of such effects and impacts on collectors consuming contaminated particles has attracted only limited attention.
Combining concepts and research approaches from ecotoxicology and basic stream ecology would facilitate development of a common integrated framework for understanding the role of FPOM, and assessing anthropogenic impacts on FPOM dynamics in stream networks.
Ozone application is an effective tool to reduce loads of (micro)pollutants in wastewater, however, its ecotoxicological implications are largely unknown. Therefore, the feeding rates of a ...leaf-shredding invertebrate (
Gammarus fossarum) exposed to secondary (=non-ozone) or ozone treated wastewater were investigated to assess potential ecotoxicological effects. Two repetitive experiments resulted in significantly higher feeding rates for gammarids exposed to ozone compared to non-ozone treated wastewater sampled from a treatment plant equipped with a full-scale ozonation. A further experiment confirmed these results also for wastewater from the same treatment plant, when ozonation was conducted at the lab-scale. However, the deviations in dissolved organic carbon profiles of ozone and non-ozone wastewater did not seem to be the driving factor for the effects observed. Two additional experiments displayed on the one hand a higher feeding rate of
G. fossarum if exposed to ten-fold enriched eluates from solid phase extraction cartridges loaded with ozone compared to non-ozone treated wastewater. On the other hand, the mean feeding rate of gammarids exposed to non-ozone treated wastewater, which contained hardly any (micro)pollutants (i.e. pharmaceuticals), was at the same level as wastewater from the same source additionally treated with ozone. These results suggest that not an alteration in the organic matrix but a reduction in the load of micropollutants most likely triggered the effects in the bioassay applied. Hence, the feeding rate of
G. fossarum appears to be a well-suited bioassay to indicate alterations in ecotoxicological properties of wastewater due to the application of advanced oxidation processes like ozonation.
► Ozonation of municipal wastewater reduces ecotoxicity for gammarids. ► Alteration in organic matrix caused by ozonation did not affect gammarids. ► Loads of micropollutants seem to trigger the effects in the
Gammarus feeding assay. ► Feeding assays suggest to be suitable to evaluate advance oxidation techniques.
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