Matthias Liess

..By focusing on the ecological effect of selected environmental factors, trait-based approaches offer an increased realism for risk assessment of toxicants on the ecosystem level...

..The results emphasize the importance of considering ecological traits and recolonization processes on the landscape level for ecotoxicological risk assessment...

..Possible mechanisms that sustain the effects of toxicants may be delayed life-history effects on the individual level and elevated competition because of altered population structure on the population level...

..We conclude that competition needs to be considered in order to understand and predict recovery of size structure...

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..Realistic prediction of community recovery dynamics requires consideration of the species' life-cycle traits...

..g. losses with surface runoff)...

..Usage of SPEAR(organic) as a stressor-specific longitude-independent measure will facilitate detection of community disturbance by organic toxicants...

..Hence, natural communities might be disturbed for a longer period by toxic exposure than predicted from single-species tests alone...

..Our findings illustrate the importance of considering more environmentally relevant conditions (i.e. low maternal food level, short-term exposure) when linking effects observed in laboratory tests to potential risks in the field...

..These findings indicate that environmental context is more important for ecotoxicological evaluation than assumed previously...

..We concluded that a pulsed FV exposure may result in long-term reduction of r that can be predicted only with more environmentally relevant toxicity tests, as described in the present study...

..Such spatially explicit mapping of risk enables the planning of adaptation and mitigation strategies including vegetated buffer strips and nonagricultural recolonization zones along streams...

..magna is least sensitive among the arthropods tested and that, for neonicotinoid insecticides, an insect like the mosquito C. pipiens would be more suitable for predicting effects on sensitive species...

..The sensitivities for several taxa are listed, and use of the relative sensitivity distribution to link toxicant effects in mesocosm studies and field investigations is discussed...

..We suggest that the method presented here be used for the extraction and quantitation of particle-associated polar pesticides...

..Field investigations showed that the screening approach produced appropriate estimates of ecological risk from pesticide runoff for selected regions in Finland, France and Germany...

..1 up to 1 microg/L. In contrast, no substantial recovery occurred in the continuous-exposure regime...

..Therefore, we suggest RP for a first quick and cost-effective location of potential runoff hot spots at the landscape level...

..These results show that the alarm response can be inhibited by low levels of fenvalerate, and this inhibition seems to increase larval mortality due to predation...

..In cases of exposure to such toxicants, the monitoring of feeding activity may predict long-term effects on population parameters...

..Owing to interspecific interactions, the recovery of one species can only be assessed by considering its community context...

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..1, while in the control series it was around 0.3. The results indicate that concentrations of some toxicants that are nontoxic in standard tests can cause harmful population-level effects when combined with UV...

..We conclude that the exposure and effect model can act as an effective and cost-saving tool to identify high risk areas of insecticide exposure and to support stream management...

..We conclude that the Chemcatcher is suitable for the monitoring of polar organic toxicants and presents an alternative to conventional spot sampling in the monitoring of episodically occurring pollutants...

..Short-term contamination events may be underestimated in passive sampling when the receiving phase is biofouled or a diffusion-limiting membrane is employed...

..pipiens. Based on these results, we suggest that competing zooplankton species, such as D. magna, could be used for the control of mosquito species such as Cx. pipiens. This approach could be beneficial for the management of wetlands...

..e., high conservation value and low nuisance and disease transmission risk) for conservation activities, and conversely for control measures...

..1 microg/L) and, thus, effects of the toxicant are not compensated. Accordingly, the response to toxicants at the population level when negative interaction is present differs from the response at individual level...

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..Our study expands the applicability of the Chemcatcher for monitoring trace concentrations of pesticides with frequent occurrence in water...

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..Our findings demonstrate that pesticides may influence the structure and function of lotic ecosystems and that the SPEAR approach can be used as a powerful tool in biomonitoring over large spatial scales...

..These probably provided a source of organisms for downstream recolonization and amelioration of effects at high RP...

..By contrast, reproductive outputs of survivors exposed continuously remained impaired. These results suggest that a refined risk assessment should consider exposure duration because it influences the magnitude of effects and recovery...

..We conclude that assessing biotic interactions is essential to understand and hence predict the effects and recovery from toxicant stress in communities...

..We recommend the Nanocosm system as a novel tool for the simplified integration of competition into environmental and ecotoxicological research as well as for the assessment of risk due to stressors...

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..8 and 0.5%, respectively. Therefore, the promotion of competing species might be an appropriate ecological approach for the control of Aedes spp. in temporary ponds in these areas...

..Therefore, we conclude that to tackle the current pressing challenges, ecotoxicology has to progress using both the bottom-up and top-down approaches, similar to digging a tunnel from both ends at once...

..These results showed thus that non-sigmoidal concentration-response relationship and sizes of individuals should be considered in monitoring programmes and risk assessment...

..In comparison, stream B had only farmyard runoff and non-point sources, which caused high peaks of herbicide and a contamination by insecticides. Consequently, high-water phases generated 70% of the total pesticide load...

..We found parathion-ethyl concentrations of 0.3 microg l(-1), diuron up to 17.3 microg l(-1), ethofumesate up to 51.1 microg l(-1), metamitron up to 92 microg l(-1) and prosulfocarb up to 130 microg l(-1)...

..Therefore the factor "risk of runoff" is considered to express a significant proportion of the variability in macroinvertebrate communities caused by stressors of agricultural origin...

..The authors assume that in limited-food conditions, lethal and sublethal effects reduced competition between individuals, resulting in significantly increased final survival...

..71; p<or=0.01; tebuconazole: r2=0.77; p<or=0.01. The present model successfully explains the pesticide concentrations associated with single entry events caused by runoff, especially at concentration levels above (>or=0.5 microg/l)...

..The use of models as both interpretive and predictive tools is discussed, with suggestions of appropriate methods for different protection goals...