In vivo effect confirmation of anti-androgenic compounds in sediment contact tests with Potamopyrgus antipodarum.

In order to investigate the sensitivity of Potamopyrgus antipodarum to anti-androgenic compounds, three spiked sediment tests were performed. The substances benzanthrone (7H-benz[de]anthracen-7-one), traseolide (ATII) and androstenone (5α-Androst-16-en-3-one) were previously identified in an effect-directed analysis study of the river Schijn in the north of Belgium. Although, in previous studies, all of the three compounds exhibited anti-androgenic activities in vitro, only the oxy-PAH benzanthrone had significant stimulating effects on the snails' reproduction.

Sediment contact test with Potamopyrgus antipodarum in effect-directed analyses-challenges and opportunities.

Background And Scope: Effect-directed analysis is increasingly used for the identification of key toxicants in environmental samples and there is a growing need for in vivo biotests as diagnostic tools. Within this study, we performed an in vivo sediment contact test, applicable on both native field samples and their extracts or fractions, in order to be able to compare the results from both field and laboratory studies.

Material And Methods: A sediment contact test with the prosobranch snail, Potamopyrgus antipodarum, was carried out on extracts and fractions of field sediments from three European river basins.

A new risk assessment approach for the prioritization of 500 classical and emerging organic microcontaminants as potential river basin specific pollutants under the European Water Framework Directive.

Given the huge number of chemicals released into the environment and existing time and budget constraints, there is a need to prioritize chemicals for risk assessment and monitoring in the context of the European Union Water Framework Directive (EU WFD). This study is the first to assess the risk of 500 organic substances based on observations in the four European river basins of the Elbe, Scheldt, Danube and Llobregat. A decision tree is introduced that first classifies chemicals into six categories depending on the information available, which allows water managers to focus on the next steps (e.

Effect directed analysis of riverine sediments--the usefulness of Potamopyrgus antipodarum for in vivo effect confirmation of endocrine disruption.

In vivo tests are not commonly used in effect directed analysis (EDA) approaches. In the present study, a novel methodology was developed whereby Potamopyrgus antipodarum, which is known to be sensitive to endocrine disrupting compounds, was used as test organism. Field sediments from a polluted site in the north of Belgium were extracted and fractionated using three coupled and automatically switched normal-phase HPLC columns.

Modeling the chemical and toxic water status of the Scheldt basin (Belgium), using aquatic invertebrate assemblages and an advanced modeling method.

Self-Organizing Maps have been used on monitoring sites in several Scheldt sub-basins to identify the main aquatic invertebrate assemblages and relate them to the physico-chemical and toxic water status. 12 physico-chemical variables and 2 estimates of toxic risk were available for a dataset made up of a total of 489 records. Two of the five defining clusters reflecting a relatively clean environment were composed by very well diversified functional feeding groups and sensitive taxa.

In situ cage experiments with Potamopyrgus antipodarum--a novel tool for real life exposure assessment in freshwater ecosystems.

In situ experiments are an important tool within ecotoxicological research but there is a lack of suitable methodologies especially for freshwater invertebrate species. Within this study, a novel in situ methodology with Potamopyrgus antipodarum was developed. Snails were inserted into cages, made of Plexiglas measuring 7 × 9 × 7 cm(3) and fixed with stainless steel pins into the sediment at the relevant sampling sites.

Assessment of stream biological responses under multiple-stress conditions.

Background, Aim And Scope: Due to the numerous anthropogenic stress factors that affect aquatic ecosystems, a better understanding of the adverse consequences on the biological community of combined pressures is needed to attain the objectives of the European Water Framework Directive. In this study we propose an innovative approach to assess the biological impact of toxicants under field conditions on a large spatial scale.

Materials And Methods: Artificial Neural Network (ANN) analyses, focusing on impacts at the community level, were carried out to identify the relative importance of environmental and toxic stress factors on the patterns observed in the aquatic invertebrate fauna from the Scheldt basin (Belgium).

Characterizing field sediments from three European river basins with special emphasis on endocrine effects - A recommendation for Potamopyrgus antipodarum as test organism.

The assessment of endocrine disrupting potentials of field sediments has until now been mostly limited to classical chemical analysis, in vitro assays and in vivo bioassays performed with vertebrates. There is an urgent need for easy, cheap and reproducible invertebrate tests which may be applied in certain monitoring activities. Since the mudsnail Potamopyrgus antipodarum is known to be tolerant to natural stressors, but also sensitive to endocrine disrupting chemicals, it is very likely that this organism could be suitable for the assessment of endocrine effects of e.

Diagnosis of ecosystem impairment in a multiple-stress context--how to formulate effective river basin management plans.

The Water Framework Directive (WFD) of the European Union requires member states to attain a good ecological status for all water bodies by the year 2015. This implies that the bioecological protection endpoint itself is upfront, next to abiotic chemical quality standards, as tools to protect those endpoints. Within the requirements of the Directive, ecological status and abiotic conditions will be monitored extensively.

Toward an integrated assessment of the ecological and chemical status of European river basins.

Here, recommendations to improve ecological and chemical status assessments in accordance with the European Water Framework Directive (WFD) are made on the basis of experience gained from the MODELKEY project database, linking existing biological and chemical monitoring data of 3 case study river basins (Elbe, Scheldt, and Llobregat). The data analysis within and across river basins revealed major obstacles to be tackled, including scarcity of matching ecological and chemical monitoring sites for cause-effect relationships as well as a general lack of stressor-specific metrics for single biological quality elements (BQE) to enable a comprehensive risk assessment of all predominant stressors, including toxicity. An example of such a metric, which is recommended for the BQE of benthic macroinvertebrates, is the trait-based species-at-risk index (SPEAR) that correlated well with a respective measure for toxic stress, referred to as toxic units, based on simple mixture toxicity concepts.

Water quality indices across Europe--a comparison of the good ecological status of five river basins.

The European Water Framework Directive (WFD) requires the definition of near-natural reference conditions to determine the extent of water bodies' deviation from "good ecological status" caused by stress gradients. However, the classification of ecological quality depends on the assessment method applied and the stressor concerned. While assessment methods that are generally applicable would be favourable, many European countries employ the locally developed water quality metrics that assess the impact of organic pollution (including eutrophication) and the associated decrease in dissolved oxygen.

MODELKEY. Models for assessing and forecasting the impact of environmental key pollutants on freshwater and marine ecosystems and biodiversity.

Background: Triggered by the requirement of Water Framework Directive for a good ecological status for European river systems till 2015 and by still existing lacks in tools for cause identification of insufficient ecological status MODELKEY (http:// www.modelkey.org), an Integrated Project with 26 partners from 14 European countries, was started in 2005.