La biosurveillance

National audienceLorsque l'on cherche a proteger les ecosystemes contre des agressions exterieures, en general liees a l'activite humaine, qui perturbent leurs mecanismes biologiques, l'idee la plus simple est de chercher au sein des organismes vivants les temoins de ces perturbations. La notion de bio-surveillance vient de la

Apport de la modélisation aux études écotoxicologiques

National audienceL'ecotoxicologie s'interesse aussi bien aux effets qu'au devenir des toxiques dans les ecosystemes. Une molecule donnee se caracterise donc par deux types de comportements modelisables selon que l'on considere son devenir au sein des ecosystemes ou son action sur les biocenoses. Les ecotoxicologues ont egalement mis au point des biomarqueurs qui permettent de detecter les effets des polluants sur le terrain, les modeles multivaries sont alors les plus performants pour aider a la comprehension des phénomènes complexes apparaissant in situ

The role of ecotoxicology for monitoring ecosystem health

The proposed EC Water Framework Directive (WFD) incorporates somenew concepts in the field of water protection. Most of these concepts relyon the use of applied ecology of water ecosystems. The most importantfeature is that the classification of water quality is to be based on directbiological measurements of ecosystem health. It means that real biologicalcommunities should be sampled and the taxa identified. A diagnosis onecosystem health should result from this. The diagnosis is derived fromcomparing impacted zones with reference zones, where minimum humanpressure is proven

Pesticide risk assessment and management in a globally changing world—report from a European interdisciplinary workshop

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA [Axe_IRSTEA]DTAM-QT2-ADAPTATION [TR2_IRSTEA]ARCEAU [TR2_IRSTEA]DTAMGlobal climate change will affect worldwide agriculture in many ways. The anticipated or already occurring changes raise concerns about the sustainability of production and the ability of agriculture to feed human populations. This appeals to sustainable agriculture providing ecosystem services more efficiently than today, and accordingly to substantial evolutions of pesticide risk assessment (RA) and risk management (RM). The RA/RM issues were discussed by two European research networks in a 2011 workshop. The RA-RM-monitoring conceptual cycle tends to be virtual, with poor connections between certain steps. The design of more comprehensive emissions scenarios could improve the accuracy of predicted runoff transport, while the microcosm/mesocosm approach could help establish causal relationships between fate / exposure and populations / communities. Combined with ecological modelling, effects can be extrapolated to higher spatial and temporal scales. Risk management of diffuse sources should be designed simultaneously at the watershed and individual plot scales. Monitoring is key to assessing the effectiveness of risk reduction measures reduce and evaluate the overall quality of the aquatic compartment. More flexible monitoring strategies clearly linked to RM decisions are therefore needed. Although some technical questions remain, it is time to apply passive samplers more routinely. A set of research and development needs covering the whole RA/RM cycle is listed in conclusion

Behavioural and Physiological Responses of Gammarus pulex Exposed to Cadmium and Arsenate at Three Temperatures: Individual and Combined Effects

This study aimed at investigating both the individual and combined effects of cadmium (Cd) and arsenate (AsV) on the physiology and behaviour of the Crustacean Gammarus pulex at three temperatures (5, 10 and15°C). G. pulex was exposed during 96 h to (i) two [Cd] alone, (ii) two [AsV] alone, and (iii) four combinations of [Cd] and [AsV] to obtain a complete factorial plane. After exposure, survival, [AsV] or [Cd] in body tissues, behavioural (ventilatory and locomotor activities) and physiological responses (iono-regulation of [Na+] and [Cl−] in haemolymph) were examined. The interactive effects (antagonistic, additive or synergistic) of binary mixtures were evaluated for each tested temperature using a predictive model for the theoretically expected interactive effect of chemicals. In single metal exposure, both the internal metal concentration in body tissues and the mortality rate increased along metallic gradient concentration. Cd alone significantly impaired both [Na+] and [Cl−] while AsV alone had a weak impact only on [Cl−]. The behavioural responses of G. pulex declined with increasing metal concentration suggesting a reallocation of energy from behavioural responses to maintenance functions. The interaction between AsV and Cd was considered as ‘additive’ for all the tested binary mixtures and temperatures (except for the lowest combination at 10°C considered as “antagonistic”). In binary mixtures, the decrease in both ventilatory and locomotor activities and the decline in haemolymphatic [Cl−] were amplified when respectively compared to those observed with the same concentrations of AsV or Cd alone. However, the presence of AsV decreased the haemolymphatic [Na+] loss when G. pulex was exposed to the lowest Cd concentration. Finally, the observed physiological and behavioural effects (except ventilation) in G. pulex exposed to AsV and/or Cd were exacerbated under the highest temperature. The discussion encompasses both the toxicity mechanisms of these metals and their interaction with rising temperature

Selection of reliable biomarkers from PCR array analyses using relative distance computational model: Methodology and proof-of-concept study

10.1371/journal.pone.0083954PLoS ONE812-POLN

La biosurveillance de l'environnement

International audienceThe most simple idea concerning ecosystems protection against external perturbations is to measure directly the effects on living organisms. Biomonitoring originates from that idea. This is particularly true for chemical inputs in the environment. chemical analysis cannot be comprehensive in that respect. Biomonitoring methods have been developed at the laboratory and in the field to achieve ecosystems protection.Lorsque l'on cherche à protéger les écosystèmes contre des agressions extérieures qui perturbent leurs mécanismes biologiques, l'idée la plus simple est de chercher au sein des organismes vivants les témoins de ces perturbations. La notion de bio-surveillance vient de là. Cela est particulièrement vrai en ce qui concerne les rejets de produits chimiques dans l'environnement. Les analystes peuvent détecter des traces de produits chimiques dans des matrices très complexes mais ne peuvent être exhaustives. Les chercheurs ont donc développé depuis de nombreuses années des méthodes de biosurveillance tant au laboratoire que sur le terrain