LES ESCARGOTS BIO-INDICATEURS DE LA QUALITE DES SOLS - Snail watch : analyse en laboratoire ou in situ de la biodisponibilité des contaminants

http://www2.ademe.fr/servlet/KBaseShow?sort=-1&cid=96&m=3&catid=10143fiche outil 4 pagesCe document est une fiche outil présentant les possibilités d'utilisation des escargots pou analyse en laboratoire ou in situ de la biodisponibilité des contaminants. Cette fiche a été mise en ligne sur le site de l'ADEME/ sites pollués et sols/ outils méthodologiques: http://www2.ademe.fr/servlet/KBaseShow?sort=-1&cid=96&m=3&catid=1014

Sustainable control of grassland small mammals

International audienceSmall mammals such as the European rabbits, the plateau pikas, the prairie dogs have been traditionally perceived as pests and targeted for control on a large scale despite their importance as key-stone species in their native ecosystem. This is also the case for the fossorial form of the water vole (Arvicola terrestris). This species can reach large population densities and causes heavy damage to grassland with subsequent economic losses for farmers (9,000 to 25,000 € for a 70 ha farm during an outbreak year in Franche-Comté, France). However, higher population densities of A. terrestris and also of Microtus arvalis, help maintaining a large and rich community of vole predators. Such non-target species (red kite, common buzzard, wild boar, red fox, etc.) are impacted, some of them heavily, by the unconditional use of rodenticides (e.g. bromadiolone). In order to minimize the use of rodenticides in controlling A. terrestris populations, a long term research program has been undertaken since the late 80s, aiming at identifying the key-parameters of such regional systems. Based on a systems approach, this collaborative research network involves academic researchers, farmer, game, conservationist organizations and governmental and local administrations together. On a regional scale (area of about 2500 km2), Delattre et al. (1992), Giraudoux et al. (1997), Fichet et al. (2000) provided evidence that M. arvalis and A. terrestris population dynamic patterns correlate with land composition. On a sectorial scale (area of about 25 km2), Delattre et al. (1996), Delattre et al. (1999) showed for M. arvalis that landscape heterogeneity dampen population fluctuations and may modulate prey/predator relationships; Duhamel et al. (2000) that A. terrestris outbreak epicentres occur in homogeneous grassland and Foltete et al. (2008) that hedgerow networks slow down the propagation of travelling waves. On a local scale (area of about 0.01 km2), Delattre et al. (2006), Morilhat et al. (2007, 2008) showed that A. terrestris population growth was enhanced by larger gallery networks of Talpa europea, was slowed down by ploughing and cattle tramping and was modified by neighbouring landscape (10 - 100 ha). This led to a number of recommendations, now implemented for a more sustainable control of A. terrestris (Delattre and Giraudoux 2009) with substantial decrease in rodenticide utilization and lesser impact on non-target species. Poster downloadable at: http://pagesperso-orange.fr/giraudoux/PosterSETAC_120416_1200.pd

Trophic transfer of pesticides : The fine line between predator–prey regulation and pesticide–pest regulation

Acknowledgments JF benefited from a Marie Skłodowska-Curie fellowship (European Commission, project "VOLES", 660718). VB was employed with this project funds. We are very grateful to Deon Roos for reviewing drafts. We thank Alessandro Massolo, Thibault Moulin and Francis Raoul for helpful suggestions. This work benefited from long-term data collected at Zone atelier (ILTER) Arc jurassien (http://zaaj.univ-fcomte.fr) and its financial support. DATA availability statement All code and data used for this manuscript are available on Github https://zenodo.org/badge/latestdoi/233555669 (Baudrot et al., 2020).Peer reviewedPostprin

Chemical extractions and predicted free ion activities fail to estimate metal transfer from soil to field land snails.

International audienceThis study investigates the relevance of several soil chemical extractions (calcium chloride, acetic acid, citric acid and a four-step sequential procedure) and predicted free metal ion activities in the soil solution to characterise the transfer of trace metals (Cd, Pb, and Zn) from soil to snail soft tissues over a large smelter-impacted area (Metaleurop Nord, Nord-Pas-de-Calais, France). The study was first performed on six snail species together and then specifically on Cepaea sp. and Oxychilus draparnaudi. When the six species were considered together, the accumulation of metals depended mostly on the species. When significant, total or extractable metal concentrations, or the predicted free ion activities, accounted for less than 7% of the variation of the metal concentrations in the snail tissues. Species-specific analyses showed that extractable concentrations explained approximately 25% of the variation of the metal concentrations in O. draparnaudi, and up to 8% in Cepaea snails. When using total soil concentrations and soil properties as explanatory variables, the models were generally slightly better, explaining up to 42% of the variance. The soil extraction procedures and predicted free ion activities used in this study did not accurately estimate the metal transfer from soil to snails and could not be used in risk assessment

Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota

Tracking pan-continental trends in environmental contamination using sentinel raptors — what types of samples should we use?

Biomonitoring using birds of prey as sentinel species has been mooted as a way to evaluate the success of European Union directives that are designed to protect people and the environment across Europe from industrial contaminants and pesticides. No such pan-European evaluation currently exists. Coordination of such large scale monitoring would require harmonisation across multiple countries of the types of samples collected and analysed-matrices vary in the ease with which they can be collected and the information they provide. We report the first ever pan-European assessment of which raptor samples are collected across Europe and review their suitability for biomonitoring. Currently, some 182 monitoring programmes across 33 European countries collect a variety of raptor samples, and we discuss the relative merits of each for monitoring current priority and emerging compounds. Of the matrices collected, blood and liver are used most extensively for quantifying trends in recent and longer-term contaminant exposure, respectively. These matrices are potentially the most effective for pan-European biomonitoring but are not so widely and frequently collected as others. We found that failed eggs and feathers are the most widely collected samples. Because of this ubiquity, they may provide the best opportunities for widescale biomonitoring, although neither is suitable for all compounds. We advocate piloting pan-European monitoring of selected priority compounds using these matrices and developing read-across approaches to accommodate any effects that trophic pathway and species differences in accumulation may have on our ability to track environmental trends in contaminants

Impact of Pesticides on Red Kite Population

Poisoning by pesticides is reported as a main cause of Red kite decrease. Based on available data on lethal intoxication, we aim to quantify the impact of pesticide poisoning on the “German-French-Spanish” population of Red kite since 1990. According to the WWF/Adena, 435 kites were poisoned in Spain from 1990 to 2005. In France, 51 intoxicated specimens were identified from 1992 to 2002. No data were found for Germany. Using the rate of cadaver discovery of 3% proposed by WWF/Adena, this would represent 14,500 specimens poisoned in Spain and 1700 in France. An age-structured model of population dynamic (Leslie matrix) was built to project pesticide consequences on Red kite population between 1990 and 2009. Population size was estimated at 110,000 specimens in 1990 for the 3 countries. The Leslie matrix developed has a growth rate of 1. It is assumed that an individual may lived up to 15 years and reproduced from 3 years. We assumed that a pair produced 1.5 fledged young per year (0.75 female). Survival rate was 0.55 the first year and then, increased to 0.88 for adults. Results showed that pesticides would be responsible of a 22% decrease according to the scenario used here. Anticholinesterasic chemicals (i.e., organophosphorous and carbamates) would contribute to 19% and anticoagulants to 2%, respectively. The results varied dramatically according to the rate of cadaver discovery retained, this key factor has to be assessed more precisely. Present results suggest that anticholinesterasic compounds used in Spain are the main responsible of the current decline followed by anticoagulant rodenticides

Agriculture et campagnols : quels impacts sur les écosystèmes franguignons ?

National audienceLes pullulations de campagnol terrestre et de campagnol des champs, deux espèces de rongeurs vivant principalement dans les prairies, sont périodiquement d’une actualité préoccupante pour les exploitations agricoles. Les deux espèces sont les proies principales d’un riche cortège de prédateurs qui contribue à la biodiversité régionale et à leur régulation, mais dont les reports de prédation peuvent impacter localement des espèces d’intérêt cynégétique ou patrimonial. Ces systèmes complexes modulent également la transmission d’un certain nombre de zoonoses intéressant la santé publique et vétérinaire. Ils sont étudiés depuis maintenant une trentaine d’année dans la Zone atelier Arc jurassien (http://zaaj.univ-fcomte.fr). Ils conduisent à des jeux d’acteurs subtils par lesquels des points de convergence doivent être trouvés entre des services écosystémiques qui peuvent apparaître contradictoires a priori : protection des cultures et qualité des produits alimentaires, protection des espèces patrimoniales, production cynégétique, santé, voire tourisme. Ces questions ne concernent plus seulement les zones d’altitude du massif du Jura, mais aussi le Morvan et les zones de grande culture de basse altitude où techniques culturales simplifiées et semis direct se popularisent.L’objectif de cet exposé est de montrer quels sont les principaux processus en cause et leur dynamique à long terme, qui, de plusieurs manières, portent conséquences sur la faune et la flore régionale des espaces dits « naturels » bourguicomtois, dont la quasi-totalité sont en fait anthropogènes, c’est-à-dire le résultat transitoire d’économies agricole et forestière adaptatives, dans un contexte biogéographique donné

Scavenging of rodent carcasses following simulated mortality due to field applications of anticoagulant rodenticide

International audienceWorldwide, agricultural uses of anticoagulant rodenticides (ARs) cause poisonings of non-target wildlife as observed in France where bromadiolone is used to control water vole outbreaks. Following bromadiolone field application, a part of the vole population may die above-ground of the treated plots and thus, can represent an important risk of secondary poisoning for scavengers. In this study, water voles were trapped in a non-treated area and their carcasses were placed aboveground in plots located in an area where a vole outbreak occurred. Then, the environmental persistence, the diurnal and nocturnal scavenging rates of water vole carcasses were assessed in autumn 2011 and in spring 2012. The diurnal scavenger species were also identified. The environmental persistence of the carcasses to reach at least a scavenging rate of 87.5 % was 0.5–1.5 day. The average rates of diurnal and nocturnal scavenging ranged from 67 to 100 % and 5 to 100 %, respectively. They depended on the composition of the scavenger community present near the monitored plots; diurnal scavenging rates being higher with corvids than with raptors. In autumn, the red kite and the common buzzard were the main scavengers in one of the plots, what suggests a high risk of poisoning for these raptors during post-nuptial migration. So, the collection of vole carcasses after treatments and the limitations of bromadiolone applications when high densities of predators/scavengers are observed could be implemented to mitigate the risks of secondary poisoning

Bioconcentration of cadmium and toxic effects on life-history traits of pond snails (Lymnaea palustris and Lymnaea stagnalis) in laboratory bioassays.

International audienceWe studied the bioconcentration and the individual effects of Cd on life-history traits of Lymnaea stagnalis and Lymnaea palustris exposed to increasing Cd concentrations for 4 weeks in controlled conditions. Internal Cd concentrations were linearly correlated to Cd concentrations of exposure in both foot and viscera of L. stagnalis and in the foot of L. palustris, and they were linked by a logistic relationship with environmental contamination in the viscera of L. palustris. If LC50S were higher than the highest Cd concentrations of exposure (L. stagnalis: 160 microg L(-1); L. palustris: 320 microg L(-1)), other dose-dependent responses affecting life-history traits were noted in both species. In L. stagnalis, EC50 for growth was evaluated at 142 microg L(-1) and growth inhibition was correlated with internal Cd concentrations by a linear relationship. L. palustris was more sensitive to Cd than L. stagnalis because its EC50-growth was three times lower (58 microg L(-1) after 28 days). Dose-dependent responses were obtained for several parameters of fecundity of L. palustris. EC50 for the mean number of egg masses or mean number of eggs per individual were close to 60 microg L(-1), whereas for the mean number of eggs per egg mass, the EC50 was higher, with a value of 124 microg L(-1). The percentage of hatching versus the total number of eggs was 60% in controls, and no embryos were able to hatch at the lowest tested Cd concentration, 40 microg L(-1). The high sensitivity of fertility was due to Cd blocking embryo development, particularly for the latest embryonic stages just before hatching. The present results constitute useful data to develop laboratory tests using pond snails for freshwater risk assessment