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Corridors écologiques et connectivité acoustique : une nouvelle approche pour préserver la biodiversité sonore
No full textBioacoustique et acoustique environnementale; GABE - Acoustique du Bâtiment et de l'Environnement: GBIO - BioacoustiqueNational audienceLa fragmentation des habitats, provoquée par les activités humaines, limite non seulement les déplacements des espèces, mais entrave également la propagation des signaux sonores essentiels à leur communication. La connectivité acoustique, concept émergent, mesure dans quelle mesure un paysage permet la transmission des sons biologiques, en tenant compte des obstacles tels que la pollution sonore ou les caractéristiques du terrain. Grâce à des outils d’enregistrement audio et à l’éco-acoustique, cette approche permet d’évaluer la biodiversité et l’impact des pressions anthropiques sur les paysages sonores. Appliquée aux corridors écologiques, elle révèle comment le bruit et la fragmentation affectent les paysage sonore. Cette méthodologie ouvre ainsi de nouvelles perspectives pour intégrer la connectivité sonore dans les stratégies de conservation et préserver les fonctions écologiques face aux défis de la fragmentation
Temporal stability in genetic origin of juvenile green turtle recruits at remote western Indian Ocean islands
No full textInternational audienceThe increasing anthropogenic and climatic pressures on marine ecosystems raise concerns about the sustainability of their functions, uses and conservation. Marine megafauna such as marine turtles are particularly vulnerable to these pressures due to their life cycle and the variability of habitats they occupy during their life cycle. Understanding how juvenile population dynamics respond to environmental conditions is crucial for designing effective conservation strategies. The present study investigates whether the genetic composition of juvenile green turtles at recruitment sites changes over time. A total of 346 juveniles were sampled at four key recruitment sites in the South Western Indian Ocean - SWIO (Glorieuses, Mayotte, Reunion and Aldabra) during two sampling phases at an interval between 6 and 17 years depending on the site. Based on mtDNA control region sequences, genetic structures were compared between periods within each site. Even if subtle changes in genetic composition may not be detectable with current genetic resolution, our results suggest that the structure of the juvenile green turtle population has not significantly changed over the course of the study period. Such stability in population structure may be correlated with the stability of regional oceanic currents over the last decades in the SWIO, as well as the dynamics of nesting populations in the different regional genetic stocks contributing in regional juvenile green turtle production
Potential role of coypus (Myocastor coypus) in the epidemiology of botulism in wetlands
No full textInternational audienceBotulism in wild birds is a widespread disease. Decaying carcasses of wild birds are known to amplify and perpetuate the disease through the “carcass-maggot” cycle. The role that other vertebrates may play in this epidemiological system has been poorly addressed until now. Among these, the role of the coypu (Myocastor coypus), a widespread invasive alien species raises questions. The aim of our study was to investigate the possible carriage and shedding of Clostridium botulinum C/D (responsible for avian botulism outbreaks in France) in coypus living near a pond with recurrent avian botulism outbreaks. A total of 106 coypus were opportunistically swabbed. The gene encoding the botulinum neurotoxin C/D was detected using a PCR approach. Samples positive for C. botulinum C/D in coypus and in wild birds during previous outbreaks were compared using a MLVA method (Multilocus Variable-Number Tandem-Repeat Analysis). Seven rectal swabs were positive for C. botulinum type C/D indicating a prevalence of 8% [3–16%]. MLVA comparison showed that the same MLVA profile was detected in coypus as from liver samples collected from dead birds during previous outbreaks. This shows that coypus can be asymptomatic carriers (whether permanent or transient needs to be further determined) and active or passive shedders of C. botulinum C/D with a MLVA profile identical to that of the strains responsible for clinical signs in birds in the past. These findings suggest that coypus may play a role in the epidemiology of botulism as potential sources and spreaders of C. botulinum C/D in the waterfowl environment, thus opening up new avenues of research to explore
Gestion de la pollution chimique des eaux de surface françaises :Quels enseignements tirer de la première décennie de surveillance au titre de la directive cadre sur l’eau (2009-2020) ?: Synthèse en français de l’étude« Multiyear and seasonal wide‑scale indicators for French surface waters contamination by WFD substances »parue dans Environmental Science and Pollution Researchhttps://doi.org/10.1007/s11356-024-35511-z
No full textThis document presents the summary in French of a detailed scientific study, published in Environmental Science and Pollution Research, on the management of chemical pollution in French surface waters between 2009 and 2020. The study analyses Water Framework Directive (WFD) monitoring data for 101 substances to assess contamination trends and the effectiveness of emission reduction policies. It introduces new, unbiased indicators for quantifying contamination and risk, taking into account the heterogeneity of laboratory quantification limits. The results show an overall reduction in pollution, but highlight growing concerns about metals and the importance of socio-environmental factors, such as agricultural and urban use, in the seasonality and transfer of pollutants. The study concludes with recommendations for improving the monitoring and management of chemical substances.Ce document présente la synthèse en français d'une étude scientifique détaillée, publiée dans Environmental Science and Pollution Research, concernant la gestion de la pollution chimique des eaux de surface françaises entre 2009 et 2020. L'étude analyse les données de surveillance de la Directive Cadre sur l’Eau (DCE) pour 101 substances afin d'évaluer les tendances de contamination et l'efficacité des politiques de réduction des émissions. Elle introduit de nouveaux indicateurs non biaisés pour quantifier la contamination et le risque, notamment en tenant compte de l'hétérogénéité des limites de quantification des laboratoires. Les résultats montrent une réduction globale de la pollution, mais soulignent des préoccupations croissantes concernant les métaux et l'importance des facteurs socio-environnementaux, comme les usages agricoles et urbains, dans la saisonnalité et le transfert des polluants. En conclusion, l'étude formule des recommandations pour améliorer la surveillance et la gestion des substances chimiques
Appui à la mise en oeuvre du décret n° 2022-1758 du 30 décembre 2022 relatif à l’instauration d’un système de recueil d'informations sur les captures et mises à mort accidentelles des espèces de l’annexe IV (point a) de la directive 92/43/CEE : Méthodologie de sélection des couples Espèces - Activités
No full textLe décret n° 2022-1758 du 30 décembre 2022 impose la mise en place d’un système de recueil d’informations (SRI) sur les captures et mises à mort accidentelles des espèces protégées relevant de l’annexe IV de la directive 92/43/CEE. Cette expertise a pour objectif de proposer une méthodologie scientifique robuste permettant d’identifier et de hiérarchiser les couples espèces–activités concernés par ce dispositif.L’analyse distingue clairement les notions d’installations, ouvrages, travaux, activités, pressions et menaces afin d’assurer une application homogène du décret. Trois grands types d’activités sont considérés comme prioritaires :• La production d’énergie renouvelable (éoliennes terrestres),• Les infrastructures linéaires de transport (routes, voies ferrées),• Le stockage d’eau en bassins ouverts (retenues collinaires, bassins d’orage, méga-bassines).La présélection des taxons de l’annexe IV a été réalisée par croisement avec le référentiel TAXREF v18. Après exclusion des groupes pour lesquels la faisabilité de suivi est limitée (insectes, mollusques, cétacés), 100 taxons continentaux ont été retenus (amphibiens, reptiles, poissons et mammifères terrestres).Chaque couple espèce–activité a été évalué selon deux critères :1. Degré d’impact sur l’état de conservation (faible, moyen, fort).2. Faisabilité de suivi, prenant en compte l’accessibilité des sites,la détectabilité et l’identification des cadavres.Cette approche permet de cibler les situations où la mortalité accidentelle est significative ou insuffisamment documentée. Elle constitue une base opérationnelle pour l’édiction d’arrêtés ministériels définissant les obligations de suivi, les territoires concernés, et les modalités de collecte et transmission des données.Ce cadre méthodologique fournit ainsi un outil d’aide à la décision pour satisfaire aux exigences européennes tout en optimisant les efforts de suivi sur les espèces et activités à plus forts enjeux de conservation
S-Methyl-l-Cysteine Sulfoxide: A Hidden Layer of Defences Against Herbivorous Insects in Brassicaceae
No full textInternational audiencePlants defend themselves against herbivorous insects through diverse morphological and biochemical traits. Non‐protein amino acids (NPAAs) are an important component of the plant metabolome, although their defensive function remains largely unexplored. Here, we investigated the role of S‐methyl‐l‐cysteine sulfoxide (SMCSO), a sulphur‐containing NPAA accumulated in Brassicaceae, in mediating plant defence against herbivorous insects. SMCSO was quantified in inflorescences, leaves (young and old) and roots (primary and secondary) of 14 Brassicaceae species. Additionally, feeding tests on artificial substrates supplemented with physiological SMCSO levels were conducted with both generalist and specialist herbivorous insects feeding on one of the different plant parts studied. In line with the optimal defence theory, we found higher SMCSO levels in reproductive than vegetative tissues, and in young leaves and primary roots compared to old leaves and secondary roots, respectively. SMCSO also exerted a consistent phagodeterrent effect on generalist herbivores, while specialists showed variable responses from deterrence to stimulation. This study provides the first evidence of the influence of this compound on herbivore feeding behaviour, with effects depending on the diet breadth. These findings broaden our understanding of plant chemical defence complexity and highlight the ecological role of NPAAs in plant–insect interactions
PlanktonFlow76 - A curated FlowCam dataset for plankton classification
No full textThis dataset contains a curated collection of FlowCAM images acquired at INRAE UMR DECOD (Rennes, France) during a multi-year mesocosm experiment in controlled aquatic systems. FlowCAM imaging was used to capture planktonic organisms and particles for ecological monitoring and analysis, and images were segmented using ZooProcess.This dataset contains a curated collection of FlowCAM images acquired at INRAE UMR DECOD (Rennes, France) during a multi-year mesocosm experiment in controlled aquatic systems. FlowCAM imaging was used to capture planktonic organisms and particles for ecological monitoring and analysis, and images were segmented using ZooProcess.The dataset is provided in two forms: Raw dataset: ~130,000 images directly collected with the FlowCAM and segmented by ZooProcess (PlanktonFlow-ready starting at the preprocessing step). Processed dataset: ~190,000 images obtained after PlanktonFlow pre-processing (augmentation, splitting, and other steps) and ready for downstream analysis. Images are organized by taxonomic classes (species) as identified by experts at UMR DECOD. As with any manual classification, occasional errors or ambiguous categories may be present.This resource can support ecological studies, machine learning model development, and reproducibility of the associated research. For further details, please refer to the associated publication and the open-source codebase available on GitHub
Homogeneous fish communities use intertidal salt marshes at high tide, despite environmental diversity: insights from a large-scale monitoring program on French coasts
No full textInternational audienceSalt marshes have dramatically declined in area throughout history and are still subject to numerous anthropogenic pressures. These habitats appear essential for certain fish species, which use them in high abundances. Some studies suggested that fish habitat use of salt marshes could greatly depend on the condition of the vegetation and notably its management. However, most of these studies were restricted to limited numbers of sites or samples, making it difficult to confirm these assumptions. To meet this challenge, a large-scale, standardized and temporally coordinated monitoring program has been set up on a network of 18 salt marshes distributed over the French coasts of the English Channel and the Atlantic, with the aim of describing fish communities and identifying potential driving environmental factors of fish diversity and abundances. Creeks were environmentally characterized and sampled for fish in three seasons in 2015, 2017, 2019 and 2021. Fish captures were greatly variable in abundances among space and time, poorly diversified (<= 10 species per sample), and largely dominated by mullets, gobies and seabasses. The abundances of the main fish taxa in the captures were poorly explained by the environmental variables considered. Overall, only seafront and salinity might have conditioned the occurrence and abundance of some species across the network. Our results emphasize the crucial importance of long-term, large-scale monitoring initiatives to deal with the inherent variability of fish community composition in salt marshes, and the need for further research to better understand the utilization of this habitat by fish
Natal dispersal patterns in a social wild mammal: what does family tell us?
No full textInternational audienceNatal dispersal is a key process in ecology and evolution. Similarities of dispersal patterns between relatives can lead to small-scale kin structure within populations with consequences on population dynamics and genetics. Most studies have focused on birds, lizards, and small mammals. How family effects may shape sex-specific natal dispersal patterns in a large-sized social mammal remains unexplored. We fill this gap thanks to a 30 year-long monitoring of a wild boar population. This polytocous, polygynous, and size dimorphic species displays a matrilineal social organization. From the monitoring of individuals from early life to adulthood, we characterized natal dispersal patterns by investigating the propensity to disperse and the dispersal distance. As expected for a species subjected to strong sexual selection, offspring males dispersed more often and farther than females. Looking specifically at similarities of dispersal patterns among relatives within a group, we found that offspring females from the same family displayed more similar dispersal propensity and distance than females from different groups, highlighting family effects. However, this dispersal pattern did not hold for males. Family effects can thus shape natal dispersal patterns in a sex-specific way in social mammals, and are key to understand individual variation in dispersal patterns
Beporzókat segítő beavatkozások hatékonysága városi élőhelyeken Európában
No full textInternational audienceA beporzók fontos jelentőséggel bírnak, mivel alapvető szerepet töltenek be az ökoszisztémákműködésében és az emberi jólét fenntartásában. Míg a mezőgazdasági területeken már régótavizsgálják a beporzókat segítő beavatkozásokat, városi környezetben csak az utóbbi időbenkezdett el gyorsan növekedni az ezzel foglalkozó kutatások száma. Viszont ezek az eredményekeddig nem lettek összesítve, ami nehezíti a hatékony szakpolitikai döntések meghozását. Enneka hiányosságnak a pótlására, összehasonlítottuk a beporzó-barát módon (kezelt területek) és ahagyományosan kezelt (kontroll) városi zöldterületeket a növényzet, a virágkínálat és abeporzók szempontjából, 28 európai eredeti adatsor alapján, összevont és adatsorszintűvizsgálattal. Elemzésünk 1051 mintavételi területre terjedt ki, melyek különfélebeavatkozásokat (területkezelés elhagyása, ritkább kaszálás, virágvetés, illetve ezekkombinációi) és élőhelyeket (parkok, gyepek, útszegélyek, illetve magán- és közkertek)foglaltak magukban. A városi beporzókat segítő beavatkozások általában kedvezően hatottak anövényekre és a beporzókra, bár a hatások taxononként, beavatkozástípusonként, élőhelyenkéntés térben-időben eltérhettek. Az összevont elemzések szinte kizárólag pozitív, és sohasemnegatív hatásokat mutattak, míg a részletes, adatsoronkénti vizsgálatok többnyire pozitív vagysemleges, de ritkán negatív hatásokat tártak fel. A legnagyobb előnyt a poszméhek és a lepkékélvezték. A beavatkozások közül a virágvetés, az élőhelyek közül pedig az útszegélyek,valamint az északnyugat-európai helyszínek mutatták a legerősebb pozitív hatást. Noha aszabályozások, irányelvek és monitorozási gyakorlatok egyre fejlődnek, bizonyos beporzó-csoportok (pl. bogarak), régiók (pl. mediterrán térség) és új típusú beavatkozások (pl. talajbanfészkelő rovarok támogatása) esetében továbbra is hiányosak az ismeretek. A továbbinemzetközi együttműködésen alapuló kutatások hozzájárulhatnak ahhoz, hogy a településekolyan ellenálló és többfunkciós városi élőhelyeket alakítsanak ki, melyek elősegítik az emberek,a növények és a beporzók együttélését