Portail HAL de l'OFB
Not a member yet
3699 research outputs found
Sort by
Poissons migrateurs amphihalins, espèces diadromes : de quoi parle-t-on ?
No full textInternational audienceBased on an in-depth analysis of the international literature on the subject, this note sets out and illustrates, using French examples, five criteria that can be used in various combinations to classify a species as an amphihaline migratory. An initial list of species likely to be considered as such is proposed for mainland France and the overseas territories. Finally, the various approaches for validating these criteria are briefly presented. This work should continue by comparing the various species mentioned here with these criteria, which may be refined.Basé sur une analyse approfondie de la littérature internationale sur le sujet, cette note expose et illustre avec des exemples français cinq critères dont les différentes combinaisons permettent de qualifier une espèce de migratrice amphihaline. Une première liste des espèces susceptibles de pouvoir être considérées ainsi est proposée pour la métropole et les outremers. Enfin, les principales approches permettant de valider ces critères sont présentées brièvement. Ce travail devra se poursuivre en confrontant les différentes espèces mentionnées ici à ces critères éventuellement précisés
Grosse altise du colza : limiter les larves et les risques associés
No full textInternational audienc
Incorporating Neglected Insect Larvae in Species Inventories: DNA Barcoding as an Effective Tool for All‐Stage Invertebrate Identification in Tree Holes
No full textAnalytical script and processed data can be found at the following GitHub repository: https://github.com/Lucasire/CANOPE_larvae.git.Article de 11 p.Analytical script and processed data can be found at the following GitHub repository: https:// github.com/Lucasire/CANOPE_ larvae.gitInternational audienceInvertebrates, especially insects, are an integral part of biodiversity. Many species live in forest ecosystems where they play a key role in decomposing wood and maintaining ecosystem functions. Nevertheless, global changes, like fires, storms, and pest outbreaks, are impacting insect diversity, reinforcing the need for long-term biomonitoring to understand and tackle these issues. Forests are heterogeneous ecosystems with tree-related microhabitats (TReMs) such as tree holes, which are important for ecosystem diversity. Conventional identification approaches for species inventories are frequently hampered by the extensive and hidden diversity of insect larval stages. Thus, there is a crucial need to develop tools that facilitate inventories of these ecological niches and allow the incorporation of such hidden diversity into long-term monitoring studies. To that end, we explored the biodiversity found in tree holes within French state forests using DNA barcoding and addressed challenges associated with traditional morphological identification methods. Results demonstrate the successful application of DNA barcoding in identifying nearly 62% of all invertebrates sampled from tree holes to the species level. Sampled invertebrates comprised 44% of larvae (566 individuals), of which nearly 50% could be assigned a species name. In total, 108 species and 173 barcode index numbers (BINs, used as species proxy) were molecularly inventoried, and 39% of these identified species were solely represented by larvae in our sampling. Our study highlights the usefulness of DNA-based identification methods and the significance of including larvae in biodiversity assessments to gain insights into species abundance and functional diversity. It also underscores the necessity of ongoing and parallel developments of DNA reference libraries to improve species molecular identification rates and accuracy, and the need to investigate potential non-destructive alternatives for biomonitoring. These efforts aim to ensure thorough and precise monitoring of invertebrate communities in tree holes and similar microhabitats
Brown trout passage efficiency through a baffle series in a long culvert, assessed by fish translocation and by natural migration monitoring
No full textInternational audienceThe passage efficiency of brown trout through a 73 m long culvert equipped with 10 notched baffles, was studied using PIT telemetry and two approaches: (1) fish translocation from upstream to downstream of the culvert, (2) monitoring of the natural migration of downstream individuals. The migration rate of translocated individuals was higher (90%) than that of naturally migrating individuals (42%). The attraction efficiency was assessed at 94.4% and 93.1%, the passage efficiency at 94.7% and 83.3%, and the overall passage efficiency at 89.4% and 77.6% for translocated and naturally migrating individuals respectively. The majority of individuals passed through the culvert (overall passage time) fairly rapidly but the approach times were longer for translocated individuals, impacting their overall passage times (median value 24 h 40 min vs. 11 h 16 min for naturally migrating fish). For translocated fish, large individuals crossed the structure faster than small ones. For fish in natural migration, individuals that passed through the structure were smaller than those that did not. For translocated fish only, the approach time decreased with increasing water level. The majority of trout approached the culvert during the day and the luminosity changes at its entrance and exit did not seem to be a limiting factor for their passage
Mismatches between the current marine Natura 2000 network and seabird distributions call for enhanced protected areas off metropolitan France
No full textInternational audienceSeabirds are among the most threatened vertebrates, under pressure from fisheries bycatch, climate change, overfishing, and human disturbance. In France, demographic studies have highlighted adult survival as a key factor in population trends, which calls for large-scale marine conservation efforts. In this context, the Natura 2000 policy requires the designation of Special Protection Areas (SPAs) to protect seabirds under the Birds Directive. To assess the completeness of the French marine SPA network, data from aerial, boat, and coastal surveys, as well as tracking devices and distribution models, were collected for 57 seabird taxa. This data collection allowed the EU minimum criteria for a coherent SPA network to be spatially implemented, and the most ecologically valuable areas for seabirds around metropolitan France to be identified and prioritised, and overlaid with the current French SPA network and Marine Important Bird Areas (mIBAs) to identify potential inconsistencies. This analysis revealed seabird hotspots outside the existing ecological network, confirming some insufficiencies for coherent seabird conservation. Although data dependent, this analysis highlighted the limitations of using global proportion coverage to assess network coherence when coverage of biodiversity and abundance hotspots was not achieved. Furthermore, these results summarised the main target areas for policy makers to effectively improve seabird conservation around metropolitan France. In a context of increasing demands for marine spatial planning, improvements in this knowledge, the SPA network and conservation actions are required
L'utilisation de l'ADNe/ADNa pour la surveillance des espèces non indigènes marines : État des lieux et recommandations concernant le descripteur D2 de la DCSMM
No full textRapport réalisé pour le compte de l’Office Français pour la Biodiversité par le Centre National de la Recherche Scientifique, représenté par l’Institut des Sciences de l’Evolution de Montpellier (UMR 5554).Coordinateurs : Cécile Massé (OFB) et Frédérique Viard (CNRS-ISE-M)Collaborateur : Axel Gayot (CNRS-ISE-M)Ce travail a été réalisé afin d'alimenter les réflexions en amont de la constitution éventuelle d'un programme de surveillance s'appuyant sur l'utilisation d'ADN environnemental (ADNe) ou d'ADN d'assemblages (ou massal) (ADNa), dédié aux espèces non-indigènes marines, en soutien au descripteur 2 de la Directive Cadre Stratégie pour le Milieu Marin. Il s'appuie sur deux volets : 1) une revue systématique de la littérature récemment publiée (2019-2024), réalisée selon les standards de "Collaboration for Environmental Evidence" qui visent en particulier à éviter les biais d'opinion d'une revue bibliographique classique et 2) les résultats d'une enquête réalisée avec un questionnaire envoyé à des acteurs académiques et non académiques français, utilisant ou non des outils basés sur l'utilisation d'ADNe/ADNa, afin d'évaluer leurs objectifs, les méthodes employées et leur perception de ces approches. La synthèse des deux volets met en relief différents points dont la pertinence de ces approches ADNe/ADNa pour des suivis et surveillance d'ENI, associé à un intérêt des acteurs nationaux pour la mise en œuvre de ces approches dans ce contexte. Néanmoins, d'importants biais de cibles (milieux d'études ou groupes taxonomiques) et une grande hétérogénéité des pratiques ressortent de ces deux volets, ce qui pénalise encore l'approche dans le cadre d'un réseau de surveillance. Afin de consolider l'approche pour déployer un tel réseau, une série de recommandations sont faites, partant des objectifs fins de la surveillance, de la levée de verrous actuels à la mise en œuvre d'un centre de ressources dédié
Spatial covariation between wild boars and other mammals in peri-urban landscapes: insights for management from southern France
No full textInternational audienceGlobal urbanization is rapidly increasing, transforming ecosystems and favoring generalist species that adapt to human-modified environments. The wild boar, a highly adaptable species, is expanding its range and increasingly observed in urban and peri-urban areas, where it can cause accidents, damage, and health concerns. To mitigate their presence, non-lethal control strategies such as vegetation clearing in peri-urban parks and wastelands are being implemented to reduce the number of suitable resting sites. However, the ecological consequences of such habitat modifications on other wildlife species remain poorly understood. This knowledge gap limits the development of effective urban wildlife management strategies that seeks to balance ecological, social and economic considerations without harming wild boar populations and urban ecosystems. In this context, we used camera trapping to study the covariation between wild boars and other mammal species in a peri-urban area, with the aim of guiding targeted and effective management strategies. Here, we show a widespread presence of wild boars but no spatial or temporal covariation between the wild boars and the other species. In contrast, we found strong spatial structuring in mammal communities, primarily driven by small carnivores (mustelids, genets, cats, foxes) and a minimal influence of temporal variation, confirming that spatial factors, rather than seasonal changes, largely shaped species distributions. The study of the temporal variation across months indicated minimal seasonal structuring but revealed substantial within-site variability in month-to-month species abundance, with a general abundance gradient driven by common species like wild boar, cat, and fox. In conclusion, our results show that the lack of spatial covariation between wild boar and other species prevents reliable predictions, supporting a targeted rather than general approach to vegetation management
AMOBIO : Analyse multicritère des effets exercés par les obstacles en cours d’eau sur les communautés biologiques (diatomées, macroinvertébrés, poissons). Rapport scientifique et technique final
No full textFish and macro-crustacean assemblages are relevant ecological indicators for monitoring rivers of tropical islands
No full textInternational audienceUnderstanding how tropical rivers change in response to human-induced disturbances represents a major challenge for management and conservation. However, monitoring networks based on ecological indicators remain scarce in oceanic islands, where freshwater indigenous fish and macro-crustacean assemblages are dominated by diadromous species. We investigated the relevance of these taxa for assessing the ecological status of rivers in two tropical islands, Reunion and Mayotte, Indian Ocean, to fulfill objectives of the European Water Framework Directive in overseas regions. Beyond providing insights on ecological responses of fish and macro-crustacean assemblages, we proposed a methodological framework to designed stressors-specific multimetric index by selecting primarily shared metrics between and within islands to improve the robustness and interpretation of this index. Numerous candidate metrics were tested to reflect the alterations induced by three stressors categories (i.e., continuity alteration, agricultural and urbanisation stresses) on the diversity, abundance, or size-structure of assemblages. Our results demonstrated that fish and macro-crustacean assemblages were sensitive to multiple stressors, but the ecological responses were more congruent when facing continuity alterations, compared to land use changes associated with agriculture or urbanization. These migratory species are understandably vulnerable to river fragmentation, but their oceanic dispersive stage favor exchanges between watersheds, which in turn can promote the resilience and persistence of local populations in degraded areas. In such insular context, we thus suggested using fish and macro-crustaceans to firstly assess the state of ecological continuity, whereas other taxa, such as diatom or macroinvertebrates, can be complementary to reflect the alteration of water quality
Compte-rendu de la réunion du comité scientifique et éditoriale de la revue Naturae - 11 mars 2025
No full textLa première réunion du comité scientifique et éditorial de la revue Naturae s’est tenue le 11 mars 2025.Cette journée fut l’occasion de présenter une synthèse complète depuis le lancement de la revue en 2017 (nombre d’articles publiés, refusés, thématiques abordées, structures des auteurs, nombres de relecteurs, etc.) mais aussi de faire le point sur les nouveautés et les projets en cours tel que la conversion des articles en xml.L’après-midi a permis aux membres de ce comité scientifique et éditorial d’échanger sur d’éventuels difficultés rencontrées, d’améliorations possibles et d’identifier les orientations et stratégies souhaitées pour les années à venir