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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
Demographic Insights and Spatial Distribution of the Commerson’s Dolphin (Cephalorhynchus commersonii) off the Kerguelen Archipelago (Southern Indian Ocean)
No full textInternational audienceThe Commerson’s dolphin (Cephalorhynchus commersonii) includes two subspecies, one of which, C. c. kerguelensis, is endemic to the Kerguelen Archipelago (southern Indian Ocean). Despite high conservation stakes associated with its geographical isolation (the other subspecies is only found in southern South America), the Kerguelen Commerson’s dolphin remains poorly studied. Herein, we used observation and photo-identification data from a long-term monitoring program implemented since 2012 to assess the spatial distribution and demographic parameters of this subspecies. Using geostatistical models, we found high probabilities of encounters of dolphins in fjord-type habitats in the Gulf of Morbihan and along the southern and northern coasts of the archipelago. From capture-mark-recapture models (Robust Design and POPAN), annual survival of individuals in the Gulf of Morbihan was estimated at 0.82 ± 0.23, with an abundance in this area ranging from 40 to 100 dolphins per year between 2012 and 2020. However, high temporary migration rates in and out of the Gulf of Morbihan were detected and supported by photo-identification data, with individuals confirmed traveling up to 130 km outside this area, generating uncertainty in demographic estimates. Our findings, while providing baseline insights, highlight the need for improved knowledge on the feeding ecology and movements of dolphins to be able to produce spatial and demographic information that can be used to assess the conservation status of the Kerguelen Commerson’s dolphin
Towards Ressource-Efficient Deep Learning for Train Scene Semantic Segmentation
No full textInternational audienceIn this paper, we present a promising application of scaling techniques for segmentation tasks in a railway environment context to highlight the advantages of task specific models tailored for on-board train use. Smaller convolutional neural networks (CNNs) do not focus on accuracy but resource efficiency. Our models are scaled using skip connections as well as quantization in order to form lightweight models trained specifically for our context. The proposed models have been evaluated both in terms of segmentation performance and efficiency on state of the art scene segmentation datasets namely RailSem19 and Cityscapes. We have obtained models with less than 3.5M parameters and a minimum of 78.4% of segmentation accuracy showing that lightweight models can effectively segment the railway surroundings
« En quoi la pratique des exercices spirituels permet-elle de clarifier la vision stratégique ? »
No full textInternational audienceLes dirigeants de PME font face à un environnement stratégique complexe et incertain, dont les contours du futur sont anxiogènes et ambigus. L'avenir s'est transformé aujourd'hui en une pratique risquée et contestée. Les dirigeants cherchent des moyens supplétifs pour orienter leur avenir. S'exercer à la pratique des exercices spirituels, c'est utiliser une boite à outils visant à travailler sur soi afin de clarifier quotidiennement les actions à entreprendre. Il s'agit d'entraîner l'esprit à un mode de vie philosophique, à une transformation de soi pour prendre conscience de ses marges de manœuvre et favoriser à mieux clarifier la signification des évènements ainsi que d'y voir plus clair sur le chemin à suivre. Comment, dès lors, la pratique des exercices spirituels, en tant que technique de soi favorisant la réflexivité, peut-elle accompagner les dirigeants dans ce processus de clarification, en transformant leur représentation mentale et en leur permettant d'élaborer une vision stratégique à la fois créative, structurée et adaptée aux enjeux de l'avenir
Breeding seabird assemblage of Rapa, Austral Islands, Eastern Polynesia
No full textInternational audienceRapa Island, located in Eastern Polynesia, hosts 12 species of breeding seabirds, now primarily found on its ten peripheral islets. These seabirds face various threats, such as invasive mammals that prey on eggs and chicks, as well as invasive plants that encroach upon and degrade their breeding habitats. Major island restoration projects are currently underway on several islets, focusing on the removal of invasive mammals and plants. We present data collected here between 2017 and 2024 and, together with published and unpublished surveys since 1921, compile details on the distribution, population, and breeding seasons of these seabird species
The role of seabird foraging strategies on the uptake of mercury: A case study using gulls and shearwaters from the Portuguese coast
No full textInternational audienceMercury (Hg) is a non-essential element that bioaccumulates and biomagnifies in food webs through site-specific biogeochemical processes. Seabirds are valuable bioindicators of Hg contamination, yet certain regions, like the Portuguese coast, remain under represented. This study measured Hg concentrations in the blood of yellow legged gulls (Larus michahellis), Audouin’s gulls (Ichthyaetus audouinii), and Cory’s shearwaters (Calonectris borealis) breeding along the Portuguese coastline. The influence of foraging ecology on Hg contamination was investigated using stable isotopes (δ13C, δ15N, δ34S) along with GPS-loggers. Thus, 52 % of the adults were at low risk (0.95–4.8 μg g-1 dry weight, dw), while 37 % were at moderate risk of Hg toxicity (>4.8 μg g-1 dw). The highest trophic positions (indicated by δ15N values) were associated with higher Hg concentrations, particularly in gulls from Deserta Island. Yellow-legged gulls foraging in terrestrial habitats (inferred from lower δ13C and δ34S values and GPS data) generally exhibited lower Hg concentrations, although patterns varied between regions. Gulls from Deserta Island had elevated Hg concentrations, likely because they feed on discarded demersal fish. In contrast, those from Porto showed some of the lowest concentrations, likely because they fed on terrestrial food. However, other factors not evaluated here, like age, sex, or even phylogeny could have also influenced Hg uptake and bioaccumulation and should not be disregarded in future research. This study highlights the critical role of foraging strategies in Hg contamination and stresses the importance of estimate food web-specific baseline isotopic composition to better understand how these differences may impact Hg trophic transfer
Faire participer à la transition écologique : un cadre d’analyse
No full textLe rapport s'intéresse aux différents processus participatifs mobilisés dans le cadre des transitions écologiques. Face à la multiplication des démarches qualifiées de « participatives », souvent hétérogènes et difficilement comparables, un cadre d’analyse est proposé pour mieux appréhender leurs logiques de conception et de déploiement, ainsi que les formes d’écocitoyenneté qu’elles contribuent à encourager. Deux dimensions de ces processus sont explorées :- le design participatif : pourquoi, comment et pour quels publics le processus est-il pensé ?- le rôle du citoyen au sein de ces dispositifs et processus
