HAL Collection UNC (Univ. de la Nouvelle Calédonie)
Not a member yet
7579 research outputs found
Sort by
Three‐dimensional conservation planning of fish biodiversity metrics to achieve the deep‐sea 30×30 conservation target
No full textInternational audienceAccelerating rate of human impact and environmental change severely affects marine biodiversity and increases the urgency to implement the Convention on Biological Diversity (CBD) 30×30 plan for conserving 30% of sea areas by 2030. However, area‐based conservation targets are complex to identify in a 3‐dimensional (3D) ocean where deep‐sea features such as seamounts have been seldom studied mostly due to challenging methodologies to implement at great depths. Yet, the use of emerging technologies, such as environmental DNA combined with modern modeling frameworks, could help address the problem. We collected environmental DNA, echosounder acoustic, and video data at 15 seamounts and deep island slopes across the Coral Sea. We modeled 7 fish community metrics and the abundances of 45 individual species and molecular operational taxonomic units (MOTUs) in benthic and pelagic waters (down to 600‐m deep) with boosted regression trees and generalized joint attribute models to describe biodiversity on seamounts and deep slopes and identify 3D protection solutions for achieving the CBD area target in New Caledonia (1.4 million km 2 ). We prioritized the identified conservation units in a 3D space, based on various biodiversity targets, to meet the goal of protecting at least 30% of the spatial domain, with a focus on areas with high biodiversity. The relationship between biodiversity protection targets and the spatial area protected by the solution was linear. The scenario protecting 30% of each biodiversity metric preserved almost 30% of the considered spatial domain and accounted for the 3D distribution of biodiversity. Our study paves the way for the use of combined data collection methodologies to improve biodiversity estimates in 3D structured marine environments for the selection of conservation areas and for the use of biodiversity targets to achieve area‐based international targets.Planeación tridimensional de la conservación de las medidas de biodiversidad de peces para lograr el objetivo de conservación 30x30 de mar profundo Resumen El impacto antropogénico y el cambio ambiental acelerados afectan gravemente a la biodiversidad marina y aumentan la urgencia de aplicar el plan 30x30 del Convenio sobre la Diversidad Biológica (CDB) para conservar el 30% de las zonas marinas para el 2030. Sin embargo, la identificación de objetivos de conservación basados en zonas es compleja en un océano tridimensional (3D) en el que rara vez se han estudiado las características de las profundidades marinas, como los montes marinos, sobre todo por la dificultad de aplicar metodologías a grandes profundidades. No obstante, el uso de tecnologías emergentes, como el ADN ambiental combinado con marcos actuales de modelación, podría ayudar a resolver el problema. Recopilamos datos de ADN ambiental, acústica de ecosonda y video en 15 montes marinos y taludes de islas profundas del mar del Coral. Modelamos siete medidas de comunidades de peces y 45 abundancias de especies individuales y unidades taxonómicas moleculares (UTOM) en aguas bentónicas y pelágicas (hasta 600 m de profundidad) con árboles de regresión reforzada (ARR) y modelos de atributos conjuntos generalizados (MACJ) para describir la biodiversidad en los montes marinos y taludes profundos e identificar soluciones de protección en 3D para alcanzar el objetivo de área del CDB en Nueva Caledonia (1.4 millones de km 2 ). Priorizamos las unidades de conservación identificadas en un espacio 3D con base en varios objetivos de biodiversidad para cumplir el objetivo de proteger al menos el 30% del dominio espacial con un enfoque en las zonas con una gran biodiversidad. La relación entre los objetivos de protección de la biodiversidad y el área espacial protegida por la solución fue lineal. El escenario que protegía el 30% de cada medida de biodiversidad preservó casi el 30% del dominio espacial considerado y consideró la distribución tridimensional de la biodiversidad. Nuestro estudio prepara el camino para el uso de metodologías combinadas de recopilación de datos con el fin de mejorar las estimaciones de biodiversidad en entornos marinos estructurados en 3D para la selección de áreas de conservación y para el uso de objetivos de biodiversidad con el fin de alcanzar objetivos internacionales basados en áreas
L'inscription hypothécaire, commencement d'exécution du cautionnement
No full textInternational audienc
Assessing past marine social-ecological systems transformations in the southwestern Indian Ocean: A case study approach
No full textInternational audienceMarine social-ecological systems across the Western Indian Ocean (WIO) face unprecedented pressures, demanding interventions and approaches designed to create new and sustainable systems of human-environment interactions. Transformation theory offers frameworks for understanding systemic change, but the empirical testing in marine contexts remains limited, particularly at regional scales. This study addresses this gap by analyzing three marine transformation case studies in the WIO region: seabird bycatch mitigation in South African fisheries, fisheries co-management in Tanzania, and regional tuna fisheries management through the Indian Ocean Tuna Commission. Each case was analyzed through Olsson's three-phase transformation framework (Preparing for change, Navigating transition, and Building resilience) while tracking the evolution of knowledge systems, leadership functions, and transformation attributes including scope, depth, and speed. Our findings reveal contrasting strategies for scaling transformative change and some common patterns. Notably, an inverse relationship between governance scale and transformative depth was found: local and national initiatives achieved deeper transformations through market incentives and community capacity building respectively, while regional governance faced greater barriers due to competing national interests and institutional inertia. All transformations required decades of sustained effort and specific actor functions to guide transformation, such as actors providing information and knowledge, actors leading and guiding action, and those connecting people and coordinating effort. Strong leadership functions were also found to help overcome resistance to change. These case studies emphasize that although some common patterns emerge, unlocking the potential for successful transformation in marine social-ecological systems of the WIO is context-dependent, with no one-size-fits-all solution. Success depends on the alignment of problem framing, institutional capacity, actor interests, and value alignment within specific socio-political contexts
Towards Participatory Monitoring of Global Changes at a Local Scale: Challenging the Contribution of Living Labs
No full textInternational audienceAssessing the local scale effects of global changes and share related knowledge with the population may bea key to rural society robustness in the Anthropocene. In line with transdisciplinarity trend, one approachaims to refine knowledge of global change impacts by integrating vernacular knowledge and local observa-tions. However, bridging the gap between theory and practice remains a significant challenge. Living labsare emerging in many regions as a science-society dialogue tool, enabling participatory data collection at alocal scale and analysis that combines scientific knowledge with vernacular expertise.We present experiments from a living-lab in the Cévennes, a Mediterranean mountain rural region in southFrance. Its climate is characterised by summer droughts and a high precipitation variability. Small hy-draulic heritage punctuates the watersheds, reflecting the populations’ adaptation to this variability and thedevelopment of deep vernacular hydrological knowledge. Nowadays, climate change combined to societalmutations (mains water usages and tourism development especially) induces an increasing water scarcity.The region has experimented water scarcity crises in 2017, 2021 and 2022, making hydrology a major localconcern. In this context, the living lab fosters the creation and animation of a inhabitants/scientists coop-eration to propose and experiment water management adapted to the local context.At the current state of this living-lab, the co-collection of data is effective through participatory mappingand participative observation procedure of water flows and biochemistry. This could lead to high resolutiondatabase. However, many questions remain regarding the participatory monitoring that could guaranteelong-term monitoring of relevant and reliable indicators of local-scale effects of global change: Are scientifi-cally relevant indicators the same as those of interest to local inhabitants? How can they be engaged overtime? What measurement tools should be implemented? How should this data be shared? Based on theexperience of this living lab, we will present our results and questioning about the participatory approachesfor global changes monitoring at a local scale and about the inhabitants/critical-zone scientists cooperation
Actes du SDFIA 2025: Premier symposium doctoral francophone en intelligence artificielle
No full textInternational audienceLes actes du SDFIA 2025 rassemblent des travaux doctoraux francophones couvrant un large spectre de l’IA, de la vision par ordinateur aux systèmes multi‑agents, de l’IA explicable aux modèles robustes d’estimation, jusqu’aux applications sécurité réseau et énergie. Organisé le 9 octobre 2025 à l’issue de l’école d’automne RobIA’25, l’événement met l’accent sur la reproductibilité, la diffusion open source et la rigueur méthodologique. Les articles longs présentent des contributions expérimentales et comparatives (classification d’images, génération pour classes rares, détection d’intrusions), tandis que les articles courts explorent consensus du second ordre, ViT pour la détection de piétons, SSL pour obstacles routiers, et filtres de Kalman robustes. L’ensemble témoigne de la vitalité de la recherche doctorale francophone, avec des résultats applicables à l’agriculture, la mobilité, la cybersécurité, l’éducation et le photovoltaïque
Coral Skeletal Cores as Windows Into Past Symbiodiniaceae Community Dynamics
No full textInternational audienceThe symbiosis between the dinoflagellate Symbiodiniaceae family and reef-building corals underpins the productivity of coral reefs. This relationship facilitates the deposition of calcium-carbonate skeletons that build the reef structure thanks to the energy derived from photosynthesis. The loss of Symbiodiniaceae from coral tissues-resulting in coral bleaching-impedes coral growth and can lead to mass mortality if the symbiosis fails to recover. Given that Symbiodiniaceae communities are dynamic and can shift in response to environmental stressors in the decades to centuries-long lifespan of coral colonies, understanding these changes is crucial. Although the reconstruction of Symbiodiniaceae communities from coral skeleton records has recently been demonstrated as feasible, no studies have yet assessed reconstructions across different species and locations. Here, we present an approach to use coral skeletons for reconstructing the Symbiodiniaceae community on decadal and centennial scales and for resolving dynamics related to coral species and the environmental history of sampling locations. For this, we used dated coral skeleton cores from Porites lobata and Diploastrea heliopora, species commonly used as climate archives, sampled in Palau and Papua New Guinea. We also examined the effect of various DNA extraction protocols on community reconstruction. Here we show that the reconstructed Symbiodiniaceae communities significantly varied across all cores and DNA extraction methods, with decalcification-based protocols enhancing the retrieval of skeletal-bound DNA. Moreover, we observed distinct community dynamics related to the specific coral host and sampling location. Notably, associations of Symbiodiniaceae dynamics with past heat stress events were apparent in cores of both species from Palau. Our findings enable a deeper understanding of the temporal and spatial variability in Symbiodiniaceae communities, offering insights that may refine the use of paleobiological proxies in climate studies and reveal broader ecological trends and microbially aided adaptation pathways in corals.</div
Native Title Policy as Equal Opportunity for Australian Aboriginals and Torres Strait Islanders: ‘Repressive authenticity’ in settler-colonial Australia
No full textInternational audienc
Oxygen supersaturation has negligible effects on warming tolerance across diverse aquatic ectotherms
No full textInternational audienceUnder the midday sun, when photosynthesizers are producing oxygen, shallow aquatic ecosystems can become supersaturated with oxygen (>100% air saturation) while they simultaneously peak in water temperature. It has been suggested that oxygen supersaturation could protect water-breathing animals from mortality during heatwaves because of the potential role of oxygen in governing thermal tolerance. Here, we conducted a circumglobal assessment of the effects of ecologically relevant oxygen supersaturation (150%, hyperoxia) on warming tolerance (here, measured using critical thermal maximum, CT max ) in 14 aquatic ectotherms from diverse marine and freshwater environments (10 fishes, four decapod crustaceans), in a series of 24 experiments that included 147 CT max trials and 1,451 animals using two warming rates (0.3°C min −1 and 1°C h −1 ). In 10 of 14 species, there was no effect of oxygen supersaturation relative to normoxic controls. In four species (two tropical reef fishes and two marine decapod crustaceans), we found mixed evidence for effects of oxygen saturation, with most of the effects being small ( ca . 0.2°C–0.3°C). Thus, contrary to predictions, we conclude that oxygen supersaturation is unlikely to protect most water-breathers from heatwaves and therefore few species distribution models or climate risk assessments will benefit from incorporating oxygen supersaturation
