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Ecological barrier crossing strategies in small migratory birds depend on wing morphology and plumage color
No full textInternational audienceRecent tracking technologies have revealed remarkable diel flight altitude changes over the Sahara Desert in small migratory birds. However, the drivers and traits behind these strategies remain poorly understood, partly because few species and barriers have been studied. Using a dataset from 67 recovered multi-sensor loggers across 17 species, we examined how small landbirds cross two major marine barriers (the Bay of Biscay, the Mediterranean Sea) and the Sahara. We then used a comparative approach to test the influence of wing morphology, wing structure, and plumage color on flight altitude. Birds showed important differences across barriers: over the desert, they averaged 1,600 m at night and 2,800 m during prolonged daytime flights, while marine crossings occurred lower (750 m), sometimes just above water. Flight altitude increased with wing area, and species with shorter wing bones and darker plumage flew higher over the Sahara, likely to enhance heat dissipation and reduce solar heating. These findings refine hypotheses on barrier-crossing strategies and suggest broader ecological and evolutionary implications
B.A.-BA du traçage - contexte des ponds
No full textMaitriseIn a hydrological context such as the study of wetlands, but also that of “chemical and/or biological reactors,” the question often arises of performing tracing to access the intrinsic variables of this reactor, such as: water residence time, the presence of short circuits, the potential for mitigating pollution peaks, etc. The tracer is usually chemical in nature and, after injection, must be measured at regular intervals at the outlet of the system to be characterized. These measurements provide a chronicle of the injected element, which can then be used to deduce the above-mentioned indicators by statistical processing of the residence time distribution, known as “RTD.”However, when faced with the reality on the ground, many questions arise, such as: what is the appropriate tracer, how much should be chosen and how should it be injected, how often should it be sampled and how should it be analyzed, what indicators will I obtain and how should they be calculated, etc.This slideshow presents a number of elements that attempt to answer these various questions using concrete examples, thereby facilitating the task of the operator, who often only has one attempt due to time, budget, and “contamination” of the environment once the first tracing has been carried out.Dans un contexte hydrologique comme l’étude des zones humides mais aussi celui des « réacteurs chimiques et/ou biologiques » se pose souvent la question de réaliser un traçage pour accéder aux variables intrinsèques de ce réacteur telles que : le temps de séjour de l’eau, la présence de courts circuits, le potentiel d’atténuation de pics de pollution…La nature du traceur est le plus généralement chimique et après son injection, il est nécessaire de le doser à fréquence régulière en sortie du système que l’on souhaite qualifier. Grâce à ces dosages on obtient une chronique de l’élément injecté qui permet ensuite de déduire les indicateurs mentionnés plus haut par traitement statistique de la distribution des temps de résidence appelée « RTD ».Toutefois lorsque l’on est confronté à la réalité du terrain, de nombreuses questions se posent comme : quel est le traceur approprié, quelle quantité choisir et comment l’injecter, à quelle fréquence l’échantillonner et comment l’analyser, quels indicateurs vais-je obtenir et comment les calculer etc.Ce diaporama présente ainsi un certain nombre d’éléments qui tentent de répondre à ces différentes questions grâce à des cas concrets, et ainsi faciliter la tâche de l’opérateur qui bien souvent n’a droit qu’à un seul essai pour des raisons de temps, de budget et de « souillure » du milieu une fois le premier traçage réalisé
Integrating metaecosystem framework with ecosystem service dynamics in sociohydrosystems
No full textInternational audienceSociohydrosystems provide vital ecosystem services such as water purification, flood regulation, and climate regulation. However, understanding the complex relationships among ecosystem processes, hydrosystem dynamics, and ecosystem services is crucial. The metaecosystem framework, which is focused on the flows of organisms, matter, and energy among ecosystems across spatial and temporal scales, provides valuable tools for more holistic ecosystem assessments. The present article shows that a unified framework is crucial for understanding how ecosystem services are influenced by spatiotemporal dynamics of organisms, matter, and energy, advancing our understanding of how changes in one area of the hydrosystem translate into changes in other areas. The proposed framework also helps identify synergies and trade-offs among ecosystem services and the influence of environmental conditions. Finally, this unified framework enhances our ability to inform decision-making; design adaptive management strategies that consider changing environmental conditions, especially in the context of climate change; and mitigate social inequalities
A novel protocol for rapid deployment of heart rate data storage tags in Atlantic bluefin tuna Thunnus thynnus reveals cardiac responses to temperature and feeding
No full textInternational audienceThe Atlantic bluefin tuna (ABFT) is a highly prized species of large pelagic fish. Studies of their environmental physiology may improve understanding and management of their populations, but this is difficult for mature adults because of their large size. Biologging of heart rate holds promise in investigating physiological responses to environmental conditions in free-swimming fishes but it is very challenging to anesthetize large ABFT for invasive surgery to place a tag in the body cavity near to the heart. We describe a novel method for rapid deployment of a commercially available heart-rate tag on ABFT, using an atraumatic trocar to implant it in the musculature associated with the cleithrum. We performed three sequential experiments to show that the tagging method (1) is consistently repeatable and reliable, (2) can be used successfully on commercial fishing boats and does not seem to affect fish survival, and (3) is effective for long-term deployments. In experiment 3, a tag logged heart rate over 80 days on a 60-kg ABFT held in a farm cage. The logged data showed that heart rate was sensitive to prevailing seasonal temperature and feeding events. At low temperatures, there were clear responses to feeding but these all disappeared above a threshold temperature of 25.5°C. Overall, the results show that our method is simple, rapid, and repeatable, and can be used for long-term experiments to investigate physiological responses by large ABFT to environmental conditions
Etude pilote pour la surveillance des espèces exotiques envahissantes par intelligence artificielle
No full textInternational audienceDéveloppement d'un outil de surveillance par acquisition d'images avec reconnaissance automatique des espèces exotiques envahissantes par intelligence artificiell
La restauration des marais salés du littoral Manche-Atlantique: Document d'aide à la décision
No full textInternational audienceThis ` Decision-support document for coastal marsh restoration operations, aims to support project leaders in this complex process by providing elements of knowledge and reflection based on feedback from experience and multidisciplinary research. This is not a turnkey guide providing the miracle recipe for successful depolderisation, but an accompanying tool. It mainly concerns the marshes of theChannel-Atlantic facade, but some of the principles and methods proposed apply to a broader field.This tool is intended for managers of natural areas and/or promoters of projects to reconnect with the sea, but it is also aimed at all those who are interested, studying or questioning salt marshes and their restoration.This book is the result of the DPM (Programmed Reclamation of Small Coastal Marshes) partnership research program coordinated by the Universities of Western Brittany, Southern Brittany and Rennes. This program conducted from 2021 to 2025 aimed to characterize the ecological and social dynamics involved in the initial phases of the de-polderisation processes. It follows the program 'Environmental Relevance of the restoration of the Small Marshes and Salt Meadows' (PEPPS 2018-2021) which analyzed these dynamics over longer periods. The DPM research program involves researchers belonging mainly to two research teams: the Laboratory of Geoarchitecture - Territories, Urbanization, Biodiversity, Environment, and the CNRS 6553 EcoBio UMR. It was carried out in close collaboration with the managers of the spaces concerned but also other managers and experts: National Nature Reserves of the Bay of Saint-Brieuc, of the Bay of l'Aiguillon and of Séné, Conservatoire du littoral, Regional Natural Reserve of the Loc'h Ponds, Forum of the Atlantic marshes...The DPM program was funded by the Fondation de France as part of the program “The futures of the worlds of the coastline and the sea ”, but also by the Conservatoire du littoral, the Office Français de la Biodiversité, the University of Brest and the University of Southern Brittany.Ce “ Document d’aide à la décision pour les opérations de restauration de marais littoraux ”, vise à accompagner les porteurs de projets dans ce processus complexe en fournissant des éléments de connaissance et de réflexion s’appuyant sur des retours d’expérience et des travaux de recherche pluridisciplinaires. Il ne s’agit pas d’un guide clé en main fournissant la recette miracle de la dépoldérisation réussie, mais d’un outil d’accompagnement. Il concerne principalement les marais de lafaçade Manche-Atlantique, mais certains des principes et méthodes proposés s’appliquent sur un champ plus large.Cet outil est à destination des gestionnaires d’espaces naturels et/ou porteurs de projets de reconnexion à la mer, mais il s’adresse aussi à tous ceux qui s'intéressent, étudient ou s'interrogentsur les marais salés et leur restauration.Cet ouvrage est issu du programme de recherche partenarial DPM (Dépoldérisation Programmée de petits Marais littoraux) coordonné par les Universités de Bretagne Occidentale, Bretagne Sud et de Rennes. Ce programme mené de 2021 à 2025 visait à caractériser les dynamiques écologiques et sociales intervenant dans les phases initiales des processus de dépoldérisation. Il fait suite au programme “ Pertinence Environnementale de la restauration des Petits marais et Prés-salés ” (PEPPS 2018-2021) qui analysait ces dynamiques sur des temps plus longs. Le programme de recherche DPM associe des chercheurs appartenant principalement à deux équipes de recherche : le Laboratoire Géoarchitecture - Territoires, Urbanisation, Biodiversité, Environnement, et l’UMR CNRS 6553 EcoBio. Il a été porté en étroite collaboration avec les gestionnaires des espaces concernés mais aussi d’autres gestionnaires et experts : Réserves Naturelles Nationales de la Baie de Saint-Brieuc, de la Baie de l’Aiguillon et de Séné, Conservatoire du littoral, Réserve Naturelle Régionale des Étangs du Loc’h, Forum des marais atlantiques…Le programme DPM a été financé par la Fondation de France dans le cadre du programme“ Les futurs des mondes du littoral et de la mer ”, mais aussi par le Conservatoire du littoral, l’Office Français de la Biodiversité, l’Université de Bretagne Occidentale et l’Université Bretagne Sud
Sensitivity of Headwater Streams to Climate Change: A Case Study on the Thermal Regime of Streams in the Vosges Mountains
No full textInternational audience1) ContextStream temperature is a crucial indicator of the health of aquatic ecosystems. It influences numerous processes such as the distribution of aquatic species along the stream, chemical and biochemical reactions, and reproduction (Olden and Naiman (2010)). Monitoring stream temperature therefore provides valuable insight into the overall condition of river systems. Stream temperature is driven by a wide range of factors, which can be grouped into three main categories (Dugdale et al. (2017)) : - Hydrological and climatic drivers, which control the rates of heating and cooling. These include air temperature, shortwave and longwave radiation, advective phenomena, precipitation, and more; - Second and third categories include watershed characteristics, hy-drogeology, and channel hydromorphology.2) Material and methodsThe study focuses on two headwater streams. First, the Soultzbach is located in northern Alsace, in a semi-oceanic climate and alternates between two types of soils, podzols and cambisols. The studied section of the stream (5.5 km) covers four different geological features, namely colluvion, sandstone, sandy clay and alluvium. The surrounding vegetation is composed of deciduous trees and conifers. Second, the small Fecht.It is located in southern Alsace, under the same climate. The studied reach is 3.3 km long for the small Fecht, 1.4 km long for its first tributary and 2 km long for its second tributary. It only covers one type of soil, podzols, but five different geological features, namely peaty alluvium and peat, glacial deposites, Vosges granite, fluvioglacial formations, and alluvial fan reworking glacial material. The surrounding vegetation iscomposed of mixed forest, deciduous forest and coniferous forest. The choice of these two distinct sites is partly motivated by the comparison of the dynamics of the hyporheic exchanges. These potential differences will be implemented as components of a mechanistic modelacross two different soil types. Moreover, several types of numerical models can be used to simulate stream temperature dynamics. This study focuses on mechanistic (physically based) models, which are particularly useful for simulating scenarios involving changes in stream configuration, unlike regression-based or stochastic models (Caissie (2006)).To accurately simulate stream temperatures using a mechanistic approach, it is essential to quantify both incoming and outgoing energy fluxes as precisely as possible. Among these energy fluxes, the most important are radiative and evaporative fluxes (Dugdale et al, 2018; Caissie, 2006; Caissie, 2016; Maheu et al, 2014;Morin et Couillard, 1990) at the surface, and the hyporheic exchanges, especially for shallow headwaterstreams (Ouellet et al. (2020); Caissie and Luce (2017). To quantify these hyporheic fluxes, a chain ofsensors will be installed at the two aforementioned headwater stream catchments. The field data collectedwill be used to implement a mechanistic thermal balance model specifically adapted to headwater streamsfor improved representativeness. A particular emphasis is placed on hyporheic fluxes. Indeed, as highlightedby Caissie and Luce (2017), Kurylyk et al. (2017) and Ouellet et al. (2020), a deeper understanding ofhyporheic exchanges is still required. These exchanges are estimated using temperature and pressure datameasured in situ from the hyporheic zone. An inversion model is then applied to derive key physical pa-rameters of this zone. Based on these parameters, conductive and advective fluxes between the hyporheic zone and the river are calculated. This is one of the first steps leading to the establishment of the thermalbalance of headwater streams.3) ObjectivesThe objectives are to :- Estimate the fluxes of matter and energy between the studied rivers and their aquifer;- Model the thermal balance of the two headwater streams studied;- Estimate quantitatively and qualitatively the impact of climate change and watershed management onriver temperatur
Visualization and quantification of coral reef soundscapes using CoralSoundExplorer software
No full textInternational audienceDespite hosting some of the highest concentrations of biodiversity and providing invaluable goods and services in the oceans, coral reefs are under threat from global change and other local human impacts. Changes in living ecosystems often induce changes in their acoustic characteristics, but despite recent efforts in passive acoustic monitoring of coral reefs, rapid measurement and identification of changes in their soundscapes remains a challenge. Here we present the new open-source software CoralSoundExplorer , which is designed to study and monitor coral reef soundscapes. CoralSoundExplorer uses machine learning approaches and is designed to eliminate the need to extract conventional acoustic indices. To demonstrate CoralSoundExplorer ’s functionalities, we use and analyze a set of recordings from three coral reef sites, each with different purposes (undisturbed site, tourist site and boat site), located on the island of Bora-Bora in French Polynesia. We explain the CoralSoundExplorer analysis workflow, from raw sounds to ecological results, detailing and justifying each processing step. We detail the software settings, the graphical representations used for visual exploration of soundscapes and their temporal dynamics, along with the analysis methods and metrics proposed. We demonstrate that CoralSoundExplorer is a powerful tool for identifying disturbances affecting coral reef soundscapes, combining visualizations of the spatio-temporal distribution of sound recordings with new quantification methods to characterize soundscapes at different temporal scales
L’Iroise à table. Carnet de recettes côtières soutenables et manuel de préservation de la diversité bioculturelle alimentaire
No full textInternational audienc
Lignes directrices pour l’élaboration de listes d’espèces faunistiques à proposer à la protection en France
No full textThis document establishes a methodological framework for identifying wildlife species (excluding marine species) to be proposed for protection in France under article L411-1 of the Environment Code. This methodological framework is based on a series of selection criteria that aim to take into account the vulnerability of the studied species, France's territorial responsibility towards them, and the species' ecosystemic role.This work is inspired by numerous European and French studies related to species conservation.Ce document pose un cadre méthodologique, afin d’identifier des espèces de faune (hors espèces marines) à proposer à la protection au titre de l’article L411-1 du code de l’environnement. Ce cadre méthodologique s’appuie sur une série de critères de sélection, qui visent à prendre en compte la vulnérabilité des espèces étudiées, la responsabilité territoriale de la France à leur égard, ainsi que le rôle écosystémique des espèces. Ce travail s’inspire de multiples travaux européens et français en lien avec la conservation des espèces