Deep-sea sediments form a major reservoir in the global carbon (C) cycle and C burial in these sediments constitutes a major process that sequesters C on geological time scales. Organic matter sinking from surface waters is the main food source for deep-sea organisms, and their feeding and foraging activities control whether this organic C is recycled into the water column or buried in sediments ('carbon sequestration'). Food supply to the deep-sea benthos is reliant on phytoplankton growth in the euphotic zone, and changes in community composition, export flux or timing of bloom events will directly affect the supply to and turnover of POC at the seafloor and, subsequently, C sequestration. However, due to the remoteness of the deep-sea floor, our knowledge of the interplay between organic matter characteristics, benthic biodiversity and the early diagenesis of POC in the deep sea is very limited, and we can therefore neither reliably assess nor predict the consequences of climate change for this important ecosystem service. The detailed study of benthic C cycling in areas of strong natural fluctuations in POC flux characteristics, and/or pronounced climate-induced change in the pelagic environment, seems a promising way to gain urgently needed information on the potential impact of climate change on the cycling or burial of C in deep-sea sediments, while at the same time improving our understanding of the interplay between POM characteristics and benthic communities, and its function in the early diagenesis of POM. Sea ice is a unique feature of polar marine ecosystems and the fact that small temperature differences can have large effects on the extent and thickness of this sea ice makes polar marine ecosystems particularly sensitive to climate change. Indeed, major ecosystem shifts related to retreating sea ice have been reported from both the Arctic and Antarctic. Ice algae account for up to 25 % of the primary production (PP) in ice covered areas on the deep Arctic shelf, and even more in the Arctic Basin, and thus are likely to form an integral part of the diet of deep-sea organisms. Moreover, ice algal blooms differ considerably from phytoplankton in terms of timing and distribution, thus providing higher organisms with food when and where other food is scarce. Ice algae also contain very high concentrations of so-called "micronutrients", essential substances that many marine organisms can not synthesize themselves. The retreat of sea ice and subsequent loss of ice algae as food source is thus likely to significantly impact on deep-sea food webs and ecosystems. However, despite much speculation, very little information is available on the importance of ice algae as food for benthic organisms. We therefore propose to investigate the potential consequences of a climate-induced loss of ice algae (and possible shift to phytoplankton) as a food source for Arctic deep-sea food webs via two different approaches: A. Ice algae and phytoplankton differ in their bulk Carbon isotope signatures, as well as in the Carbon isotope signatures of certain essential fatty acids. We will thus use this difference in isotopic signature to trace the uptake of ice algal and phytoplankton biomass by benthic fauna. B. A series of in situ tracer experiments: we will label both ice algae and planktic algae with a tracer, add them to sediment cores obtained from the seafloor (so-called 'mesocosms'), and subsequently follow whether and how they are metabolized by the deep-sea organisms. This work will be carried out in the Canadian Arctic in collaboration with Professor Philippe Archabault from the University of Quebec, during field campaigns in the Gulf of St. Lawrence and the Beaufort Sea.

ECOINDUS analyses the ecological transition of the gas industry by questioning its low-carbon promises in the biogas and hydrogen industries, its regional variations in France and the public policies that support them. Based on a comparative survey of the biogas and hydrogen industries in Bretagne and Nouvelle Aquitaine, we will attempt to determine whether the gas industry is genuinely making a transition, including not only decarbonisation but also democratisation of decision-making and territorialisation of projects (their integration into a specific social and eco-system). Two main assumptions guide the research: that power relationships in the conventional gas industry are reproduced in the biogas and hydrogen industries; that transition provides an opportunity for subversion of the dominant model at the local scale depending on the capacity of local coalitions of actors to seize the existing political instruments. Analysing how low-carbon policies and projects in the gas industry are built, ECOINDUS stresses the ability of incumbent energy companies to translate into acceptable terms the government injunction to move towards carbon neutrality. Studying the relationships between cross-sectoral ecological transition policies, the gas industry and the areas where the projects are located, ECOINDUS highlights the new local political capacities offered by the ecological transition to redefine, not only a local variety of transition adapted to the legacies of the territories and greater participation of citizens in energy issues, but also the relevant scale at which the transition is debated. The contribution of ECOINDUS is threefold. Empirically, the project will provide new data about the ecological transition in the gas industry, which has not been investigated in the case of France. Analytically, it develops our understanding of the political impacts of ecological transition policies on local dynamics and industrial organisation. Theoretically, it extends the framework of the institutional order towards the political work of policy solution building and the local scale of the government of an industry

Numerous studies in science education, environmental education and sustainable development education have identified expressions of fatalism and disengagement among young people facing the ongoing environmental crisis. Yet we know that to engage youth in school and as citizens, one must take into account their social identity, their projects and further connect teaching practices and examples to the places they live in. Relying on sustainable development (SD) principles and in order to properly address the concerns of young people from different cultures living there, this research in intercultural environmental and sustainable development education (EIEDD) proposes to develop an innovative, comparative theoretical framework in order to analyse how 16 year old persons envisage SD issues linked to the river nearby. Four case studies will be conducted in very different cultural and environmental contexts. Data will be collected through questionnaires (N = 300) and individual interviews (N = 100). The aim is to characterize a number of "portraits types" of young persons describing their relationships to scientific knowledge and territories, and their dispositions and citizen practices with respect to social, political, economic, ethical or ecological issues they associate with SD of their neighboring river. Two case studies will be conducted in Quebec and two will be done in France. In each of these contexts, the first case study shall imply young people living in a multicultural area while the second will focus on young people from rural areas whose governance is guided by sustainable development principles, in order to identify common cultural elements or contrasts, more or less globalized, in France and Quebec, in a comparative way. The selected zones are the Seine River in France and the St.Lawrence River in Quebec, pursuing ongoing researchs made by the co-directors of this project. Secondly, young people interviewed will develop an interdisciplinary representation of the main issues they link with SD of the nearby river and will suggest citizen initiatives with the support of teachers of science and historyor geography, with actors involved in the area and members of the research team. These interdisciplinary representations and eco-citizen actions will be co-developed and disseminated in virtual ways within the four cultural contexts concerned.

The arctic environment is changing at an alarming rate and it is essential to understand the consequences of such changes on arctic biodiversity. Longterm monitoring programmes of key arctic species are the backbone of scientific research aiming at studying these ecological consequences. The Circumpolar Biodiversity Monitoring Program of the Arctic Council recommends that such monitoring should be conducted and coordinated at a pan-arctic scale, and should involve indigenous participants. However, these monitoring programmes are still mainly operated by national research institutions, with a very uneven distribution of study sites across the Arctic and little involvement of local communities. In this context our project will handle the following key questions: What is the best, most efficient survey design for pan-arctic monitoring? Are current monitoring plans adequate, and how can they be improved? How can participatory citizen science best contribute to pan-Arctic long-term monitoring? What are the current participatory initiatives, and how can they be improved? We will focus on land vertebrates and seabirds which are acknowledged indicator species of arctic change and emblematic species for local communities. Using interviews of representatives of institutions funding arctic research and of representatives of arctic communities, we will assess their perceptions and expectations of pan-arctic, long-term participatory research activities on land vertebrates and seabirds. Further, we will use pan-arctic data on existing monitoring programmes of land vertebrates and seabirds, to test the hypothesis that this network of monitoring sites is unevenly distributed relative to environmental gradients. These analyses will allow us to propose a revised, ecologically sound network of key monitoring sites for land vertebrates and seabirds, that allows the most efficient study of these key species on a pan-arctic scale while fully involving local communities in participatory citizen science programmes.

The 2022 fire season in France has demonstrated that areas previously thought to have little chance of burning, such as the Landes de Gascogne area (LGA), are becoming increasingly flammable as the climate continues to warm and dry. Recent increases in area burned in France and elsewhere globally suggest area burned responses nonlinearly to climate change in forest ecosystems. Our understanding of fire behaviour and its effects has been developed under the narrow, modern-day, range of environmental condition. A more comprehensive understanding of the area burned in response to increased atmospheric warming is key to improve our ability to forecast how climate and wildfire will interact to shape ecosystems and impact society. The objective of our project is to improve our ability to project future climate-wildfire interactions in the LGA by leveraging paleo-data (paleo-fire and paleo-vegetation) and modelling to capture a larger portion of the natural range of variability in ecosystem flammability. We will use the LANDIS-II forest landscape succession and disturbance model, parameterized with paleo data, to run simulations over the past 3000 years to quantify how vegetation and area burned changed under a wider range of climatic conditions. We will use this understanding to simulate the study area into the future using projected climate data to quantify how landscape flammability changes as a function of vegetation composition and climate. The results of this project will provide key information on fire activity under changing climate and support the development of mitigation strategies.