Extreme climatic events (ECEs), such as marine heatwaves (MHWs), are a major threat to biodiversity. Understanding the variability in ecological responses to recurrent ECEs within species and underlying drivers arise as a key issue owing to their implications for conservation and restoration. Yet, our knowledge on such ecological responses is limited since it has been mostly gathered following “single-event approaches” focused on one particular e [...]
Durant l’été 1999, une mortalité massive d’invertébrés benthiques fixés a été observée en de nombreux points de la côte méditerranéenne française à l’est du Rhône. Une telle extension géographique suggérait l’existence d’une anomalie climatique à l’origine directe ou indirecte du phénomène. Les mesures systématiques de la température de l’eau de surface (1 mesure/30 min) et de la structure thermique verticale de 0 à 55 m (à fréquence bimensuelle) [...]
The differential response of marine populations to climate change remains poorly understood. Here, we combine common garden thermotolerance experiments in aquaria and population genetics to disentangle the factors driving the population response to thermal stress in a temperate habitat-forming species: the octocoral Paramuricea clavata. Using eight populations separated from tens of meters to hundreds of kilometers, which were differentially impa [...]
In order to reduce the contamination of marine ecosystems by plastic materials, the scientific community is engaged in the development of biodegradable substitutes for conventional plastics. While certain candidates have been successfully tested in coastal marine environments, the degradation process in deep-sea environments remains poorly understood. This study examined the degradation of two industrial biopolyesters, a poly(3-hydroxybutyrate-co [...]
1. Species Distribution Models (SDMs) assume stable relationships between species and their environment from which predictions are made. These relationships are likely to vary with changing environments, and predictions might depend more on modelling choices than on empirical data. Reliability assessments of predictions are necessary to support policy-making. 2. We identified environmental extrapolations among potential predictions of cetacean [...]
This cumulative thesis reconstructs past changes in surface primary productivity and carbonate dissolution in the western South Atlantic Ocean, particularly the southernmost Brazilian continental margin, focusing on the Marine Isotope Stages 5 – 1. Comprising two published articles, one submitted manuscript, and this integrative text, this PhD thesis aims to contribute to our understanding of the mechanisms behind such variations and the dynamics [...]
1998 est la seconde année du programme de coopération franco-tunisien "Aquaculture 2001" centré sur la restructuration de la recherche tunisienne dans le domaine de l'aquaculture. Les 10 projets scientifiques sélectionnés en 1996 ont été engagés en 1997 dans le cadre d'un programme global de 5 années (1997-2001). En 1997, la priorité a été donnée aux aspects de formation, d'information et de documentation. Le bilan très positif tiré par le comité [...]
Le REPHY est le REseau PHYtoplanctonique géré par l'IFREMER généralisé à l'ensemble du littoral français depuis 1984 et son objectif principal est la protection de la santé publique et des cheptels aquacoles qui peuvent être menacés par la présence de certains microorganismes phytoplanctoniques dans l'eau de mer. Ce réseau permet également la collecte de données sur les successions des populations et le smv1 des événements exceptionnels (par exem [...]
En 1995, aucun naissain d' huître n'est sorti del' écloserie de la SASV. Le manque de maîtrise de l'élevage larvaire n'avait pas permis de produire des juvéniles comme en 1994. Des essais d'élevage larvaire ont donc été renouvelés en 1996. En cas de réussite, de nouveaux essais de grossissement étaient prévus sur les sites pilotes déjà testés les années précédentes.
Des enregistrements semi-continus (1/30 min) de paramètres physico-chimiques (T,S, OD et pH) ont été réalisés de 1998 à 2000, à 1,50 m de profondeur dans des eaux littorales méditerranéennes (Marseille), associés à des enregistrements d'irradiance et de vitesse et direction du vent. Les données physico-chimiques ont été traitées pour en synthétiser l'information à différentes échelles de temps (inter-annuel, saisonnier, quotidien et horaire) et, [...]
As on land, oceans exhibit high temporal and spatial temperature variation. This "ocean weather" contributes to the physiological and ecological processes that ultimately determine the patterns of species distribution and abundance, yet is often unrecognized, especially in tropical oceans. Here, we tested the paradigm of temperature stability in shallow waters (<12.5 m) across different zones of latitude. We collated hundreds of in situ, high tem [...]
The Gray's sea fan, Paramuricea grayi (Johnson, 1861), typically inhabits deep littoral and circalittoral habitats of the eastern temperate and tropical Atlantic Ocean. Along the Iberian Peninsula, where P. grayi is a dominant constituent of circalittoral coral gardens, two segregating lineages (yellow and purple morphotypes) were recently identified using single-copy nuclear orthologues. The mitochondrial genomes of 9 P. grayi individuals coveri [...]
Quantifying changes in functional community structure driven by disturbance is critical to anticipate potential shifts in ecosystem functioning. However, how marine heatwaves (MHWs) affect the functional structure of temperate coral-dominated communities is poorly understood. Here, we used five long-term (> 10 years) records of Mediterranean coralligenous assemblages in a multi-taxa, trait-based analysis to investigate MHW-driven changes in funct [...]
Anomalous warming of the upper ocean is increasingly being observed in the Mediterranean Sea. Extreme events, known as marine heatwaves (MHWs), can have a profound impact on marine ecosystems, and their correct detection and characterization are crucial to define future impact scenarios. Here, we analyze MHWs observed over the last 41 years (1982-2022) in the Mediterranean sea surface temperatures (SSTs). We show that the intensification in frequ [...]
Climate change is one of the biggest emerging threats to marine biodiversity in the Mediterranean Sea. In this chapter, we focus on the recurrent and large scale mass mortality events (MMEs) induced by marine heatwaves (MHWs), and their immediate and long-term impacts on structural octocorals from highly diverse coralligenous communities. By combining an accurate characterization of present and expected thermal stress conditions in coastal seawat [...]
Ecologists must understand how marine life responds to changing local conditions, rather than to overall global temperature rise, say Amanda E. Bates and 16 colleagues.
Understanding the factors and processes that shape intra-specific sensitivity to heat stress is fundamental to better predicting the vulnerability of benthic species to climate change. Here, we investigate the response of a habitat-forming Mediterranean octocoral, the red gorgonian Paramuricea clavata (Risso, 1826) to thermal stress at multiple biological and geographical scales. Samples from eleven P. clavata populations inhabiting four localiti [...]
Aim How historical and contemporary eco-evolutionary processes shape the patterns of genetic diversity and differentiation across species' distribution range remains an open question with strong conservation implications. Focusing on the orange stony coral, Astroides calycularis, we (a) characterized the pattern of neutral genetic diversity across the distribution range; (b) gave insights into the underlying processes; and (c) discussed conservat [...]