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One of the current challenges in today’s ecology research is to understand and quantify the effects of climate changes on biodiversity. In order to detect possible trends in biodiversity patterns, it is necessary to conduct long-term observations in various and representative environments. This is always challenging, even more difficult in marine habitats and in the Southern Ocean in particular. Since 2012, a submarine observatory of the coastal benthos has been in operation in the Kerguelen Islands. Eight contrasting sites are monitored using photo and video surveys, loggers, and settlement plots. To quantify potential changes, several photographic analysis techniques are also complemented by scuba diving and ROV (Remotely Operated Vehicle) observations. Investigator scientists have developed and improved new protocols that will be carried out in the long term by the staff of the National Natural Reserve of the French Southern Territories. In order to provide reliable support of species identification, the Proteker program supported by IPEV, French Polar Institute, is currently developing several field guides that should improve the identification of the main taxa being monitored. In light of their abundance in coastal environments of the Kerguelen Islands, and because they are among the most visible invertebrates and the easiest of organisms to consider for monitoring surveys, we first focused on echinoderms. Results of this first study are presented here. For each echinoderm species, a spreadsheet provides the species name with synonymies, a description of diagnostic features, the recorded distribution, as well as three different types of illustrations: (i) living specimens in their environment, which is useful for scuba divers, (ii) fresh collected specimens out of water, and (iii) specimens fixed in ethanol. Therefore, species can be identified alive while diving, but also after sampling in the field, and after several years in the laboratory. An assessment of Kerguelen’s coastal echinoderms is also given.

International audience; Ecosystem engineering species alter the physical structure of their environment and can create or modify habitats , having a massive impact on local biodiversity. Coralligenous reefs are highly diverse habitats endemic to the Mediterranean Sea built by calcareous benthic organisms among which Crustose Coralline Algae are the main engineering species. We analyzed the diversity of Lithophyllum stictiforme or L. cabiochiae in coralligenous habitats combining a multiple barcode and a population genomics approach with seascape features. Population genomics allowed disentangling pure spatial effects from environmental effects. We found that these taxa form a complex of eight highly divergent cryptic species that are easily identifiable using classic barcode markers (psbA, LSU, COI). Three factors have a significant effect on the relative abundances of these cryptic species: the location along the French Mediterranean coast, depth and Photosynthetic Active Radiation (PAR). The analysis of around 5000 SNPs for the most abundant species revealed genetic differentiation among localities in the Bay of Marseille but no differentiation between depths within locality. Thus, the effect of depth and PAR on cryptic species communities is not a consequence of restricted connectivity but rather due to differential settlement or survival among cryptic species. This differential is more likely driven by irradiance levels rather than by pressure or temperature. Both the genetic and species diversity patterns are congruent with the main patterns of currents in the Bay. Ecological differentiation among these engineering cryptic species, sensitive to ocean warming and acidification, could have important consequences on the diversity and structure of the coralligenous communities .

International audience; La végétation marine des îles Kerguelen, inventaire de la flore et première analyse de ses affinités biogéographiques.Conçu comme une base de référence indispensable à la gestion et à la conservation de la flore marine dans l’aire marine protégée des Terres australes françaises (réserve naturelle nationale des Terres australes françaises), l’inventaire de la flore marine des îles Kerguelen a été mis à jour sur la base d’un examen approfondi de la littérature et des bases de données scientifiques, du premier rapport de l’expédition Ross, en 1840, jusqu’aux travaux les plus récents. Ce travail a aussi pour objectif de constituer un point de départ pour de futures investigations utilisant les outils de la systématique moléculaire, et pour le suivi des effets du changement global sur les écosystèmes marins subantarctiques. Après un bref historique des campagnes scientifiques menées, une liste de 166 espèces a été établie (103 Rhodophyta, 35 Chlorophyta et 28 Ochrophyta [Phaeophyceae]). Les travaux récents ont montré l’existence de divergences récurrentes entre la taxinomie actuelle, établie sur des caractères morphologiques et la délimitation moléculaire des espèces, préconisant une révision de la systématique des macroalgues. Une première analyse des affinités biogéographiques de la flore marine des îles Kerguelen a été cependant réalisée et les résultats préliminaires se sont révélés en partie congruents avec les grandes régions actuellement reconnues dans l’océan Austral, suggérant l’importance du phénomène de dispersion sur de longues distances pour expliquer les motifs de distribution observés.; Conceived as a baseline for the management and conservation of the marine protected area of the French Southern Territories (réserve naturelle nationale des Terres australes françaises), the checklist of marine macroalgae of the Kerguelen Islands was updated based on an extensive review of the literature and scientific databases, from the first report of the Ross expedition, in 1840, to the most recent works. This work was also conceived as a starting point for forthcoming investigations using molecular systematics tools and for monitoring the effects of global change on sub-Antarctic marine ecosystems. After a brief history of scientific campaigns, a list of 166 species was established (103 Rhodophyta, 35 Chlorophyta and 28 Ochrophyta [Phaeophyceae]). Molecular systematics studiess have shown the existence of recurrent discrepancies between the established, morphology-based taxonomy and molecular species delimitation, calling for a revision of systematics. Nevertheless, a first analysis of biogeographical affinities of the marine flora of the Kerguelen Islands is carried out and preliminary results are partially congruent with the main regions currently recognized in the Southern Ocean suggesting the importance of long-distance dispersal to explain the observed distribution patterns.

Daily weather regimes are defined around the Kerguelen Islands (Southern Ocean) based on daily 500 hPa geopotential height anomalies derived from the ERA5 ensemble reanalysis over the period 1979-2018. Ten regimes are retained as significant. Their occurrences are highly consistent across reanalysis ensemble members. Regimes show weak seasonality and non-significant long-term trends in their occurrences. Their sequences are usually short (1-3 days), with extreme persistence values above 10 days. Seasonal regime frequency is mostly driven by the phase of the Southern Annular Mode over Antarctica, mid-latitude dynamics over the Southern Ocean like the Pacific South American mode, and to a lesser extent, tropical variability, with significant but weaker relationships with El Niño Southern Oscillation. At the local scale over the Kerguelen Islands, regimes have a strong influence on measured atmospheric and oceanic variables, including minimum and maximum air temperature, mostly driven by horizontal advections, sea water temperature recorded 5 m below the surface, wind speed and sea level pressure. Relationships are weaker for precipitation amounts. Regimes also modify regional contrasts between observational sites in Kerguelen, highlighting strong exposure contrasts. The regimes allow improving our understanding of weather and climate variability and interactions in this region; they will be used in future work to assess past and projected long-term circulation changes in the southern mid-latitudes.

International audience; Members of the trochoidean genus Margarella (Calliostomatidae) are broadly distributed across Antarctic and sub-Antarctic ecosystems. Here we used novel mitochondrial and nuclear gene sequences to clarify species boundaries and phylogenetic relationships among seven nominal species distributed on either side of the Antarctic Polar Front (APF). Molecular reconstructions and species-delimitation analyses recognized only four species: M. antarctica (the Antarctic Peninsula), M. achilles (endemic to South Georgia), M. steineni (South Georgia and Crozet Island) and the morphologically variable M. violacea (=M. expansa, M. porcellana and M. pruinosa), with populations in southern South America, the Falkland/Malvinas, Crozet and Kerguelen Islands. Margarella violacea and M. achilles are sister species, closely related to M. steineni, with M. antarctica sister to all these. This taxonomy reflects contrasting biogeographic patterns on either side of the APF in the Southern Ocean. Populations of Margarella north of the APF (M. violacea) showed significant genetic variation but with many shared haplotypes between geographically distant populations. By contrast, populations south of the APF (M. antarctica, M. steineni and M. achilles) exhibited fewer haplotypes and comprised three distinct species, each occurring across a separate geographical range. We hypothesize that the biogeographical differences may be the consequence of the presence north of the APF of buoyant kelps – potential long-distance dispersal vectors for these vetigastropods with benthic-protected development – and their near-absence to the south. Finally, we suggest that the low levels of genetic diversity within higher-latitude Margarella reflect the impact of Quaternary glacial cycles that exterminated local populations during their maxima.

International audience; In a world of declining biodiversity, monitoring is becoming crucial. Molecular methods , such as metabarcoding, have the potential to rapidly expand our knowledge of biodiversity, supporting assessment, management, and conservation. In the marine environment, where hard substrata are more difficult to access than soft bottoms for quantitative ecological studies, Artificial Substrate Units (ASUs) allow for standardized sampling. We deployed ASUs within five regional seas (Baltic Sea, Northeast Atlantic Ocean, Mediterranean Sea, Black Sea, and Red Sea) for 12-26 months to measure the diversity and community composition of macroinvertebrates. We identified invertebrates using a traditional approach based on morphological characters, and by metabarcoding of the mitochondrial cytochrome oxidase I (COI) gene. We compared community composition and diversity metrics obtained using the two methods. Diversity was significantly correlated between data types. Metabarcoding of ASUs allowed for robust comparisons of community composition and diversity, but not all groups were successfully sequenced. All locations were significantly different in taxonomic composition as measured with both kinds of data. We recovered previously known regional biogeographical patterns in both datasets (e.g., low species diversity in the Black and Baltic Seas, affinity between the Bay of Biscay and the Mediterranean). We conclude that the two approaches provide complementary information and that metabarcoding shows great promise for marine monitoring. However, until its pitfalls are addressed, the use of metabarcoding in monitoring of rocky benthic assemblages should be used in addition to classical approaches rather than instead of them.

Species flocks (SFs) fascinate evolutionary biologists who wonder whether such striking diversification can be driven by normal evolutionary processes. Multiple definitions of SFs have hindered the study of their origins. Previous studies identified a monophyletic taxon as a SF if it displays high speciosity in an area in which it is endemic (criterion 1), high ecological diversity among species (criterion 2), and if it dominates the habitat in terms of biomass (criterion 3); we used these criteria in our analyses. Our starting hypothesis is that normal evolutionary processes may provide a sufficient explanation for most SFs. We thus clearly separate each criterion and identify which biological (intrinsic) and environmental (extrinsic) traits are most favourable to their realization. The first part focuses on evolutionary processes. We highlight that some popular putative causes of SFs, such as key innovations or ecological speciation, are neither necessary nor sufficient to fulfill some or all of the three criteria. Initial differentiation mechanisms are diverse and difficult to identify a posteriori because a primary differentiation of one type (genetic, ecological or geographical) often promotes other types of differentiation. Furthermore, the criteria are not independent: positive feedbacks between speciosity and ecological diversity among species are expected whatever the initial cause of differentiation, and ecological diversity should enhance habitat dominance at the clade level. We then identify intrinsic and extrinsic factors that favour each criterion. Low dispersal emerges as a convincing driver of speciosity. Except for a genomic architecture favouring ecological speciation, for which assessment is difficult, high effective population sizes are the single intrinsic factor that directly enhances speciosity, ecological diversity and habitat dominance. No extrinsic factor appeared to enhance all criteria simultaneously but a combination of factors (insularity, fragmentation and environmental stability) may favour the three criteria, although the effect is indirect for habitat dominance. We then apply this analytical framework to Antarctic marine environments by analysing data from 18 speciose clades belonging to echinoderms (five unrelated clades), notothenioid fishes (five clades) and peracarid crustaceans (eight clades). Antarctic shelf environments and history appear favourable to endemicity and speciosity, but not to ecological specialization. Two main patterns are distinguished among taxa. (i) In echinoderms, many brooding, species-rich and endemic clades are reported, but without remarkable ecological diversity or habitat dominance. In these taxa, loss of the larval stage is probably a consequence of past Antarctic environmental factors, and brooding is suggested to be responsible for enhanced allopatric speciation (via dispersal limitation). (ii) In notothenioids and peracarids, many clades fulfill all three SF criteria. This could result from unusual features in fish and crustaceans: chromosome instability and key innovations (antifreeze proteins) in notothenioids, ecological opportunity in peracarids, and a genomic architecture favouring ecological speciation in both groups. Therefore, the data do not support our starting point that normal evolutionary factors or processes drive SFs because in these two groups uncommon intrinsic features or ecological opportunity provide the best explanation. The utility of the three-criterion SF concept is therefore questioned and guidelines are given for future studies.

The coralligenous habitat was studied at the large Mediterranean scale, by applying a standardized, non-destructive photo-sampling protocol, developed in the framework of the CIGESMED project. the results provided evidence to support the following statements: (a) the assemblage pattern is not homogeneously distributed across the four Mediterranean ecoregions studied (biotic gradients hypothesis); and (b) the assemblage pattern does not change significantly when the information is aggregated to higher taxonomic levels (taxonomic sufficiency hypothesis). Surrogate taxonomic categories higher than species, such as genus and family, can be used to reveal the multivariate pattern of the coralligenous assemblages. Although preliminary at the pan-Mediterranean scale, these outcomes set the scene for future comparisons as more data sets become available but also for comparisons between taxonomic and functional patterns. 1.2.3.4., CNRS - ANRFrench National Research Agency (ANR)Centre National de la Recherche Scientifique (CNRS) [12-SEAS-0001-01, 12-SEAS-0001-02, 12-SEAS-0001-03]; General Secretariat for Research and TechnologyGreek Ministry of Development-GSRT [12SEAS-2-C2]; Turkiye Bilimsel ve Teknolojik Arastirma KurumuTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112Y393], CNRS - ANR, Grant/Award Numbers: 12-SEAS-0001-01, 12-SEAS-0001-02, 12-SEAS-0001-03; General Secretariat for Research and Technology, Grant/Award Number: 12SEAS-2-C2; Turkiye Bilimsel ve Teknolojik Arastirma Kurumu, Grant/Award Number: 112Y393

International audience

International audience; The French National Committee for Scientific Diving (CNPS) is an inter-agency committee on scientific diving activities. French marine universities, research institutes (CNRS-INEE/INSU/INSHS, DRASSM, EPHE, IFREMER, INRA, INSERM, IPEV, IRD, IRSTEA) and the National Museum (MNHN) are involved or represented. The CNPS, created in 1999, is the scientific diving representative of the Ministry of Higher Education and Research to the Ministry of Labor. It includes personalities chosen for their expertise in the field of professional use of diving (scientific and technical diving, training), the law of the sea, the hyperbaric medicine and the European scientific diving panel (ESDP). The aims of this group of experts are: a) to observe the evolution of the professional scientific diving practices worldwide, b) to define common frameworks and promote the best practices, c) to provide high-level expertise and advices to Ministries of Labor and Research, d) to monitor the innovations in scientific diving, technology, field practices and hyperbaric medicine, e) to share informations and feedback with the French scientific divers community, f) to participate in the training of scientific divers, and g) to represent France at the ESDP. The CNPS has been fully involved since 2009 in the formulation of new laws and regulations dedicated to professional diving with the Ministry of Labor. The French scientific diving community is very diversified, for historical reasons, due to its 18 000 km long coastline and a strong presence overseas, through the involvement of researchers in global science issues and international collaborations. This poster presents the aims, activities and key results obtained by the CNPS. It also sets out some perspectives, especially actions in favour of a convergence of European practice patterns and standards.

International audience; The Kerguelen Islands are part of the French Southern Territories, located at the limit of the Indian and Southern oceans. They are highly impacted by climate change, and coastal marine areas are particularly at risk. Assessing the responses of species and populations to environmental change is challenging in such areas for which ecological modelling can constitute a helpful approach. In the present work, a DEB-IBM model (Dynamic Energy Budget – Individual-Based Model) was generated to simulate and predict population dynamics in an endemic and common benthic species of shallow marine habitats of the Kerguelen Islands, the sea urchin Abatus cordatus. The model relies on a dynamic energy budget model (DEB) developed at the individual level. Upscaled to anindividual-based population model (IBM), it then enables to model population dynamics through time as a result of individual physiological responses to environmental variations. The model was successfully built for a reference site to simulate the response of populations to variations in food resources and temperature. Then, it was implemented to model population dynamics at other sites and for the different IPCC climate change scenarios RCP 2.6 and 8.5. Under present-day conditions, models predict a more determinant effect of food resources on population densities, and on juvenile densities in particular, relative to temperature. In contrast, simulations predict a sharp decline in population densities under conditions of IPCC scenarios RCP 2.6 and RCP 8.5 with a determinant effect of water warming leading to the extinction of most vulnerable populations after a 30-year simulation time due to high mortality levels associated with peaks of high temperatures. Such a dynamic model is here applied for the first time to a Southern Ocean benthic and brooding species and offers interesting prospects for Antarctic and sub-Antarctic biodiversity research. It could constitute a useful tool to support conservation studies in these remote regions where access and bio-monitoring represent challenging issues.

International audience; The understanding of ecosystem services is essential to support sustainable use and preservation of ecosystems. Coralligenous habitats, main contributors of the Med iterranean marine biod iversity, are yet und erstud ied in term of services provid ed. This stud y presents an original small-scale approach to investigate the services provided by coralligenous habitats of a French stud y area consisting of two marine sites (Marseille and Port-Cros sites) in order to cover two contrasted anthropogenic pressure despite the small-scale. Our results are based on the opinions of 43 experts who ranked 15 services in terms of existence and level of importance for human well-being: supporting ecological functions were consid ered the most important, then provisioning and cultural services. Regulating services were consid ered uncertain d ue to a lack of knowled ge. The small-scale approach highlighted a need for a referential frame to determine the existence of services (e.g. geographical and temporal scales, benefits and beneficiaries levels).

International audience; We investigated the validity of Autonomous Reef Monitoring Structures (ARMS) as monitoring tools for hard bottoms across a wide geographic and environmental range. We deployed 36 ARMS in the northeast Atlantic, northwest Mediterranean, Adriatic and Red Sea at 7–17 m depth. After 12–16 months, community composition was inferred from photographs, in six plate-faces for each ARMS. Overall, we found a highly significant effect of sea region, site (within seas), and plate-face on community composition. Plate-faces thus represent distinct micro-habitats and provide pseudo-replicates, increasing statistical power. Within each sea region taken individually, there was also a highly significant effect of site and plate-face. Because strong effects were obtained despite the fusion of taxonomic categories at high taxonomic ranks (to ensure comparability among biogeographic provinces), ARMS photo-analysis appears a promising monitoring tool for each sea region. We recommend keeping three ARMS per site and analyzing more numerous sites within a sea region to investigate environmental effects.

13 páginas, 7 figuras, 1 tabla., 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 habitatforming species: the octocoral Paramuricea clavata. Using eight populations separated from tens of meters to hundreds of kilometers, which were differentially impacted by recent mortality events, we identify 25°C as a critical thermal threshold. After one week of exposure at this temperature, seven of the eight populations were affected by tissue necrosis and after 30 days of exposure at this temperature, the mean % of affected colonies increased gradually from 3 to 97%. We then demonstrate the weak relation between the observed differential phenotypic responses and the local temperature regimes experienced by each population. A significant correlation was observed between these responses and the extent of genetic drift impacting each population. Local adaptation may thus be hindered by genetic drift, which seems to be the main driver of the differential response. Accordingly, conservation measures should promote connectivity and control density erosion in order to limit the impact of genetic drift on marine populations facing climate change., The authors gratefully acknowledge the funding support given by the Alan Program (CC Doctoral Fellowship), by CSIC-Uruguay (Call Programa de pasantías en el exterior 2015) and by the Portuguese Foundation for Science and Technology (Fundação para a Ciència e a Tecnologia; FCT) which funded JBL Postdoctoral grant (SFRH/ BPD/74400/2010). Authors are also grateful to the MEDCHANGE project funded by the Agence Nationale pour la Recherche (ANR) and to the Spanish Ministry of Economy and Competitivity (http://www.mineco.gob.es) through the Biorock (CTM2009-08045), Smart (CGL2012-32194) and CSI-Coral (CGL2013-43106-R). Temperature data series data is part of the regional temperature observation network T-MEDNet (www.t-mednet.org); we thank J.M. Dominici for providing the data for the Réserve Naturelle de Scandola. The authors also thank the staff of Experimental Aquarium Facilities at the Institute of Marine Sciences E. Martinez and M. Delgado for the technical support provided. EC, JG, CL, PL and NT are part of the Marine Conservation research group MEDRECOVER www.medrecover.org (2009 SGR 1174) while RC and MR are part of the Marine Biogeochemistry and Global Change Research group (2014SGR1029) from the Generalitat de Catalunya.

Life history traits are among the major forces influencing the spatial organisation of biodiversity. Brooding species, lacking a planktonic larval phase, have a weak potential for dis - persal and are prone to displaying strong spatial genetic structures of their populations. Selfreproduction allows a single individual to establish a new population. Using nuclear markers to assign specimens to species (1004 specimens) and sequences of the 16S mitochondrial gene (for a subset of 479 specimens) to estimate genetic differentiation, we analyzed spatial and bathymetric sampling of 14 locations along the French Mediterranean coast in order to investigate the genetic effects of brooding and self-reproduction on the Amphipholis squamata species complex. The spatial organisation of the complex appeared chaotic, illustrating the random nature of dispersal in these brooding organisms. Bayesian dating confirmed the old age of the species complex (approximately 10 million yr). The different species displayed contrasted levels of genetic diversity and differentiation, despite their similar and extreme self-reproduction rates. This study illustrates the role of stochastic dispersal on species assemblages and genetic structure, and suggests a strong influence of past demographic history on population genetic structure of co-distributed species.

15 pages; International audience; Sterechinus is a very common echinoid genus in benthic communities of the Southern Ocean. It is widely distributed across the Antarctic and South Atlantic Oceans and has been the most frequently collected and intensively studied Antarctic echinoid. Despite the abundant literature devoted to Sterechinus, few studies have questioned the systematics of the genus. Sterechinus bernasconiae is the only species of Sterechinus reported from the Pacific Ocean and is only known from the few specimens of the original material. Based on new material collected during the oceanographic cruise INSPIRE on board the R/V Melville, the taxonomy and phylogenetic position of the species are revised. Molecular and morphological analyses show that S. bernasconiae is a subjective junior synonym of Gracilechinus multidentatus (Clark). Results also show the existence of two genetically distinct subclades within the so-called Sterechinus clade: a Sterechinus neumayeri subclade and a subclade composed of other Sterechinus species. The three nominal species Sterechinus antarcticus, Sterechinus diadema, and Sterechinus agassizi cluster together and cannot be distinguished. The species Sterechinus dentifer is weakly differentiated from these three nominal species. The elucidation of phylogenetic relationships between G. multidentatus and species of Sterechinus also allows for clarification of respective biogeographic distributions and emphasizes the putative role played by biotic exclusion in the spatial distribution of species.

International audience; The Kerguelen archipelago, isolated in the Southern Ocean, shelters a blue mussel Mytilus metapopulation far from any influence of continental populations or any known hybrid zone. The finely carved coast leads to a highly heterogeneous habitat. We investigated the impact of the environment on the genetic structure in those Kerguelen blue mussels by relating allele frequencies to habitat descriptors. A total sample comprising up to 2248 individuals from 35 locations was characterized using two nuclear markers, mac-1 and Glu-5’, and a mitochondrial marker (COI). The frequency data from 9 allozyme loci in 9 of these locations were also reanalysed. Two other nuclear markers (EFbis and EFprem’s) were monomorphic. Compared to Northern-Hemisphere populations, polymorphism in Kerguelen blue mussels was lower for all markers except for the exon Glu-5’. At Glu-5’, genetic differences were observed between samples from distinct regions (FCT=0.077), as well as within two regions, including between samples separated by less than 500 meters. No significant differentiation was observed in the AMOVA analyses at the two other markers (mac-1 and COI). Like mac-1, all allozyme loci genotyped in a previous publication, displayed lower differentiation (Jost's D) and FST values than Glu-5'. Power simulations and confidence intervals support that Glu-5’ displays significantly higher differentiation than the other loci (except a single allozyme for which confidence intervals overlap). AMOVA analyses revealed significant effects of the giant kelp Macrocystis and wave exposure on this marker. We discuss the influence of hydrological conditions on the genetic differentiation among regions. In marine organisms with high fecundity and high dispersal potential, gene flow tends to erase differentiation, but this study showed significant differentiation at very small distance. This may be explained by the particular hydrology and the carved coastline of the Kerguelen archipelago, together with spatially variable selection at Glu-5’.

15 pages, 4 figures, 2 tables, supporting information http://onlinelibrary.wiley.com/doi/10.1002/ece3.1324/suppinfo, Studying population-by-environment interactions (PEIs) at species range margins offers the opportunity to characterize the responses of populations facing an extreme regime of selection, as expected due to global change. Nevertheless, the importance of these marginal populations as putative reservoirs of adaptive genetic variation has scarcely been considered in conservation biology. This is particularly true in marine ecosystems for which the deep refugia hypothesis proposes that disturbed shallow and marginal populations of a given species can be replenished by mesophotic ones. This hypothesis therefore assumes that identical PEIs exist between populations, neglecting the potential for adaptation at species range margins. Here, we combine reciprocal transplant and common garden experiments with population genetics analyses to decipher the PEIs in the red coral, Corallium rubrum. Our analyses reveal partially contrasting PEIs between shallow and mesophotic populations separated by approximately one hundred meters, suggesting that red coral populations may potentially be locally adapted to their environment. Based on the effective population size and connectivity analyses, we posit that genetic drift may be more important than gene flow in the adaptation of the red coral. We further investigate how adaptive divergence could impact population viability in the context of warming and demonstrate differential phenotypic buffering capacities against thermal stress. Our study questions the relevance of the deep refugia hypothesis and highlights the conservation value of marginal populations as a putative reservoir of adaptive genetic polymorphism. In marine conservation, the deep-refugia hypothesis proposes that disturbed shallow and marginal populations of a given species can be replenished by mesophotic populations. Combining reciprocal transplant and common garden experiments with population genetics analyses we question the relevance of this hypothesis in the red coral, Corallium rubrum. Our study highlights the conservation value of marginal populations as a putative reservoir of adaptive genetic polymorphism. © 2015 Published by John Wiley & Sons Ltd., This study was funded by the “Provence–Alpes–Côte d'Azur” region (J-B. Ledoux Doctoral Fellowship) and by the IFB Foundation (Institut Français de la Biodiversité), the environmental department of TOTAL-FINA-ELF group, an “Action Concertée Initiative” (ACI) program “Jeunes chercheurs 2003” (number JC5360) from the French Research Ministry and the MEDCHANGE project funded by the Agence Nationale pour la Recherche (ANR) J-B. L. is supported by a post-doctoral grant SFRH/BPD/74400/2010 from Fundacão para a Ciência e Tecnologia (FCT; Portugal)

Development of the brooding schizasterid Abatus cordatus, a subantarctic echinoid endemic to Kerguelen, is described. Females spawn nonbuoyant eggs 1300 μm in diameter, which are fertilized by elongated sperm (head 1 μm wide and 15 μm long). The main characteristics of this development are (1) incomplete cleavage beginning at the animal pole that becomes holoblastic, giving a filled wrinkled blastula 26 days after fertilization; (2) apparent (fate-mapping studies have not been done) external migration of mesenchyme cells, in the perivitelline space, from the animal to the vegetal pole during gastrulation while the archenteron invaginates; (3) hatching occurring at the end of the gastrulation (65 days after fertilization); (4) differentiation of the vestibule from a thickening of the oral epidermis as soon as the end of gastrulation is attained; and (5) production of a juvenile directly from the gastrula without any larval stage. The juvenile that leaves the brood chamber is 2 mm in diameter and about 250 days old. A. cordatus is a true completely direct developer (no larva and no metamorphosis). We propose to use (1) the term perigastrulation, as a tentative one until more definitive studies are available, to describe the hypothetical peculiar movement of cells during gastrulation and (2) the terms of direct development only for completely direct developing species and abbreviated development for species that have more or less transformed plutei.

International audience; Extisting biodiversity databases contain an abundance of information. To turn such information into knowledge , it is necessary to address several information-model issues. Biodiversity data are collected for various scientific objectives, often even without clear preliminary objectives, may follow different taxonomy standards and organization logic, and be held in multiple file formats and utilising a variety of database technologies. This paper presents a graph catalogue model for the metadata management of biodiversity databases. It explores the possible operation of data mining and visualization to guide the analysis of heterogeneous biodiversity data. In particular, we would propose contributions to the problems of (1) the analysis of heterogeneous distributed data found across different databases, (2) the identification of matches and approximations between data sets, and (3) the identificaton of relationships between various databases. This paper describes a proof of concept of an infrastructure testbed and its basic operations, presenting an evaluation of the resulting system in comparison with the ideal expectations of the ecologist.

11 pages; International audience; Broadcasting is the predominant spawning behavior among benthic marine invertebrates, mainly associated with planktotrophic and planktonic lecitotrophic development. Broadcasting allows genetic mixing that should contribute to increase the genetic diversity of a female clutch. Conversely, in brooding species characterized by protected development, oocytes are retained and only sperm is released, which is supposed to limit the number of males that contribute to a female clutch. This spermcasting behavior together with egg retention, unusually frequent among Antarctic marine invertebrates, putatively give brooders low dispersal capacities which may reduce genetic mixing and generate genetic and kinship structure at a small spatial scale. Like many other Antarctic marine benthic invertebrates, the irregular sea urchin Abatus agassizii is a spermcaster that broods its young. In this study, we assessed the genetic diversity among 66 adults using 6 polymorphic microsatellite loci and performed progeny array analyses in order to evaluate the number of mates per female as well as genetic structure at a small spatial scale. A. agassizii exhibited a polyandric system with 2–5 mates per female regardless of population density. Bayesian analyses suggested the absence of genetic structure along our 20-m transect, while relatedness among individuals did not differ from that expected under panmixia. Finally, we conclude that a limited number of males contribute to a female clutch, probably as a consequence of limited sperm dispersal and that movement of adults may be sufficient to avoid kinship structure in the population.

Data produced within marine and terrestrial biodiversity research projects that evaluate and monitor Good Environmental Status, have a high potential for use by stakeholders involved in environmental management. However, environmental data, especially in ecology, are not readily accessible to various users. The specific scientific goals and the logics of project organization and information gathering lead to a decentralized data distribution. In such a heterogeneous system across different organizations and data formats, it is difficult to efficiently harmonize the outputs. Few tools are available to assist. For instance standards and specific protocols can be applied to interconnect databases. Such semantic approaches greatly increase data interoperability. This communication present the recent results and the consortium IndexMEED (Indexing for Mining Ecological and Environmental Data) activity that aims to build new approaches to investigate complex research questions, and support the emergence of new scientific hypotheses based on graph theory Auber et al. 2014). Current developments in data mining based on graphs, as well as the potential for relevant contributions to environmental research, particularly about strategic decision-making, and new ways of organizing data will be presented (David et al. 2015). In particular, the consortium makes decisions on how i) to analyze heterogeneous distributed data spread throughout different databases combining molecular and habitat characteristics data [3], ii) to create matches and incorporate some approximations, iii) to identify statistical relationships between observed data and the emergence of contextual patterns using a calculation library and distributed calculation center at the European level, iv) to encourage openness and sharing data while complying with the general principles of FAIR (Findable, Accessible, Interoperable, Re-usable and citable) in order to enhance data value and their utilization. IndexMEED participants are now exploring the ability of two scientific communities (ecology sensu lato and computer sciences) to work together, using several studies cases. The ECOSCOPE project aims to meet the need to access structured and complementary omics-datasets to better understand biodiversity state and its dynamics. Indeed, the ECOSCOPE case study targets to visualize, through the graph approach, links between datasets and databases from genetics to ecosystems. Another case study, displaying anthropology fossils and omics on the same graph, will also be presented. DEVOTES (DEVelopment Of innovative Tools for understanding marine biodiversity and assessing good Environmental Status) and CIGESMED (Coralligenous based Indicators to evaluate and monitor the "Good Environmental Status" of the MEDiterranean coastal water) European projects, conducted by IMBE, are focused on photo quadrats, cartography and omics data of the marine hard bottom in order to discover context patterns helpful to build decision support system building. Study case "65 Millions d'observateurs" French project is testing AskOmics to provide a graph-based querying interface using RDF (Resource Description Framework) and SPARQL technologies. Scientific questions can be resolved by the new data mining approaches that offer new ways to investigate heterogeneous environmental data with graph mining (Muñoz et al. 2017). The uses of data from biodiversity research demonstrate the prototype functionalities (David et al. 2016) and introduce new perspectives to analyze environmental and societal responses including decision-making at large scale, both at the information system level and the observing system level than at the observed system level.

10 páginas, 3 figuras, 4 tablas., A new method based on photographic sampling coupled with in situ observations was applied to 53 stations along the French Mediterranean coast, to assess the integrity of coralligenous reefs affected by different levels of anthropogenic pressure. The conservation state of the assemblages characterizing these habitats was then assessed by an index – the INDEX-COR – that integrates three metrics: (i) the sensitivity of the taxa to organic matter and sediment deposition, (ii) the observable taxonomic richness, and (iii) the structural complexity of the assemblages. The sensitivity of INDEX-COR was tested and showed good correlation with the Level of Pressure calculated for each station according to expert judgment and field observations., We would like to thank the French Protected Marine Areas Agency (AAMP) for its financial support to this project (convention n°3211545/ F). We also thank the Marine Protected Areas involved in the INDEXFig. 3. Color-coded representation of the conservation state of coralligenous habitats along the coasts of Provence. Orange: poor status; yellow: moderate status; green: good status; blue: high status. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) S. Sartoretto et al. Marine Pollution Bulletin xxx (xxxx) xxx–xxx 8 COR program for their technical support (boats and divers), especially the directors and the staff of the “Parc Marin de la Côte Bleue”, the “Observatoire Marin du Littoral des Maures” and the “Aire Marine Protégée de la Côte Agathoise”. This work was also supported by the ERA-NET (SeasEra) CIGESMED Program (contract 2014/3/3211985).

Dans le cadre du consortium IndexMeed (Indexing for Mining Ecological and Environmental Data); National audience; Cet article présente la partie architecture et services de la thèse de R. DAVID, intitulé Méthodes et outils pour le suivi à large échelle des habitats coralligène en Méditerranée : du système d'observation au système d'information. Il présente les processus d'indexation et de qualification de données hétérogènes et distantes, basés sur des services WEB. Ceux-ci permettent de construire des graphes à partir de données et de thesaurus concernant les habitats coralligènes en Méditerranée orientale et occidentale et de les exploiter avec des objectifs d'indication et d'aide à la décision.

WOS: 000449618200117, PubMed ID: 27932909, Background Over the last decade, inventorying and monitoring of marine biodiversity has significantly benefited from the active engagement of volunteers. Although several Citizen Science projects concern tropical reef ecosystems worldwide, none of the existing initiatives has yet specifically focused on their Mediterranean equivalents. Mediterranean coralline reefs, known as "coralligenous", are bioherms primarily built by calcifying rhodophytes on hard substrates under dim-light conditions; they are considered hotspots of biodiversity and are extremely popular among divers due to their complex structure, conspicuous biological wealth and high aesthetic value. Nevertheless, data on their distribution, structure and conservation status is lacking for several Mediterranean areas while they are vulnerable to an increasing number of threats. New information In the framework of CIGESMED SeasEra (ERAnet) project a specialized Citizen Science project was launched, aiming to engage enthusiast divers in the study and monitoring of Mediterranean coralligenous assemblages through the gathering of basic information regarding their spatial occurrence, assemblage structure and associated pressures or threats. For its active implementation, a data collection protocol and a multilingual website were developed, comprising an educational module and a data submission platform. Georeferenced data reporting focuses on: (a) basic topographic and abiotic features for the preliminary description of each site, and the creation of data series for sites receiving multiple visits; (b) presence and relative abundance of typical conspicuous species, as well as (c) existence of pressures and imminent threats, for the characterization and assessment of coralligenous assemblages. A variety of tools is provided to facilitate end users, while divers have the choice to report additional information and are encouraged to upload their photographs. The long-term goal is the development of an active community of amateur observers providing widespread and ecologically significant data on coralligenous assemblages.

What is "coralligenous"? What is commonly called coralligenous is, actually, a complex seascape (i.e. a submerged landscape) developing in dim light conditions, which is present exclusively in the Mediterranean Sea. Coralligenous habitat is mainly created by calcified red algae, which are constructing reef-like structures for thousands of years over marine rocky bottoms. In this respect coralligenous formations are considered to be the Mediterranean equivalent of the tropical coral reefs. At the same time, some other organisms-which are called 'eroders'-such as sponges of the genus Cliona or sea urchins-pierce and consume the calcareous substrate and thus contribute to increase the structural complexity of the coralligenous formations. This calcareous substrates also support several long-living species (sponges, gorgonians, bryozoans, corals), which are contributing to the structuring of the coralligenous habitat. Finally, a large number of invertebrates (such as nudibranchs, crustaceans, ascidians, echinoderms, molluscs) and fishes are associated with coralligenous habitats, a fact which further contributes toward the characterization of the coralligenous habitat as a unique biodiversity hotspot. Why do we observe coralligenous habitats? They are unique habitats worldwide and among the richest and most beautiful seascapes to observe during scuba diving. Thanks to their complexity, they shelter a great number of ecologically, aesthetically and commercially valuable species, some of which are also protected by National and International Laws. Coralligenous habitats are often threatened by the human behaviour. Intense anchoring, irresponsible diving, (over)fishing, litter dumping, alongside with sea surface warming (due to climatic change) and alien species invasions, are among the main threats which can induce negative effects on the health status of coralligenous habitats. By participating into the CIGESMED for divers-Citizen Science for CIGESMED project you contribute to the exploration and the conservation of the coralligenous habitats and the marine environment, while at the same you can increase your knowledge about the marine biodiversity.

13 pages, 2 figures, 3 tables, The Southern Ocean benthic communities are characterized by their levels of endemism and their diversity of invertebrate brooding species. Overall, biological processes acting within these species remain poorly understood despite their importance to understand impacts of ongoing global change. We take part in filling this gap by studying the genetic structure over different spatial scales (from centimeters to tens of kilometers) in Abatus cordatus, an endemic and brooding sea urchin from the Kerguelen Islands. We developed three microsatellites and two exon-primed intron crossing markers and conducted a two-scale sampling scheme (from individuals to patches) within two dense localities of Abatus cordatus. Between patches, all pairwise comparisons, covering distances from few meters (between patches within locality) to 25 km (between localities), revealed significant genetic differentiation, a higher proportion of the molecular variance being explained by the comparisons between localities than within localities, in agreement with an isolation by distance model. Within patches, we found no significant correlation between individual pairwise spatial and genetic distances, except for the most polymorphic locus in the patch where the largest range of geographical distances had been analyzed. This study provides an estimation of the dispersal capacities of Abatus cordatus and highlights its low recolonization ability. Similar low recolonization capacities are thus expected in other Antarctic and Subantarctic brooding invertebrate species and suggest a high vulnerability of these species facing global change, Development of EPIC markers, corresponding salaries, and genotyping was possible owing to two European networks of excellence, NoE MARBEF (GOCE-CT-2003-505446) and NoE Marine Genomics Europe (GOCE-CT-2004-505403) and a French ANR Antflock. Logistic and collection of Abatus cordatus were supported by the program Macrobenthos no 195 of the French Polar Institute (IPEV), and thanks to Thomas Abiven for help in samples collection and management in fieldwork

Defining the scale of connectivity among marine populations and identifying the barriers to gene flow are tasks of fundamental importance for understanding the genetic structure of populations and for the design of marine reserves. Here, we investigated the population genetic structure at three spatial scales of the red gorgonian Paramuricea clavata (Cnidaria, Octocorallia), a key species dwelling in the coralligenous assemblages of the Mediterranean Sea. Colonies of P. clavata were collected from 39 locations across the Mediterranean Sea from Morocco to Turkey and analysed using microsatellite loci. Within three regions (Medes, Marseille and North Corsica), sampling was obtained from multiple locations and at different depths. Three different approaches (measures of genetic differentiation, Bayesian clustering and spatially explicit maximum-difference algorithm) were used to determine the pattern of genetic structure. We identified genetic breaks in the spatial distribution of genetic diversity, which were concordant with oceanographic conditions in the Mediterranean Sea. We revealed a high level of genetic differentiation among populations and a pattern of isolation by distance across the studied area and within the three regions, underlining short effective larval dispersal in this species. We observed genetic differentiation among populations in the same locality dwelling at different depths, which may be explained by local oceanographic conditions and which may allow a process of local adaptation of the populations to their environment. We discuss the implications of our results for the conservation of the species, which is exposed to various threats.

Identifying microevolutionary processes acting in populations of marine species with larval dispersal is a challenging but crucial task because of its conservation implications. In this context, recent improvements in the study of spatial genetic structure (SGS) are particularly promising because they allow accurate insights into the demographic and evolutionary processes at stake. Using an exhaustive sampling and a combination of image processing and population genetics, we highlighted significant SGS between colonies of Corallium rubrum over an area of half a square metre, which sheds light on a number of aspects of its population biology. Based on this SGS, we found the mean dispersal range within sites to be between 22.6 and 32.1 cm, suggesting that the surveyed area approximately corresponded to a breeding unit. We then conducted a kinship analysis, which revealed a complex half-sib family structure and allowed us to quantify the level of self-recruitment and to characterize aspects of the mating system of this species. Furthermore, significant temporal variations in allele frequencies were observed, suggesting low genetic drift. These results have important conservation implications for the red coral and further our understanding of the microevolutionary processes acting within populations of sessile marine species with a larval phase.

The genetic structure of a lagoon specialist, the bivalve Cerastoderma glaucum, was studied from 4 nuclear microsatellite loci and sequences from a 514 bp mitochondrial DNA region. Both marker types revealed strong differentiation among populations that is likely due to the highly fragmented distribution of this species. The geographic location and strength of the major divisions were different between the genomes. The deepest phylogeographic split in mtDNA grouped Aegean Sea and Ponto-Caspian region populations against the more western populations, whereas nuclear data singled out Ionian Sea populations or indicated a Ponto-Caspian character of nuclear DNA from the Ionian Sea. In agreement with their presumably rapid post-glacial establishment, the northern populations showed evidence of founder effects and strong genetic drift in their genetic structuring. Two unexpected geographic disjunctions were detected in the mtDNA, but not in the microsatellite characteristics, of the studied populations. We suspect long-distance dispersal via migrating birds to be a probable dispersal means among isolated lagoon habitats and to have generated the disjunctions by contributing to the post-glacial spread of C. glaucum to its northern distribution area. The discrep- ancies between the nuclear and mitochondrial genetic characteristics of the populations could be a result of selective sweeps in mtDNA, sex-biased dispersal, biased effective sex ratio or differential introgression of the genomes. The high level of differentiation found between the main genetic groups led us to conclude that the taxonomy of Cerastoderma needs revision, but we acknowledge that due to hybridization the taxa can be occasionally impossible to delineate.

Within the brittle star genus Amphipholis, individuals are generally small, gonochoric, broadcast spawners, and species often have restricted distribution areas. In contrast, A. squamata (Ophiuroidea, Echinodermata)—a species complex found worldwide—is hermaphroditic and broods its young. We used 2 complementary methods to estimate the selfing rates of this species in the north- western Mediterranean Sea. First, we analysed 190 specimens from Les Goudes (France) using 3 co- dominant microsatellites and deduced the selfing rates from heterozygote deficiency, developing an original method to infer confidence intervals. Not a single heterozygote was discovered, leading to estimated selfing rates of 1.0 for all species, with an inferior limit between 0.77 and 0.98. In 7 other European localities, not a single heterozygote was found. Second, we analysed 91 brooders and their 369 offspring using 7 nuclear markers. All progeny had DNA fingerprints identical to those of the par- ents, confirming that selfing rates are very high. Such high selfing rates, by contributing to coloniza- tion success (Baker's rule), may solve the paradox of cosmopolitism for these ophiuroids that lack a larval phase that would, in theory, ensure dispersal.

10 pages; International audience; The biogeography of the Southern Ocean reflects complex interactions between major macro-evolutionary forces and biotic elements. Major gateway openings, the establishment of the Antarctic Circumpolar Current and climate cooling are deeply connected to the composition, abundance and distribution of the Southern Ocean marine benthic fauna. Glacial episodes of the Quaternary heavily impacted the distribution of the genetic variation of the Southern Ocean biota. The genus Nacella includes 12 nominal species in different provinces of the Southern Ocean. In this study, we compared patterns of mitochondrial DNA diversity in three Nacella species from Antarctic Peninsula, Kerguelen Island and Patagonia. Low levels of genetic diversity and absence of genetic structure characterise each one of them showing the strong impact of ice advances and retreats over their respective demographics. Haplotype diversity, short genealogies and demographic inference recorded suggest the occurrence of a more dramatic demographic process in Antarctic Peninsula than in the sub-Antarctic.

14 pages; International audience; Preliminary analyses revealed the presence of at least five mitochondrial clades within the widespread sea urchin Echinocardium cordatum (Spatangoida). In this study, we analyzed the genetic (two mitochondrial and two nuclear sequence loci) and morphological characteristics (20 indices) from worldwide samples of this taxon to establish the species limits, morphological diversity and differentiation. Co-occurring spatangoid species were also analyzed with mitochondrial DNA. The nuclear sequences confirm that mitochondrial lineages correspond to true genetic entities and reveal that two clades (named A and B1) hybridize in their sympatry area, although a more closely related pair of clades (B1 and B2), whose distributions widely overlap, does not display hybridization. The morphology of all E. cordatum clade pairs was significantly differentiated, but no morphological diagnostic character was evidenced. By contrast, other spatangoid species pairs that diverged more recently than the E. cordatum clades display clear diagnostic characters. Morphological diversity thus appears responsible for the absence of diagnostic characters, ruling out stabilizing selection, a classical explanation for cryptic species. Alternative classical explanations are (i) environmental plasticity or (ii) a high diversity of genes determining morphology, maintained by varying environmental conditions. We suggest a new hypothesis that the observed morphological diversity is selectively neutral and reflects high effective population sizes in the E. cordatum complex. It is supported by the higher abundance of this taxon compared with other taxa, a trend for the genetic and morphological diversity to be correlated in Europe, and the higher genetic and morphological diversities found in clades of E cordatum (except B1) than in other spatangoid samples in Europe. However, the Pacific clades do not confirm these trends.

International audience; In the context of global climate change, variations in sea surface temperature, sea level change and latitudinal shifts of oceanographic currents are expected to affect marine biodiversity of the sub-Antarctic islands located near the polar front, such as the Kerguelen Islands, particularly in coastal waters. Sampling sites of previous oceanographic programmes focused on the Kerguelen Islands were revis-ited during three scientific summer cruises aboard the trawler La Curieuse (2011–2014). Among 18 coastal sites explored using scuba diving, 8 were selected for monitoring, as representative of the Kerguelen sub-Antarctic marine habitats, to be progressively equipped with sensors and settlement plots. Remotely operated vehicle (ROV) observations and beam trawling (at 50 m and 100 m) have also been used to contextualise them. Eight sites – in the Morbihan Bay (4), and in the north (2) and south (2) of the Kerguelen Islands – are now monitored by photo and video surveys, with temperature loggers installed at 5 m and 15 m depth, and settlement plots at about 10 m depth. Temperature data have been recovered yearly since 2011 at some sites (those equipped first). Biodiversity found on settlement plots will be characterised yearly by metagenomics. The often harsh conditions at sea involve using robust underwater equipment and simple investigation techniques and protocols to ensure the permanence and the reliability of the equipment installed.

Although biodiversity has been extensively studied over the last centuries, recent evidences suggest that links between collected data are still be missing. In order to fill this knowledge gap and at the initiative of the CNRS Institute of Ecology and Environment (INEE), IndexMed, a unique and multidisciplinary consortium consisting of ecologists, sociologists, economists, mathematicians, IT specialists and astronomers was created. Through exploratory projects, IndexMed develops new methods for analyzing data on Mediterranean biodiversity and implements solutions based on interoperability technologies already deployed in other disciplines. In particular, IndexMed aims to build a prototype of such data graphs and "data cubes". This paper will first explore the ability of tools and methods by means of graphs to connect biodiversity objects with non-centralized data. It will then introduce the use of algorithms and graphs to analyze environmental and societal responses and presents a prototype under development.

The genus Abatus (Echinoidea: Spatangoida: Schizasteridae), endemic to the Southern Ocean, consists of several species which, like many other Antarctic marine invertebrates, brood their offspring. The modality of fertilization is not known in these species, whose direct observation and sampling are difficult. Parentage analyses by means of molecular markers may help to gain information on this stage of the life-cycle. In this pilot study, we analysed a brooding female and her offspring with dominant molecular markers—RAPD (Random Amplified Polymorphic DNA). We established that each cohort present in the brooding pouches, i.e. gastrulae and juveniles, originated from at least two distinct father genotypes. Our original method of analysis of dominant marker data should have vast applications since it allows one to test, not only (1) the hypothesis that the progeny of a given mother originates from a single father, but also (2) the temporal stability of the paternal gene pool.