Maritime Transportation: Let\u27s Slow Down a Bit

Maritime transportation is a major contributor to the world economy, but has significant social and environmental impacts. Each impact calls for different technical or operational solutions. Amongst these solutions, we found that speed reduction measures appear to mitigate several issues: (1) collision with wildlife; (2) collision with non-living objects; (3) underwater noise; (4) invasive species; and (5) gas emission. We do not pretend that speed reduction is the best solution for each individual issue mentioned in this paper, but we argue that it could be a key solution to significantly reduce these threats all together. Further interdisciplinary research is required to balance private economic costs of speed reduction measures with environmental and social benefits emerging from all mitigated issues

From In Situ to satellite observations of pelagic Sargassum distribution and aggregation in the Tropical North Atlantic Ocean

International audienceThe present study reports on observations carried out in the Tropical North Atlantic in summer and autumn 2017, documenting Sargassum aggregations using both ship-deck observations and satellite sensor observations at three resolutions (MSI-10 m, OLCI-300 m, VIIRS-750 m and MODIS-1 km). Both datasets reported that in summer, Sargassum aggre-gations were mainly observed off Brazil and near the Caribbean Islands, while they accumulated near the African coast in autumn. Based on in situ observations, we propose a five-class typology allowing standardisation of the description of in situ Sargassum raft shapes and sizes. The most commonly observed Sargassum raft type was windrows, but large rafts composed of a quasi-circular patch hundreds of meters wide were also observed. Satellite imagery showed that these rafts formed larger Sargassum aggregations over a wide range of scales, with smaller aggregations (of tens of m 2 area) nested within larger ones (of hundreds of km 2). Match-ups between different satellite sensors and in situ observations were limited for this dataset, mainly because of high cloud cover during the periods of observation. Nevertheless, comparisons between the two datasets showed that satellite sensors successfully detected Sargassum abundance and aggregation patterns consistent with in situ observations. MODIS and VIIRS sensors were better suited to describing the Sargas-sum aggregation distribution and dynamics at Atlantic scale, while the new sensors, OLCI and MSI, proved their ability to detect Sargassum aggregations and to describe their (sub-) mesoscale nested structure. The high variability in raft shape, size, thickness, depth and biomass density observed in situ means that caution is called for when using satellite maps of Sargassum distribution and biomass estimation. Improvements would require additional in situ and airborne observations or very high-resolution satellite imagery

Etude de la présence et des variations du nombre de structures absorbant les UV chez <I>Grateloupia turuturu</I> Yamada (Halymeniaceae, Rhodophyta) de Bretagne (France).

Le biofouling est un problème que rencontre toute surface immergée. Les algues sont particulièrement concernées par ce processus qui peut mener à leur mort ; ce qui les conduit à développer des mécanismes de défense pour faire face à cette colonisation. Dans le cadre de notre étude, Grateloupia turuturu a été choisie comme modèle afin d’isoler des structures aux propriétés antifouling. Les objectifs de notre étude étaient (1) d\u27identifier et de décrire chez G. turuturu des structures similaires aux cellules glandulaires observées chez certaines espèces de l’ordre Bonnemaisoniales et (2) de déterminer les variations du nombre de structures observées en relation avec le site de prélèvement, le stade de développement de l’algue et la présence d’épiphytes. La microscopie à fluorescence ainsi que la microscopie confocale ont été utilisées pour isoler et décrire des structures similaires aux cellules glandulaires préalablement décrites dans la littérature. La densité de telles structures a été déterminée sur des individus prélevés aléatoirement sur trois sites en Bretagne (Ile Callot, Pointe du Diable, et Fort Bloqué), caractérisés par des conditions hydrodynamiques et une exposition aux épiphytes différentes, et à 3 stades de développement (gamétophyte, tétrasporophyte et carposporophyte). Des structures fluorescentes isolées et groupées ont été mises en évidence et décrites. Les individus provenant de la Pointe du Diable présentent un plus grand nombre de structures fluorescentes que les thalles provenant des deux autres sites. De plus, les structures fluorescentes sont trouvées plus nombreuses sur le stade carposporophyte que sur les stades tétrasporophytes et gamétophytes. Enfin, leur nombre augmente avec la présence d’épiphytes.Biofouling is a potential problem for any surface immersed in the sea. For algae this can lead to its death; they have therefore developed biofouling defence mechanisms to prevent biofouling. Grateloupia turuturu was chosen as a model to isolate some structures with antifouling properties. The aims of our study were then (1) to identify and describe in G. turuturu structures similar to gland-cells observed in a variety of species from the order Bonnemaisoniales and (2) to determine their variability in relation to site, stages of development, and the presence of epiphytes. Fluorescent and confocal microscopy was used to highlight structures similar to gland-cells. Using epifluorescence microscopy, the number of “gland cells-like structures” was determined on individuals sampled from three sites in French Brittany (Callot Island, Pointe du Diable, and Fort Bloqué), characterized by different hydrodynamic and fouling exposure conditions, and from three life history phases (gametophyte, tetrasporophyte and carposporophyte). Isolated and grouped fluorescent structures were detected and characterized. Significant variations in the density of those fluorescent structures were found between site and life-history stages. Individuals from the Pointe du Diable had significantly more fluorescent structures than thalli from the two other sites, and they were more numerous on carposporic plants than on either tetrasporophytes or immature gametophytes. More “gland cells-like structures” were also present on plants bearing epiphytes.</p

Chemodiversity and Bioactivity within Red and Brown Macroalgae Along the French coasts, Metropole and Overseas Departements and Territories

International audienceThis chapter contains sections titled : Introduction, Exploitation of marine algal resources, Why a focus on red and brown seaweeds ? Marine red seaweeds and biological activities, Marine brown seaweeds and biological activities, The use of metabolites from marine red and brown algae for their chemical defense, The use of metabolites as chemomarkers for taxonomy, Industrial uses of metabolites from marine red and brown algae, Conclusion, Acknowledgments, Reference

Marine Species Introduced on the French Channel-Atlantic Coasts: A Review of Main Biological Invasions and Impacts

International audienceThe impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biological invasions often result in significant losses in the economic value, biological diversity and function of invaded ecosystems. This review presents the main pathways of introduction of non-indigenous species and the main benthic taxonomic groups being established and/or invasive along the French Channel-Atlantic coasts. A focus is put on main invasive marine species in the intertidal and subtidal zones of Brittany (France), among macroalgae (Sargassum muticum, Grateloupia turuturu, Undaria pinnatifida, Codium fragile and Gracilaria vermiculophylla), halophytes (Spartina alterniflora) and benthic invertebrates (Mollusks: Crepidula fornicata, Crassostrea gigas and Venerupis philippinarum). The species biology, introduction vectors, reproductive and dispersal capacities are considered, together with proliferation patterns along the Channel-Atlantic coasts. The ecological impacts of these species on the environment are also described, as well as the European regulations existing to limit alien species introduction and some examples of struggle against the invaders including eradication trials and biomass valorization. Last, the on-going impacts of global changes on alien species invasiveness along the Channel- Atlantic coasts are discussed

Étude du genre Cystoseira des côtes bretonnes (taxinomie, écologie et caractérisation de substances naturelles)

Le long des côtes de l Atlantique Nord-Est, le genre Cystoseira (algues brunes, famille des Sargassacceae) se décline principalement en cinq espèces établies dans les cuvettes de l étage médiolittoral. Au-delà de l intérêt écologique de ces organismes, leur valorisation potentielle en tant que sources naturelles de composés bioactifs peut aujourd hui être envisagée. Cependant, une telle démarche peut se voir freinée par des questions taxinomiques restées sans réponse depuis le début du XXème siècle. Le premier volet de ce projet de thèse consiste à résoudre ces difficultés, en combinant des approches aujourd hui classiques (analyses phylogénétiques issues de données moléculaires) à des études chimiques exploitant de nouvelles techniques analytiques (RM7N et LC-MS), pour proposer un cadre taxinomique à chaque espèce. En s appuyant sur les données phylogénétiques les plus récentes, nos résultats ont permis de mettre en évidence la pertinence de critères chimiques pour illustrer les relations de parenté existant au sein du genre, et nous avons également pu obtenir des cartes d identité chimique de chaque taxon. Un chimiomarqueur de type méroditerpène a été identifié et isolé chez Cystoseira nodicaulis. La deuxième partie du travail consiste en une étude écologique des populations du genre Cystoseira du littoral breton. Contrairement au phénomène d étagement des macroalgues sur l étage médiollttoral, bien connu dans les zones tempérées, peu de données existent sur la répartition des macroalgues peuplant les cuvettes de l estran. Nous avons pu mettre en évidence une répartition précise des espèces dans les cuvettes de l estran, sous la dépendance de gradients de facteurs environnementaux. Nous avons également caractérisé l évolution spatio-temporelle de certaines variables des populations. Grâce à une étude complémentaire sur les pigments principaux de ces algues par HPLC, nous avons pu montrer l existence d une photo- adaptation aux niveaux intra- et inter-populationnels. Enfin, ce projet propose d étudier les phlorotannins des cinq espèces bretonnes. Ces molécules sont connues pour leur activité antioxydante et la variété de leurs rôles in vivo. Aussi, le but de cette dernière étude est de mettre au point des protocoles d extraction et de purification adaptés à ces composés, d en caractériser la structure chimique, et d en déterminer des activités au moyen de test in vitro. Une première démarche de quantification nous a permis d appréhender les variations interspécifiques et saisonnières des teneurs en composés phénoliques chez les cinq espèces étudiées. Dans un deuxième temps, nous avons purifié et caractérisé partiellement les composés phénoliques extraits des algues, et enfin, nous avons pu déterminer les variations saisonnières du phloroglucinol, que nous avons pu identifier comme étant le composé phénolique majoritaire de C. tamariscifolia.Along the North-East Atlantic, the genus Cystoseira (brown algae, family Sargassaceae) is composed of five main species and their populations settle in rock pools from the intertidal zone Beyond the ecological value of these organisms they are now more and more studied as a source of natural products However, taxonomical issues within this genus must be solved first So we investigated the taxonomy of the five species occurring m Brittany using two strategies phylogenetic analyses (thanks to molecular markers) and chemical analyses (using NMR and LC-MS) Using recent phylogenetic data, our results highlighted the relevancy of the use of chemical criteria to illustrate the phylogenetic relationships This way we were able to associate a "chemical ID card" to each species We also isolated a meroditerpene from Cystoseira nodicaulis. The second part of our work was an ecological study of several populations settled in Brittany Concerning the emerged substrata of the intertidal zone, the available data about zonation patterns are plethoric, conversely, few authors have investigated the distribution of macroalgae in tide pools. We highlighted a singular distribution pattern for the Cystoseira species that must be under the dependency of environmental factors. We also demonstrated the spatio-temporal variability several variables of the populations. Additionally, we showed through the quantification of the main pigments by HPLC that different photo-adaptive behaviors exist within and between populations. Finally, we investigated the phlorotannins of the Cystoseira species. These molecules are known to exhibit se biological activities and many ecological roles have been demonstrated in the literature. We developed a new protocol for the purification and quantification of the compounds and we also determined their radical-scavenging activity. This way, we revealed specific differences and seasonal patterns in phlorotannin production. We also purified phenolics and identified the main kind of compounds in the extracts. We identified phloroglucinol in Cystoseira tamariscifolia, and revealed a seasonal evolution of its production, in relation with its phenology.BREST-BU Droit-Sciences-Sports (290192103) / SudocSudocFranceF

Les espèces marines introduites sur la façade Manche-Atlantique : invasions biologiques ou immigration contrôlée ?

National audienc

Study of the biodiversity of Sargassaceae (Fucales, Phaeophyceae) in temperate and tropical climat (ecology, chemotaxonomy and source of bioactive compounds)

Quatre genres de Sargassaceac présentant de forte biomasse en Bretagne et/ou dans le Pacifique Sud ont été choisi comme modèles de cette étude. Les objectifs étant i) de mieux comprendre l écologie chimique des Sargassaceae en milieu tempéré et en milieu tropical, ii) de rechercher des chimiomarqueurs spécifiques à certaines espèces et iii) de rechercher de molécules potentiellement bioactives. Ainsi, un travail pluridisciplinaire a été entrepris avec l étude de l écologie chimique des Sargassaceae, en Bretagne d une part, via l étude des variations spatio-temporelles de certains composés de défenses synthétisés par Sargassum muticum, Bjfurcaria bifurcata et Cystoseira baccata associé à un suivi écologique de ces espèces et dans le Pacifique Sud d autre part, via l étude de ces mêmes composés de défenses au sein de Turbinaria sp. et Sargassum sp provenant de différents sites. Parallèlement, deux études de chimiotaxonomie ont été menées. D une part sur le genre Turbinaria afin d identifier un ou des chimiomarqueur(s) permettant de discriminer T. ornata et de T. conoides. Et d autre part sur B. bifurcata afin de mieux comprendre la répartition géographique des types chimiques existants au sein de cette espèce. Puis, pour répondre au troisième objectif de cette thèse, trois activités biologiques ont été recherchées en priorité au sein des espèces étudiées: la cytotoxicité, l activité anti-inflammatoire et la neurotoxicité. Les résultats de cette étude ont permis i) de mettre en évidence l impact des conditions environnementales sur les variables biologiques et écologiques étudiées chez ces espèces en milieu tempéré comme en milieu tropical; ii) d identifier l acide turbinarique comme étant un chimiomarqueur de l espèce T. conoides et de mettre en évidence l existence d éeotypes chez B. bifurcata; iii) de rapporter l activité anti-phospholipase A2 d acides gras issus d algues du Pacifique Sud et l activité antiradicalaire et antioxydante de l éléganolone isolée chez B. bifurcata.Four Sargassaceae genus presenting high biomass in Brittany and/or in the South Pacificwere chosen as models of this study. The aims of this works were i) to understand the chemical ecology of Sargassaceae in temperate and tropical environment, ii) to characterize specific chemomarkers from certain species and iii) to identify potential bioactive molecules. Then, a pluridisciplinary work was carry out with the study of the chemical ecology of Sargassaceae, in Brittany on one hand, with the study of the spatio-temporal variations of certain defense compounds of Sargassum muticum, Bifurcaria bifurcata and Cystoseira baccata associated with an ecological survey of these species and in the South Pacific on the other hand, with the study of these same defense compounds within Turbinaria sp. and Sargassun sp from various sites. At the same time, two chemotaxonomical studies were led. On the Turbinaria genera to identify one or several chemomarker(s) allowing discriminating T. ornata and T. conoides. And on the other hand, on B. bifurcata to understand the geographical distribution of the existing chemical types within this species. Then, to answer the third objective of this work, three biological activities were looked for first and foremost within the studied species: cytotoxicity, anti-inflammatory activity and neurotoxicity. The results allowed i) to highlight the impact of the environmental conditions on the biological and ecological variables studied to these species in temperate and tropical enviromnents; ii) to identify the acid turbinaric as a chemomarker of T. conoides and to highlight the existence of ecotypes from B. bifurcata; iii) to report the anti-phospholipase A2 activity of fatty acids stemming from tropical seaweeds and the antiradical and antioxidant activities of eleganolone isolated from B. bifurcata.BREST-BU Droit-Sciences-Sports (290192103) / SudocPLOUZANE-Bibl.La Pérouse (290195209) / SudocSudocFranceF

Temporal variation in pigment and mycosporine-like amino acid composition of the red macroalga Palmaria palmata from Brittany (France): hypothesis on the MAA biosynthesis pathway under high irradiance

WOS:000520805600001Changes in pigment (chlorophyll-a, carotenoids and phycobiliproteins) and mycosporine-like amino acid (MAA) composition were studied in the red edible macroalga Palmaria palmata, harvested between February 2018 and February 2019 at 2 sites from Brittany (France). The results occuring in natural conditions revealed a high seasonal variability that can be related to a combination of environmental parameters, including light, nutrients, temperature, salinity and pH, which may have synergistic or antagonistic effects. A decrease in pigments was observed in summer, matching with the increase in irradiance at the same period. On the contrary, the increase in light from February to May has caused an increase in the total MAA content, confirming the UV-photoprotective role attributed to these compounds. Analysis of the results coupled with the biosynthesis pathway suggests that some MAAs are favoured in the occurrence of high irradiance. In this sense, asterina-330 was synthetized only between March and July and not the rest of the year, supporting its importance in photoprotection. In addition, analysis revealed that nutrient availibility could have a significant influence on MAAs since their synthesis seemed to be limited in summer, despite significant exposure to light. However, this decrease could be due to another potential role of MAAs as a nitrogen source for macroalgae. Thus, the diversity of these compounds and the different synthesis pathways could be explained by different roles including photo-protection and nitrogen source, making MAA multi-purpose protective agents which could play a key role in the adaptation of this species to its changing environment