60268 résultat(s)
ICES

The Working Group on Offshore Renewable Energy (WGORE) focuses on coordinating scientific knowledge application for offshore energy installations. It aims to optimize ICES service in managing tidal, wave and offshore wind energy by assessing environmental impacts, regulatory processes, and future challenges. In this report we give an overview of the work done on cumulative effects assessment of offshore renewables, chemical usage impacts, and env [...]

ICES

The main terms of reference for the ICES Working Group for the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) were to update, quality check, and report relevant data for the working group, to update and audit the assessment and forecasts of the stocks, to produce a first draft of the advice on the fish stocks, and to prepare planning for benchmarks in future years. Ecosystem changes have been analytically considered in the [...]

Dekov Vesselin m., Koschinsky Andrea, Yamanaka Toshiro, Petersen Sven, Paul Sophie A.l.expand

Mineralogy, geochemistry and sulfur (S) isotope composition of native sulfur (S0) precipitated at intraoceanic and intracontinental back-arc rift, submarine and subaerial volcanic arc, sediment and sediment-free mid-ocean ridge, hot spot, accretionary wedge, and submarine and continental cave settings were investigated with a main goal to understand the mode of formation of all the types of native S at the modern seafloor. Native S occurs as vari [...]

Ruffell Sean c., Talling Peter j., Baker Megan l., Pope Ed l., Heijnen Maarten s.expand

The largest canyons on Earth occur on the seafloor, and seabed sediment flows called turbidity currents play a key role in carving these submarine canyons. However, the processes by which turbidity currents erode submarine canyons are very poorly documented and understood. Here we analyse the first detailed time-lapse bathymetric surveys of a large submarine canyon, and its continuation as a less-deeply incised channel. These are also the most co [...]

Sepúlveda-Zúñiga E.a., Villacís L.a., Maidana N.i., Sagredo E., Moreno P.i.

The Pacific sector of Northwestern Patagonia (NWP, 40°-44°S) is key for examining the interaction between climate variability, explosive volcanism, and human influences on southern mid-latitude ecosystems. A limited number of studies in this region, however, have focused on aquatic ecosystem and hydrologic balance (HB) changes throughout the Holocene. Here we report a fossil diatom record from Lago Pichilaguna, a small closed-basin lake located i [...]

Silva Rafael Oliveira, Leite Mariangela Garcia Praça, Krahl Guilherme, Rudnitzk Isaac, Santos Soares Igor Alexexpand

Isolated carbonate platform (ICP) deposits have been extensively studied due to their high sensitivity to sea-level variations and hydrocarbon reservoir potential. Oceanic seamounts/plateaus such as the Rio Grande Rise (RGR) off south-east Brazil, are significant sites for investigating drowned ICPs, as they record the existence of former oceanic volcanic islands. The Geological Survey of Brazil dredged hundreds of samples from the RGR summit, co [...]

Huang Yi, Colin Christophe, Bassinot Franck, Yu Zhaojie, Dubois-Dauphin Quentinexpand

Radiogenic neodymium isotope compositions (εNd) are used as a tracer for water mass circulation and continental weathering at different timescales. However, uncertainties remain in the relative roles of these two factors in driving past seawater εNd variability in settings under the influence of terrestrial or riverine sediment inputs. In this study, Nd isotopes of mixed planktonic foraminifera species and δ18O and δ13C of Cibicidoides wuellersto [...]

Nicolae Lerma Alexandre, Valentini Nico, Bayle Paul, Bertin Xavier, Ganthy Florianexpand

The role of infragravity waves (IG waves) in beach and dune erosion or in flood hazard has been extensively studied on open beaches. In contrast, the detailed characterization of IG waves and their contribution to the Total Water Level (TWL) along the shore of inlets received little attention so far. In such environment, there is a real lack of in situ observations of waves and hydrodynamics conditions at appropriate spatial and temporal coverage [...]

Randrianarivo Mahery, Gasimandova Lahitsiresy max, Tsilavonarivo Johanès, Razakandrainy Andriamanjato, Philippe Jacquesexpand

Large-scale disturbances and local stressors, most notably bleaching events, sedimentation, and overfishing, impact coral reefs around Madagascar. To enhance reef resilience, managers have established several marine protected areas (MPAs) since 1966. Here, we assess the effects of MPAs on the resilience potential of coral reefs using a multi-factor Recovery Index (RI), based on a multi-criteria analysis: the Technique for Order Preference by Simi [...]

Along the northern Mid-Atlantic Ridge (nMAR), in habitats under moderate (<10°C) hydrothermal influence on the Snake Pit vent field (SP), large assemblages dominated by Bathymodiolin mussels remain poorly characterised, contrary to those in warmer habitats dominated by gastropods and alvinocaridid shrimps that were recently described. In this study, we assessed and compared the population structure, biomass, diversity and trophic interactions of [...]

Since the Millenium Ecosystem Assessment in 2005 (MEA, 2005), biodiversity has been considered the keystone to sustain ecosystem services and consequently the human well-being. Major drivers of change affecting biodiversity were listed including overexploitation of natural resources, Joss and degradation of natural habitats, exotic species introductions leading to bioinvasions, global change taking into account climate deregulation and ocean acid [...]

Petalas Christina, Turcotte-Van de Rydt Antoine, Ducatez Simon, Guigueno Mélanie f.

Abandoning a brood to maximize lifetime reproductive success may result from the current costs affecting future reproductive opportunities. In certain contexts, clutch abandonment can be an evolved breeding strategy rather than a generalized response to stressors such as inclement weather and predation. Obligate brood parasitism, a reproductive strategy in which a parasitic species relies solely on other species to raise its young, imposes fitnes [...]

In areas where oyster or mussel culture is very intensive, declines of growth rate and decreases of survival rate have occurred. For these reasons, plans have been proposed to regulate the cultivated biomasses in order to fit the carrying capacity of the different ecosystems (Heral et al 1990; Heral, 1991). In areas where new aquaculture of molluscs is beginning, oyster or mussel farmers need to know how large the extension of the culture could b [...]

Ifremer

Les réflexions menées pour l'élaboration des cahiers d'objectifs des laboratoires de la Direction des RessourcesVivantes, durant l'année 1992, ont permis de concrétiser l'idée d'un nouveau réseau de surveillance axé sur la Ressource que représentent les coquillages d'élevage, en complément des réseaux existants relatifs à l'Environnement littoral (REMI, REPHY, RNO). Les laboratoires conchylicoles côtiers de l'Ifremer (Port-en-Bessin, La Trinité-s [...]

Goulletquer Philippe, Joly Jean-Pierre, Gerard Andre, Le Gagneur Eric, Moriceau Jacquesexpand

Triploid oysters C. gigas were produced in 1990 by treating fertilized eggs with cytochalasin B. Triploids, treated diploids, and controls were deployed in early 1991 in a high carrying capacity ecosystem on the Eastern Coast of Normandy (France). A monthly monitoring in 1992 showed that triploid yielded significantly higher growth rate and biochemical composition. However, growth was more heterogeneous. No evidence was found for a bimodal distri [...]

L'huitre plate, huitre indigène de la France métropolitaine, est consommée depuis des siècles; ainsi, dès le début de notre ère, elle est expédiée jusgu'a Rome. S'il apparait qu'il existe dès cette époaue des bassins destinés a stocker, les cog1,1illages après leur cueillette (Grelon, 1978), il semble que, sur le littoral français, la culture de~ hultres ne se développe pas, contrairement au savoir-faire mis en oeuvre par les romains et rapporté [...]