Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
13,203 Research products, page 1 of 1,321

  • Publications
  • Research data
  • Other literature type
  • Article
  • English
  • ArchiMer - Institutional Archive of Ifremer

10
arrow_drop_down
Relevance
arrow_drop_down
  • Open Access English
    Authors: 
    FAO;
    Publisher: FAO
    Country: France

    The 2nd meeting of the Working Group on Shrimp and Groundfish of the North Brazil Guianas Shelf was held in Barbados 17-18 May, 2018. The meeting brought together 25 participants including Working Group members, fisheries officers, fisherfolk representatives, academia, government organizations and FAO. The scope of the working group is to provide scientific and management advice for the sustainable management of the shrimp and groundfish resources of the Northern Brazil-Guianas shelf in the WECAFC Region. The participants reviewed and analyzed the current state of data collection and fisheries management for each country in the North Brazil Guianas Shelf. Also, an update was made on the WECAFC-FIRMS partnership and the outcomes of the 1st Meeting of the Fisheries Data and Statistics Working Group that took place in Barbados, 14-16 May 2018.The assessment of data limited fisheries was presented as an approach to consider for the North Brazil Guianas Shelf shrimp and groundfish fisheries. Additionally, the current status and necessary steps to develop a sub-regional EAF management plan for shrimp and groundfish were discussed, as well as the need to enhance capacity in stock assessment techniques in the sub-region.The Governance Effectiveness Assessment Framework (GEAF) was presented as a mean to assess the CLME+ Strategic Action Programme (SAP). This assessment would be developed for the fisheries of the North Brazil Guianas shelf based on indicators covering the main issues in the sub-region: fisheries, pollution and biodiversity/habitats.Working Group participants also reviewed and discussed the draft regional strategy for bycatch management in the WECAFC Area developed by the REBYC II LAC project.Finally, based on working group discussions and the requirements for sustainable management of the shrimp and groundfish resources of the North Brazil Guianas Shelf, a draft recommendation was prepared for consideration of the upcoming 17th session of WECAFC.

  • Publication . Article . Other literature type . 2020
    Open Access English
    Authors: 
    Delphine Destoumieux-Garzón; Laura Canesi; Daniel Oyanedel; Marie-Agnes Travers; Guillaume M. Charrière; Carla Pruzzo; Luigi Vezzulli;
    Publisher: HAL CCSD
    Country: France
    Project: EC | VIVALDI (678589)

    International audience; In the marine environment, bivalve mollusks constitute habitats for bacteria of the Vibrionaceae family. Vibrios belong to the microbiota of healthy oysters and mussels, which have the ability to concentrate bacteria in their tissues and body fluids, including the hemolymph. Remarkably, these important aquaculture species respond differently to infectious diseases. While oysters are the subject of recurrent mass mortalities at different life stages, mussels appear rather resistant to infections. Thus, Vibrio species are associated with the main diseases affecting the worldwide oyster production. Here, we review the current knowledge on Vibrio-bivalve interaction in oysters (Crassostrea sp.) and mussels (Mytilus sp.). We discuss the transient versus stable associations of vibrios with their bivalve hosts as well as technical issues limiting the monitoring of these bacteria in bivalve health and disease. Based on the current knowledge of oyster/mussel immunity and their interactions with Vibrio species pathogenic for oyster , we discuss how differences in immune effectors could contribute to the higher resistance of mussels to infections. Finally, we review the multiple strategies evolved by pathogenic vibrios to circumvent the potent immune defences of bivalves and how key vir-ulence mechanisms could have been positively or negatively selected in the marine environment through interactions with predators.

  • Open Access English
    Authors: 
    Kao, S. J.; Dai, M. H.; Wei, K. Y.; Blair, N. E.; Lyons, W. B.;
    Publisher: Amer Geophysical Union
    Country: France

    Significantly older C-14 ages by 2500-7900 years are found for sedimentary total organic carbon (TOC) when compared to ages of codeposited surface-dwelling foraminifera in the southern Okinawa Trough. This age discrepancy increases with rising sea level since the Last Glacial Maximum. A progressive shift in TOC delta C-13 toward more negative values with rising sea level reflects an increasing fractional contribution of terrestrial organics (soil organics, plant debris, and/or fossil organics) to the buried organic pool. Organic matter previously stored on the East China Sea shelf during sea level lowstand and riverine material from Taiwan may be the sources that cause the delta C-13(TOC) to shift to more terrestrial values. During the Holocene when sea level is above -40 m, delta C-13(TOC) values stabilize within a narrow range (-22.3 to -22.8 parts per thousand) while age discrepancies continue to increase and less chemically weathered sediments are deposited. The increase in age discrepancy between TOC and foraminifera in the Holocene may be due to a wetter climate that drove higher rates of physical weathering on Taiwan and greater transport rates of fossil organic C-bearing lithogenic sediment to the ocean. The climate impact on the relative delivery of fossil and nonfossil TOC in depositional settings influenced by fluvial sources should be considered in interpretations of sedimentary C isotope records.

  • Open Access English
    Authors: 
    Jean-Claude Sibuet; Enyuan He; Minghui Zhao; Xinming Pang; Frauke Klingelhoefer;
    Publisher: Nature Publishing Group
    Country: France

    Abstract In the late 90’s, some faults identified within oceanic crust were demonstrated to be artifacts arising from out-of-plane scattering along linear sediment-buried fault scarps. Symmetrical mantle reflections observed southwest northern Sumatra on seismic reflection profiles have been identified as faults cutting through the upper mantle down to unprecedented depths reaching ~45 km. Seawater being conveyed along sub-vertical re-activated fracture zones (FZs) to the upper mantle, the mantle portions of FZs are serpentinized and act as mirrors for seismic rays. We suggest that the mantle features are not faults but artifacts resulting from out-of-plane reflections on these mirrors. Two perpendicular seismic profiles crossing the same FZ display two dipping features down to 30 km, which cannot be explained as faults from recent tectonic and structural constraints but merely as out-of-plane reflections on this FZ. This result confirms that most of mantle reflections observed southwest northern Sumatra are fakes rather than faults.

  • Open Access English
    Authors: 
    Stefano Ciavatta; Susan Kay; S. Saux-Picart; Momme Butenschön; Julian Icarus Allen;
    Publisher: Amer Geophysical Union
    Country: France

    This paper presents the first decadal reanalysis simulation of the biogeochemistry of the North West European shelf, along with a full evaluation of its skill, confidence, and value. An error-characterized satellite product for chlorophyll was assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The results showed that the reanalysis improved the model simulation of assimilated chlorophyll in 60% of the study region. Model validation metrics showed that the reanalysis had skill in matching a large data set of in situ observations for 10 ecosystem variables. Spearman rank correlations were significant and higher than 0.7 for physical-chemical variables (temperature, salinity, and oxygen), similar to 0.6 for chlorophyll and nutrients (phosphate, nitrate, and silicate), and significant, though lower in value, for partial pressure of dissolved carbon dioxide (similar to 0.4). The reanalysis captured the magnitude of pH and ammonia observations, but not their variability. The value of the reanalysis for assessing environmental status and variability has been exemplified in two case studies. The first shows that between 325,000 and 365,000 km(2) of shelf bottom waters were vulnerable to oxygen deficiency potentially threatening bottom fishes and benthos. The second application confirmed that the shelf is a net sink of atmospheric carbon dioxide, but the total amount of uptake varies between 36 and 46 Tg C yr(-1) at a 90% confidence level. These results indicate that the reanalysis output data set can inform the management of the North West European shelf ecosystem, in relation to eutrophication, fishery, and variability of the carbon cycle.

  • Open Access English
    Authors: 
    Gaxiolacastro, G; Alvarezborrego, S;
    Publisher: Gauthier-Villars
    Country: France
  • Publication . Other literature type . 2018
    Open Access English
    Authors: 
    Sclafani, Patricia; Cappelletto, Margherita; Barbanti, Andrea; Cadiou, Jean-francois; Chevalier-de Corbiac, Claudiane; Herrouin, Guy; Ruel, Colin; Ciappi, Elena;
    Country: France
    Project: EC | BLUEMED (727453)

    In the framework of the BLUEMED project, the coordination action supporting the development of the BLUEMED Research and Innovation Initiative for blue jobs and growth in the Mediterranean area (www.bluemed-initiative.eu/), an overview and analysis of funding schemes available at different levels, from national to European and international, has been carried out. This task is part of the activities devoted to strengthening cooperation to consolidate and implement the BLUEMED Strategic Research and Innovation Agenda (SRIA). It complements the BLUEMED interconnecting Platforms developed by the four BLUEMED operational working groups on knowledge, economy, technology and policy, to update the SRIA and serves as reference tool in the process of developing an operational network of research funders and key players to favour synergies and coordinate the realization of the BLUEMED actions. This report can be considered a background document to initiate and facilitate dialogue and interaction between research funding agencies of different countries and European Institutions. Once the strategic alignment of agendas on areas of mutual interest has been identified, the aim is to lay the groundwork for operational alignment towards the launch of transnational actions. As a first step, a catalogue (Annex I and II) has been compiled for reviewing marine and maritime RTDI strategies. The collected information has been analysed to address opportunities of alignment for joint implementation of the BLUEMED SRIA (section 2) and finally provide a set of preliminary recommendations to develop the BLUEMED Implementation plan (section 3), one of the key deliverables of the project.

  • Open Access English
    Authors: 
    Sarra Chenouf; Mathieu Merzereaud; Pascal Raux; José Antonio Pérez Agúndez;
    Publisher: MDPI AG
    Country: France

    Commercial bans due to harmful algal blooms (HABs), which are natural events, question the sustainability of human activities in marine and coastal areas. A risk assessment of these bans is important to support decision-making to better manage and mitigate their impacts. However, data are sparse and difficult to collect. The dataset presented in this paper includes “estimated closures of scallop fishing areas” due to HAB toxicity along the French coasts of the English Channel. The closure data were simulated for each scallop (Pecten maximus) fishing area through an algorithm applied to the in situ dataset from the French monitoring network REPHYTOX. The methodology of the production of closure data consists of comparing phycotoxin concentration in scallop to regulatory thresholds of phycotoxins, and then, simulating the number and duration of closures based on the monitoring strategies and closure mechanisms as defined in the regulations. These data only cover closures related to regulatory threshold exceedances of phycotoxins in shellfish. Closures induced by the lack of sampling or other reasons (e.g., failures in toxin analysis) are not included in the dataset because of the lack of information. Data are produced during the scallop fishing season. Facing the non-existence of such a closure database due to the lack of centralized management of local closure decrees, this dataset can be used to analyse the management strategies to deal with HABs and to highlight the governance challenges related to these strategies. It is also useful to study the link between the ecological and the socioeconomic dimensions of HABs, and to describe how toxin concentrations in shellfish translate into socioeconomic impacts and management challenges. This methodology can be applied to other species, other areas and other economic activities.

  • Publication . Article . Other literature type . 2010
    Open Access English
    Authors: 
    Laurent Brodeau; Bernard Barnier; Anne-Marie Tréguier; Thierry Penduff; Sergei K. Gulev;
    Publisher: HAL CCSD
    Country: France

    We develop, calibrate and test a dataset intended to drive global ocean hindcasts simulations of the last five decades. This dataset provides surface meteorological variables needed to estimate air-sea fluxes and is built from 6-hourly surface atmospheric state variables of ERA40. We first compare the raw fields of ERA40 to the CORE.v1 clataset of Large and Yeager (2004). used here as a reference, and discuss our choice to use daily radiative fluxes and monthly precipitation products extracted from satellite data rather than their ERA40 counterparts. Both datasets lead to excessively high global imbalances of heat and freshwater fluxes when tested with a prescribed climatological sea surface temperature. After identifying unrealistic time discontinuities (induced by changes in the nature of assimilated observations) and obvious global and regional biases in ERA40 fields (by comparison to high quality observations), we propose a set of corrections. Tropical surface air humidity is decreased from 1979 onward, representation of Arctic surface air temperature is improved using recent observations and the wind is globally increased. These corrections lead to a significant decrease of the excessive positive global imbalance of heat. Radiation and precipitation fields are then submitted to a small adjustment (in zonal mean) that yields a near-zero global imbalance of heat and freshwater. A set of 47-year-long simulations is carried out with the coarse-resolution (2 degrees x 2 degrees) version of the NEMO OGCM to assess the sensitivity of the model to the proposed corrections. Model results show that each of the proposed correction contributes to improve the representation of central features of the global ocean circulation. (c) 2009 Elsevier Ltd. All rights reserved.

  • Open Access English
    Authors: 
    Tony Gardon; Céline M. O. Reisser; Claude Soyez; Virgile Quillien; Gilles Le Moullac;
    Publisher: Amer Chemical Soc
    Country: France

    Plastic pollution in the environment is increasing at global scale. Microplastics (MP) are derived from degradation of larger plastic items or directly produced in microparticles form (<5 mm). Plastics, widely used in structures and equipments of pearl farming, are a source of pollution to the detriment of the lagoon ecosystem. In order to evaluate the impact of MP on the physiology of Pinctada margaritifera, a species of ecological and commercial interests, adult oysters were exposed to polystyrene microbeads (micro-PS of 6 and 10 μm) for 2 months. Three concentrations were tested: 0.25, 2.5, 25 μg L-1 and a control. Ingestion and respiration rate and assimilation efficiency were monitored on a metabolic measurement system to determine the individual energy balance (Scope For Growth, SFG). Effects on reproduction were also assessed. The assimilation efficiency decreased significantly according to micro-PS concentration. The SFG was significantly impacted by a dose-dependent decrease from 0.25 μg L-1 (p < 0.0001). A negative SFG was measured in oysters exposed to 25 μg L-1. Gonads may have provided the missing energy to maintain animals’ metabolism through the production of metabolites derived from germ cells phagocytosis. This study shows that micro-PS significantly impact the assimilation efficiency and more broadly the energy balance of P. margaritifera, with negative repercussions on reproduction.

Send a message
How can we help?
We usually respond in a few hours.