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.
K. Mathias Wegner; Damien Piel; Damien Piel; Maxime Bruto; Uwe John; Uwe John; Zhijuan Mao; Marianne Alunno-Bruscia; Marianne Alunno-Bruscia; Bruno Petton; +3 more
K. Mathias Wegner; Damien Piel; Damien Piel; Maxime Bruto; Uwe John; Uwe John; Zhijuan Mao; Marianne Alunno-Bruscia; Marianne Alunno-Bruscia; Bruno Petton; Bruno Petton; Frédérique Le Roux; Frédérique Le Roux;
International audience; Bacteria of the Vibrio genus are the most predominant infectious agents threatening marine wildlife and aquaculture. Due to the large genetic diversity of these pathogens, the molecular determinants of Vibrio virulence are only poorly understood. Furthermore, studies tend to ignore co-evolutionary interactions between different host populations and their locally encountered Vibrio communities. Here, we explore the molecular targets of such co-evolutionary interactions by analyzing the genomes of nine Vibrio strains from the Splendidus-clade showing opposite virulence patterns towards two populations of Pacific oysters introduced into European Wadden Sea. By contrasting Vibrio phylogeny to their host specific virulence patterns, we could identify two core genome genes (OG1907 and OG 3159) that determine the genotype by genotype (G × G) interactions between oyster larvae and their sympatric Vibrio communities. Both genes show positive selection between locations targeting only few amino acid positions. Deletion of each gene led to a loss of the host specific virulence patterns while complementation with OG3159 alleles from both locations could recreate the wild type phenotypes matching the origin of the allele. This indicates that both genes can act as a genetic switch for Vibrio-oyster coevolution demonstrating that local adaptation in distinct Vibrio lineages can rely on only few genes independent of larger pathogenicity islands or plasmids.
The problem of the clogging up of sea water pipes by Mytilus edulis larvae is a very real problem. A study has been made of the ways to destroy these larvae, (1) by electricity (publication in preparation), (2) by ultrasound. This last technique has given interesting data, but exploitation of results on a large scale presents many difficulties. An interesting general phenomenon is to be underlined. For ultrasound treatments of short duration (10s), many larvae are simply stressed and recover later on. For longer treatments, there is actual dislocation of the larvae and instant mortality, this mortality increases with time.
Ce rapport présente les résultats obtenus lors d'un programme d'études destinées à évaluer les apports liquides, solides et polluants introduits dans l'étang de Berre, du fait du réseau hydrographique local.
Publication . Article . Other literature type . 2005
The wide continental shelf of the Gulf of Lion (up to 70 km) has been the object of numerous investigations since the early days of oceanography. Yet, the question of sequences duration, the mechanisms of deposition and factors implied remained unanswered. A study of a very dense grid of Very High Resolution (VHR) seismic reflection (Sparker) data associated with surficial cores both, collected by IFREMER between 1992 and 2001 on the outer shelf and upper slope offshore of Sète in the Languedoc region gives a new insight into these issues. Analysis of the 3D geometry of the sedimentary record reveals a basic depositional pattern consisting of a pair of horizontally juxtaposed and downlapping prisms. Prism PI with low angle clinoforms (<1°) lies on the upper part of the shelf and is interpreted to be prodeltaic-offshore deposits. Prism PII with steeply dipping clinoforms (approximately 4°) lies on the outer shelf between 40 and 70 km from the present day coastline and is interpreted to be littoral deposits. Results obtained from integrating lithology, palynology, micropaleontology, seismic stratigraphy, stratigraphic simulation, support the hypothesis that the basic depositional pattern records a 100 000-years glacioeustatic (interglacial/glacial) cycle. As previously suggested by Aloïsi [Aloïsi, J.C., 1986. Sur un modèle de sédimentation deltaïque: contribution à la connaissance des marges passive, Thèse de Doctorat d'Etat. Université de Perpignan, 162 pp], prisms PI corresponds to deposition at high sea level and prisms PII to deposition during low sea level at glacial maxima. Five sequences of paired prisms capped by five major erosion surfaces have been identified and modelled showing that the corresponding glacioeustatic cycles (the last five cycles at least) are recorded on the shelf of the western part of the Gulf of Lion.
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.
Kao, S. J.; Dai, M. H.; Wei, K. Y.; Blair, N. E.; Lyons, W. B.;
Kao, S. J.; Dai, M. H.; Wei, K. Y.; Blair, N. E.; Lyons, W. B.;
Publisher: Amer Geophysical Union
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.