Éditeur(s) : Royal Soc
Résumé : Since its description from the Galapagos Rift in the mid-1980s, Archinome rosacea has been recorded at hydrothermal vents in the Pacific, Atlantic and Indian Oceans. Only recently was a second species described from the Pacific Antarctic Ridge. We inferred the identities and evolutionary relationships of Archinome representatives sampled from across the hydrothermal vent range of the genus, which is now extended to cold methane seeps. Species delimitation using mitochondrial cytochrome c oxidase subunit I (COI) recovered up to six lineages, whereas concatenated datasets (COI, 16S, 28S and ITS1) supported only four or five of these as clades. Morphological approaches alone were inconclusive to verify the identities of species owing to the lack of discrete diagnostic characters. We recognize five Archinome species, with three that are new to science. The new species, designated based on molecular evidence alone, include: Archinome levinae n. sp., which occurs at both vents and seeps in the east Pacific, Archinome tethyana n. sp., which inhabits Atlantic vents and Archinome jasoni n. sp., also present in the Atlantic, and whose distribution extends to the Indian and southwest Pacific Oceans. Biogeographic connections between vents and seeps are highlighted, as are potential evolutionary links among populations from vent fields located in the east Pacific and Atlantic Oceans, and Atlantic and Indian Oceans; the latter presented for the first time.
Proceedings Of The Royal Society B-biological Sciences (0962-8452) (Royal Soc), 2013-11 , Vol. 280 , N. 1770 , P. 1-9

Droits : 2013 The Author(s) Published by the Royal Society. All rights reserved.
http://archimer.ifremer.fr/doc/00157/26814/24961.pdf
DOI:10.1098/rspb.2013.1876
http://archimer.ifremer.fr/doc/00157/26814/

Éditeur(s) : Elsevier
Résumé : Deep-sea bivalves of the subfamily Bathymodiolinae (family Mytilidae) are very widespread and form dense beds in reduced environments such as hydrothermal vents and cold seeps. Bathymodiolus mussels recently discovered on African cold seeps strangely resemble Gulf of Mexico and Barbados seep species. This raises intriguing questions regarding their taxonomic relationships and their dispersal capabilities across the Atlantic equatorial belt. The morphological study of the shell and soft parts of mussels from either sites of the Atlantic shows that they form two distinct groups: the Bathymodiolus boomerang group (also including Bathymodiolus heckerae and a species from Africa), and the Bathymodiolus childressi group (also including Bathymodiolus mauritanicus and one species from Barbados). Phylogenetic relationships inferred from the nucleotide sequences of the ribosomal DNA internal transcribed spacer (ITS-2) and mitochondrial cytochrome c oxidase subunit I (COI) confirmed morphological analyses and the existence of two amphi-Atlantic complexes of species. Both ITS2 and COI phylogenies indicate almost no difference between the two eastern Atlantic seep mussels (Bathymodiolus sp. A and B. mauritanicus) and their western Atlantic counterparts (B. boomerang and Bathymodiolus sp. B; Barbados Prism cold seeps). In the B. boomerang complex, B. heckerae seems to differ from the Barbados and the African species, whereas these latter two are not distinguishable. In the B. childressi complex, relationships are less clear and do not support the description of new species from the Barbados. Past and present-day connections across the Atlantic are discussed in the light of both larval dispersal capabilities of the mussels and the equatorial Atlantic circulation to appreciate whether these species could represent true amphi-Atlantic species.
Deep Sea Research Part I: Oceanographic Research Papers (0967-0637) (Elsevier), 2007-11 , Vol. 54 , N. 11 , P. 1890-1911

Droits : 2007 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2007/publication-4064.pdf
DOI:10.1016/j.dsr.2007.07.004
http://archimer.ifremer.fr/doc/00000/4064/

Éditeur(s) : Geological Soc Amer, Inc
Résumé : Pockmarks are seafloor depressions commonly associated with fluid escape from the seabed and are believed to contribute noticeably to the transfer of methane into the ocean and ultimately into the atmosphere. They occur in many different areas and geological contexts, and vary greatly in size and shape. Nevertheless, the mechanisms of pockmark growth are still largely unclear. Still, seabed methane emissions contribute to the global carbon budget, and understanding such processes is critical to constrain future quantifications of seabed methane release at local and global scales. The giant Regab pockmark (9 degrees 42.6' E, 5 degrees 47.8' S), located at 3160 m water depth near the Congo deep-sea channel (offshore southwestern Africa), was investigated with state-of-the-art mapping devices mounted on IFREMER's (French Research Institute for Exploitation of the Sea) remotely operated vehicle (ROV) Victor 6000. ROV-borne micro-bathymetry and backscatter data of the entire structure, a high-resolution photo-mosaic covering 105,000 m(2) of the most active area, sidescan mapping of gas emissions, and maps of faunal distribution as well as of carbonate crust occurrence are combined to provide an unprecedented detailed view of a giant pockmark. All data sets suggest that the pockmark is composed of two very distinctive zones in terms of seepage intensity. We postulate that these zones are the surface expression of two fluid flow regimes in the subsurface: focused flow through a fractured medium and diffuse flow through a porous medium. We conclude that the growth of giant pockmarks is controlled by self-sealing processes and lateral spreading of rising fluids. In particular, partial redirection of fluids through fractures in the sediments can drive the pockmark growth in preferential directions.
Geology (0091-7613) (Geological Soc Amer, Inc), 2014-01 , Vol. 42 , N. 1 , P. 63-66

Droits : 2013 Geological Society of America
http://archimer.ifremer.fr/doc/00186/29731/28293.pdf
DOI:10.1130/G34801.1
http://archimer.ifremer.fr/doc/00186/29731/

Éditeur(s) : Gauthier-Villars
Résumé : Global changes in marine geochemistry, on scales between one thousand and one million years permit the detailed correlation of sedimentary sequences in different ocean basins. The condition is that the geochemical signals are at least approximately dated by biostratigraphy (and magnetostratigraphy, where applicable). Through mutual reenforcement of chemostratigraphy and biostratigraphy unusually high stratigraphic resolution can be obtained. The integration of chemostratigraphy and biostratigraphy opens new avenues for analyzing the record-producing system within the framework of systemic stratigraphy. This type of stratigraphy focuses on global change in sea level, climate, and general geologic setting. It attempts to identify the underlying causes of global stratigraphic signals by considering 1) changes in input of matter and energy ; 2) changes in spatial distribution of sediments ; and 3) temporary changes in the partitioning of materials between active geochemical reservoirs. Examples from Pleistocene and Neogene deep-sea records illustrate the concepts and tools of this type of analysis.
Oceanologica Acta, Special issue (0399-1784) (Gauthier-Villars), 1981

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00246/35689/34197.pdf
http://archimer.ifremer.fr/doc/00246/35689/

Résumé : Introduction: To develop its 2005-2009 strategic plan, IFREMER made two prospective analysis studies in 2003: a thematic prospective analysis and a sectorial prospective analysis. The "aquafarming" sectorial prospective analysis, based primarily on an IFREMER idea, particularly brought to light the difference in nature of problems posed by the future evolution of shellfish farming, fish farming and other stockbreeding (pearl farming and shrimp farming). In addition, the prospective analyses made on an international scale by the FAO (2002, 2004) and the IFPRI (2003) emphasise that the development of aqua farming is the required condition for satisfying world demand of consumer aquatic products, given the foreseeable weak growth, indeed, the stagnation of caught-fish production. Considering the weak development of sea fish farming in France, a country with a long tradition of shellfish farming, it has seemed necessary to deepen the thinking about the prospective analysis devoted to sea fish farming by widening it to include all players interested in this production sector. The goal is to ensure that the strategic plan's objectives, stated in the 2005-2008 four-year contract, define a strategy fully compliant with one of IFREMER's three missions in particular: Contribute to the economic development of the maritime world.
Introduction : Pour élaborer son plan stratégique 2005-2009, l'Ifremer a réalisé en 2003 deux exercices de prospective : une prospective thématique, et une prospective sectorielle. La prospective sectorielle « aquaculture », fondée essentiellement sur une réflexion Ifremer, a mis notamment en évidence la différence de nature des problèmes posés par les évolutions futures de la conchyliculture, de la pisciculture et des autres élevages (perliculture et crevetticulture). Par ailleurs, les prospectives réalisées à l'échelle internationale par la FAO (2002, 2004) et l'IFPRI (2003) soulignent que le développement de l'aquaculture est la condition nécessaire de satisfaction de la demande mondiale d'approvisionnement en produits aquatiques de consommation, compte tenu de la prévisible faible croissance, voire stagnation, de la production des pêches de capture. Considérant le faible développement de la pisciculture marine en France, pays de longue tradition conchylicole, il est apparu nécessaire d'approfondir la réflexion prospective consacrée à la pisciculture marine, en l'élargissant à tous les acteurs concernés par ce secteur de production. Le but est de s'assurer que les objectifs du plan stratégique, déclinés dans le contrat quadriennal 2005-2008, définissent une stratégie pleinement conforme à l'une des trois missions de l'Ifremer : contribuer au développement économique du monde maritime.

Droits : 2006 Ifremer
http://archimer.ifremer.fr/doc/2006/rapport-1506.pdf
http://archimer.ifremer.fr/doc/00000/1506/

Éditeur(s) : ISTPM
Résumé : The "Thalassa" undertook a cruise to measure hydrological parameters between the coasts of Algeria and the 40th parallel. A series of deep-sea samples were taken at successive depths to study zooplankton, which has been little studied in this region (Fig. A)....
La «Thalassa» a procédé en janvier 1961 à une campagne hydrologique entre la côte algérienne et le 40• parallèle. Dans son programme a été incluse une série de pêches profondes, par paliers successifs, qu'il nous a paru intéressant de faire en cette région où le zooplancton n'a été jusqu'ici que très peu étudié (fig. A). Cette opération devait être effectuée avec le filet préconisé par la Commission internationale pour l'Exploration de la Méditerranée, mais la perte de cet engin quelques jours plus tôt obligea à utiliser un filet fermant « Discovery ». De toute manière, les échantillons ainsi prélevés étant comparables entre eux, il nous était possible d'évaluer la richesse relative des différents niveaux prospectés. On ne pouvait s'attendre à trouver dans ce secteur de haute mer une variété et une densité du même ordre que celle des secteurs périphériques, sachant qu'en cette région les courants et autres échanges hydrologiques sont moindres qu'au voisinage des côtes ou dans les golfes comme ceux de Gênes ou du Lion. L'hydrologie faite par J. FURNESTIN et Ch. ALLAIN (1962) est venue renforcer cette opinion. Si les mélanges et les mouvements des eaux de divers types y sont d'un grand intérêt, ils se manifestent surtout en profondeur, au-dessous de 1 000 m et leur résonance en surface est affaiblie; quant à la couche superficielle, elle est, là comme ailleurs, influencée par les dérivations du courant atlantique qui n'y provoquent pas de contrastes aussi nets qu'à la périphérie du Bassin. C'est sans doute, compte tenu de l'imperfection qui s'attache aux pêches profondes avec l'engin de faible rendement qu'est le filet à plancton, la raison pour laquelle l'analyse quantitative du zooplancton aussi bien que celle des groupes particulièrement examinés ici (Copépodes et Chaetognathes) ne nous a apporté que des résulta ts relativement banals, Et ceux-ci seraient en somme assez décevants si, par certaines anomalies de la répartition des espèces, ils ne venaient confirmer la valeur des planctontes en tant qu'indicateurs des phénomènes hydrologiques méditerranéens (courant superficiel et mouvements profonds de convection). (OCR non contrôlé)
Revue des Travaux de l'Institut des Pêches Maritimes (0035-2276) (ISTPM), 1962-09 , Vol. 26 , N. 3 , P. 320-368

Droits : Ifremer
http://archimer.ifremer.fr/doc/1962/publication-4191.pdf
http://archimer.ifremer.fr/doc/00000/4191/

Éditeur(s) : Society for Sedimentary Geology
Résumé : The Kramis deep-sea fan extends over 45 km at the base of the western Algerian continental slope between 2000 and 2550 m water depth and covers an area of approximately 1200 km2. The Kramis Fan was initiated after Messinian time, evolved during the Plio-Quaternary, and, is still active, as proved by submarine cable breaks during the 1954 Orléansville earthquake. The Kramis Fan is fed by two perpendicular canyons: the Kramis Canyon and the Khadra Canyon, merging in a single E–W-oriented channel confined at the foot of the slope. It is strongly asymmetric with a super-developed levee on the right-hand side of the channel, the Kramis Ridge. Based on recent multibeam, side-scan sonar, and sediment core data (Maradja, 2003 and 2005, Prisma, 2004, and Prisme, 2007 cruises), we describe the morphology and internal structure of the fan and particularly the sediment ridge, showing marked lateral changes in the sediment-wave morphology and their association with a series of large scours in the intermediate part of the ridge aligned in the continuity of the Khadra Canyon direction. Overall, the Kramis Ridge is formed by turbidity currents overspilling the ridge crest, which is 100 m above the channel floor, with two exceptions. In the distal part of the ridge the subdued ridge-crest height probably causes continuous overspill, testified by sediment waves migrating parallel to the channel. The scours occur in the intermediate part of the ridge where the ridge height is only 50–60 m; scours are interpreted as the result of cyclic steps due to flow stripping of currents provided by the intersection of the Khadra Canyon with the Kramis Canyon and Channel system. The scours probably postdate the main growth of the Kramis Ridge and induce the local erosion of the ridge, which could correspond to a new channel initiation cutting the ridge. The superposition or the interaction of flows with different directions is responsible of the amplification of the size of the sediment waves with erosional downside flanks and their transformation in scours. The Kramis Fan provides a clear example of flow interaction to explain the presence of large sediment waves and scours on modern submarine fans.
SEPM Special Publication (1060-071X) (Society for Sedimentary Geology), 2012 , Vol. 99 , P. 293-308

Droits : 2012 SEPM (Society for Sedimentary Geology)
http://archimer.ifremer.fr/doc/00129/24021/21978.pdf
http://archimer.ifremer.fr/doc/00129/24021/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : The volcanic island of Mayotte (374 km super(2)) is part of the Comoros Archipelago, which is situated on the North of Mozambic's Canal (Indian Ocean). Mayotte is composed of two islands and some thirty small islands distributed in a lagoon of more than 1,000 km super(2). Being one of the French Republic's Territorial Collectivity, this island is characterized by a very fast demographic evolution (growth rate : 5.8 %), which constitutes the foundation of the development problematic. Most of local halieutic production comes from the reef (nearly 2,000 t in 1999), the technic of "palangrotte" (deep line) is still dominating. The fishing fleet is composed of monoxyl pirogues and polyester fishing boats for the 1,200 fishermen. The first FADs (Fish Aggregating Devices) were installed in 1989. Now, 5 FADs are situated in the lagoon whereas 10 others have been installed out of it. If it is very hard to evaluate economic impact of FAD in Mayotte, their success seems to be limited because of several local constraints : fear to fish out of the lagoon, little interest in tuna, lack of formation. Nevertheless, faced to the demographic evolution and the decrease of the reef ressources, a program of fishing development on FAD has been initiated in 1998, with those following themes : realization of a new prototype of FAD, experimental fishing program with vertical drift "long line", teaching programs for the local fishermen. Today, it is too early to analyze the informations already collected, but the results are very promising, and validate the technical improvement of the new prototype.Original Abstract: L'ile volcanique de Mayotte (374 km super(2)) fait partie de l'archipel des Comores situe au Nord du canal du Mozambique (ocean Indien). Mayotte comprend deux iles et une trentaine d'ilots repartis dans un lagon de plus de 1 000 km super(2). Collectivite territoriale de la Republique francaise, l'ile se caracterise par une evolution demographique tres rapide (taux de croissance: 5,8 %), qui constitue le socle de toutes les problematiques de developpement. L'essentiel de la production halieutique provient du milieu recifal (environ 2 000 t en 1999), la peche a la ligne de fond reste la technique dominante. La flottille de peche est constituee de pirogues monoxyles et de barques polyester pour une population de 1 200 pecheurs. Les premiers DCP mahorais furent installes en 1989. A ce jour, on denombre cinq DCP dans le lagon et dix hors lagon. Il semble que leur succes soit reste limite en raison de plusieurs contraintes locales : peur de la peche hors lagon, peu d'interet pour les poissons pelagiques, manque de formation. Neanmoins, face a l'explosion demographique et a l'appauvrissement des ressources lagonaires, un nouveau programme de developpement de la peche sur DCP a ete initie en 1998. Ce programme comporte trois axes : realisation d'un nouveau prototype de DCP, lancement d'un programme de peches experimentales a la palangre verticale derivante et formation des pecheurs. A ce jour, les informations obtenues sont trop parcellaires pour etre analysees mais les donnees et observations realisees sur les nouveaux dispositifs permettent de valider leur conception technique.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15290/12647.pdf
http://archimer.ifremer.fr/doc/00042/15290/

Éditeur(s) : Taylor and Francis
Résumé : A new cumacean genus and species, Thalycrocuma sarradini gen. et sp. nov., belonging to the family Nannastacidae is described from several sites of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37N, 1700 m depth). The new genus differs from others in the family by males lacking exopods on the pereopods 3 and 4 and having an antenna with a five-articulate peduncle and a short flagellum. This is the first cumacean species that could be considered, at the moment, as endemic from hydrothermal vent areas. Data on the accompanying fauna including other cumacean species (Cyclaspis longicaudata, Bathycuma brevirostre, Procampylaspis sp. and Makrokylindrus sp.) and some ecological remarks are included. A key for the currently known genera of the family Nannastacidae is provided and the taxonomic position of some genera is discussed.
Marine Biology Research (1745-1000) (Taylor and Francis), 2008-06 , Vol. 4 , N. 3 , P. 180-192

Droits : 2008 Taylor & Francis Group
http://archimer.ifremer.fr/doc/2008/publication-4358.pdf
DOI:10.1080/17451000801898576
http://archimer.ifremer.fr/doc/00000/4358/

Éditeur(s) : Elsevier
Résumé : The ZoNeCo programme is devoted to the evaluation of the marine resources of the Economic Zone of New Caledonia. The results are essentially dependent on the quality of the seafloor mapping. From 1993 to 1996, four geological and geophysical surveys using the EM12 DUAL multibeam echosounder provided swath-mapping and acoustic imagery data of the seafloor of selected sites on the northern and southern parts of the Norfolk ridge, the Loyalty basin, around the Loyalty islands and in the westernmost part of the Economic Zone of New Caledonia. The accuracy of these documents shows the morphology of the seafloor in detail and allows rocky substratum to be differentiated from muddy bottom. It allows favorable emplacements of future exploratory fishing surveys to be determined. The benefits of swath mapping are illustrated by the Halipro 2 deep sea trawling cruise (1996) which used the swath mapping data of ZoNeCo 1 cruise (1993) on the southern prolongation of the New Caledonia mainland and Loyalty Islands.
Le programme ZoNéCo a pour objectif l'évaluation des ressources marines de la zone économique de Nouvelle-Calédonie. Les résultats du programme dépendent essentiellement de la qualité de la cartographie des fonds marins. De 1993 à 1996, au cours de quatre campagnes bathymétriques et géophysiques, une couverture bathymétrique et d'imagerie a été effectuée en utilisant le sondeur multifaisceaux EM 12 DUAL sur des sites choisis sur les segments Nord et Sud de la ride de Norfolk, dans le bassin des Loyauté, autour des îles Loyauté ainsi qu'à l'ouest de la zone économique de Nouvelle-Calédonie. La qualité des cartes obtenues permet de préciser la morphologie du fond mais aussi de différencier un substratum rocheux d'un substratum couvert par des sédiments et d'identifier les sites favorables à la réalisation de campagne de pêche exploratoire. Les bénéfices de la bathymétrie multifaisceaux sont illustrés, à partir des données de ZoNéCo 1 (1993), par la campagne de chalutage profond Halipro 2 (1996) sur la prolongation méridionale de la Grande Terre de Nouvelle-Calédonie et des îles Loyauté.
Oceanologica Acta (0399-1784) (Elsevier), 1999-11 , Vol. 22 , N. 6 , P. 641-650

Droits : 1999 Ifremer / CNRS / IRD / Editions scientifique et mtdicales Elsevier SAS
http://archimer.ifremer.fr/doc/1999/publication-833.pdf
DOI:10.1016/S0399-1784(00)88955-0
http://archimer.ifremer.fr/doc/00000/833/

Éditeur(s) : Editions de l’institut Universitaire Européen de la Mer
Résumé : Epsilonematids are epifaunal nematodes characterized by an epsilon-shaped body and the presence of ambulatory setae, which are used in their locomotion. Nematodes belonging to this family were recently found in deep sea, especially in cold-water coral and seamount ecosystems. Akanthepsilonema oceanopolis sp. nov. (Nematoda: Epsilonematidae) is described from sediments of the Condor Seamount (North-East Atlantic Ocean) at 206 m water depth. Its main features are a heterogeneous cuticule with large horn-like dorsal spines both in anterior and in posterior regions; the presence of eight subcephalic setae arranged in two rows and the ratio maximum/minimum body diameter larger than two. The taxonomic position of this new species within the genus is discussed and a key to all species from the genus was added.
Les nématodes de la famille des Epsilonematidae se caractérisent par un corps en forme d’epsilon et par la présence de soies ambulatoires servant à la mobilité. Des représentants de cette famille ont récemment été découverts en environnement marin profond, notamment au niveau des récifs de coraux d’eau froide et des monts sous-marins. La nouvelle espèce Akanthepsilonema oceanopolis (Nematoda : Epsilonematidae) est décrite des sédiments du mont sous-marin Condor, situé dans l’Atlantique nord-est, collectés à 206 m de profondeur. Ses principaux caractères sont la présence d’une cuticule hétérogène munie de grandes épines dorsales recourbées, à la fois dans les régions antérieure et postérieure ; la présence de quatre paires de soies subcéphaliques disposées en deux rangées et un ratio diamètre maximal/diamètre minimal du corps supérieur à deux. La position taxinomique de cette espèce au sein du genre Akanthepsilonema est discutée et une clé des espèces connues du genre est donnée.
An aod - les cahiers naturalistes de l’Observatoire marin (2263-5718) (Editions de l’institut Universitaire Européen de la Mer), 2014 , Vol. 3 , N. 1 , P. 1-10

Droits : Editions de l’institut Universitaire Européen de la Mer
http://archimer.ifremer.fr/doc/00199/31050/29470.pdf
http://archimer.ifremer.fr/doc/00199/31050/

Éditeur(s) : Elsevier Science Bv
Résumé : Volcaniclastic successions are well-described in volcanic arc setting but rare in hotspot environments. The present work proposes a facies model of volcaniclastic sedimentation related to basaltic hotspot volcanoes as exemplified by the Piton de la Fournaise volcano (La Réunion Island). The facies model is based on a multi-scale approach combining high-resolution multibeam and backscatter data, deep-water photographs, side scan imagery and Kullenberg piston cores. Data show that a wide range of gravity flows and erosional features develop in the active volcaniclastic sedimentary system. Coastal and submarine instabilities are the main processes shaping the volcano's submarine morphology. Meanwhile, the evolution and dynamics of the sedimentary system are strongly linked with the morpho-structural evolution of the subaerial part of the volcano. The proposed model is characterized by a cyclic succession of stages: (1) a growing stage during which sedimentary activity is mainly restricted to proximal and mid-slope areas; (2) a collapse stage that entirely reshapes the morphology of the submarine slopes; and (3) an erosional stage related to a slow down of volcanic activity, enabling the development of large deep-sea fans.
Marine Geology (0025-3227) (Elsevier Science Bv), 2013-03 , Vol. 337 , P. 35-52

Droits : 2013 Published by Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00137/24798/22939.pdf
DOI:10.1016/j.margeo.2013.01.004
http://archimer.ifremer.fr/doc/00137/24798/

Éditeur(s) : Museum National d'Histoire Naturelle
Résumé : Two new species of the deep-sea genus Acanthocope (A. carinata n. sp. et A. annata n. sp.) were collected in the North Atlantic abyssal plain. Phenetic relationships between the 10 species of this genus are studied utilising 34 morphological features by way of a numerical taxonomic approach (cluster and principal components analysis). Results are discussed through biogeographical considerations. [NOT CONTROLLED OCR]
DescriPtion de deux espèces nouvelles d'Isopode Asellote, Acanthocope armata n. sp. et A. carinata n. sp., récoltées dans la plaine abyssale de l'Atlantique nord. Recherche des affinités systématiques entre espèces du genre Acanthocope Beddard, 1885, par l'application des méthodes de la taxinomie numérique. Considérations biogéographiques. [OCR NON CONTRÔLE]
Bulletin du Museum National d'Histoire Naturelle (Museum National d'Histoire Naturelle), 1972 , Vol. 36 , N. 30 , P. 379-393

Droits : Museum National d'Histoire Naturelle
http://archimer.ifremer.fr/doc/1972/publication-5031.pdf
http://archimer.ifremer.fr/doc/00000/5031/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The lower Pleistocene Kritika Member of the Rhodes Formation is composed of predominantly siliciclastic deposits that are sometimes intercalated with hardbottoms formed by drowning of former beachrock beds. A wide variety of sclerobionts occur in this environment, very different from the poorest soft‐bottom populations occurring in other levels of the Kritika Member. The most characteristic, abundant and frequently diverse are the encrusting forms: coralline algae, bivalves, serpulid worms, and bryozoans. Numerous other groups of sessile and vagile organisms are associated with these crust‐forming communities. A number of skeletal organisms (sometimes including zooxanthellate coral colonies) formed small carbonate buildups on top of several beachrock beds. Boring organisms also occur. Evidence for a two‐step deepening succession over the previously formed beachrock is provided by palaeontological and sedimentological data. The rapidly cemented sandy‐conglomeratic beds were first colonised by a relatively shallow‐water (around 20 m) biocoenosis of mostly encrusting organisms. Another association, with encrusting and erect organisms, was later established in a deeper environment (20-40 m). A comparison with Holocene beachrock occurring on the coast of Rhodes was also undertaken. Their submerged part provided habitat for poorer but similar biotas to those occurring in the Kritika Member. The lower Pleistocene beachrock and associated organogenic fossil assemblages indicate repeated drowning episodes during deposition of the Kritika Member and provide help in sequence stratigraphic interpretations of these siliciclastic deposits. Notably, they can be used as indicators of relative sea‐level changes.
ISSN: 0031-0182

hal-00795591
https://hal.archives-ouvertes.fr/hal-00795591
DOI : 10.1016/j.palaeo.2012.09.007

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : This summary tackles the development of fisheries in the Caribbean using fads. It highlights the principal causes which explain why, in spite of more than thirty years of experimenting, fishing on fads has not developed as much as had been hoped. Whereas the deep-sea production of pelagic fish by the continental countries of the region has considerably increased since the early eighties, that of the Lesser Antilles has grown more slowly. Anchored fads have given the boats of the small-scale fisheries from three islands (Guadeloupe, Martinique and Curacao) access to these pelagic resources. The various modes of development and management of the fads observed in each island are described. The first available data are used to provide some indications of the effects of the various strategies implemented and the changes induced by this new fishing technique.Original Abstract: Cette synthese concerne la region Atlantique Centre-Ouest (FAO 31) mais elle aborde principalement le developpement des DCP ancres de la zone Caraibe. Trois sites principaux font l'objet d'un developpement particulier ; il s'agit des iles pour lesquelles l'activite de peche professionnelle est actuellement effective autour des DCP : la Guadeloupe, la Martinique et Curacao. L'introduction de DCP dans l'Atlantique Centre-Ouest est signalee pour la premiere fois en 1969, a Panama City (Floride). Il s'agit alors de dispositifs cotiers. Les especes ciblees sont des petits poissons pelagiques. Au debut des annees quatre-vingt, l'implantation de DCP ancres autour des petits etats insulaires de la Caraibe pour la peche des grands poissons pelagiques est consideree comme une priorite par les scientifiques reunis lors du 36e congres du Gulf and Caribbean Fisheries Institute (GCFI). Beaucoup d'experiences DCP conduites dans la region ont permis de conclure a une bonne efficacite agregative quels que soient les choix technologiques operes (DCP lourds ou legers). Malgre cela, tres peu d'iles tirent actuellement benefice de l'avantage que procurent les DCP pour l'exploitation des ressources en grands pelagiques frequentant leurs eaux. Les problemes de transfert et les difficultes a passer de la phase experimentale a la phase operationnelle sont probablement a l'origine de ce paradoxe. Le developpement d'une reelle cooperation regionale sur le theme devrait permettre, aux petits etats insulaires notamment, de mieux profiter des migrations des grands poissons pelagiques dans leurs eaux.

Droits : Ifremer
http://archimer.ifremer.fr/doc/00042/15279/12665.pdf
http://archimer.ifremer.fr/doc/00042/15279/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Since the early 1980's, the Secretariat of the Pacific Community (SPC, formerly the South Pacific Commission) has contributed to the development of FAD programmes for the artisanal fisheries sector in the Pacific region. In particular, it has put considerable efforts into developing technology that would assure a two-year average FAD lifespan, while maintaining costs under US$ 4,000 per FAD unit. From 1996 to 1998, this work led to the publication of three volumes of the SPC FAD Manual. Volume 2 of this manual, "Rigging Deep-Water FAD Moorings", describes in great detail two FAD models that were developed from the original 1983 SPC-recommended model, and gives precise instructions on the way to construct them. Despite SPC's work, the objectives set, in particular the two-year average lifespan for FADs, have not been consistently met, resulting in many FAD programmes in the region being suspended. An analysis of the reasons why this has occurred is presented, along with a short description of the practical research that could be pursued, using different objectives, to introduce new FAD programmes in the region.Original Abstract: Depuis le debut des annees quatre-vingt, le secretariat general de la communaute du Pacifique (SPC, anciennement commission du Pacifique Sud) a soutenu et accompagne le developpement de programmes DCP destines au secteur de la peche artisanale, dans la region Pacifique. Il s'est en particulier efforce de mettre au point des modeles de DCP repondant principalement aux deux criteres suivants: duree de vie superieure a deux ans et cout unitaire moyen inferieur a 4 000 dollars US. Entre 1996 et 1998, ces travaux ont abouti a la publication en trois volumes du manuel de la SPC sur les DCP. Le volume 2 de ce manuel, " La fabrication de DCP pour grandes profondeurs ", presente deux evolutions d'un modele concu en 1983 et en detaille tres precisement les methodes de fabrication. Le present document analyse les raisons pour lesquelles, malgre les efforts deployes, les objectifs fixes, et en particulier la duree de vie minimum de deux ans pour les DCP, n'ont pas ete pleinement atteints et la plupart des programmes DCP de la region ont ete interrompus. Il donne egalement une breve description des axes de recherche appliquee qui pourraient etre suivis, en se fixant d'autres objectifs, pour relancer des programmes DCP dans la region.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15291/12648.pdf
http://archimer.ifremer.fr/doc/00042/15291/

Éditeur(s) : Elsevier
Résumé : The combined use of Lu-Hf and Sm-Nd isotope systems potentially offers a unique perspective for investigating continental erosion, but little is known about whether, and to what extent, the Hf-Nd isotope composition of sediments is related to silicate weathering intensity. In this study, Hf and Nd elemental and isotope data are reported for marine muds, leached Fe-oxide fractions and zircon-rich turbidite sands collected off the Congo River mouth, and from other parts of the SE Atlantic Ocean. All studied samples from the Congo fan (muds, Fe-hydroxides, sands) exhibit indistinguishable Nd isotopic composition (epsilon(Nd)similar to - 16), indicating that Fe-hydroxides leached from these sediments correspond to continental oxides precipitated within the Congo basin. In marked contrast, Hf isotope compositions for the same samples exhibit significant variations. Leached Fe-hydroxide fractions are characterized by epsilon(Hf) values (from -1.1 to +13) far more radiogenic than associated sediments (from -7.1 to -12.0) and turbidite sands (from -27.2 to -31.6). epsilon(Hf) values for Congo fan sediments correlate very well with Al/K (i.e. a well-known index for the intensity of chemical weathering in Central Africa). Taken together, these results indicate that (1) silicate weathering on continents leads to erosion products having very distinctive Hf isotope signatures, and (2) a direct relationship exists between epsilon(Hf) of secondary clay minerals and chemical weathering intensity. These results combined with data from the literature have global implications for understanding the Hf-Nd isotope variability in marine precipitates and sediments. Leached Fe-hydroxides from Congo fan sediments plot remarkably well on an extension of the 'seawater array' (i.e. the correlation defined by deep-sea Fe-Mn precipitates), providing additional support to the suggestion that the ocean Hf budget is dominated by continental inputs. Fine-grained sediments define a diffuse trend, between that for igneous rocks and the,seawater array', which we refer to as the 'zircon-free sediment array' (epsilon(Hf)=0-91 epsilon(Nd)+3.10). Finally, we show that the Hf-Nd arrays for seawater, unweathered igneous rocks, zircon-free and zircon-bearing sediments (epsilon(Hf)= 1.80 epsilon(Nd)+2.35) can all be reconciled, using Monte Carlo simulations, with a simple weathering model of the continental crust. (C) 2008 Elsevier B.V. All rights reserved.
Earth and Planetary Science Letters (0012-821X) (Elsevier), 2009 , Vol. 277 , N. 3-4 , P. 318-326

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6451.pdf
DOI:10.1016/j.epsl.2008.10.028
http://archimer.ifremer.fr/doc/00000/6451/