Éditeur(s) : HAL CCSD AGU and the Geochemical Society
Résumé : International audience
We analyze focal mechanisms of shallow-intermediate earthquakes in a NW-SE transect along the western Betic Cordillera and Alboran Sea, and deep earthquakes located in the central Betics to constrain the state of stress at the Gibraltar Arc slow convergence area. Shallow earthquakes (< 40 km) are preferably clustered at the mountain front. A general NW-SE horizontal compression is compatible with the convergence, and NW plunging compression axes are in agreement with frontal thrust activity. Toward the Alboran Sea the earthquakes are progressively deeper, reaching intermediate depths (40-120 km) near the coast and supporting the present-day activity of subduction only in this area. The Iberian continental crust concentrates most of the intermediate seismicity and is forced to partially sink into the mantle, probably through the pull of the oceanic slab. This downdip pull together with the buoyancy of the Iberian continental crust produces the slab curvature, downdip extension in the external arc of the continental slab, and downdip compression in the inner arc. T axes highly dipping to the southeast at 90-120 km depth occur at the oceanic/continental transition. Deep earthquakes (> 620 km) show very similar focal mechanisms, fitting the general slab behavior of resistance to further descent at the 660 km discontinuity. Seismicity features evidence the present-day stress distribution in a context of transition from subduction to continental collision.
ISSN: 1525-2027

hal-00669889
https://hal.archives-ouvertes.fr/hal-00669889
DOI : 10.1029/2011GC003824

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Outbreaks of the corallivorous crown-of-thorns seastar Acanthaster planci (COTS) represent one of the greatest disturbances to coral reef ecosystems in the Indo-Pacific, affecting not only coral reefs but also the coastal communities which rely on their resources. While injection approaches are increasingly used in an attempt to control COTS densities, most of them display severe drawbacks including logistical challenges, high residual environmental impacts or low cost-effectiveness. We tested a new alternative control method based upon acidic injections of cheap, 100% natural products. We investigated the lethal doses, intra-and inter-specific disease transmission and immune responses of COTS when injected with fresh lime juice (extracted from local Citrus arantifolia) and white spirit vinegar. High COTS mortality was achieved with small volumes: 10–20 ml per seastar induced death in 89%/ 97% of injected specimens after an average 34.3 h/29.8 h for lime juice and vinegar respectively. Highest efficiency was reached for both solutions with double shots of (2 × 10 ml) in two different areas on the body: 100% mortality occurred within 12–24 h, which is similar or faster compared with other current injection methods. Multiple immune measures suggested that death was very likely caused by pH stress from the acidic solutions rather than a bacterial infection. Contagion to either conspecifics or a variety of other reef species was not observed, even at COTS densities 15 times higher than the highest naturally reported. 10 to 20 l lime juice/vinegar could kill up to a thousand COTS at a cost of less than 0.05 USD per specimen; no permits or special handling procedures are required. We conclude that injections of lime juice and vinegar offer great advantages when compared to current best practises and constitute a cheap and natural option for all reefs affected by COTS.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by/
hal-01208272
https://hal-univ-perp.archives-ouvertes.fr/hal-01208272
https://hal-univ-perp.archives-ouvertes.fr/hal-01208272/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01208272/file/journal.pone.0137605.pdf
DOI : 10.1371/journal.pone.0137605

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : El desarrollo del turismo de masas en Canarias se inició a principios de la década de los años sesenta del siglo XX. El modelo adoptado fue coetáneo y muy semejante al de otras zonas litorales del Estado español, que se vieron afectadas por un intenso proceso de urbanización. Acutalmente, el perfil del turismo que nos visita nos indica la preferencia de los centroeuropeos por este destino, predominantemente, de los alemanes y británicos. En cuanto a la oferta turística, la política de los tour-operadores, los factores medio-ambientales y patrimoniales, así como el apoyo de las instituciones y de los empresarios han sido decisivos. Por ello, este sector se ha convertido en el motor de la economía del Archipiélago.
Le développement du tourisme de masses dans les Îles Canaries a commencé au début des années 1960. Le modèle adopté repose sur les mêmes logiques que les aménagements touristiques des littoraux méditerranéens espagnols qui ont abouti à d’intenses processus d’urbanisation. Actuellement, la fréquentation touristique de l’archipel indique la préférence des clientèles de l’Ouest-européen, surtout des allemandes et britanniques. Le tourisme s’est affirmé comme le véritable moteur de l’économie de l’archipel.
The development of mass tourism in the Canary Islands started in middle of the 20th century, at the beginning of the 60’s. The adopted model was contemporary and very similar to the model of other coastal areas of the Spanish State, which were affected by an intense urbanization process. Nowadays, the profile of the tourism that visits us shows the preference of Centre-European citizens for this destiny, predominately German and British. As regards the tourist offer, the tour-operators policy, the environmental and patrimonial factors, as well as the institutional and managerial support have been definitive. That’s why this sector has become the motor of the archipelago’s economy.
Canaries

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.1082
http://journals.openedition.org/etudescaribeennes/1082

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In order to better constrain the relationship between tectonics and sedimentation of the Eastern Sardinian Margin, from the Messinian to the present day (METYSS project), a lithostratigraphic study was carried out on the Late Neogene deposits along the Cedrino Valley (eastern Sardinia). The late Neogene evolution is documented from sedimentological and tectonic analysis, biostratigraphic dating, and by mapping and logging stratigraphic sections. Previous authors have differentiated an early Pliocene marine formation from an older continental formation, possibly Miocene, the entire system being covered by late Pliocene to Quaternary lava flows. Preliminary biostratigraphic data suggest the absence of the lowermost Pliocene, based on the absence of Globorotalia margaritae and the presence of Globorotalia puncticulata, implying a sediment age between 3.81 and 2.41 Ma. At the foot of the Fiuli cliff, some mud clasts include a coccolith microflora, Tortonian in age, suggesting reworking. The Pliocene marine deposits consist of a single filling sequence instead of a succession of superimposed sequences as we would expect during this period of time; the occurrences of terms rarely respect the usual transgressive-regressive succession. Contrasting bathymetric environments (fore-shore, pro-delta, shelf or upper slope) can be abruptly superimposed on top of the other, along few meter thick intervals. A rapidly flooded term is observed in several sites and indicates a spatial variability over only a few kilometers distance. Some deep water deposits are in the middle of the infilling Pliocene sequence, whereas shallower water deposits can be repeated along a vertical section, or even interrupted by emersion. These marked differences can express syn-, or possibly post-sedimentation tectonic uplifts. The 10–25° bed dips originated through local tectonic uplift. At Fiuli, the geometry of the bedding planes is indicative of tilting toward the west, in a direction opposite to the one observed at Onifai. These Pliocene series form a wide syncline with an approximately NNE–SSW axis. This morpho-structural behavior appears to be largely atypical of this East-Sardinian coastal area.
ISSN: 1040-6182

hal-01134707
https://hal.archives-ouvertes.fr/hal-01134707
DOI : 10.1016/j.quaint.2014.11.022

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Les ressources marines constituent une richesse économique d’une grande importance pour un grand nombre de pays de la planète. Du fait de l’action de l’homme, ces ressources subissent une fragilisation et une raréfaction dues entre autres à la pollution, à la surpêche, à l’urbanisation intensive... S’ajoute à cette liste, depuis quelques années, le réchauffement de la planète qui affecte d’une manière sensible la diversité biologique marine. Pourtant les réponses internationales face à cette dégradation, au-delà du fait qu’elles sont timides, sont rares. Il faudra dès lors se rabattre sur les solutions de lutte globale contre le réchauffement de la planète entreprise par la communauté internationale afin de contrer cette dégradation.
Marine resources are a wealth of great economic importance for many countries in the world. Due to the action of man, these resources undergo embrittlement and rarification among others to pollution, overfishing, urbanization, intensive ... Added to this list in recent years, the global warming that affects a significantly marine biodiversity. Yet the international response to this degradation, beyond the fact that they are shy, is rare. It will therefore fall back on solutions to the global fight against global warming taken by the international community to counter this degradation.
Danemark
Mexique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.4421
http://journals.openedition.org/etudescaribeennes/4421

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The cyanobacteria-derived neurotoxin β-methylamino-l-alanine (BMAA) represents a plausible environmental trigger for amyotrophic lateral sclerosis (ALS), a debilitating and fatal neuromuscular disease. With the eutrophication of water bodies, cyanobacterial blooms and their toxins are becoming increasingly prevalent in France, especially in the Brittany region. Cyanobacteria are monitored at only a few recreational sites, preventing an estimation of exposure of the human population. By contrast, phosphorus, a limiting nutrient for cyanobacterial growth and thus considered a good proxy for cyanobacteria exposure, is monitored in many but not all surface water bodies. Our goal was to develop a geographic exposure indicator that could be used in epidemiological research. We considered the total phosphorus (TP) concentration (mg/L) of samples collected between October 2007 and September 2012 at 179 monitoring stations distributed throughout the Brittany region. Using readily available spatial data, we computed environmental descriptors at the watershed level with a Geographic Information System. Then, these descriptors were introduced into a backward stepwise linear regression model to predict the median TP concentration in unmonitored surface water bodies. TP concentrations in surface water follow an increasing gradient from West to East and inland to coast. The empirical concentration model included five predictor variables with a fair coefficient of determination (R2 = 0.51). The specific total runoff and the watershed slope correlated negatively with the TP concentrations (p = 0.01 and p < 10− 9, respectively), whereas positive associations were found for the proportion of built-up area, the upstream presence of sewage treatment plants, and the algae volume as indicated by the Landsat red/green reflectance ratio (p < 0.01, p < 10− 6 and p < 0.01, respectively). Complementing the monitoring networks, this geographical modeling can help estimate TP concentrations at the watershed level, delivering a proxy for cyanobacteria exposure that can be used along with other risk factors in further ALS epidemiologic case–control studies
ISSN: 0160-4120

hal-01175538
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01175538
DOI : 10.1016/j.envint.2015.04.007
PUBMED : 25913322

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : L’arrestation en mai 2013 d’Amadé Ouérémi, leader emblématique des « infiltrés » du parc national du mont Péko, a ouvert la voie à une politique publique de relance de la conservation et de remise en tourisme de cette aire protégée de 34 000 hectares presque entièrement colonisée par la culture du cacao. Mais cette reprise en main du parc matérialisée par un projet de « déguerpissement », se heurte à des logiques d’intérêts et à des tensions qui, si elles ne sont pas maîtrisées, risquent de compromettre durablement à la fois tout projet de remise en tourisme et la paix relative dans l’ouest ivoirien.
The arrest in May 2013 of Amade Oueremi, the emblematic leader of mont Peko national park infiltrators, opened the way to a public policy of conservation and tourism development of this 34 000 ha protected area almost entirely colonized by cocoa farms. But the takeover of the park materialized by an eviction project that does not go ahead, faces logics of interests and tensions which, if not controlled, may permanently compromise both in any rehabilitation tourism project and relative peace in western Ivory Coast.
Côte d’Ivoire

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.9418
http://journals.openedition.org/etudescaribeennes/9418

Éditeur(s) : Elsevier Science Bv
Résumé : Estuaries and coastal waters are essential nursery habitats for many marine species, and especially for flatfishes. Thus, investigating how anthropogenic disturbances affect the quality of these habitats is of major importance to understand their consequences on the population renewal of marine species. The aim of the present study was to analyse the effects of estuarine habitat degradation on the population of the common sole in the Eastern Channel, a key species in the fish community and fisheries in this area. We especially focused on the drastic drop in the surface area and on the low water quality of the Seine estuary, the main river of the Eastern Channel. A geographic Information System (GIS) was used to develop quantitative maps of sole nursery habitats in the Eastern Channel by using a habitat suitability model based on bathymetry and sediment structure. This approach indicated that juvenile densities are low in the Seine estuary with regards to other nursery sectors. Then, thanks to historical maps of the Seine estuary, habitat suitability maps were built for key dates in the modifications of this estuary since 1850. This backward predictive approach suggests that habitat loss in the Seine estuary has led to a 42% decrease of its nursery capacity. As the density of juvenile sole in the Seine estuary is low in comparison to other sectors, this represents only a 3% loss at the sole population scale, in the Eastern Channel. However, when we assumed that prior to anthropogenic disturbance the juvenile density in the Seine estuary might have been equivalent to the current density of adjacent sectors with higher quality, the loss in abundance could be nearly 23% (8-36%). Results suggest that the loss in habitat surface combined with habitat degradation has led to an important loss in the contribution of the Seine estuary nursery to the whole sole population in the Eastern Channel. (C) 2009 Elsevier BM. All rights reserved.
Journal Of Sea Research (1385-1101) (Elsevier Science Bv), 2010-07 , Vol. 64 , N. 1-2 , P. 34-44

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00008/11921/9799.pdf
DOI:10.1016/j.seares.2009.08.003
http://archimer.ifremer.fr/doc/00008/11921/

Éditeur(s) : Elsevier
Résumé : The main feature of the Congo-Angola margin in the Gulf of Guinea is the Congo (ex-Zaire) deep-sea fan composed of a submarine canyon directly connected to the Congo River, a channel and a [sediment] lobe area. During the multi-disciplinary programme called BIOZAIRE conducted by Ifremer from 2000 to 2005, two CTD-O2 sections with discrete water column samples were performed (BIOZAIRE3 cruise: 2003-2004) to study the influence of the Congo River discharges, both in the surface layer and in the deep and near-bottom layers. The surface layer water is greatly diluted with river water that has a heavy particle load. The deep layer is affected by episodic turbidity currents that flow in the deep Congo channel and reach deep areas far from the coast. Previous studies revealed deep anomalies in oxygen (deficit) and nutrient (excess) concentrations at not, vert, similar4000 m depth and assumed that they resulted from mineralisation of the particulate organic matter from the Congo River. The BIOZAIRE3 sections were designed to explore these phenomena in more detail near the Congo channel. Oxygen and nutrients were measured as well as additional parameters, including stable isotopes of oxygen and carbon, dissolved inorganic carbon and pH. For the surface layer, the effect of the Congo River was studied with reference to salinity. Deviations from the theoretical dilution of various inorganic solutes suggested the occurrence of mineralisation and consumption processes. For the deep layer, the network of CTD-O2 stations gave a more detailed description of the deep anomalies than in previous studies. From the east-west section, anomalies appeared on the bottom at 4000 m depth and became slightly shallower when they spread to the west. They were also present north and south on the bottom along the 4000 m isobath. In these deep waters, the decrease in the o13C values of dissolved inorganic carbon confirmed that the mineralisation of organic matter plays a role in generating these anomalies. The location of the origin of this deep anomaly is debated. Here, arguments are given in favour of mineralisation of the particulate organic matter input that overflows from the Congo channel at not, vert, similar4000 m depth during turbidity current events. Other authors suggest that this input comes from downslope particle transport. Anomalies of the same origin, but weaker, also occurred deeper on the Congo lobe, where the Congo channel ends, but with a significant pH decrease on the bottom which was not seen at 4000 m depth.
Deep Sea Research Part II: Topical Studies in Oceanography (0967-0645) (Elsevier), 2009-11 , Vol. 56 , N. 23 , P. 2183-2196

Droits : 2009 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6737.pdf
DOI:10.1016/j.dsr2.2009.04.002
http://archimer.ifremer.fr/doc/00000/6737/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Dans les Antilles françaises, l’utilisation des espaces et des territoires pose des questions et suscite des problèmes aussi nombreux que complexes. Les unes et les autres, dépendant des caractéristiques propres à l’environnement et au contexte des milieux insulaires, sont tributaires des paramètres propres au contexte local, et notamment de facteurs identitaires. Les données historiques et les pesanteurs socio-culturelles y sont en effet souvent déterminantes. Il en résulte des situations qui d’attitudes et de comportements qui aujourd’hui encore se situent dans le domaine d’un non-droit, qu’il soit délibéré ou subi, ou à l’inverse génèrent de telles attitudes ou comportements.Les besoins de toute nature (occupation, utilisation, exploitation, valorisation, etc.) envers les espaces fonciers, au profit d’intérêts privés très divers et fréquemment conflictuels, s’y heurtent en outre à de nombreux obstacles, en particulier lorsqu’ils font l’objet d’une mobilisation à des fins touristiques. Ils tiennent autant à la superficie limitée des territoires, qu’à la rareté croissante des terres disponibles. Les impacts négatifs en sont aggravés par les exigences de conservation environnementale, qui se heurtent aux exigences des politiques d’urbanisme et de tourisme, qui tendent à se superposer et s’opposer en matière d’urbanisation touristique du littoral, espace aussi convoité que fragile.
In the French West Indies, the use of spaces and territories raises numerous and complex questions and problems. Both depend on the particular characteristics of the environment and the context of islands, and on parameters specific to the local context, including identity factors. The historical and socio-cultural constraints are indeed often critical. This results in situations that proceed, or conversely generate, attitudes and behaviours that still lie in the field of non-law, whether will full or suffered.The needs of any kind (occupation, use, exploitation, valuation, etc.) for land areas for the benefit of different and often conflicting private interests, stumble also many obstacles, especially when they are mobilized for tourism. They are due as much to the limited size of the territories, as to the increasing scar-city of available land. The negative impacts are exacerbated by the demands of environmental conservation that face the requirements of planning policies and tourism, which tend to overlap and oppose in tourist urbanization of coastal areas, which are spaces as coveted as fragile .
Martinique
Guadeloupe
Guyane française
Saint-Barthélemy
Saint-Martin

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6770
http://journals.openedition.org/etudescaribeennes/6770

Éditeur(s) : Neidine Editeurs
Résumé : This text presents a review of the various technologies for exploitation of renewable marine energy resources. Il exposes the solutions offered by tide and currents, swell and waves, the marine wind energy, the Ocean Thermal Energy, the osmotic energy and specifies the various degrees of technological maturity for each solution. This new economic activity on the littoral and coastal areas also contains indirect effects in terms of management which are called back. The inter-tropical islands benefit from a very vast potential for the insertion of these renewable sources of energy in their mix of energy production. Although the exploitation of these energies is not still the object of a programming in New Caledonia, an overview of the specificities of the country allows to think that certain medium term solutions will be possible.
Ce texte présente une revue des différentes technologies d’exploitation des ressources énergétiques qui peuvent être tirées de la mer. On expose ainsi les solutions offertes par la marée et les courants, la houle et les vagues, l’éolien marin, l’énergie thermique des mers, l’énergie osmotique et on précise les degrés de maturité technologique très échelonnés de chaque solution. Cette nouvelle activité économique sur l’espace littoral et côtier comporte également des effets indirects en termes d’aménagement qui sont rappelés. Les îles inter-tropicales bénéficient d’un très vaste potentiel pour l’insertion de ces EMR dans leur mix de production énergétique. Bien que l’exploitation de ces énergies ne fasse pas encore l’objet d’une programmation en Nouvelle-Calédonie, un rappel des spécificités du pays permet de penser que certaines solutions seront envisageables à moyen terme.
Tai Kona (2269-7535) (Neidine Editeurs), 2013-09 , N. 4 , P. 24-40

Droits : Tai kona
http://archimer.ifremer.fr/doc/00174/28504/26853.pdf
http://archimer.ifremer.fr/doc/00174/28504/

Éditeur(s) : Inter-research
Résumé : Benthic primary production and respiration were investigated at 4 sites representative of the major coastal communities bordering the Sahara Desert in the Banc d'Arguin, Mauritania, Western Africa. These sites correspond to intertidal Zostera noltii beds (270 km(2)), intertidal bare sediments (88 km(2)), subtidal Cymodocea nodosa beds (374 km(2)), and subtidal bare sediments (311 km(2)). At each site, production-irradiance relationships were established in situ in November 2008 and January 2010, and used to calculate daily carbon fluxes for these communities. In intertidal areas, compared to emersion, the gross maximal photosynthetic rates for Z. noltii bed and bare sediment communities were on average 8-and 7-fold higher during immersion, respectively; community respiration rates were 3-and 18-fold higher during immersion, respectively. The Z. noltii bed was autotrophic during the 2 study periods, with a mean (+/- 95% probability limit) daily net community production of 71.3 +/- 58.6 mmol C m(-2) d(-1). Conversely, net community production was always negative in intertidal regions and subtidal bare sediments (average -7.3 +/- 46.7 mmol C m(-2) d(-1) and -47.0 +/- 38.9 mmol C m(-2) d(-1), respectively); the C. nodosa bed was negative in November (-96.2 +/- 85.1 mmol C m(-2) d(-1)) and positive in January (33.4 +/- 82.6 mmol C m(-2) d(-1)). Community respiration was highest in subtidal communities, indicating active mineralization of organic matter and demonstrating that Z. noltii beds are likely to increase the bio logical richness of the Banc d'Arguin by exporting energy. Our results confirm the ecological importance of seagrass beds in the net coastal carbon fluxes and justify their protection.
Marine Ecology Progress Series (0171-8630) (Inter-research), 2014 , Vol. 501 , P. 11-23

Droits : Inter-Research 2014 · www.int-res.com
http://archimer.ifremer.fr/doc/00189/29987/28496.pdf
DOI:10.3354/meps10683
http://archimer.ifremer.fr/doc/00189/29987/

Éditeur(s) : Elsevier
Résumé : Seasonal variations in nutrient inputs are described for the main rivers (Loire and Vilaine) flowing into the northern Bay of Biscay. The river plumes are high in N/P ratio in late winter and spring, but not in the inner plume during the summer. Conservative behavior results in most nutrients entering the estuary and eventually reaching the coastal zone. Temporal and spatial aspects of phytoplankton growth and nutrient uptake in the northern Bay of Biscay distinguish the central area of salinity 34 from the plume area. The first diatom bloom appears offshore in late winter, at the edge of the river plumes, taking advantage of haline stratification and anticyclonic "weather windows." In spring, when the central area of the northern shelf is phosphorus-limited, small cells predominate in the phytoplankton community and compete with bacteria for both mineral and organic phosphorus. At that period, river plumes are less extensive than in winter, but local nutrient enrichment at the river mouth allows diatom growth. In summer, phytoplankton become nitrogen-limited in the river plumes; the central area of the shelf is occupied by small forms of phytoplankton, which are located on the thermocline and use predominantly regenerated nutrients.
Journal of Marine Systems (0924-7963) (Elsevier), 2008-07 , Vol. 72 , N. 1-4 , P. 309-319

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2007/publication-2354.pdf
DOI:10.1016/j.jmarsys.2007.03.010
http://archimer.ifremer.fr/doc/00000/2354/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : La mer des Caraïbes abrite une diversité de biotopes littoraux qui favorisent l’installation de trois écosystèmes - les récifs coralliens, les mangroves et les herbiers – riches et complexes. On y trouve également d’autres formations uniques tels les stromatolithes ou les trous bleus. Des conditions climatiques et océanographiques homogènes permettent à l’ensemble du bassin Caraïbe de constituer une unité sur les plans floristique et faunistique. Cette unité n’exclut pas une diversité biologique exceptionnelle avec notamment des espèces endémiques à la zone ; ce qui confère aux côtes des pays caribéens un intérêt écologique, paysager et scientifique certain. La reconnaissance sur le plan international et régional de l’importance de la Mer des Caraïbes mais aussi de sa fragilité a permis au milieu marin caribéen d’acquérir son statut de patrimoine naturel.En plus des services écosystémiques qu’elle rend (ressources halieutiques, protection des littoraux…), la Mer des Caraïbes constitue un atout indéniable dans le cadre du développement touristique de la zone aussi bien par le balnéaire que, plus récemment, par l’écotourisme. Ce dernier s’appuie généralement sur des aires marines protégées et doit permettre un développement durable des îles.A partir d’une étude de cas, le parc marin de Saba, l’objectif de cette étude est d’analyser les rapports entre patrimoine naturel marin et l’écotourisme, ainsi que les impacts économiques, sociaux et environnementaux de la mise en valeur de ces ressources.
The Caribbean Sea is home to a diversity of coastal habitats that support the installation of three rich and complex ecosystems - coral reefs, mangroves and seagrasses -. There are also other unique formations such as stromatolites or blue holes. Oceanographic and climatic conditions allow homogeneous throughout the Caribbean basin to form a unit in terms of flora and fauna. This unit does not exclude an exceptional biological diversity, including species endemic to the area, which give the coasts of the Caribbean countries an ecological, landscape and some science. Recognition on the international and regional importance of the Caribbean Sea but also its fragile marine environment has allowed the Caribbean to gain its status as a natural heritage.In addition to the ecosystem services it render (fisheries, coastal protection ...), the Caribbean Sea is a definite asset in the development of tourism in the area by the seaside as well as, more recently, ecotourism. The latter is generally based on marine protected areas and should facilitate the sustainable development of islands.From a case study, the Saba Marine Park, the objective of this study is to analyze the relationship between natural heritage and marine ecotourism, as well as economic, social and environmental development of these resources.
Saba

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5487
http://journals.openedition.org/etudescaribeennes/5487

Éditeur(s) : Elsevier
Résumé : We investigated the influence of bioturbation by macrofauna on the vertical distribution of living (stained) benthic foraminifera in marine intertidal sediments. We investigated the links between macrofaunal bioturbation and foraminiferal distribution, by sampling from stations situated on a gradient of perturbation by oyster-farming, which has a major effect on benthic faunal assemblages. Sediment cores were collected on the French Atlantic coast, from three intertidal stations: an oyster farm, an area without oysters but affected by oyster biodeposits, and a control station. Axial tomodensitometry (CT-scan) was used for three-dimensional visualization and two-dimensional analysis of the cores. Biogenic structure volumes were quantified and compared between cores. We collected the macrofauna, living foraminifera, shells and gravel from the cores after scanning, to validate image analysis. We did not investigate differences in the biogenic structure volume between cores. However, biogenic structure volume is not necessarily proportional to the extent of bioturbation in a core, given that many biodiffusive activities cannot be detected on CT-scans. Biodiffusors and larger gallery-diffusors were abundant in macrofaunal assemblage at the control station. By contrast, macrofaunal assemblages consisted principally of downward-conveyors at the two stations affected by oyster farming. At the control station, the vertical distribution of biogenic structures mainly built by the biodiffusor Scorbicularia plana and the large gallery-diffusor Hediste diversicolor was significantly correlated with the vertical profiles of living foraminifera in the sediment, whereas vertical distributions of foraminifera and downward-conveyors were not correlated at the station affected by oyster farming. This relationship was probably responsible for the collection of foraminifera in deep sediment layers (> 6 cm below the sediment surface) at the control station. As previously suggested for other species, oxygen diffusion may occur via the burrows built by S. plana and H. diversicolor, potentially increasing oxygen penetration and providing a favorable microhabitat for foraminifera in terms of oxygen levels. By contrast, the absence of living foraminifera below 6 cm at the stations affected by oyster farming was probably associated with a lack of biodiffusor and large gallery-diffusor bioturbation. Our findings suggest that the effect of macrofaunal bioturbation on the vertical distribution of foraminiferal assemblages in sediments depends on the effects of the macrofauna on bioirrigation and sediment oxidation, as deduced by Eh values, rather than on the biogenic structure volume produced by macrofauna. The loss of bioturbator functional diversity due to oyster farming may thus indirectly affect infaunal communities by suppressing favorable microhabitats produced by bioturbation.
Journal of Experimental Marine Biology and Ecology (0022-0981) (Elsevier), 2009-03 , Vol. 371 , N. 1 , P. 20-33

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6146.pdf
DOI:10.1016/j.jembe.2008.12.012
http://archimer.ifremer.fr/doc/00000/6146/

Éditeur(s) : Société Géologique de France
Résumé : Numerous data obtained during recent marine geophysical surveys have been compiled together in order to present the structural framework of Niger Delta and adjacent areas. Seismic reflection results show that the delta slope is characterized by intense diapiric deformations and that the overall structure of the delta is fairly comparable to the structures of the Gulf Coast province margin or of Angolan margin. Seismics as well as gravity and magnetic measurements indicate the existence in the vicinity of the Niger delta of two oceanic trends apparently related to an early phase of opening of the South Atlantic. Both trends can tentatively be correlated on land with the major structures known in the southern and northern Benue trough. A comparion between the whole area (Niger Delta and Benue trough) and another intracratonic chain-the Pyrenees mountains - is briefly discussed. [NOT CONTROLLED OCR]
J. Min. Geol. (Société Géologique de France), 1976 , Vol. 13 , N. 1 , P. 12-28

Droits : Société Géologique de France
http://archimer.ifremer.fr/doc/1976/publication-5171.pdf
http://archimer.ifremer.fr/doc/00000/5171/

Éditeur(s) : Université de Bretagne Occidentale
Résumé : The stock of Lambi, Strombus gigas (gastropod: strombidae), coastal benthic resource, has been exploited artisanally since the prehistoric period in Martinique. Nowadays, three lines of work exploit the species: free diving, nets (since the middle of the century) and scuba diving since 1985. This report presents the activity of each line of work, surveyed directly from 1986 to 1987: fishing zones and resource allocation, production, effort and performance, detail of catches (by length). The socio economic characteristics of the lambi fishermen are studied. The significant production of leisure fishing is also estimated. The decrease in the production and performance, as well as the lowering of the size of the first catch for about thirty years show that the stock is overexploited. The biological phenomenon of the stock: growth of the shell (length and shell lip), growth in weight, acquiring of sexual maturity, natural mortality are studied. The factors of mortality through fishing are estimated by class of length for the current exploitation regime by pseudo-cohort analysis. If the results confirm that the stock is overexploited, the level of overexploitation of the stock cannot be specified because of the presence of a number of lipped adults not yet too exploited in water deeper than 20 metres. The analysis of the dynamic process of the exploited population indicates two ways to the production of the stock: the forcing of the recruitment and the regulation of the exploitation regime. The lack of economic profitability of the production of juveniles over 30 mm and the difficulties raised by their collection in their natural habitat lead to the rationalization of the exploitation. The production and performance (by recruits) simulations performed for different exploitation regimens indicate that the only two conceivable options are the introduction of a minimum catch size, i.e. lambi with forming lip, and the regulation of the fishing effort. The socio-economic implications of the introduction of the determined management measures show that their applicability level is very low, because of the Martinique fishermen polyactivity, their low socio-economic level and mostly because of the free access to the resource. As a consequence, it is suggested to create new professional structures with a wide jurisdiction, in order to locally manage the marine areas, their use and their resources. (unverified OCR)
Le stock de lambi, Strombus gigas (gastéropode: strombidae), ressource benthique côtière, est exploitée artisanalement depuis l'époque préhistorique en Martinique. Trois métiers exploitent actuellement l'espèce: plongée libre, filets (depuis le milieu du siècle) et plongée en scaphandre autonome depuis 1985. Ce rapport présente l'activité de chaque métier, suivie de 1986 à 1987 par une enquête directe: zones de pêche et allocation de la ressource, productions, efforts et rendements, composition en longueur des captures. Les caractéristiques socioéconomiques des pêcheurs de lambi sont étudiées. La production d'une pêche plaisancière non négligeable est estimée. La diminution de la production, des rendements et l'abaissement de la taille de première capture depuis une trentaine d'années révèlent que le stock est surexploité. Les phénomènes biologiques du stock: croissance de la coquille (longueur et pavillon), croissance en poids, acquisition de la maturité sexuelle, mortalité naturelle sont étudiés. Les coefficients de mortalité par pêche sont estimés par classe de longueur pour le régime d'exploitation actuel par l'analyse de pseudo-cohorte. Si les résultats confirment l'état surexploité du stock, le niveau de surexploitation ne peut être précisé en raison de l'existence d'adultes pavillonnés encore peu exploités sur les fonds de plus de 20 mètres. L'analyse des processus dynamiques de la population exploitée indique deux voies pour restaurer la production du stock: le forçage du recrutement et la régulation du régime d'exploitation. Le manque de rentabilité économique de l'élevage des juvéniles au-delà de 30 mm et les difficultés pour leur collecte dans le milieu naturel conduisent à rechercher la rationalisation de l'exploitation. Les simulations de la production et du rendement par recrue réalisées pour différents régimes d'exploitation indiquent que seule la mise en place d'une taille minimale de capture, i.e le lambi au pavillon en formation, et une régulation de l'effort de pêche sont envisageables. Les implications socio-économiques de la mise en oeuvre des mesures de gestion déterminées montrent que leur niveau d'applicabilité est très faible, en raison de la polyactivité des pêcheurs martiniquais, de leur faible niveau socioéconomique et surtout, du régime de libre accès à la ressource. Aussi, il est proposé la création de nouvelles structures professionnelles aux compétences larges, qui permettraient, pour chacun des bourgs, une gestion locale de l'espace marin, des usages et des ressources. OCR NON CONTRÔLE

Droits : 1993 UBO
http://archimer.ifremer.fr/doc/1993/these-3751.PDF
http://archimer.ifremer.fr/doc/00000/3751/

Résumé : Until 1960, the Black scallop Chlamys varia was relatively abundant along the French Atlantic coasts. Today most of these natural beds have disappeared. Because mollusc hatchery and nursery techniques have been mastered, the reintroduction of this species, under control, was carried out in several areas and particularly in the bay of Arcachon, from 1989 to 1992. Good results were obtained in hatchery and nursery but the development of the juveniles in the natural fields was poor. The growth of Chlamys varia was satisfactory but heavy mortalities were rapidly recorded which could not be related to the hydrobiological conditions. This species seems to be very sensitive to short emersion and removal operations which are incompatible with aquaculture processes.
Jusqu'en 1960, le pétoncle noir Chlamys varia était largement distribué sur les côtes atlantiques françaises. Actuellement, la plupart de ces gisements se sont raréfiés. Les techniques de reproduction contrôlée de mollusques étant maintenant relativement maîtrisées, des essais de réimplantation de cette espèce ont pu être tentés dans plusieurs sites ostréicoles, dont le Bassin d'Arcachon, de 1989 à 1992. Les essais de grossissement se sont soldés par un échec. Si de bonnes croissances ont été enregistrées dans le Bassin d'Arcachon au cours de ces trois années, ces performances ont été contrariées par de très fortes mortalités apparaissant peu de temps après la mise en place des élevages. Bien que l'espèce soit considérée comme relativement sensible aux facteurs du milieu, les conditions hydrobiologiques régnant sur la baie à cette période ne peuvent expliquer ces résultats. Chlamys varia semble mal supporter les diverses manipulations (emersion de courte durée, dégrappage) difficilement contournables au cours d'un cycle aquacole.

Droits : 1994 Ifremer
http://archimer.ifremer.fr/doc/1994/rapport-1567.pdf
http://archimer.ifremer.fr/doc/00000/1567/

Éditeur(s) : Elsevier Science Bv
Résumé : The ontogeny of osmoregulationwas investigated in Litopenaeus stylirostris by studying salinity tolerance and osmoregulatory capacity. Shrimp at different larval and postlarval stages were exposed to various salinities and survival was monitored for 24 h. Survival rates exceeded 80% at salinity over 25 ppt (750 mOsm.kg(-1)) at all the stages. At salinities below to 25 ppt, salinity tolerance was higher in nauplii and zoeae than in mysis larvae. Postlarval stages were able to withstand lower salinities, e.g. 6.0 ppt (176 mOsm.kg(-1)) at PL9 stage, but they were more sensitive than larvae to salinities over 35 ppt (1035 mOsm.kg(-1)). Zoea and mysis larvae slightly hyper-regulated at all tested salinities. After metamorphosis, postlarvae progressively acquired the adult pattern of hyper-hypo-osmoregulation: At PL9, the estimated isosmotic salinity was 24.5 ppt (720 mOsm.kg(-1)); below and over this salinity, animals hyper-regulated and hypo-regulated, respectively. Finally, we determine the effects of lowering salinity at different animal development stages. We conclude that seawater salinity (35 ppt) is optimum during larval stages; but for postlarval stages, lowering salinity at 27 ppt leads to a better growth in 19 days compared to those maintained at 35 ppt (1.07 mg vs 0.47 mg). These results are in agreement with penaeid natural life cycle during which larvae are released in oceanic water while juveniles live in coastal areas where salinity is more fluctuant. (c) 2012 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier Science Bv), 2012-09 , Vol. 362-363 , P. 10-17

Droits : 2012 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00107/21843/20058.pdf
DOI:10.1016/j.aquaculture.2012.07.026
http://archimer.ifremer.fr/doc/00107/21843/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Aim : To assess gaps in the representation of taxonomic, phylogenetic and functional diversity among coastal fishes in Mediterranean marine-protected areas (MPAs).
ISSN: 1366-9516

hal-01135644
https://hal.archives-ouvertes.fr/hal-01135644
DOI : 10.1111/ddi.12280