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ArchiMer, Institutional Archive of Ifremer (French Research Institute for Exploitation of the Sea) (9,234 recursos)
Archimer, is the institutional repository of Ifremer (French Research Institute for Exploitation of the Sea). It provides freely available scientific or technical documents online (publications, theses, conference proceedings, etc) in all fields related to oceans (oceanography, aquaculture, fisheries, etc). The site is available in French and English.

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Mostrando recursos 1 - 20 de 141

1. Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling - Auger, Pierre-amael; Machu, Eric; Gorgues, Thomas; Grima, Nicolas; Waeles, Mathieu
A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the NorthWest African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the...

2. Evaluating changes in marine communities that provide ecosystem services through comparative assessments of community indicators - Kleisner, Kristin M.; Coll, Marta; Lynam, Christopher P.; Bundy, Alida; Shannon, Lynne; Shin, Yunne-jai; Boldt, Jennifer L.; Borges, Maria F.; Diallo, Ibrahima; Fox, Clive; Gascuel, Didier; Heymans, Johanna J.; Juan Jorda, Maria J.; Jouffre, Didier; Large, Scott I.; Marshall, Kristin N.; Ojaveer, Henn; Piroddi, Chiara; Tam, Jorge; Torres, Maria A.; Travers-trolet, Morgane; Tsagarakis, Konstantinos; Van Der Meeren, Gro I.; Zador, Stephani
Fisheries provide critical provisioning services, especially given increasing human population. Understanding where marine communities are declining provides an indication of ecosystems of concern and highlights potential conflicts between seafood provisioning from wild fisheries and other ecosystem services. Here we use the nonparametric statistic, Kendall׳s tau, to assess trends in biomass of exploited marine species across a range of ecosystems. The proportion of ‘Non-Declining Exploited Species’ (NDES) is compared among ecosystems and to three community-level indicators that provide a gauge of the ability of a marine ecosystem to function both in provisioning and as a regulating service: survey-based mean trophic level,...

3. Nickel isotope fractionation during tropical weathering of ultramafic rocks - Ratie, G.; Jouvin, D.; Garnier, J.; Rouxel, Olivier; Miska, S.; Guimaraes, E.; Cruz Veira, L.; Sivry, Y.; Zelano, I.; Montarges Pelletier, E.; Thil, F.; Quantin, C.
Although Ni isotopes have been shown to be significantly fractionated in terrestrial samples, their use in continental environmental studies has not yet been evaluated. The present study focuses on an ultramafic (UM) massif (Barro Alto, Goias, Brazil) because such areas are naturally rich in Ni. We present developed lateritic weathering profiles. The goal of the study is to evaluate the potential of using Ni isotopes in environmental continental studies by combining its isotopic signature with mineralogy, in order to better understand the geochemical cycling of Ni in UM settings during weathering. As such, Ni isotope values were measured in samples...

4. Fishing for space: Fine-scale multi-sector maritime activities influence fisher location choice - Tidd, Alex N.; Vermard, Youen; Marchal, Paul; Pinnegar, John; Blanchard, Julia L.; Milner-gulland, E. J.
The European Union and other states are moving towards Ecosystem Based Fisheries Management to balance food production and security with wider ecosystem concerns. Fishing is only one of several sectors operating within the ocean environment, competing for renewable and non-renewable resources that overlap in a limited space. Other sectors include marine mining, energy generation, recreation, transport and conservation. Trade-offs of these competing sectors are already part of the process but attempts to detail how the seas are being utilised have been primarily based on compilations of data on human activity at large spatial scales. Advances including satellite and shipping automatic...

5. Histopathological assessment of liver and gonad pathology in continental slope fish from the northeast Atlantic Ocean - Feist, S. W.; Stentiford, G.d.; Kent, M. L.; Ribeiro Santos, Ana; Lorance, Pascal
The deep-sea environment is a sink for a wide variety of contaminants including heavy metals and organic compounds of anthropogenic origin. Life history traits of many deep-water fish species including longevity and high trophic position may predispose them to contaminant exposure and subsequent induction of pathological changes, including tumour formation. The lack of evidence for this hypothesis prompted this investigation in order to provide data on the presence of pathological changes in the liver and gonads of several deep-water fish species. Fish were obtained from the north east region of the Bay of Biscay (north east Atlantic Ocean) by trawling...

6. Etude des interactions hôte/virus chez l’huître creuse Crassostrea gigas et son virus Ostreid herpesvirus 1 - Segarra, Amelie
Ostreid herpesvirus type 1 (OsHV-1) can be considered one of the major infectious agents in Pacific oysters, Crassostrea gigas, in France and all around the world. Differences in terms of mortality among infected animals were reported suggesting a genetic basis of the susceptibility to the OsHV-1 infection. In this context, the main objective of this thesis was to understand the interactions between Pacific oysters and OsHV-1, in particular, the molecular basis of the viral cycle. Results showed that the virus is able to replicate in the host regardless of its stage of development or its susceptibility. However, multiplication kinetics is...

7. Identifying marine pelagic ecosystem management objectives and indicators - Trenkel, Verena; Hintzen, Niels T.; Farnsworth, Keith D.; Olesen, Christian; Reid, David; Rindorf, Anna; Shephard, Samuel; Dickey-collas, Mark
International policy frameworks such as the Common Fisheries Policy and the European Marine Strategy Framework Directive define high-level strategic goals for marine ecosystems. Strategic goals are addressed via general and operational management objectives. To add credibility and legitimacy to the development of objectives, for this study stakeholders explored intermediate level ecological, economic and social management objectives for Northeast Atlantic pelagic ecosystems. Stakeholder workshops were undertaken with participants being free to identify objectives based on their own insights and needs. Overall 26 objectives were proposed, with 58% agreement in proposed objectives between two workshops. Based on published evidence for pressure-state links,...

8. A comparative study of marine litter on the seafloor of coastal areas in the Eastern Mediterranean and Black Seas - Ioakeimidis, C.; Zeri, C.; Kaberi, H.; Galatchi, M.; Antoniadis, K.; Streftaris, N.; Galgani, Francois; Papathanassiou, E.; Papatheodorou, G.
In the present work, abundance, spatial distribution and qualitative composition, of benthic marine litter, were investigated in five study areas from the Eastern Mediterranean and Black Seas (Saronikos, Patras and Echinades Gulfs; Limassol Gulf; Constanta Bay). Surveys were performed using the monitoring protocol proposed by the Technical Group for Marine Litter. Densities ranged from 24 items/km(2) to 1211 items/km(2), with the Saronikos Gulf being the most affected area. Plastics were predominant in all study areas ranging from 45.2% to 95%. Metals and Glass/Ceramics reached maximum values of 21.9% and of 22.4%. The size distribution of litter items showed that >=...

9. From egg production to recruits: connectivity and inter-annual variability in the recruitment patterns of European anchovy in the northwestern Mediterranean - Ospina-alvarez, Andres; Catalan, Ignacio A.; Bernal, Miguel; Roos, David; Palomera, Isabel
We show the application of a Spatially-Explicit Individual-Based Model (SEIBM) to understand the recruitment process of European anchovy. The SEIBM is applied to simulate the effects of inter-annual variability in parental population spawning behavior and intensity, and ocean dynamics, on the dispersal of eggs and larvae from the spawning area in the Gulf of Lions (GoL) towards the coastal nursery areas in the GoL and Catalan Sea (northwestern Mediterranean Sea). For each of seven years (2003-2009), we initialize the SEIBM with the real positions of anchovy eggs during the spawning peak, from an acoustics-derived eggs production model. We analyze the...

10. Relationships among fisheries exploitation, environmental conditions, and ecological indicators across a series of marine ecosystems - Fu, Caihong; Large, Scott; Knight, Ben; Richardson, Anthony J.; Bundy, Alida; Reygondeau, Gabriel; Boldt, Jennifer; Van Der Meeren, Gro I.; Torres, Maria A.; Sobrino, Ignacio; Auber, Arnaud; Travers-trolet, Morgane; Piroddi, Chiara; Diallo, Ibrahima; Jouffre, Didier; Mendes, Hugo; Borges, Maria Fatima; Lynam, Christopher P.; Coll, Marta; Shannon, Lynne J.; Shin, Yunne-jai
Understanding how external pressures impact ecosystem structure and functioning is essential for ecosystem-based approaches to fisheries management. We quantified the relative effects of fisheries exploitation and environmental conditions on ecological indicators derived from two different data sources, fisheries catch data (catch-based) and fisheries independent survey data (survey-based) for 12 marine ecosystems using a partial least squares path modeling approach (PLS-PM). We linked these ecological indicators to the total biomass of the ecosystem. Although the effects of exploitation and environmental conditions differed across the ecosystems, some general results can be drawn from the comparative approach. Interestingly, the PLS-PM analyses showed that...

11. Let's go beyond taxonomy in diet description: testing a trait-based approach to prey-predator relationships - Spitz, Jerome; Ridoux, Vincent; Brind'Amour, Anik
1. Understanding ‘Why a prey is a prey for a given predator?’ can be facilitated through trait-based approaches that identify linkages between prey and predator morphological and ecological characteristics and highlight key functions involved in prey selection. 2. Enhanced understanding of the functional relationships between predators and their prey is now essential to go beyond the traditional taxonomic framework of dietary studies and to improve our knowledge of ecosystem functioning for wildlife conservation and management. 3. We test the relevance of a three-matrix approach in foraging ecology among a marine mammal community in the northeast Atlantic to identify the key functional...

12. EquiMar. Deliverable D2.2. Wave and tidal resource characterisation - Venugopal, Vengatesan; Davey, Thomas; Smith, Helen; Smith, George; Holmes, Brian; Barrett, Sean; Prevosto, Marc; Maisondieu, Christophe; Cavalieri, Luigi; Bertotti, Luciana; Lawrence, John; Girard, Francoise
This report gives guidance relevant to the resource assessment of sites considered for the deployment of wave and tidal energy converters. Areas considered include: instrumentation and measurement; techniques and requirements for wave and tidal parameterisation; wave-current interaction; spatial and temporal variation. A number of case studies are also included examining several European sites.

13. Geomorphological classification in Bay of Biscay. Morpho-sedimentary mapping of the seabed in selected areas - De Chambure, Laurent; Bourillet, Jean-francois; Bartel, Claire
Les coraux d’eau froide, contrairement aux coraux tropicaux, n’ont pas besoin de lumière et peuvent se développer en profondeur. Les espèces constructrices comme Lophelia pertusa et Madrepora occulata ont une distribution mondiale et sont présentes de la Norvège à la Grèce sous forme de monts carbonatés ou de récifs. Menacés par l’évolution des conditions environnementales et les actions anthropiques, les coraux d’eau froide sont actuellement classés comme écosystème vulnérable par plusieurs institutions internationales. Dans les eaux européennes, les indicateurs pour mesurer l’impact des pêcheries et l’efficacité des mesures de protection manquent encore. Le projet européen CoralFish vise à étudier l’interaction...

14. Genetic structure of the reef grouper Epinephelus merra in the West Indian Ocean appears congruent with biogeographic and oceanographic boundaries - Muths, Delphine; Tessier, Emmanuel; Bourjea, Jerome
The reef fauna connectivity of the West Indian Ocean (WIO) is one of the least studied globally. Here we use genetic analyses of the grouper Epinephelus merra (Bloch 1793) to determine patterns of connectivity and to identify barriers to dispersal in this WIO marine area. Phylogeographic and population-level analyses were conducted on cytochrome b sequences and microsatellites (13 loci) from 557 individuals sampled in 15 localities distributed across the West Indian Ocean. Additional samples from the Pacific Ocean were used to benchmark the WIO population structure. The high level of divergence revealed between Indian and Pacific localities (of about 4.5%...

15. Introduction to the BASIN Special Issue: State of art, past present a view to the future - St John, M. A.; Barange, M.; Benway, H.; Flynn, K. J.; Holt, J.; Merino, G.; Martin, A.; Mitra, A.; Melle, W.; Sanders, R.; Trenkel, Verena M.; Grigorov, I.; Hoffman, E.

16. Eruption of a deep-sea mud volcano triggers rapid sediment movement - Feseker, Tomas; Boetius, Antje; Wenzhofer, Frank; Blandin, Jerome; Olu, Karine; Yoerger, Dana R.; Camilli, Richard; German, Christopher R.; De Beer, Dirk
Submarine mud volcanoes are important sources of methane to the water column. However, the temporal variability of their mud and methane emissions is unknown. Methane emissions were previously proposed to result from a dynamic equilibrium between upward migration and consumption at the seabed by methane-consuming microbes. Here we show non-steady-state situations of vigorous mud movement that are revealed through variations in fluid flow, seabed temperature and seafloor bathymetry. Time series data for pressure, temperature, pH and seafloor photography were collected over 431 days using a benthic observatory at the active Hakon Mosby Mud Volcano. We documented 25 pulses of hot...

17. Coriolis data centre. Annual report 2014 - Carval, Thierry; Bernard, Vincent; Bonnat, Armel; Coatanoan, Christine; Detoc, Jerome; Gatti, Julie; Maronny, Jean-paul; Petit De La Villeon, Loic

18. Investigating the coupling between small pelagic fish and marine top predators using data collected from ecosystem-based surveys - Certain, G.; Masse, Jacques; Van Canneyt, O.; Petitgas, Pierre; Doremus, G.; Santos, M. B.; Ridoux, Vincent
The present study is a general multivariate analysis of the spatial association between small pelagic fishes and their predators (seabirds, marine mammals and fisheries), using 6 yr (18000 km) of transects surveyed in spring in the Bay of Biscay, France. We describe 4 groups of prey-predator association, with explicit distinction of prey size: (1) terns and anchovies (10 to 15 cm), (2) common dolphins, common murres, sprat and sardine (<20 cm), (3) gannets, horse mackerel and mackerel (15 to 25 cm) and (4) bottlenose dolphin, horse mackerel and mackerel (25 to 40 cm). Our analysis also illustrates the great variability...

19. Scallop larval survival from erythromycin treated broodstock after conditioning without sediment - Holbach, Marine; Robert, Rene; Boudry, Pierre; Petton, Bruno; Archambault, Philippe; Tremblay, Rejean
Pathogenic bacteria are known to be one of the main factors affecting Pecten maximus larval survival in hatcheries. As a result, juvenile production often relies on the use of antibiotics during larval culture. However, limitations of the usage of chemicals such as chloramphenicol in aquaculture have been reinforced due to their negative environmental impact and alternatives are accordingly needed. Thus, the importance of bacterial transfer from oocytes to larvae has been studied here as well as procedures to limit larval mortality in P. maximus. In order to reduce bacterial contamination during larval development, we focused on two periods, broodstock conditioning...

20. Assessment of oocyte and trochophore quality in Pacific oyster, Crassostrea gigas - Boulais, Myrina; Corporeau, Charlotte; Huvet, Arnaud; Bernard, Ismael; Quere, Claudie; Quillien, Virgile; Fabioux, Caroline; Suquet, Marc
Pacific oyster hatchery production remains highly variable, partially due to inconsistent gamete quality. However, little attention has been paid to oocyte quality in Pacific oyster compared to important vertebrate aquaculture species such as fishes. The aims of the present study were to identify criteria of oocyte and trochophore quality used as predictive tools for embryo developmental success at the D-larval stage. Twenty-six potential proxies of oocyte and trochophore quality were studied on 25 mature females, as determined using histology. Some morphological and biochemical characteristics of mature oocytes were described. Protein appeared to be the main constituent of fully mature Pacific...

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