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Aquaculture is one of the most prosperous economic sectors. Nevertheless, the natural outbreaks of several infectious diseases make the sector to deal with important economic losses. One of the most important pathogens in the Mediterranean Sea is nodavirus (NNV). NNV is the agent causing viral encephalopathy and retinopathy in more than 170 fish species including some of the most impact in Spanish hatcheries as European sea bass (Dicentrarchus labrax). Antimicrobial peptides (AMPs) are short aminoacidic sequences which constitute important mediators of the innate immune response in teleost fish. AMPs can kill directly a broad range of pathogens such as bacteria or viruses and modulate the host immune response leading to a more effective clearance of pathogens. These properties along with the world emergency in antimicrobial resistance (AMR) make AMPs good candidates to replace traditional antimicrobials. Therefore, we aimed to analyze the molecular regulation of European sea bass defensin beta genes upon NNV infection and after NNV vaccination. To achieve our objective, European sea bass were infected with NNV and samples of head-kidney (HK), brain and gonad were taken. In addition, gonadal cells from healthy males were in vitro stimulated with NNV. Then, ovary samples of control females or vaccinated against NNV (pBAD vaccine) were taken, as well as fertilized eggs and larvae from the same groups. To support our data, we also analyzed in silico the potential antiviral activity of the protein encoded by the studied genes. Our results show that defensin beta 1 gene is up-regulated upon in vivo NNV infection even if in the in silico study showed the lesser predicted activity. Interestingly, the in vitro NNV challenge resulted in no variation of the defensin beta 1 gene, while defensin beta 2.1 and 2.2 genes were blocked upon this stimulus. Strikingly, females vaccinated with pBAD greatly down-regulate defensin beta 2.2 expression. Moreover, larvae from vaccinated mother up-regulate all defensin beta genes. In conclusion, defensin beta 1 gene seems to be involved in the defense against viruses while defensin beta 2 genes appear to possess a more specific function in gonad. Evaluación de los efectos de las microalgas, incluidas en dietas de dorada, sobre el crecimiento, supervivencia y resistencia a infecciones. ALGAFISH

International audience; This preliminary study explored the capture potential of the Marquesan Islands for fish larvae, especially endemic species, with the set up of light traps on either offshore site or coastal site between January and March 2012. Among the 323 fish larvae belonging to 29 captured species, 151 fish larvae belonging to five species were endemic. Light traps captured more endemic larvae in coastal site than in offshore sites. Overall, this study allows to better understand larval supply of endemic fish species in an isolated region such as the Marquesan Islands.

The present study aims to evaluate differences in the incorporation efficiency and the possible interactions among highly unsaturated fatty acids (HUFA) during enrichment and starvation of Artemia nauplii. Artemia franciscana nauplii were enriched with emulsions containing docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) or arachidonic acid (AA, 20:4n-6) as sole HUFA or with different ratios of these HUFA during 24 h at 28°C and subsequently starved for 24 h at the same temperature. The comparison of HUFA incorporation efficiency when supplying the three HUFA separately showed a less efficient enrichment of DHA as compared to AA or EPA. DHA incorporation was always accompanied by an EPA increase, indicating the metabolic conversion of DHA to EPA by the nauplii during the enrichment process. When offering the HUFA together, we found no competitive interaction of EPA or of AA on DHA incorporation. Only in the case of the 97% (% total fatty acids) n-3 HUFA emulsion, some negative interference might have occurred between the HUFA, as it gave a lower incorporation of 22:6n-3 and 20:5n-3 than the emulsions with lower n-3 HUFA content. During the subsequent starvation of EPA- or DHA-enriched Artemia, relative EPA and DHA losses were similarly high in both treatments. In contrast, the presence of DHA in naupliar lipids increased the EPA retention, which might however be related to DHA retroconversion.

Evaluer, maintenir et restaurer les conditions écologiques des rivières nécessitent des mesures du fonctionnement de leurs écosystèmes. De par leur complexité, notre compréhension de ces systèmes est imparfaite. La prise en compte des incertitudes et variabilités liées à leur évaluation est donc indispensable à la prise de décision des gestionnaires. En analysant des données nationales (~ 1654 sites), les objectifs principaux de cette thèse étaient de (1) tester certaines hypothèses intrinsèques aux bio-indicateurs et (2) d'étudier les incertitudes de l'évaluation écologique associées à la variabilité temporelle des bio-indicateurs et à la prédiction des conditions de référence. (1) Ce travail met en évidence (i) le rôle prépondérant des facteurs environnementaux naturels dans la structuration des communautés aquatiques en comparaison des facteurs anthropiques (définis à l'échelle du bassin versant, du corridor riparien et du tronçon), (ii) les réponses contrastées des communautés aquatiques aux pressions humaines (dégradations hydro-morphologiques et de la qualité de l'eau) et (iii) plus généralement, les forts impacts des barrages et de l'altération de la qualité de l'eau sur les communautés aquatiques. (2) Une méthode Bayésienne a été développée pour estimer les incertitudes liées à la prédiction des conditions de référence d'un indice piscicole (IPR+). Les incertitudes prédictives de l'IPR+ dépendent du site considéré mais aucune tendance claire n'a été observée. Par comparaison, la variabilité temporelle de l'IPR+ est plus faible et semble augmenter avec l'intensité des perturbations anthropiques. Les résultats de ce travail confirment l'avantage d'indices multi-métriques basés sur des traits fonctionnels par rapport à ceux relatifs à la composition taxonomique. Les sensibilités différentes des macrophytes, poissons, diatomées et macro-invertébrés aux pressions humaines soulignent leur complémentarité pour l'évaluation des écosystèmes fluviaux. Néanmoins, de futures recherches sont nécessaires à une meilleure compréhension des effets d'interactions entre types de pressions et entre pressions humaines et environnement. Sensitive biological measures of ecosystem quality are needed to assess, maintain or restore the ecological conditions of rivers. Since our understanding of these complex systems is imperfect, river management requires recognizing variability and uncertainty of bio-assessment for decision-making. Based on the analysis of national data sets (~ 1654 sites), the main goals of this work were (1) to test some of the assumptions that shape bio-indicators and (2) address the temporal variability and the uncertainty associated to prediction of reference conditions.(1) This thesis highlights (i) the predominant role of physiographic factors in shaping biological communities in comparison to human pressures (defined at catchment, riparian corridor and reach scales), (ii) the differences in the responses of biological indicators to the different types of human pressures (water quality, hydrological, morphological degradations) and (iii) more generally, the greatest biological impacts of water quality alterations and impoundments. (2) A Bayesian method was developed to estimate the uncertainty associated with reference condition predictions of a fish-based bio-indicator (IPR+). IPR+ predictive uncertainty was site-dependent but showed no clear trend related to the environmental gradient. By comparison, IPR+ temporal variability was lower and sensitive to an increase of human pressure intensity. This work confirmed the advantages of multi-metric indexes based on functional metrics in comparison to compositional metrics. The different sensitivities of macrophytes, fish, diatoms and macroinvertebrates to human pressures emphasize their complementarity in assessing river ecosystems. Nevertheless, future research is needed to better understand the effects of interactions between pressures and between pressures and the environment.

International audience; Eurofl eets is a key research infrastructure, essential for collecting in situ marine data sets from global oceans, regional seas and coastal waters. Research vessels carry and operate shipborne observation equipment and facilitate deployment and handling of a large range of observing and sampling instruments. The infrastructure is also evolving, with fixed ocean seafl oor observation and mobile surface and subsea autonomous technologies presenting challenges to the existing fl eet to deploy and maintain. Meeting the complex end user needs of European scientists across disciplines and geographic locations is an expensive and complex exercise requiring coordination at national and international levels, and the use of common standards and approaches. To meet the expected challenges, Eurofl eets+ (An alliance of European marine research infrastructure to meet the evolving needs of the research and industrial communities) project is undertaking Joint Research Activities (JRA) with key industry partners. Specifi cally, the objective of JRA 3.2 led by CSIC, with the Marine Institute and industry partners Hampidjan, MacArtney AS and SEAONICS is the study and conceptual development of equipment for deep sea operations from research vessels co-designed by research and industry partners.Improving interoperability of Large Exchangeable Instrumentation (LEXI) is a primary aim of Eurofl eets+, especially in terms of improvement and standardisation of tools/rigging for more effi cient operations.The collaborative approach aims to develop a new deep-sea winch design, a multipurpose crane/handling system for deep water operations and a dual mode handling system designed for the deployment and recovery of research tools through moon-pools or/and over the side.

A nested ice flow model was developed for eastern Dronning Maud Land to assist with the dating and interpretation of the EDML deep ice core. The model consists of a high-resolution higher-order ice dynamic flow model that was nested into a comprehensive 3-D thermomechanical model of the whole Antarctic ice sheet. As the drill site is on a flank position the calculations specifically take into account the effects of horizontal advection as deeper ice in the core originated from higher inland. First the regional velocity field and ice sheet geometry is obtained from a forward experiment over the last 8 glacial cycles. The result is subsequently employed in a Lagrangian backtracing algorithm to provide particle paths back to their time and place of deposition. The procedure directly yields the depth-age distribution, surface conditions at particle origin, and a suite of relevant parameters such as initial annual layer thickness. This paper discusses the method and the main results of the experiment, including the ice core chronology, the non-climatic corrections needed to extract the climatic part of the signal, and the thinning function. The focus is on the upper 89% of the ice core (appr. 170 kyears) as the dating below that is increasingly less robust owing to the unknown value of the geothermal heat flux. It is found that the temperature biases resulting from variations of surface elevation are up to half of the magnitude of the climatic changes themselves.

Dans le monde entier les introductions d'espèces dans de nouvelles régions constituent une préoccupation écologique croissante ; ces introductions peuvent conduire à des modifications drastiques des écosystèmes, entre autres du fait de la compétition avec des espèces indigènes et également par la modification des réseaux de flux d'énergie dans les écosystèmes. La moule verte Perna viridis est une espèce récemment introduite dans les eaux côtières américaines et qui s'est rapidement disséminée le long des côtes du Sud-Est des États-Unis. Cependant, il n'existe pour le moment que très peu d'informations concernant la structure des populations, et leur dynamique en réponse à la variabilité environnementale locale. Les efflorescences de marées rouges formées par le dinoflagellé toxique Karenia brevis sont fréquentes le long des côtes de Floride bordant le Golfe du Mexique, et la tolérance de P. viridis a l'égard de ces événements et des brévitoxines (PbTx) associées n'est pas connue. En outre, comme P. viridis est une espèce invasive, la potentielle concurrence (ressources trophiques, espace, ...) avec des bivalves indigènes comme l'huître Crassostrea virginica, est une préoccupation majeure dans les systèmes côtiers de Floride. Cette étude vise à caractériser la dynamique des populations établies de P. viridis populations établies et leur réponse aux efflorescences naturelles de K. brevis. Les effets des efflorescences à K. brevis ont été évalués à partir des résultats d'un suivi de la croissance, de la mortalité, du recrutement, de la gamétogenèse et de la composition biochimique des tissus (protéines, glycogène et lipides) durant trois ans. En outre, les concentrations en PbTx dans les tissus ont été analysées afin de déterminer l'absorption, l'accumulation et des taux d'élimination de ces toxines. Par ailleurs, les données recueillies sur le terrain et des informations de la littérature ont été utilisées pour élaborer un modèle énergétique individuel DEB pour modéliser la croissance et la reproduction de P. viridis. Avant l'apparition de la première efflorescence à K. brevis, P. viridis présentait des taux de croissance rapide (6-11 mm mois-1) et un taux de survie élevé (mortalité <1%). Au cours des efflorescences à K. brevis, le taux de croissance a chuté de façon significative et une bioaccumulation de PbTx dans les tissus mous a été observée. Les concentration élevées en PbTx dans les tissus ont persisté longtemps après la dissipation de l'efflorescence et les taux de mortalité élevés se sont maintenus, ce qui a réduit fortement l'abondance de P. viridis. À la fin de l'efflorescence, la concentration en PbTx dans les moules était presque le double de celle relevée chez l'huître indigène Crassostrea virginica pour des individus prélevés à la même période ; chez P. viridis, la concentration en PbTx est restée supérieure à la limite réglementaire pour la consommation humaine pendant 16 semaine, alors qu'elle est revenue en dessous de ce seuil en 2 1⁄2 semaines chez C. virginica. La composition biochimique des tissus et la reproduction n'ont pas parues affectées par ces évènements ; P. viridis réalise sa gamétogénèse durant toute l'année et a mis en place une stratégie de ponte intermittente partielle ; elle présentait durant toute l'année une grande stabilité de la concentration en composés de réserve. L'absence de cycle saisonnier marqué de la composition biochimique suggère que la ressource trophique est suffisante pour soutenir la gamétogenèse tout au long de l'année. Cependant, la première année du suivi, deux évènement majeurs de ponte et de recrutement ont été observés au printemps et à l'automne. Au cours de la deuxième année de suivi, l'analyse histologique montre que le même patron de ponte massive est observé au printemps ; cependant, à cette période, les efflorescences toxiques ont persisté et le recrutement a été inhibé, ce qui suggère que la fécondation et / ou le développement et la survie des larves ont été affectés par la présence de K. brevis et des ichthyotoxines et hémolysines associées. Ces résultats indiquent que même si des concentrations tissulaires élevées en PbTx peuvent réduire la croissance de P. viridis, la gamétogenèse n'est elle pas inhibée, ce qui permet à la population de moule verte de subsister, même si la mortalité individuelle était élevée. Les concentrations élevées et persistantes en PbTx dans les tissus peuvent augmenter le risque de transfert trophique longtemps après les efflorescences, ce qui pourrait avoir des répercussions négatives sur d'autres pêcheries importantes, en plus des conséquences sur la chaîne alimentaire. Même s'il ne peut pas être établi avec certitude que la réduction de la croissance, de la survie et du recrutement sont bien dus aux marées rouges, nos observations suggèrent que K. brevis est un facteur important dans les changements radicaux observés de la structure et de la dynamique de la population de P. viridis. Le présent travail a permis, à partir d'un suivi pluri-annuel, de caractériser la dynamique des populations de P. viridis établies localement. En outre, le développement d'un modèle mécaniste de bioénergétique (DEB) a permi d'établir des prévisions sur la croissance et la reproduction de la moule verte à partir d'un forçage par les conditions environnementales. Ce travail a permis de synthétiser nos connaissances sur P. viridis et aide à comprendre la dynamique de la population et les potentialités de l'espèce pour entrer en concurrence avec les populations de l'huître locales C. virginica.  Worldwide, introductions of exotic species to new regions is of rising concern which can lead to catastrophic ecosystem alterations through competition with native species and disruption in energy flow. Perna viridis is a recently introduced bivalve species to US coastal waters and has vigorously spread throughout the southeastern US. However, little information regarding population structure and response to local environmental factors has been reported. Red tide blooms formed by the toxic dinoflagellate Karenia brevis are frequent along the Gulf coast of Florida and as a recently introduced species, it is unclear what tolerance P. viridis has toward these events and associated brevetoxins (PbTx). Further, as an invasive species ecological concerns have risen regarding potential for spread and competition with native bivalve species, particularly the eastern oyster Crassostrea virginica. This study aimed to characterize the population dynamics of established P. viridis populations and their response to naturally occurring K. brevis blooms. This was completed through monitoring of growth, mortality, juvenile recruitment, gametogenesis and biochemical composition (protein, glycogen and lipid) throughout a three year monitoring period to evaluate the effects of K. brevis blooms. Additionally, tissue PbTx concentrations were analyzed to determine uptake, accumulation and elimination rates. Data collected from the field and information reported in the literature were used to create a functional DEB model to predict individual growth and reproduction of P. viridis under environmentally realistic conditions. Prior to onset of the first K. brevis bloom event, P. viridis showed rapid growth rates (6 – 11 mm month-1) and high survival (mortality <1%). However, during K. brevis blooms growth rate dropped significantly and bioaccumulation of PbTx in the soft tissue was observed. High tissue PbTx concentrations persisted long after bloom dissipation and high rates of mortality ensued, severely reducing population densities. PbTx in mussels nearly doubled that of oysters sampled during the same time and remained above the regulatory limit for significantly longer, 2 1⁄2 weeks and 16 weeks, respectively. Biochemical composition and reproduction appeared unaffected, exhibiting year round gametogenesis with a partial, intermittent spawning strategy and stability in reserves. A lack of significant seasonal cycles in biochemical composition suggests sufficient food and energy availability to support the observed year round gametogenesis. While continuous spawning capabilities were evident two major peaks in spawning and recruitment were observed (spring and fall), suggesting reduced fertilization and / or larval development and survival due to the presence of K. brevis and associated ichthyotoxins and hemolysins. These results indicate that while high tissue PbTx concentrations may lead to reduced growth in P. viridis, gametogenesis is not inhibited, allowing the population to survive K. brevis bloom exposure and reproduce, even while individual mortality was high. Prolonged bioconcentration of PbTx may lead to increased threat of post bloom trophic transfer, resulting in negative impacts on other important fisheries and higher food web implications. While it cannot be conclusively determined that the cause of reduced growth, survival and recruitment is due to red tide events, the parallels observed suggest that K. brevis is an important factor in the drastic changes in population structure. Through the work presented here, population dynamics of locally established P. viridis populations were characterized through monthly monitoring and the development of a DEB model to accurately predict the growth and reproduction under dynamic environmental conditions. This work aims to synthesize our knowledge on the individual bioenergetics of P. viridis and to aid in understand population dynamics and potential for competition with local C. virginica populations

Spectral albedo in high resolution, from 290 to 1050 nm, has been measured at Neumayer, Antarctica, (70&deg;39' S, 8&deg;15' W) during the austral summer 2003/2004. At 500 nm, the spectral albedo nearly reaches unity, with slightly lower values below and above 500 nm. Above 600 nm, the spectral albedo decreases to values between 0.45 and 0.75 at 1000 nm. For one cloudless case an albedo up to 1.01 at 500 nm could be determined. This can be explained by the larger directional component of the snow reflectivity for direct incidence, combined with a slightly mislevelled sensor and the snow surface not being perfectly horizontal. A possible explanation for an observed decline in albedo is an increase in snow grain size. The theoretically predicted increase in albedo with increasing solar zenith angle (SZA) could not be observed. This is explained by the small range of SZA during albedo measurements, combined with the effect of changing snow conditions outweighing the effect of changing SZA. The measured spectral albedo serves as input for radiative transfer models, describing radiation conditions in Antarctica.

The Tambaqui (Colossoma macropomum) transcriptome at sex differentiation stage. 11. International Symposium on Reproductive Physiology of Fish

Ce chapitre aborde la responsabilité civile dans les cas de déversement d'hydrocarbures dans la mer provenant de navires pétroliers et des installations offshore au Brésil. Nous analyserons la légalité des dommages punitifs accordés par les tribunaux brésiliens en plus des dommages-intérêts compensatoires. Abstract: This paper addresses civil liability for offshore oil spills caused by oil tankers and offshore facilities in Brazil. It will analyse the legality of punitive damages awarded by Brazilian courts in addition to compensatory damages.