Use of Lagrangian simulations to hindcast the geographical position of propagule release zones in a Mediterranean coastal fish

The study of organism dispersal is fundamental for elucidating patterns of connectivity between populations, thus crucial for the design of effective protection and management strategies. This is especially challenging in the case of coastal fish, for which information on egg release zones (i.e. spawning grounds) is often lacking. Here we assessed the putative location of egg release zones of the saddled sea bream (Oblada melanura) along the south-eastern coast of Spain in 2013. To this aim, we hindcasted propagule (egg and larva) dispersal using Lagrangian simulations, fed with species-specific information on early life history traits (ELTs), with two approaches: 1) back-tracking and 2) comparing settler distribution obtained from simulations to the analogous distribution resulting from otolith chemical analysis. Simulations were also used to assess which factors contributed the most to dispersal distances. Back-tracking simulations indicated that both the northern sector of the Murcia region and some traits of the North-African coast were hydrodynamically suitable to generate and drive the supply of larvae recorded along the coast of Murcia in 2013. With the second approach, based on the correlation between simulation outputs and field results (otolith chemical analysis), we found that the oceanographic characteristics of the study area could have determined the pattern of settler distribution recorded with otolith analysis in 2013 and inferred the geographical position of main O. melanura spawning grounds along the coast. Dispersal distance was found to be significantly affected by the geographical position of propagule release zones. The combination of methods used was the first attempt to assess the geographical position of propagule release zones in the Mediterranean Sea for O. melanura, and can represent a valuable approach for elucidating dispersal and connectivity patterns in other coastal species

Spatial genetic structure in the saddled sea bream (Oblada melanura [Linnaeus, 1758]) suggests multi-scaled patterns of connectivity between protected and unprotected areas in the Western Mediterranean Sea

Marine protected areas (MPAs) and networks of MPAs are advocated worldwide for the achievement of marine conservation objectives. Although the knowledge about population connectivity is considered fundamental for the optimal design of MPAs and networks, the amount of information available for the Mediterranean Sea is currently scarce. We investigated the genetic structure of the saddled sea bream ( Oblada melanura) and the level of genetic connectivity between protected and unprotected locations, using a set of 11 microsatellite loci. Spatial patterns of population differentiation were assessed locally (50-100 km) and regionally (500-1000 km), considering three MPAs of the Western Mediterranean Sea. All values of genetic differentiation between locations (Fst and Jost's D) were non-significant after Bonferroni correction, indicating that, at a relatively small spatial scale, protected locations were in general well connected with non-protected ones. On the other hand, at the regional scale, discriminant analysis of principal components revealed the presence of a subtle pattern of genetic heterogeneity that reflects the geography and the main oceanographic features (currents and barriers) of the study area. This genetic pattern could be a consequence of different processes acting at different spatial and temporal scales among which the presence of admixed populations, large population sizes and species dispersal capacity, could play a major role. These outcomes can have important implications for the conservation biology and fishery management of the saddled sea bream and provide useful information for genetic population studies of other coastal fishes in the Western Mediterranean Sea

Simulation numerique directe du transfert de matiere autour d'unegoutte dans un liquide immiscible

International audienceÀ partir du diagramme empirique de Clift et des propriétés physico-chimiques du système d'extraction considéré dans l'étude, la forme de la goutte est supposée sphérique dans un premier temps. A partir de simulations numériques directes, l'effet de paramètres physiques clés (tels que le rapport de viscosité entre la goutte et la phase continue, le rapport de densité, le coefficient de distribution du soluté, etc.) et de la nature de l’écoulement sur la physique du problème est étudié et analysé

Considérations sur l’étiologie du « raide » des Agneaux à la mamelle

Charton André. Considérations sur l’étiologie du «raide» des Agneaux à la mamelle. In: Bulletin de l'Académie Vétérinaire de France tome 108 n°6, 1955. pp. 239-246

Quotas regulation is necessary but not sufficient to mitigate the impact of SCUBA diving in a highly visited marine protected area

When effectively managed, Marine Protected Areas (MPAs) can produce wide ecosystem benefits that can foster, directly and indirectly, local economies. Tourism is one of the sectors mainly benefited by the effect of conservation. SCUBA diving represents an important tourism activity, especially in the context of MPAs, where it is one of the few activities often fostered rather than limited, for its capacity to integrate environmental and socio-economic sustainability. However, SCUBA diving can also produce negative impacts on the environment when tourism frequentation exceeds a sustainable threshold, these potentially generating negative effects on the sector itself. In this study, we (1) investigated the impact of SCUBA diving in one of the most frequented diving areas of the Mediterranean Sea (Cabo de Palos - Islas Hormigas marine reserve), and (2) assessed the potential benefits over time related to the adoption of a regulation change for the diving activity (i.e., formally adoption of diving quotas). Specifically, we compared demographic (density of alive and dead colonies) and morphometric (height, width and complexity) characteristics of the false coral (Myriapora truncata) between dived and fully protected (non-dived) locations over four diving seasons (one before and three after the change in diving quotas). The density of alive colonies of the false coral was, on average, six times lower in dived locations compared to controls, highlighting a clear impact of SCUBA diving (consistent over time). Colonies were also significantly smaller in dived locations. The diving quotas produced a significant reduction of the ratio dead/total colonies in the dived locations soon after their adoption, but these benefits disappeared over the following years, possibly due to a gradual decline in operators' and divers' observance and concern, rather than an increasing number of dives. This suggests that the adoption of effective regulations is crucial for the environmental sustainability of diving tourism in protected areas and can provide positive effects, but an effort is needed to ensure that compliance is consistent over time, and that low-impact diving practices are adopted by this important recreational sector

Taux moyen et variance des séromucoïdes totaux chez la brebis normale, au cours d’un « cycle d’élevage »

Charton André, Faye P., Hervy A. Taux moyen et variance des séromucoïdes totaux chez la Brebis normale, au cours d’un «Cycle d’élevage ». In: Bulletin de l'Académie Vétérinaire de France tome 119 n°6, 1966. pp. 225-228

Identification, au microscope électronique, d'un Myxovirus isolé d’une lésion de pneumonie du veau

Berkaloff A., Faye P., Charton André. Identification, au microscope électronique, d’un Myxovirus isolé d’une lésion de pneumonie du veau. In: Bulletin de l'Académie Vétérinaire de France tome 118 n°5, 1965. pp. 201-207

Séromucoïdes : variations de taux chez l’agneau en fonction de l’âge

8 fois plus élevé que celui de l’adulte dans les heures qui suivent la naissance, le taux des séromucoïdes de l’agneau, très largement fluctuant, décroît rapidement dès les premiers jours ; il n’est plus qu’une fois et demie supérieur au taux de l’adulte à la fin de la première semaine. Il ne rejoint cependant ce dernier, en se stabilisant, que vers 4 mois

A probable giant planet imaged in the Beta Pictoris disk

Since the discovery of its dusty disk in 1984, Beta Pictoris has become the prototype of young early-type planetary systems, and there are now various indications that a massive Jovian planet is orbiting the star at ~ 10 AU. However, no planets have been detected around this star so far. Our goal was to investigate the close environment of Beta Pic, searching for planetary companion(s). Deep adaptive-optics L'-band images of Beta Pic were recorded using the NaCo instrument at the Very Large Telescope. A faint point-like signal is detected at a projected distance of ~ 8 AU from the star, within the North-East side of the dust disk. Various tests were made to rule out with a good confidence level possible instrumental or atmospheric artifacts. The probability of a foreground or background contaminant is extremely low, based in addition on the analysis of previous deep Hubble Space Telescope images. The object L'=11.2 apparent magnitude would indicate a typical temperature of ~1500 K and a mass of ~ 8 Jovian masses. If confirmed, it could explain the main morphological and dynamical peculiarities of the Beta Pic system. The present detection is unique among A-stars by the proximity of the resolved planet to its parent star. Its closeness and location inside the Beta Pic disk suggest a formation process by core accretion or disk instabilities rather than a binary-like formation process.Comment: 5 pages, 3 figures, 1 table. A&A Letters, in pres

Présence, dans le sérum d’Ovins, d’anticorps inhibant l’hémagglutination par Myxovirus parainfluenzae

Dans un lot composé de trente brebis et de leurs agneaux, la pro portion des sujets dont le sérum inhibe, à des titres élevés de dilu tion, l’hémagglutination des érythrocytes de cobaye par une souche bovine de Myxovirus parainfluenzae dépasse 80 p. 100. Les résultats obtenus, en inhibition d’hémagglutination et en séro neutralisation, avec la fraction globulinique du sérum précipitable par le sulfate d’ammoniaque, sont quantitativement plus faibles, mais qualita tivement analogues