Analyse de la dispersion larvaire des poissons récifaux à la Réunion à travers l'étude de leurs otolithes

L'objectif principal de cette étude est d'apporter des informations sur la phase dispersive des larves des poissons récifaux à La Réunion, sujet fondamental afin d'appréhender les connectivités possibles entre les îles d'une même région. Les secrets de cette phase dispersive peu connue seront recherchés via l'étude des otolithes des poissons. Les propriétés particulières des otolithes confèrent des applications qui seront utilisées dans le cadre de ce travail : discriminateur de stocks via des analyses de forme (analyse de Fourier), horloge chronologique via la lecture des stries de croissance, et marqueur environnemental via des analyses microchimiques (éléments-traces, isotopes). Quatre espèces ichtyologiques d'intérêt commercial ont été choisies : Epinephleus merra (Serranidae), Mulloidichthys flavolineatus (Mullidae), Gnathodentex aurolineatus (Lethrinidae) et Lutjanus kasmira (Lutjanidae). Les paramètres de la vie larvaire des espèces étudiées dans ce travail leur confèrent la capacité d'établir des connectivités entre La Réunion et d'autres îles de l'Océan Indien (Maurice, Rodrigues, Madagascar). Néanmoins, dans un contexte hydrodynamique normal, et en associant d'autres facteurs (isolement géographique de l'île, faible flux larvaire, effet d'île sur la côte ouest, croissances larvaires élevées), l'hypothèse d'un auto-recrutement est favorisée. Ces résultats sont à prendre en compte dans la gestion durable de ces populations ichtyques vulnérables, à La RéunionThis objective of the present study, is to give informations about the oceanic larval phase of the coral reef fishes in Reunion Island. This knowledge is fundamental in grasping the potential interrelationships between islands of the same region applied to the reef fish of Reunion Island. The secrets of this little-known dispersive phase are explored through the study of fish otoliths. The particular properties of otoliths enable the various applications that have been used in the framework of this study: as discriminators of stocks via analysis of form (Fourier analysis), as chronological clocks via microchemical analysis (trace elements, isotopes). Four ichtyological and commercial species were chosen: Epinephelus merra (Serranidae), Mulloidichthys flavolineatus (Mullidae), Gnathodentex aurolineatus (Lethrinidae) and Lutjanus kasmira (Lutjanidae). In this study, the larval parameters of these species endows them with the capacity of establishing interconnections between Reunion Island and others islands in the Indian Ocean (Mauritius, Rodrigues, Madagascar). Nevertheless, given a normal hydrodynamic context, and in associating others factors (geographic isolation of Reunion, weak larval flux, effect of the island's in the west coast, elevated larval growth), the hypothesis of auto-recruitment is favored. These results should be taken into account in the management of the halieutic vulnerable resources of the coral reefs of Reunion IslandSAINT DENIS/REUNION-Droit Lettre (974112101) / SudocBANYULS/MER-Observ.Océanol. (660162201) / SudocPARIS-Museum-Bib. d'ichtyologie (751052306) / SudocPARIS-Museum Hist.Naturelle (751052304) / SudocSudocFranceReunionFRR

PECHTRAD 2014 - Description et analyse des données de pêches traditionnelles à pied sur les platiers récifaux de la Réserve Nationale Marine de La Réunion.

This study aimed to build two databases, the first on the historic effort and catches of the traditional small-scale fisheries from 1999 till 2014, and the second one on the traditional management of fishing licenses. The first database allows for a synthetic analysis of the results obtained on the fishing activities of beach-seine, fishing rod and on octopuses, in terms of effort and catch per area and year. Technical and scientific supports were supplied implementing survey protocols and supervision of a student, both within the framework of the small-scale traditional fisheries. The study supported traditional fishermen with the mediation process for regulation revisions for the fishing activities in the MPA areas.Les travaux confiés par le GIP RNMR à l’IFREMER DOI en 2014 ont permis la constitution de deux bases de données, l’une sur les suivis historiques d’effort de pêche et de capture des « pêches traditionnelles » acquises de 1999 à 2014 et l’autre sur la gestion des cartes de pêche traditionnelle. Une analyse synthétique des résultats obtenus sur l’évolution des activités de pêche au capucin nain à la senne de plage, à la gaulette et au zourite, en termes d’efforts de pêche et de captures sur les secteurs étudiés chaque année, a été réalisé selon une approche indicateurs. Un soutien technique et scientifique a été apporté pour la mise en place des protocoles d’enquête et l’encadrement de stagiaire, dans le cadre du suivi de la pêche traditionnelle, ainsi que l’accompagnement scientifique dans le processus de médiation avec les pêcheurs traditionnels sur les projets d'évolution de la réglementation en matière de pêche sur le secteur de la Réserve Marine

Monitoring coastal uses of the Marine Reserve of La Reunion using aerial surveys, Reunion Island, France, West Indian Ocean.: Outdoor Recreation in Change – Current Knowledge and Future Challenges

International audienc

Élaboration d’un protocole de suivi de la fréquentation au sein de la Réserve naturelle marine de la Réunion, France, Océan Indien

National audienceCréée en 2007, La Réserve Naturelle Marine de La Réunion (RNMR) vise à préserver un récif frangeant qui s’étend sur près d’une quarantaine de kilomètres de linéaire côtier sur la façade occidentale de l’île. Rendue fortement attractive par ses nombreux atouts balnéaires, cette côte a été en proie à une urbanisation croissante au cours des dernières décennies. De façon concomitante, l’accroissement de la fréquentation et l’apparition de nouvelles pratiques nautiques ont alimenté la source potentielle d’impacts sur le milieu, ainsi que les risques de conflits. En vue d’apporter un meilleur éclairage sur ces problématiques et parce que la mesure de l’efficacité d’une AMP ne peut désormais plus se cantonner aux seuls indicateurs biologiques du milieu, une vaste campagne nationale visant à développer un cadre méthodologique commun de mesure de la fréquentation maritime a été initiée (Agence des Aires Marines Protégées). C’est dans ce contexte et par le biais de cette étude que la RNMR se pourvoit dès 2010 d’un cadre méthodologique et opérationnel de suivi de la fréquentation afin de développer et d’intégrer à leurs plans de gestion des indicateurs socio-économiques qui serviront, entre autres, à mesurer l’efficacité de la gestion. Entre janvier et juillet 2010, pas moins de 10 catégories d’usages dont les activités de baignade, plage, sports de glisse et pêche ont fait l’objet d’un suivi depuis un Ultra-Léger-Motorisé et à l’aide d’un appareil photographique. 48 vols ont été répartis sur cette période selon une stratification temporelle pré-établie (Été/Hiver, Vacances/Périodes scolaires, semaine/week-end et matin/Après-midi). Les données ont été intégrées à une Base d’Information Géographique offrant un arsenal d’outils d’analyse spatiale et statistique. Les premiers résultats font état d’une « fréquentation différentielle » dans le temps et l’espace, dont les pics peuvent atteindre près de 10 000 usagers. La moitié des usagers reste concentrée sur une faible portion du linéaire côtier équivalente à 8 % de la longueur totale de la réserve et se répartit sur 4 principaux sites (Boucan-Canot, l’Ermitage, la Saline et Etang-Salé) qui s’avèrent être les plus pourvus en aménités (dépressions d’arrière-récif, sable corallien) et en aménagements (stationnements, bars, maîtres-nageurs sauveteurs). En outre, le protocole de suivi de la fréquentation de la RNMR présente de nombreuses potentialités en termes de gestion et de capitalisation scientifique, lesquelles sont présentées en discussion

Élaboration d’un protocole de suivi de la fréquentation au sein de la Réserve naturelle marine de la Réunion, France, Océan Indien

The Natural Marine Reserve of La Reunion (RNMR) was established in 2007 along a weakened fringing reef which extends over forty kilometers along the western coast. These last decades, this latter was submitted to a rapid and dense urbanization, namely due to its attractive seaside assets. Simultaneously, increasing coastal activity and emergence of new practices put new issues forward, such as potential impacts on the environment, and potential conflicts that may occur. Besides, Marine Protected Areas (MPAs) effectiveness cannot longer be evaluated from biological markers only, and socio-economical parameters tend to be taken into account by high national bodies (French Agency for MPA) and managers during management plan development. From 2010, a vast French national campaign was launched to assess socio-economical needs in terms of markers, and to develop a common methodological framework for marine and coastal uses monitoring. Through this study, the RNMR equipped themselves with a methodological and operational framework for uses monitoring in order to develop and integrate markers to their management plans, permitting the measurement of management effectiveness. Between January and July 2010, 14 uses including swimming, beach going, water sports and fishing have been monitored using an ultra-light aircraft and a camera .48 flights were planned over this period according to a temporal stratification (Summer/Winter, Holidays/School days, week/weekend and morning/afternoon). Data were integrated to a Geographic Information Base offering a range of spatial analysis and statistics tools. Results show a heterogeneous users distribution in time and space which peaks can reach nearly 10,000 users. Half of users remains concentrated on a small portion of the coastline equivalent to 8% of the total coastal length of 44 kilometers and spread over four main sites (Boucan-Canot, Ermitage, La Saline and Etang-Salé) which correspond to the sites the most equipped with amenities (coral-free swimming areas, coral sand) and services (parks, bars, lifeguards). In addition, this uses’ monitoring protocol has many potentialities in terms of management and scientific accumulation of learning outcomes, which are set forth in discussion

A comparative study of the accuracy and effectiveness of Line and Point Intercept Transect methods for coral reef monitoring in the southwestern Indian Ocean islands

International audienceCoral reefs around the world are facing increasing disturbance; however, the ability to monitor them is constrained by cost and experience factors. The Line Intercept Transect (LIT) method is usually used with an expert level of identification (30 benthic categories and sometimes coral genera), but these are time-consuming, require a high level of expertise and are therefore expensive. Over the last 20 years, surveys performed by non-specialist volunteers have provided data for increasing numbers of reefs, using simplified sampling methods and more basic levels of identification. In between these extremes, new stakeholders (e.g. environmental assessment agencies, consultancy firms, marine nature reserves, etc.) requiring an intermediate level of expertise and resolution are now carrying out coral reef surveys. Across all levels, it is desirable to identify monitoring methods that optimize the data provided and the ease of implementation according to the users’ needs. In this study on surveys from Réunion Island collected between 2003 and 2013, we used multivariate analyses to compare four increasing levels of identification using the LIT method. For each level, we studied the structure of the benthic community and its spatial (reef flat vs. outer slope) and temporal (before vs. after a cyclone) variation. The most basic level of identification showed differences between the reef flat and outer slope, but did not show a significant effect of the cyclone on the benthic community. The two highest levels of identification, both of which we rated ‘expert’, showed the highest differences in variation. The intermediate level of identification supplied the same information as the expert levels, but required less effort and was therefore less expensive. Next, we compared the LIT with the Point Intercept Transect (PIT) method. At a level of identification appropriate to the interval used, PIT supplied an almost equivalent level of information as LIT, while reducing the time spent underwater. Thus, when managing coastal areas or carrying out impact studies to monitor disturbance, it may be useful to (i) perform surveys with an intermediate level of identification, and (ii) using PIT rather LIT

Políticas públicas de juventude : interfaces entre educação e formação profissional alguns apontamentos também sobre o programa de privação de liberdade

Este trabalho é o resultado de um processo de reflexões e estudos, desencadeado há mais de uma década a partir de minhas práticas profissionais e pesquisas acadêmicas sobre as políticas públicas como possibilidades de inserção social para a juventude brasileira desfavoreci da socioeconomicamente. A intenção de sistematizar a produção própria vem desde a atuação junto ao Programa Agent e Jovem de Desenvolvimento Social e Humano, na condição de Educadora Social, passando pela assessoria aos empreendimentos de Economia Popular Solidária, à Fundação de Atendimento Sócio- Educativo (FASE), e ainda pela prática docente da educação básica e técnica. De forma mais específica, revisitar esses estudos e práticas, complementando- os com a revisão bibliográfica de outras autorias, foi a estratégia metodológica que encontrei para f ocar as interfaces entre os aspectos educacionais e os da formação profissional em programas sociais para os jovens. Pela recorrência da práxis entre ação e reflexão no âmbito dessas políticas e pela relevância social do tema, que é cada vez mais atual, entendo ser razoável continuar problematizando. Também por se tratar de elemento fundamental no mosaico que constitui o processo de inserção social de jovens beneficiários das políticas públicas, com idade considerada pelas normativas trabalhistas como a fase de referência para a aprendizagem e iniciação profissional. Aborda ainda entraves à inserção social, como baixa escolaridade e precariedade na oferta de qualificação profissional, para aqueles que estiveram ou estão privados de liberdade por determinação judicial. Com efeito, cabe questionar em que medi da o Est ado vem cumprindo o que lhe é pressuposto junto às políticas sociais. Constatar as fragilidades dos programas que poderiam prevenir a vi a delituosa desses sujeitos e outorgar-lhes cidadania, como está constatado neste e em outros estudos, não seria um bom começo para propor estratégias de enfrentamento? Em que pese tratar-se de um segmento populacional que representa uma grande oportunidade para o país, também pelo seu volume numérico, o preconceito faz com que sejam vistos como problema, criando barreiras para o desenvolvimento pleno do seu potencial. Nesse sentido, o estudo é também propositivo quanto às alternativas para o enfrentamento das questões que são aqui abordadas e que afetam a vida desse segmento populacional que carece da ajuda do Estado.This work is the result of a process of reflection and study, initiated more than a decade from my professional practice and academic research on public policy and social inclusion opportunities for socioeconomically disadvantaged Brazilian youth. The aim of systematizing the production itself comes from the performance in the Young Agent Program for Social and Human Development, provided Social Educator, through assistance to enterprises of Popular Solidarity Economy, the Foundation for Social-Education ( FASE), and further the activities as a teacher of basic and technical education. More specifically, to revisit these studies and practices, complemented with a literature review, the methodological tools that were found to focus on the interfaces between the educational aspects of vocational training and social programs for youth. For the recurrence of praxis between action and reflection within these policies, I believe it is reasonable to continue questioning the subject, even by its social relevance that is more current. It should be clarified that this study restricts the sociohistorical aspects of the working world and t hose in the educational setting that points to emerge as a key element of the mosaic that constitutes the process of social inclusion of young beneficiaries of public policies, with age considered by regulations such as labor phase reference for learning and professional initiation. It also addresses barriers to social inclusion, such as low education and job insecurity in the provision of professional qualification for those who were or are deprived of t heir liberty by court order. Indeed, one must question t he extent to which the Stat e has complied with the assumption that it is close to social policies. See the weaknesses of the programs that could prevent these subjects through criminal and grant them citizenship, as is seen in this and other studies, there would be a good start t o propose coping strategies? Despite that this is a population segment that represents a great opportunity for the country, also by volume number, the bi as causes t hem to be seen as a problem by creating barriers to the full development potential. In this sense, the study is also purposeful about the alternatives for dealing with issues that are addressed here and that affect the lives of this population segment that needs the help of state

Negative sea level anomalies with extreme low tides in the South-West Indian Ocean shape Reunion Island’s fringing coral reef flats

Among induced mass-mortality events on coral reef, extreme low tides may ultimately lead to considerable reef community deaths on intertidal reef flats due to unusually long and significant aerial exposure. Here, we report an extensive coral mortality event induced by a negative sea level anomaly (nSLA) that occurred across Reunion Island during the austral winter season between June and October 2015 preceding the 2015–2016 El Niño Southern Oscillation (ENSO) event. The nSLA was strong and long in duration with a rapid drop of 35 cm in the mean sea level over a one-month period. Surveys conducted over seven reef flat sites before and after the nSLA revealed that mean coral cover drastically decreased from 54.5 ± 12.7% in early 2015, to 27.4 ± 6.9% in November 2015, which is an equivalent cover loss of 50% following the 2015 nSLA event. The shallowest sites showed a greater decrease in coral cover while the deepest parts of the reef flat remained unaffected. We found a significant correlation between the bathymetry and the relative coral cover variation. Using this relationship between depth and coral cover changes, high-resolution hyperspectral imagery and Lidar bathymetric airborne data, we mapped the impacts of this event at the scale of the whole reef. Overall the modeled loss reached 13.0 ha, which represents a decrease of 45.5% of all live coral cover in this area during the 2015 nSLA event. The impact of a nSLA on emersion times is much greater than the regular variation in tide amplitude between neap and spring tides, reaching new bathymetric ranges that are usually stable in terms of water submersion. Temporal variation of coral cover on Reunion Island reef flat revealed regular decreases to be compared with mean low-water-level events among other sea and climatic related disturbances and stressors

Fascicule technique pour la mise en œuvre du suivi "Benthos de substrats durs" du contrôle de surveillance DCE à La Réunion

Contractualisation Ifremer/Office de l'eau Réunion. Synthèse collective des travaux menés dans le cadre des Groupes de travail DCE de La Réunion réunissant des experts de l'Université de La Réunion (Lab. ECOMAR), de l'IRD de La Réunion, de l'ARVAM, de PARETO, du GIP RNMR et de la DEAL Réunion sous la coordination de la Délégation Ifremer océan Indien. Comment citer ce document : GT DCE Réunion "Benthos de Substrat Durs". 2014. Fascicule technique pour la mise en oeuvre du suivi "Benthos de Substrats Durs " du réseau de contrôle de surveillance DCE à La Réunion.Convention Ifremer/Office de l'Eau Réunion n° 14/1211501/FDe 2010 à 2012, le projet " Bon Etat : Actualisation de l’état des lieux du SDAGE, volet eaux côtières réunionnaises " (DEAL de La Réunion/Ifremer) a permis la mise en place de 4 groupes de travail DCE experts dont les travaux ont été synthétisés à travers 4 fascicules techniques définissant les conditions de mise en œuvre des différents suivis du réseau de contrôle de la surveillance (RCS) DCE en milieu marin à la Réunion. Une première version du fascicule "Benthos de substrats durs", a été produite en 2012 et validée au niveau national par les référents DCE (Cellule REBENT de l'Ifremer, Coordination nationale DCE milieu Marin, responsable projet Quadrige). Une mise à jour a été proposée en 2014 (Office de l'eau Réunion/Ifremer) dans la double perspective des recommandations nationales (GT MNHN/ONEMA) et de la programmation en 2015 de la première campagne de suivi "benthos de substrats durs" à La Réunion. Ce fascicule a vocation à constituer le support technique des méthodes et des référentiels pour la réalisation du suivi "benthos de substrats durs" du RCS DCE à La Réunion. Il précise les protocoles de prélèvement, d’analyse, de bancarisation, de synthèse et de diffusion des données. Il présente l’indicateur proposé à La Réunion pour les pentes externes des zones récifales, indicateur basé sur l'étude des données historiques, la connaissance des récifs réunionnais et approuvé par les experts locaux