Éditeur(s) : HAL CCSD Ecological Society of America
Résumé : Reliable assessment of fish origin is of critical importance for exploited species, since nursery areas must be identified and protected to maintain recruitment to the adult stock. During the last two decades, otolith chemical signatures (or "fingerprints") have been increasingly used as tools to discriminate between coastal habitats. However, correct assessment of fish origin from otolith fingerprints depends on various environmental and methodological parameters, including the choice of the statistical method used to assign fish to unknown origin. Among the available methods of classification, Linear Discriminant Analysis (LDA) is the most frequently used, although it assumes data are multivariate normal with homogeneous within-group dispersions, conditions that are not always met by otolith chemical data, even after transformation. Other less constrained classification methods are available, but there is a current lack of comparative analysis in applications to otolith microchemistry. Here, we assessed stock identification accuracy for four classification methods (LDA, Quadratic Discriminant Analysis [QDA], Random Forests [RF], and Artificial Neural Networks [ANN]), through the use of three distinct data sets. In each case, all possible combinations of chemical elements were examined to identify the elements to be used for optimal accuracy in fish assignment to their actual origin. Our study shows that accuracy differs according to the model and the number of elements considered. Best combinations did not include all the elements measured, and it was not possible to define an ad hoc multielement combination for accurate site discrimination. Among all the models tested, RF and ANN performed best, especially for complex data sets (e. g., with numerous fish species and/or chemical elements involved). However, for these data, RF was less time-consuming and more interpretable than ANN, and far more efficient and less demanding in terms of assumptions than LDA or QDA. Therefore, when LDA and QDA assumptions cannot be reached, the use of machine learning methods, such as RF, should be preferred for stock assessment and nursery identification based on otolith microchemistry, especially when data set include multispecific otolith signatures and/or many chemical elements.
ISSN: 1051-0761

hal-00644549
https://hal.archives-ouvertes.fr/hal-00644549
DOI : 10.1890/09-1887.1

Éditeur(s) : Ecole Nationale Supérieure Agronomique de Rennes
Résumé : Long-line fishing has been growing on the island of La Réunion since the beginning of the 1990s. The target species is the swordfish (Xiphias gladius), fished mainly in the tropical waters surrounding the island between longitudes 45 degree E and 60 degree E, and latitudes 17 degree S and 27 degree S. From 1998 to 2000, a finalised research programme enabled the collection of precise data concerning the lines' positions and the parameters of the fishing efforts: 3,602 nettings were thus informed by the catches (in numbers of individuals caught) and 12 descriptive variables of the effort. In parallel with this collection effort, satellite maps that described the ocean's landscape of this region of the Indian Ocean exploited by La Réunion's fisheries were made available to sailors and scientists. Extractions from these environmental variables were made at the fishing lines' positions, which allowed us to propose 20 variables describing the environmental conditions of swordfish catches applied to the nettings. In an early part of this study, after a descriptive analysis and a first selection of the variables, we used several GAM (Generalised Additive Models) to model the respective effects of effort and environmental variables on the variability of swordfish catches. We thus highlighted the predominance of factors linked to fishermen (fishing effort) on oceanographic factors in the explanation of this variability. Following these results, a summary on the biology and ecology of the swordfish was proposed in order to draw up hypotheses on the characteristics of this species' population in the Indian Ocean. The aspects linked to the individual behaviour and movements of the population were particularly highlighted. In a latter part of this study and in order to complete the empirical approach by an exploratory constructivist approach, we proposed a modelling tool in order to simulate the possible movements of individuals within the oceanic landscape described by the available satellite maps. After reading in the literature about the various forms of modelling the movements of the large pelagics, we developed an original computer modelling architecture of the multi-agent type that made it possible to manipulate in a dynamic way the satellite maps (and derived products), the individual movements of "animats" whose behaviours were based on this environmental information, and agents that clarify the process of long-line fishing in a geographical way. The computer model that was implemented (MUFINS, for MUlti-Fish INdian ocean Simulator) was next used by calibrating the behaviour of the animats on the real data originally from the analysis of commercial catches proposed in the first part, using robust techniques based on fuzzy logic. The results of the simulations were compared, on the one hand, with the large-scale hypotheses of movement proposed in the first part, and, on the other hand, to swordfish catches both real and corrected for the effect of the fishing effort modelled by the GAM models. Even if the results of these simulations in this study do not allow for proposing convincing interpretations of the underlying processes, the MUFINS tool showed its ability to address questions associated with the swordfish's behaviour in the tropical oceanic landscape and to the effects of scale transfers between the individual level and the collective level. We now envisage its use in a more operational framework, as an interface for dialogue between fishermen and scientists with a goal of sustainable management of the resource.
La peche palangriere s'est developpee a l'ile de La Reunion depuis le debut des annees 1990. L'espece cible est l'espadon (Xiphias gladius), principalement exploite dans les eaux tropicales autour de l'ile entre les longitudes 45 degree E et 60 degree E, et les latitudes 17 degree S et 27 degree S. De 1998 a 2000, un programme de recherche finalisee a permis de collecter des informations precises concernant les positions des lignes et les parametres de l'effort de peche : 3602 filages sont ainsi renseignes par les captures (en nombre d'individus captures) et 12 variables descriptives de l'effort. En parallele de cet effort de collecte, des cartes satellitales ont pu etre mises a la disposition des marins et des scientifiques, decrivant le paysage oceanique de cette region de l'ocean Indien exploitee par la pecherie reunionnaise. Des extractions de ces variables environnementales ont ete effectuees aux positions des lignes de peche, nous permettant de proposer 20 variables descriptives des conditions environnementales de captures d'espadon appliquees aux filages. Dans une premiere partie de ce travail, apres une analyse descriptive et une premiere selection des variables, on a modelise par plusieurs modeles GAM (Generalized Additive Models) les effets respectifs des variables d'effort et des variables environnementales sur la variabilite des captures d'espadon. On a ainsi mis en evidence la predominance des facteurs lies aux pecheurs (effort de peche) sur les facteurs oceanographiques dans le caractere explicatif de cette variabilite. A la suite de ces resultats, une synthese sur la biologie et l'ecologie de l'espadon a ete proposee afin de degager des hypotheses sur les caracteristiques de la population de cette espece dans l'ocean Indien. Les aspects lies au comportement individuel et aux deplacements de la population ont ete particulierement mis en evidence. Dans une deuxieme partie de ce travail et afin de completer l'approche empirique par une approche constructiviste exploratoire, nous avons propose un outil de modelisation afin de simuler les deplacements possibles d'individus au sein du paysage oceanique decrit par les cartes satellitales disponibles. Apres avoir passe en revue dans la litterature les differentes formes de modelisation des deplacements des grands, pelagiques, nous avons developpe une architecture originale de modelisation informatique de type multi-agents permettant de manipuler de maniere dynamique les cartes satellitales (et les produits derives), les mouvements individuels < d'animats >, dont les comportements sont bases sur cette information environnementale, et des agents qui explicitent le processus de capture palangriere de maniere geographique. Le modele informatique ainsi implemente (MUFINS, pour MUlti-Fish INdian ocean Simulator) a ensuite ete utilise en calibrant les comportements des animats sur les donnees reelles issues de l'analyse des captures commerciales proposee en premiere partie, a partir de techniques robustes basee sur la logique floue. Les resultats des simulations ont ete confrontes d'une part aux hypotheses de deplacement a grande echelle proposees en premiere partie, et d'autre part aux captures d'espadon reelles et corrigees de l'effet de l'effort de peche modelise par les modeles GAM. Meme si les resultats de simulations presentes dans ce travail ne permettent pas de proposer d'interpretations convaincantes des processus sous-jacents, l'outil MUFINS a demontre son aptitude a aborder les questions liees au comportement de l'espadon dans le paysage oceanique tropical et aux effets des transferts d'echelle entre le niveau individuel et le niveau collectif. On envisage desormais son utilisation dans un cadre plus operationnel, comme interface de dialogue entre les pecheurs et les scientifiques a des fins de gestion durable de la ressource.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2005/these-2592.pdf
http://archimer.ifremer.fr/doc/00000/2592/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 15-19 octobre 1999
Résumé : The Mediterranean small-scale fleet is highly adaptive, showing a dynamic fishing intensity and strategy, and exploiting seasonal abundant resources. In this area, the aggregatory behaviour under floats of juvenile fish has been used since ancient times to exploit oceanic migratory species such as dolphinfish (Coryphaena hippurus), using Fish Aggregating anchored Devices (fads). A total of 2 300 boats are engaged in this fishery from August to December, the main fishing areas being those around Malta, Tunisia, Sicily and Majorca. The fads ( arrow right m2) are made of different cheap floating materials, and are moored in fixed places, ranging from shore waters to areas 60 miles off the coast (1 500 m depth). Each boat deploys an average of 20 to 100 fads. The gears used are special surrounding nets without purse line, and traditional purse seine nets. The fishery exploits young-of-the-year dolphinfish (<6 months old), originated by a pre-spawning migration of adults from Atlantic waters. Their catches show high annual and monthly variability, depending on the recruitment and the accessibility of recruits to the fishery. Pilotfish (Naucrates ductor) and greater amberjack (Seriola dumerili) are also exploited in this fishery as by-catch. A total of about 1 000 metric tons of dolphinfish are yearly caught mainly in September-October. The fads are historically laid in August. Recently, the fads fishing period has increased in Sicily, and the fads are laid in July, so as to catch pilotfish and greater amberjak juveniles. In recent years, the interest for this fishing method and the study of these fisheries has increased in the Mediterranean. Though the market and its seasonality limit this exploitation, this fishery is economically profitable with good revenue.

Droits : Ifremer
http://archimer.ifremer.fr/doc/00042/15286/12672.pdf
http://archimer.ifremer.fr/doc/00042/15286/

Résumé : Traditionally fished by line and conical fishing basket by Venezuelan ships, the red snapper resource off the coast of French Guyana (fish belonging to the Lutjanidae family) has been experiencing intensive fishing since 1984-85 due to the boom in classic fishing techniques and the development of trawl fishing. The study evaluates the situation of this resource's potential: biology, sampling data, bio-statistics (size and sex), size-weight relationship of the three species, specific composition of the catches, describes fishing devices and prospecting, pinpoints fishing spots, gives a distribution of the Venezuelan and Martinique fishing effort.
Traditionnellement exploitée à la ligne à main et à la nasse par les navires vénézuéliens, la ressource en vivaneaux au large de la Guyane française (poissons appartenant à la famille des Lutjanidae) subit depuis 1984-85 une exploitation intense par l'accroissement des techniques de pêche classiques et le développement d'une pêcherie au chalut. L'étude fait le point sur les potentialités de cette ressource : biologie, données de l'échantillonnage, bio-statistique (taille et sexes), relation taille-poids des 3 espèces, composition spécifique des captures, décrit les engins de pêche et prospection, localise les lieux de pêche, donne une répartition de l'effort de pêche vénézuélien et chalutier martiniquais.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1986/rapport-2646.pdf
http://archimer.ifremer.fr/doc/00000/2646/

Éditeur(s) : Société des sciences naturelles de la Charente-Maritime
Résumé : During 1975, a number of rare fishes or caught out of their distr:ibution area were observed in La Rochelle, especially Chlamycloselachus anguineus Garman, 1884 (one specimen) Mitsukurina sp. (three specimens), Pseudotriakis microdon Capello, 1868 (five specimens), Somniosus sp. (one specimen), probably a new species, Zenopsis cO/1chîfer (Lowe, 1852) (one specimen) recorded for the first time from the French Atlantic coast, Puntazzo puntazzo (Gmelin, 1789) (one specimen), Hyperoglyphe percifonnîs (Mitchill, 1818) (one specimen), Glyptocephalus cynoglossus (Linné, 1758) (one specimen) caught off the coast of Vendée and Lima11da limanda (Linné, 1758) (one specimen) caught off the coast of Landes. On the other hand, the authors found two albino fishes and five specimens remarkable for their large size. They also observed nine species of fishes from the Bay of Biscay belonging to a colder fauna and eight species of fishes from the Bay of Biscay belonging to a hotter fauna. Not controlled OCR
En 1975, les auteurs ont observé à la Rochelle un certain nombre de poissons «rares» ou capturés en dehors de leur aire de répartition et plus particulièrement un exemplaire de Chlamycloselachus anguineus Garman, 1884, trois exemplaires de Mitsukurina sp., cinq exemplaires de Pseuclotriakis microdon Capello, 1868, un exemplaire de Somniosus sp., cette espèce étant probablement nouvelle, un exemplaire de Zenopsis conchifer (Lowe, 1852) signalé pour la première fois au large des côtes françaises de l'Atlantique, un exemplaire de Puntazzo plmtazzo (Gmelin, 1789), un exemplaire d'Hyperoglyphe percîformis (Mitchill, 1818), un exemplaire de Glyptocephalus cynoglossus (Linné, 1758) pêché au large de la Vendée et un exemplaire de Limanda limanda (Linné, 1758) pris au large de la côte des Landes. D'autre part, ils ont observé deux cas d'albinisme ainsi que cinq exemplaires remarquables par leur grande taille. Ils ont aussi noté la présence dans le golfe de Gascogne de neuf espèces de poissons appartenant à une faune plus froide et de huit à une faune plus chaude. OCR non contrôlé
Annales de la Société des Sciences Naturelles de la Charente-Maritime (Société des sciences naturelles de la Charente-Maritime), 1976 , Vol. 6 , N. 3 , P. 177-190

Droits : 1976 Société des sciences naturelles de la Charente-Maritime
http://archimer.ifremer.fr/doc/1976/publication-3645.pdf
http://archimer.ifremer.fr/doc/00000/3645/

Éditeur(s) : Natl Acad Sciences
Résumé : Most marine organisms disperse via ocean currents as larvae, so it is often assumed that larval-stage duration is the primary determinant of geographic range size. However, empirical tests of this relationship have yielded mixed results, and alternative hypotheses have rarely been considered. Here we assess the relative influence of adult and larval-traits on geographic range size using a global dataset encompassing 590 species of tropical reef fishes in 47 families, the largest compilation of such data to date for any marine group. We analyze this database using linear mixed-effect models to control for phylogeny and geographical limits on range size. Our analysis indicates that three adult traits likely to affect the capacity of new colonizers to survive and establish reproductive populations (body size, schooling behavior, and nocturnal activity) are equal or better predictors of geographic range size than pelagic larval duration. We conclude that adult life-history traits that affect the postdispersal persistence of new populations are primary determinants of successful range extension and, consequently, of geographic range size among tropical reef fishes.
Proceedings Of The National Academy Of Sciences Of The United States Of America (0027-8424) (Natl Acad Sciences), 2013-10 , Vol. 110 , N. 41 , P. 16498-16502

Droits : Freely available online through the PNAS open access option.
http://archimer.ifremer.fr/doc/00161/27240/25457.pdf
DOI:10.1073/pnas.1304074110
http://archimer.ifremer.fr/doc/00161/27240/

Résumé : The management of marine fish stocks has stayed non-spatial, considering spatial distributions and their consequences on demography as implicit. But the impacts of climate change and the anthropisation of habitats now require to consider spatial procedures explicitly. The work presented here starts with the question of evaluating population abundance, which requires the modelling of spatial distributions (section 1). Then an ecological understanding of the multi-scale nature of distributions is investigated (section 2). Last, we study how demographic population dynamics depends on the spatial organisation of life cycles (section 3). In this work, the approach has been to combine data acquisition at sea with statistical characterisation and modelling. The application of geostatistics to fisheries survey data provided a solution to abundance evaluation and mapping for many different survey designs. A variety of models were implemented (stationary, non-stationary, non-linear, multivariate, spatio-temporal), depending on the statistical characteristics of the data and the problem posed. Sampling bias were identified by combining different survey methods. New procedures for assessing stocks based on indicators including spatial ones were developed, which prepared for ecosystem assessments. (...)
La gestion des stocks de poissons marins est longtemps restée a-spatiale, considérant implicites les mécanismes d’organisation spatiale qui soutiennent la distribution géographique des ressources et leur dynamique démographique. Mais l’impact du changement climatique et l’anthropisation des habitats nécessitent d’en tenir compte explicitement. Partant de questions d’évaluation qui ont nécessité la modélisation des distributions spatiales (section 1), le déterminisme écologique de ces distributions a ensuite été abordé à différentes échelles (section 2) puis ont été envisagées les conséquences de l’organisation spatiale sur la dynamique démographique des populations (section 3). L’approche scientifique suivie intègre l’acquisition de données à la mer, la caractérisation statistique et la modélisation. L’application de la géostatistique aux données des campagnes halieutiques permet de proposer une solution à l’estimation d’abondance et la cartographie pour une variété de plans d’échantillonnage. Différents modèles sont mis en oeuvre (stationnaires, non-stationnaires, non-linéaires, multivariés, spatio-temporels) en fonction du comportement des données et du problème posé. Des biais d’échantillonnage sont identifiés en combinant différentes méthodes d’échantillonnage. Des procédures nouvelles d’évaluation de stocks à partir d’indicateurs dont des indicateurs spatiaux sont développées, qui préparent à l’évaluation des écosystèmes. (...)

Droits : Ifremer, UPMC
http://archimer.ifremer.fr/doc/00013/12410/9197.pdf
http://archimer.ifremer.fr/doc/00013/12410/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Installation and maintenance of FADs by the Government of Guam began in 1979, initially with funding from the Salstonstall-Kennedy Act through the Pacific Tuna Development Foundation. Current funding for the Guam FAD project is provided through the Dingell-Johnson/Wallop-Breaux Sport Fish Restoration programme, a Federal Aid Project funded by taxes collected on the purchase of fishing equipment and motorboat fuels nationwide. There are now sixteen operational FAD sites in Guam's waters. At a cost of approximately US$10,000 per system, concern for the rising costs of replacing and maintaining FAD systems has prompted the Department of Agriculture's Division of Aquatic and Wildlife Resources (DAWR) to investigate alternative FAD maintenance strategies and system design. Several cost-cutting measures being considered include the use of reliable solar-powered navigation lights to reduce the number of maintenance trips required, and switching to a newer generation of lighter, more durable buoys and mooring systems. Average time on station for a dawr fad system is nearing two years. Interestingly, in most cases where an errant system is recovered, the failure in the mooring system was observed to occur at a depth from 35 to 500 metres. These observations have led to speculation that additional protection of the mooring line down to 500 m may result in doubling the average time on station of most FAD systems.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15324/12650.pdf
http://archimer.ifremer.fr/doc/00042/15324/

Résumé : At the request of local correspondents of the statistical system, an internship about fishing vessels was organised. The goal of this internship was to show the diversity, variability and specificity of "passive" (or sleeping) vessels, depending, on the one hand, on the region or the country, and on the other hand, on the researched species. The report's table of contents: General Points Lines and ropes Selectivity Ship Owners' Report Nets Mesh Nets Cast Nets Lift Nets Traps Lines and Hooks Handlines Trolling Lines Longlines FADs Fitting out the Boats Line Haulers Gillneters Lobster Pot Boats Boulters Vessel/Species Compatibility ETS Le Drezen Visit Classification of fishing vessels List of "fishing technology" videos Documents in French about "fishing technology" Ending
A la demande des correspondants locaux du système statistique, un stage sur les engins de pêche a été organisé. Ce stage avait pour but de montrer les diversités, la variabilité et la spécificité des engins "passifs" (ou arts dormants), selon d'une part les régions, ou le pays, et d'autre part les espèces recherchées. Sommaire du rapport : Generalites Fils et cordages Sélectivité Rapport d'armement Les filets Les filets maillants Les filets lances Les filets soulevés Les pièges Les lignes et hameçons Les lignes a main Les lignes de traîne Les palangres Les D.C.P. Les aménagements des bateaux Les vireurs Les fileyeurs Les caseyeurs Les palangriers La compatibilité engin / espece Visite des ETS Le Drezen Classification des engins de pêche Liste des films vidéo en "technologie pêche" Documents en français sur "technologie pêche" Finalites

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1994/rapport-2194.pdf
http://archimer.ifremer.fr/doc/00000/2194/

Résumé : When Henry B. Plant brought the railroad to Tampa in 1884, he opened the door for many businesses to locate and flourish here. The railroad was at the center of the city's economy. From downtown it went to Port Tampa where one could board a Plant steamship to Jamaica, Cuba, New Orleans, Bermuda or other destinations. A spur of the rail line brought the train up to the west front of the hotel so guests could depart the train and walk directly into the lobby. The Tampa Bay Hotel cost approximately 2.5 million dollars to build and $500,000 to furnish. Consisting of 511 rooms, some of which were suites of 3-7 rooms, it provided a degree of luxury never before seen in Tampa. Most of the rooms had their own baths and all had electricity and telephones. In addition, guests were surrounded by a varied collection of furniture, porcelains, Venetian-style mirrors, and sculptures gathered by Mr. and Mrs. Plant in their travels in Europe. The Tampa Bay Hotel opened in 1891 amid wide fanfare and celebration. Henry Plant's dream was now a reality. The newspapers of the day described it as "brightly illuminated, filled with sumptuous decorations, thrilling music and graced with turrets, domes and minarets towering heavenward and glistening in the sun." It was a Victorian palace. The hotel was a lively place with balls, tea parties, and organized hunts during the winter social season. It was open seasonally from December to April in the 1890's. Once a guest arrived at the hotel, he needed to be entertained. Guests went wild game hunting as well as fresh and salt-water fishing. Water sports were also included like sailing, rowing, and canoeing. For the less adventuresome, there were bicycles, carriages, and rickshaws to ride you around the property. The hotel also offered golf, tennis, shuffleboard, billiards, and even a racetrack.
(Funding) Funded in part by the Institute for Museum and Library Services (IMLS), Ephemeral Cities Project.
Tampa |z 1271000 |2 ceeus
Hillsborough County |z 12057 |2 ceeus
United States of America -- Florida -- Hillsborough County -- Tampa

Droits : All rights reserved. 2005.
D29-013

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
This article documents several cases of widespread species, which usually mimic other widespread species throughout the Indo–Pacific, using endemic Marquesan species as a model and displaying endemic mimicry patterns. This discovery adds a new line of evidence to the uniqueness of the Marquesas Islands, which not only host a high number of endemic reef–fish species, but also endemic mimicry patterns.
ISSN: 0022-1112

hal-01338324
http://hal.upmc.fr/hal-01338324
http://hal.upmc.fr/hal-01338324/document
http://hal.upmc.fr/hal-01338324/file/2016_Delrieu%E2%80%90Trottin%20et%20al_When%20endemic.pdf
DOI : 10.1111/jfb.13050

Éditeur(s) : Société franco-japonaise d'océanographie
Résumé : French fishermen have been fishing porbeagle shark Lamna nasus on the edges of the continental shelf, from the Bay of Biscay to the south of Ireland. Incidentally, until the past few years, when, during summer, bluefin tunas Thunnus thynnus, albacores Thunnus alalunga and sworfishes Xiphias gladius were caught on the same line. Since 1970, some fishermen have started focusing on swordfish. The authors describe the technique and gear used for this fishery. A fishery that could largely develop in the years to come.
Les pêcheurs artisans français pêchent depuis une vingtaine d'années le requin sonneur (ou taupe) Lamna nasus sur les accores du plateau continental du Colfe de Gascogne jusqu'au Sud de l'Irlande. Incidemment jusqu'à ces dernières annees, durant l'été, des thons rouges Thunnus thynnus, des germons Thunnus alalunga et des espadons Xiphias gladius étaient capturés A l'aide de cette même palangre. Depuis 1970, quelques pêcheurs commencent à développer un effort de pêche particulier pour la capture de l'espadon. Les auteurs décrivent la technique et les engins de cette pêche qui peut se développer beaucoup plus largement dans les années à venir. [OCR NON CONTRÔLE]
Bulletin de la Société franco-japonaise d'océanographie (Société franco-japonaise d'océanographie), 1972-11 , Vol. 10 , N. 4 , P. 174-177

Droits : Société franco-japonaise d'océanographie
http://archimer.ifremer.fr/doc/1972/publication-5140.pdf
http://archimer.ifremer.fr/doc/00000/5140/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : À quelques kilomètres d’Oran, la zone côtière d’Aïn el Turck connue auparavant pour ses belles plages, a subi depuis quelques décennies une urbanisation incontrôlée touchant essentiellement son domaine public maritime (DPM). Actuellement, sur les parties hautes des plages comme Saint Roch, Paradis, Bouisseville ou Trouville s’alignent des villas de un à deux étages, des garages à bateaux et de grands hôtels. L’empiètement sur ces espaces pourtant protégés par plusieurs lois a participé à l’érosion de la bande sableuse et à la régression de l’activité touristique balnéaire. Une situation qui reflète une nette difficulté dans la gestion et la protection de cet espace convoité et fragile.Notre étude de la zone côtière d’Aïn el Turck va aborder quatre points : la relation entre la « bétonisation » du rivage et le changement du trait de côte, l’évolution de l’urbanisation et les stratégies d’occupations, les types de concurrence qui existent entre différents usagers sur l’appropriation du foncier littoral et enfin, les difficultés éprouvées dans la protection du domaine public maritime par les services gestionnaires. La méthode du travail est basée essentiellement sur deux approches : la première est la comparaison entre plusieurs photos aériennes, à différentes dates, pour l’identification des changements naturels affectant le rivage en relation avec l’évolution de l’urbanisation de la côte. La seconde est la réalisation d’entretiens avec les principaux acteurs du territoire et l’analyse des discours formulés par les différents groupes d’intérêts, souvent en situation de conflit.
A few kilometres from Oran, the coastal area of Ain el Turck previously known for its beautiful beaches, has suffered in recent decades uncontrolled urbanization affecting mainly the maritime public domain (DPM). Currently, the upper parts of beaches like St. Roch, Paradis, Trouville, Bouisseville or lined with villas from one to two floors, garages for boats and large hotels. Encroachment on these areas yet protected by several laws, participated in the erosion of the sandbank and the decline of seaside tourism. This reflected a marked difficulty in managing and protecting this fragile and coveted space.Our study of the coastal area of Ain el Turck will address four points: the relationship between 'concretisation' of shoreline and shoreline change, the evolution of urbanization and occupation strategies, types of competition between different users on the ownership of coastal land and finally, the difficulties in protecting the maritime public by managing services.The method of work is essentially based on two approaches:the first is the comparison between several aerial photographs at different dates, for identifying changes affecting the natural shoreline in relation to the evolution of the urbanization of the coast. The second is conducting interviews with stakeholders in the area and analysis of speeches made by various interest groups, often in conflict.
Algérie
Aïn el Turck

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.4431
http://journals.openedition.org/etudescaribeennes/4431

Éditeur(s) : Inter-research
Résumé : We propose a statistical approach based on multivariate analysis and general linear models to test the consequences of removal of reserve status from the Abore Reef fish assemblage of the Abore Reef reserve, New Caledonia. Consequences on fish density were examined at the level of fish assemblage, accounting for habitat. Fish counts and habitat-related information were collected before and after the removal of reserve status, both inside and outside the reserve. Species groups were constructed on the basis of additional information on behavioural characteristics and taxonomy. The impact of the removal of reserve status was assessed by using 2 habitat proxies corresponding to 2 spatial scales and by considering several criteria for grouping species. Habitat appeared to be a determining factor in explaining density variations. Significant positive effects were found for several species groups such as macrocarnivores, piscivores, herbivores, Lethrinidae and Siganidae. A counterintuitive negative effect was observed for Acanthuridae. No significant differences between the area which remained closed to fishing and the area open to fishing were found for the other species groups. The approach allows for a synoptic diagnosis of the impact of changes in reserve status at the fish assemblage level. It could be used to develop and select potential indicators for monitoring such impacts on fish assemblages in coral reef ecosystems and in other contexts.
Marine Ecology Progress Series (0171-8630) (Inter-research), 2005 , Vol. 292 , P. 271-286

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00000/10970/7574.pdf
http://archimer.ifremer.fr/doc/00000/10970/

Résumé : The availability in interesting sites and the zootechnical performances of tropical fish are two impo rt ant assets in favor of the development of fish farming in the Caribbean islands. This repor presents a technical and financial analysis of red drum farming projects in floating cages in Martinique(French West Indies). This project analysis makes it possible to compare the economic feasability of a small-scale production system with that of a semi-industrial one submitted to different technical constraints. The main criteria of the project analysis are the profitability of the funded capital, the financial feasability during the buildup period, the profitability at a steady state and the cost price. Production costs are hi gher in the the small-scale enterprises than in the semi-industrial ones, thanks to better capita] productivity and better labour productivity. An analysis of sensitivity to the variations ofbiological and economical parameters is also contained in the report. The results of these studies indicate that Caribbean fish farming could be profitable, due to the rapid buildup of the facilities and to the short production cycles. Nevertheless, attention should be paid to the risk of storms and hurricanes in this part of the world. Moreover, the analysis of sensitivity highlights the great influence of seed price. [NOT CONTROLLED OCR]
Les bonnes performances zootechniques des poissons tropicaux et la disponibilité en sites propices sont deux atouts majeurs favorables au développement de l'aquaculture de poissons dans les îles des Caraïbes. Ce rapport présente l'adaptation d'un outil de simulation technico- économique à l'éleva ge de l'ombrine en cages flottantes dans le contexte martiniquais. Cet outil permet de disposer d'éléments de comparaison sur la faisabilité de deux systèmes de production, Fun de type artisanal et l'autre de type semi- industriel, soumis à des contraintes techniquesdifférentes : rentabilité du capital investi, faisabilité financière au démarrage, rentabilité en année de routine, prix de revient. Une analyse de sensibilité des résultats aux variations de paramètres biologiques et économiques est également présentée. L'analyse de ces projets fait apparaître une rentabilité satisfaisante de l'activité, liée à la rapidité de mise en route des installations et à la brièveté des cycles de production. Line grande attention doit être cependant portée sur les risques d'accidents climatiques fréquents dans cette région du globe (cyclone, mais aussi tempête...). L'analyse de sensibilité montre la grande influence du prix d'achat de l'alevin, en particulier sur les résultats de la variante artisanale, dont le coût de production de l'ombrine rendue à quai, est plus élevé que celui de la variante semi- industrielle. [OCR NON CONTRÔLE]

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1996/rapport-4019.pdf
http://archimer.ifremer.fr/doc/00000/4019/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : The length frequency distribution of blackfin tunas (Thunnus atlanticus) shows a significant difference between fishes caught with a longline, during Ifremer experimental surveys and fishes landed by fishermen who exploit martinican FADs. The fishing technique used could probably explain this. In fact, diving surveys have confirmed the presence of great concentrations of adult blackfin tunas under FADs. Big individuals stay during long periods between 20 and 50 meters under the FAD while small ones go up to the surface to feed on little flying fishes, at dawn principally. The bait and the line used at the moment around martinican FADs do not fit to adult blackfin tunas fishing. From these observations and following the tests realized by Ifremer in La Reunion in 1990, we proposed to martinican fishermen to test a new technique based on the utilization of live bait locally called "coulirous" (Selar crumenophthalmus). In La Reunion, this technique has been successful. Live baits are hooked on a vertical longline. In Martinique, the tests to catch live bait during the night near the shore have been already successful and the first fishing experiences with vertical line are also encouraging. This paper aims at proposing and transfering this technique to martinican fishermen but technical exchanges and discussions are needed to improve this new fishing technique.Original Abstract: Une analyse des compositions en taille des thons noirs (Thunnus atlanticus) captures, d'une part, lors des peches experimentales realisees par l'Ifremer a la palangre derivante et, d'autre part, debarques par les pecheurs exploitant les DCP martiniquais montre une difference significative de la taille moyenne des individus. Les techniques de peche utilisees peuvent probablement expliquer cette difference. En effet, des observations sous-marines ont confirme a plusieurs reprises la presence de larges concentrations de thons noirs adultes sous les dispositifs. Les gros individus se tiennent preferentiellement entre 20 et 50 m de profondeur a proximite du DCP alors que les petits individus montent plus frequemment en surface pour chasser, notamment au lever du jour. L'appat et les caracteristiques des engins actuellement utilises autour des DCP martiniquais ne sont pas bien adaptes a la capture des thons noirs adultes. A partir de ce constat et sur la base des essais de palangres verticales realises au laboratoire de l'Ifremer de La Reunion en 1990, qui ont abouti a une generalisation de cette technique de peche autour des DCP reunionnais, nous avons propose aux pecheurs martiniquais de tester cette nouvelle technique basee sur l'utilisation de " coulirous " vivants (Selar crumenophthalmus). Les essais de peche de l'appat vivant, la nuit a la palangrotte, se sont reveles positifs dans plusieurs baies de la Martinique et les premiers tests sur la palangre verticale a thons noirs sont encourageants. Cette communication fait le point sur le transfert vers les pecheurs martiniquais en identifiant les mises au point necessaires pour ameliorer l'efficacite de la technique proposee.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15293/12651.pdf
http://archimer.ifremer.fr/doc/00042/15293/

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/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : The volcanic island of Mayotte (374 km super(2)) is part of the Comoros Archipelago, which is situated on the North of Mozambic's Canal (Indian Ocean). Mayotte is composed of two islands and some thirty small islands distributed in a lagoon of more than 1,000 km super(2). Being one of the French Republic's Territorial Collectivity, this island is characterized by a very fast demographic evolution (growth rate : 5.8 %), which constitutes the foundation of the development problematic. Most of local halieutic production comes from the reef (nearly 2,000 t in 1999), the technic of "palangrotte" (deep line) is still dominating. The fishing fleet is composed of monoxyl pirogues and polyester fishing boats for the 1,200 fishermen. The first FADs (Fish Aggregating Devices) were installed in 1989. Now, 5 FADs are situated in the lagoon whereas 10 others have been installed out of it. If it is very hard to evaluate economic impact of FAD in Mayotte, their success seems to be limited because of several local constraints : fear to fish out of the lagoon, little interest in tuna, lack of formation. Nevertheless, faced to the demographic evolution and the decrease of the reef ressources, a program of fishing development on FAD has been initiated in 1998, with those following themes : realization of a new prototype of FAD, experimental fishing program with vertical drift "long line", teaching programs for the local fishermen. Today, it is too early to analyze the informations already collected, but the results are very promising, and validate the technical improvement of the new prototype.Original Abstract: L'ile volcanique de Mayotte (374 km super(2)) fait partie de l'archipel des Comores situe au Nord du canal du Mozambique (ocean Indien). Mayotte comprend deux iles et une trentaine d'ilots repartis dans un lagon de plus de 1 000 km super(2). Collectivite territoriale de la Republique francaise, l'ile se caracterise par une evolution demographique tres rapide (taux de croissance: 5,8 %), qui constitue le socle de toutes les problematiques de developpement. L'essentiel de la production halieutique provient du milieu recifal (environ 2 000 t en 1999), la peche a la ligne de fond reste la technique dominante. La flottille de peche est constituee de pirogues monoxyles et de barques polyester pour une population de 1 200 pecheurs. Les premiers DCP mahorais furent installes en 1989. A ce jour, on denombre cinq DCP dans le lagon et dix hors lagon. Il semble que leur succes soit reste limite en raison de plusieurs contraintes locales : peur de la peche hors lagon, peu d'interet pour les poissons pelagiques, manque de formation. Neanmoins, face a l'explosion demographique et a l'appauvrissement des ressources lagonaires, un nouveau programme de developpement de la peche sur DCP a ete initie en 1998. Ce programme comporte trois axes : realisation d'un nouveau prototype de DCP, lancement d'un programme de peches experimentales a la palangre verticale derivante et formation des pecheurs. A ce jour, les informations obtenues sont trop parcellaires pour etre analysees mais les donnees et observations realisees sur les nouveaux dispositifs permettent de valider leur conception technique.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15290/12647.pdf
http://archimer.ifremer.fr/doc/00042/15290/

Résumé : This report is presented by Chantal Cahu for obtaining accreditation to supervise research. Since 1981, her research activity has addressed the study of reproducers' nutrition and the young stages of development of marine organisms belonging to two different branch lines, crustaceans and fish. This work, performed in a base-lined research body, IFREMER, is placed within a more general programme of aquaculture development. Indeed, whatever species are at issue, the development of aquaculture in France, as at the global level, is based on the production of juveniles in hatcheries. My work has therefore more precisely the goal of acquiring knowledge about the nutritional needs, mechanisms of digestion and the development of these animals in order to improve the production of prawn post-larvae and fish alevin in the hatchery. This work took place in three main periods that appear in this report: - The study of reproducers' nutrition and its influence on the quality of the Penaeid prawn's eggs and larvae. My work has focused mainly on the effect of lipids and vitamins on the development of eggs and larvae. - The study of the ontogenesis of the digestive functions and the nutritional needs of sea fish larvae, with bass as the model. The goal was to determine the specific nutritional needs of the young stages by studying the implementation and regulation of pancreatic and intestinal digestive enzymes. - The study of the regulation of certain developmental genes by means of nutrients, so as to understand how these nutrients behave during ontogenesis, particularly during development of the skeleton.
Ce mémoire est présentée par Chantal Cahu pour pour l'obtention d'une habilitation a diriger des recherches. Depuis 1981, son activité de recherche concerne l'étude de la nutrition des reproducteurs et des jeunes stades de développement d'organismes marins appartenant à deux embranchements différents, les crustacés et les poissons. Ce travail réalisé dans un organisme de recherche finalisée, l'Ifremer, se situe dans un programme plus général de développement de l'aquaculture. En effet, quelles que soient les espèces en jeu, le développement de l'aquaculture en France comme au niveau mondial repose sur la production de juvéniles en écloserie. Mon travail a donc plus précisément pour objectif l'acquisition de connaissances sur les besoins nutritionnels, les mécanismes de digestion et le développement des ces animaux afin d'améliorer la production de post-larves de crevettes et d'alevins de poissons en écloserie. Ce travail s'est déroulé en trois grandes périodes qui apparaissent dans ce mémoire : - L'étude de la nutrition des reproducteurs et son influence sur la qualité des oeufs et des larves de crevettes Pénéides. Mon travail a essentiellement porté sur l'effet des lipides et des vitamines sur le développement des oeufs et des larves. - L'étude de l'ontogenèse des fonctions digestives et les besoins nutritionnels des larves de poissons marins, avec le bar comme modèle. Le but était de déterminer les besoins nutritionnels spécifiques des jeunes stades, en étudiant la mise en place et la régulation des enzymes digestives pancréatiques et intestinales. - L'étude de la régulation de certains gènes du développement par les nutriments, de façon à comprendre comment ces nutriments agissent lors de l'ontogenèse, notamment lors du développement du squelette.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/rapport-2086.pdf
http://archimer.ifremer.fr/doc/00000/2086/

Éditeur(s) : Oxford university press
Résumé : Fish-aggregating devices (FADs) are increasingly used worldwide to enhance tuna catches. Meanwhile, ecosystem-based management of this fishery is constrained by a paucity of information regarding the interaction of FAD-associated tuna aggregations with their local environment. This paper reports the results of a nine-month study around a FAD moored near Martinique Island, aimed at assessing the effects of the local environment on the variability of monthly estimates of proximate tuna biomass. Dual-frequency, active acoustics provided highresolution quantitative data on the pelagic community around the FAD, from fish to micronekton forage. Geostatistics were used to compute biomass estimates of the tuna aggregation comprising most of the FADassociated fish biomass, with a sampling error of 27%. Environmental variability was summarized by a small set of principal components (PCs) derived from profiles of temperature, salinity and dissolved oxygen vs. depth; and maps of chlorophyll a derived from remotely sensed, sea-surface colour. A generalized linear model was used to relate tuna biomass to environmental PCs and revealed a positive correlation between tuna abundance and: i) a micronekton layer sensed at 38 kHz and potentially consisting of preferred prey at about 180 m depth; and ii) low subsurface salinity (60–80 m). These favourable environmental conditions may be related to thepresence of North Brazilian Current eddies that migrating tuna follow when not temporally associated with the FADs.
ICES Journal of Marine Science (1054-3139) (Oxford university press), 2009-07 , Vol. 66 , N. 6 , P. 1410-1416

Droits : 2009 Oxford university press
http://archimer.ifremer.fr/doc/2008/publication-6162.pdf
DOI:10.1093/icesjms/fsp039
http://archimer.ifremer.fr/doc/00000/6162/