Epilithic biofilm as a key factor for small-scale river fisheries on Caribbean islands Auteur(s) : Lefrançois, E. Coat, S. Lepoint, G. Vachiery, Nathalie Gros, Olivier Monti, Dominique Auteurs secondaires : Dynamique des écosystèmes Caraïbe et biologie des espèces associées (DYNECAR EA 926) ; Université des Antilles et de la Guyane (UAG) Laboratoire d'Océanologie (MARE Center) ; Université de Liège UMR 15 CIRAD-INRA ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD) Systématique, adaptation, évolution (SAE) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Wiley-Blackwell Résumé : International audience Abstract Numerous freshwater species are consumed or exploited through artisanal fisheries in the rivers of the islands of Guadeloupe, French West Indies. Autochthonous production of organic matter is limited in these flowing rivers and is mainly represented by scarce filamentous green algae and an abundant epilithic biofilm growing on wet stones in the river bed. Stable isotope analysis was used to quantify the relative importance of biofilm and other riverine allochthonous and autochthonous food sources in the diet of tropical shrimps (Palaemonidae, Atyidae and Xiphocarididae) and fishes (Gobiidae and Eleotridae) consumed by the local people. The epilithic biofilm was exploited by most species, constituted an important source of autochthonous carbon and was an important source of organic matter production at the base of freshwater food webs in Caribbean rivers. Biofilm percentages in the diet reached 32% for molluscs, 85% for atyid shrimps, 29% for xiphocaridid shrimps, 14% for palaemonid shrimps and 13% for fish. Assessment of biofilm in nine rivers showed that blue and red cyanobacteria were quantitatively dominant with a moderately rich diatom flora. These results address the interactions between river biofilm and Caribbean freshwater fauna where trophic links between consumers and their potential resources have poorly been documented. ISSN: 0969-997X hal-00744809 https://hal.univ-antilles.fr/hal-00744809 DOI : 10.1111/j.1365-2400.2010.00767.x | Partager |
Marine cage fish farming Auteur(s) : Espeut, P. Harache, Yves Lemarie, Gilles Ricard, Jean-marc Résumé : Marine capture fisheries in Jamaica is primarily artisanal in nature ansd is conducted maiinly by fishermen operating from canoes. Approximately 95% of these fishermen operate on the coastal shelf and its associated banks. The commercial species harvested comprise bottom-dwelling, coral reef species and free swimming species of finfish. Other fishery resources of commercial value include marine shrimp, conch and lobsters. Catch statistics are not available for all species, but the Department of Fisheries reports a slight decline in fishery production with production decreasing from 16 milion lbs in 1990, despite the fact that fishing efforts have doubled. Over this period the number of registered fishermen has grown from 12 000 to 16 000, al of whom are engaged in full-time fishing. There arealso part-time fishermen who are not registered. The decline in fish catch is accompanied by a decrease in fish size and quality, suggesting that the fisheries are under pressure and have already exceeded optimum production in relation to vailable resources. As a result the economic returns to fishermen are declining. There are also other problems, such as high incidence of conflicts among fishermen at sea, the high cost of purchasing boats, outboard engine fuel, and equipment, with together with the dangers involved in fishing offshore (piracy, and praedial larceny) create serious social ans economic difficulties for fishermen. Notwithstanding, there is an apparent move on the part of the fishermen to leave the industryor to seek alternative forms of employment. In fact, the Department ofFisheries reports that it is still reciving applications for new licences to operate fishing boats. This is probably due to the fact that where the basis of a community is fishing, it becomes difficult to introduce alternative forms of employment, such as cottage industries, village crafts and other trades. In 1987 the Jamaica Department of Fisheries prepared a Management plan which proposed several conservation measures to promote the efficient use of fisheries resources and to control the development of the Fishery in such a way that the country would receive highest benefits. Adequate attention was given to limitations on fishing gear, institution of closed seasons and related legislation. Strategies to diversify the marine fishing were also proposed. The 1990 five year Devlopment Plan for marine fisheries also focuses on proper resource management in order to reverse trends associated with the overexploitation of marine resources. According to the plan, emphasis will be placed on inland fisheries and mariculture in order to reduce pressure on the fisheries. Inland fisheries in the form of freshwater fish fanning has expanded significantly over the past 10 years with production increasing from less than 0,5 million lbs. in 1980 to in excess of 6.0 million lbs. in 1989. However, some freshwater fish farmers are already experiencing serious competition for water usage and, to a lesser extent for land from crop-producing farmers. The Ministry of Agriculture is of the view that marine cage culture technologically has the potential for introduction in Jamaica . This technologyhas been successfully developed in Norway and the technology is currentlty being experimentally utilized in several countries in the area. The technology, if widely utilized in Jamaica, couls significantly reduce pressure on fisheries, making fishing more cost effective and improve the economic returns to fishermen. Already there exist some technical and institutional capabilities in Jamaica to support commercial development of marine cage culture. The Department of Fisheries has highly trained personnel in aquaculture and marine fisherie, some of whom are directly responsible for the success of freshwater fish fanning. In adition, the Marine Laboratory at the Univesity of the West Indies (UWI) is caarying research on hatchery facilities for marine cage farming. The Department of Fisheries will seek the collaboration ofg the marine unit at UWI which could provide fingerlings of selected marine species for cage 1 Les pêcheries de captage marin en Jamaïque sont principalement de nature artisanale et elles sont dirigées principalement par les pêcheurs qui travaillent depuis des canoës. Environ 95 % de ces pêcheurs travaillent sur la plaine côtière et ses bancs associés. Les espèces commerciales récoltées comprennent les espèces benthiques, les espèces de corail et les espèces de poisson marin de nage libre. D'autres ressources de pêcheries de valeur commerciale comprennent la crevette, la conque et le homard. Les statistiques des pêches ne sont pas disponibles pour toutes les espèces, mais le Département des Pêcheries fait état d'une légère réduction de production de pêcheries, la production se réduisant de 16 millions de livres en 1990, en dépit du fait que les efforts de la pêche ont doublé. Sur cette période le nombre de pêcheurs inscrits a augmenté de 12 000 à 16 000, dont tous sont occupés à plein temps à la pêche. Il y a aussi des pêcheurs à mi-temps qui ne sont pas inscrits. La réduction des pêches est accompagnée d'une réduction de la taille et la qualité des poissons, ce qui implique que les pêcheries sont sous pression et qu'elles ont déjà dépassé la production optimum par rapport aux ressources disponibles. En conséquence, les rendements pour les pêcheurs sont en baisse. Il y a aussi d'autres problèmes, tels qu'un taux élevé de conflits entre les pêcheurs en mer, le coût élevé pour acheter les bateaux, le combustible pour les moteurs hors-bord, et le matériel, ainsi que les dangers impliqués dans la pêche offshore (le piratage, et le vol prédial) ont créé de graves problèmes sociaux et économiques pour les pêcheurs. Néanmoins, il y a une tendance évidente chez les pêcheurs de quitter l'industrie ou de chercher du travail dans d'autres domaines. En fait, le Département des Pêcheries signale qu'il continue de recevoir des demandes de nouveaux permis pour opérer les bateaux de pêche. Ceci est probablement attribuable au fait que là où la base d'une communauté est la pêche, il est difficile d'y introduire des formes alternatives de travail, telles que l'industrie artisanale, l'artisanat de village ou d'autres métiers. Le Département des Pêcheries de la Jamaïque a préparé en 1987 un Projet de gestion qui proposait plusieurs mesures de conservation afin d'encourager l'utilisation efficace des ressources des pêcheries et de contrôler le développement de la Pêcherie de manière que le pays touche le plus de bénéfices. Une attention adéquate a été prêtée aux limitations sur les engins de la pêche, l'établissement de saisons de clôture et les législations associées. Des stratégies pour diversifier la pêche marine ont aussi été proposées. Le Plan de développement quinquennal de 1990 pour les pêcheries marines met l'accent aussi sur la gestion de ressources appropriée afin de faire reculer les tendances associées à la surexploitation des ressources marines. Selon le plan, l'accent sera mis sur les pêcheries intérieures et la mariculture afin de réduire la pression sur les pêcheries. Les pêcheries intérieures, sous la forme de l'élevage de poissons en eau douce, ont pris leur essor sur les 10 dernières années avec une production qui s'est élevée de moins de 0,5 millions de livres en 1980 pour atteindre en 1989 plus de 6.0 millions de livres. Cependant, certains pisciculteurs en eau douce expérimentent déjà une concurrence sérieuse avec les agriculteurs pour l'usage de l'eau et, dans une moindre mesure, de la terre. Le Ministère de l'Agriculture est de l'avis que l'élevage en cage marine a technologiquement le potentiel d'être introduit en Jamaïque. La technologie a été développée avec réussite en Norvège et plusieurs pays dans la région utilisent actuellement la technologie expérimentalement. La technologie, si elle était utilisée en Jamaïque, pourrait réduire de façon significative la pression sur les pêcheries, ce qui rendrait la pêche plus économique et améliorerait les rendements aux pêcheurs. Certaines capacités techniques et institutionnelles existent déjà en Jamaïque qui pourraient soutenir le développement de l'élevage en cage marine. Le Département des Pêcheries a un personnel bien formé en aquaculture et pêcherie marine, dont certains qui sont directement responsables du succès de la pisciculture en eau douce. Par ailleurs, le Laboratoire Marin à l'Université des Antilles (UWI) mène des recherches sur les installations d'écloseries pour l'élevage en cage marine. Le Département des Pêcheries demandera la collaboration de l'unité marine à l'UWI qui pourra fournir des saumoneaux d'espèces marines sélectionnées pour la cage 1. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1993/rapport-1918.pdf http://archimer.ifremer.fr/doc/00000/1918/ | Partager |
Diel feeding periodicity, daily ration and relative food consumption in some fish populations in three reservoirs of Sri Lanka Auteur(s) : Weliange, Wasantha S. Amarasinghe, Upali S. Moreau, Jacques Villanueva, Ching-maria Éditeur(s) : EDP Sciences Résumé : Twelve diel surveys were carried out in three reservoirs of Sri Lanka viz. Minneriya, Udawalawe and Victoria, to investigate diel feeding patterns, daily ration and relative food consumption in fish populations. Stomach content weights of different size classes of various fish species in the three reservoirs in 12 diel surveys were analysed using an iterative method, MAXIMS. Predominantly herbivorous or detritivorous fish species such as Amblypharyngodon melettinus and Oreochromis niloticus exhibited one peak in the diel feeding pattern. Two peak feeding periods were evident in predominantly insectivores and/or zooplanktivores (e. g., Puntius chola and Rasbora daniconius) and interestingly in macrophyte feeders (i.e., Etroplus suratensis, Puntius filamentosus and Tilapia rendalli). It might be possible that all species with two feeding peaks in diel feeding patterns rely on vision for feeding. Food consumption per biomass (Q/B ratio) defined as amount of food consumed per unit weight of an age-structured population of fish was estimated on the basis of the average quantities of food consumed over a long period of time by various size classes in order to minimize the bias of estimates. Douze séries d'échantillonnage ont été effectuées dans trois lacs-réservoirs du Sri Lanka : Minneriya, Udawalawe et Victoria, afin d'étudier le modèle journalier d'alimentation, les rations journalières et à la consommation relative des populations de poissons. Les poids des contenus stomacaux de différentes classes de taille ont ainsi été analysés en utilisant une méthode itérative, MAXIMS. Les espèces herbivores ou détritivores telles que Amblypharyngodon melettinus et Oreochromis niloticus montrent un pic dans l'activité de nutrition. Tandis que les espèces détrivores et/ou zooplanctivores en présentent deux (ex., Puntius chola et Rasbora daniconius) de même que des espèces se nourrissant de macrophytes (ex., Etroplus suratensis, Puntius filamentosus et Tilapia rendalli). Il est possible que la vision joue un rôle chez ces espèces présentant deux pics journaliers d'alimentation. La consommation de nourriture par rapport à la biomasse (le rapport Q/B) est défini comme la quantité d'aliment consommé par unité de poids d'une population de poissons structurée en âge, sur la base de quantités moyennes de nourriture consommée sur une longue période de temps et par diverses classes de taille, afin de minimiser les biais dans les estimations. Aquatic Living Resources (0990-7440) (EDP Sciences), 2006-07 , Vol. 19 , N. 3 , P. 229-237 Droits : 2006 EDP http://archimer.ifremer.fr/doc/2006/publication-2134.pdf DOI:10.1051/alr:2006023 http://archimer.ifremer.fr/doc/00000/2134/ | Partager Voir aussi Cichlidae Cyprinidae Trophic modelling Freshwater fish Feeding chronology Diel feeding pattern Télécharger |
Contamination of some aquatic species with the organochlorine pesticide chlordecone in Martinique Auteur(s) : Coat, Sophie Bocquene, Gilles Godard, Eric Éditeur(s) : EDP Sciences Résumé : Martinique is a French overseas department whose economy relies heavily on agriculture. Organochlorine pesticides, mainly chlordecone, were used for banana cultivation to eradicate banana weevil over a period of 40 years. Chlordecone is chemically stable,and has a strong affinity for fatty tissues. It is therefore able to bioaccumulate in animals and thereby represent a threat to ecosystems and man. Soils from banana plantations in Martinique are heavily contaminated with chlordecone. Possible transfer of these molecules from agricultural watersheds to the aquatic environment and the organisms that live in it is feared. The hypothesis that ecosystems of Martinique might be highly contaminated with this organochlorine pesticide was investigated. Chlordecone levels were measured in various freshwater and marine species. Data show a heavy contamination of many carnivorous and detritivorous species (fish and prawns). Concentrations measured in wild or farmed tilapia are among the highest ever reported in the literature. Some coastal species (fish and lobster) were also found to be contaminated, although to a lesser extent. Given the biogeochemical behavior of chlordecone, the most likely route of contamination is food. Detected concentrations in marine organisms are below the tolerated limits established by authorities. however. the impact of other sources of exposure, namely, contaminated water and root vegetables, remains to be investigated. Aquatic Living Resources (0990-7440) (EDP Sciences), 2006-04 , Vol. 19 , N. 2 , P. 181-187 Droits : EDP Sciences, IFREMER, IRD 2006 http://archimer.ifremer.fr/doc/2006/publication-1662.pdf DOI:10.1051/alr:2006016 http://archimer.ifremer.fr/doc/00000/1662/ | Partager Voir aussi W Atlantic Caribbean Islands Food web Aquatic organisms Chlordecone Contamination Pesticides Télécharger |
Aquaculture activities in Fiji Auteur(s) : Vereivalu, T Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 3, pp.31-36 Résumé : Fiji has no aquaculture tradition, but the Government is engaged in aquaculture production since 1969, with the help of other countries and international organization like F.A.O. Some species have been tested: Fishes: Grass carp (Ctenopharyngodon idellus ) and Tilapia ; Molluscs: Oyster (Crassostrea echinata ) and Mussel (Mytilus viridis ); Crustacean: freshwater prawn (Macrobrachium rosenbergii ) and shrimps (Penaeus monodon, P. indicus, P. stylirostris ). Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1989/acte-1498.pdf http://archimer.ifremer.fr/doc/00000/1498/ | Partager |
Chlordecone in the marine environment around the French West Indies: from measurement to pollution management decisions Auteur(s) : Bertrand, Jacques Bodiguel, Xavier Abarnou, Alain Reynal, Lionel Bocquene, Gilles Éditeur(s) : Communication, ICES Conference and Meeting (CM), 2010, Nantes Résumé : Chlordecone is a very persistent insecticide used in banana plantations of the French West Indies between 1972 and 1993. Chlordecone residues were found in inland water, in agricultural and freshwater products, and in marine organisms. This pollution has become of great concern in 2007. Therefore, a governmental action Plan was launched to better assess the pollution and to improve the consumer’s protection. Within this plan, 1048 samples from 69 different species of marine fishes and crustaceans were collected all around both the Guadeloupe and the Martinique Islands and analyzed. The results confirm the presence of chlordecone in marine organisms, with highly variable concentrations (from the detection limit to 1000 μg.kg-1). In 17.9 % of the samples, concentrations exceeded 20 μg.kg-1, the maximum acceptable level in fish according to the French regulation (Anon, 2008). Two main features of this contamination were characterized. 1) Because of the sedimentation of contaminated suspended soil particles, the sheltered bays are more exposed to chlordecone than the open coast where terrigenous flux are dispersed. 2) Species biology, particularly their lifestyle and diet, appear to influence contamination levels. Thus, the more contaminated species live in relation with sediment or are at high trophic level. These results have directly supported political decisions in order to prevent too high exposure of consumers to chlordecone. Fishing activities in sheltered bays have been forbidden for potentially highly contaminated species like benthic crustaceans and top predators. Further studies are under way to assess the importance of the trophic transport of chlordecone within the foodweb, and to evaluate the historical deposition of this insecticide in sediment and its further bioavailability. Droits : 2010 ICES/CIEM ; Ifremer http://archimer.ifremer.fr/doc/00014/12511/9361.pdf http://archimer.ifremer.fr/doc/00014/12511/ | Partager |
Trends in freshwater and marine aquaculture Auteur(s) : Lacroix, Denis Éditeur(s) : Proceedings of 3rd East-West Fisheries conference; 24-26 Nov. 1998; Copenhagen, Denmark Résumé : The demand for fish products, from freshwater and from the sea, is globally increasing ail over the world. This major trend can be explained by the development of mankind, not only in quantity (one billion people more in the last 15 years) but also because food consumption habits are changing: for southern countries, fish products consumption is first a diversification of protein sources. For northern countries, it is a new style of eating with diet, tasteful and original products coming from the attractive « new frontier » symbolised by the sea. Global/y speaking, the aquatic product consumption raised from 9 to 13 kg./unhab./year during the last 30 years. It is now clear that catches from ail fisheries cannot match this steady increase of the demand as data collected from al/ countries reveal the stagnation of the world production since the beginning of the nineties. The reasons are now well-known: over-capacity of fishing fleets, over-fishing of many stocks, poor management of harvested species which results in about 20 millions of tons of waste while the same amount is processed into fishmeal and oil, out of direct human consumption. Droits : Ifremer http://archimer.ifremer.fr/doc/00041/15181/12518.pdf http://archimer.ifremer.fr/doc/00041/15181/ | Partager |
Enzymatic polymorphism study as help for constitution of initial broodstock for a new cultivated finfish species. Auteur(s) : Renno, J Luquet, P Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 54, pp.563-568 Résumé : Leporinus friderici is a South American promising species for fish culture. In French Guiana the "morphological species", L. friderici, L. granti, L. lebaili and L. affinis steyermarki are found. Their identification is sometimes difficult on usual criterion. To constitute an initial broodstock of L. friderici from local wild populations, the genetic structure of these species was studied. Fifteen enzyme systems, representing twenty loci, were screened. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1989/acte-1441.pdf http://archimer.ifremer.fr/doc/00000/1441/ | Partager Voir aussi French Guiana Leporinus Leporinus granti Leporinus friderici Anostomidae Pisces Embryos Mortality Genetics Freshwater fish Télécharger |
Mapping habitats in a marine reserve showed how a 30-year trophic cascade altered ecosystem structure Auteur(s) : Leleu, Kevin Remy-zephir, Brice Grace, Roger Costello, Mark J. Éditeur(s) : Elsevier Sci Ltd Résumé : Time-series studies have reported trophic cascades in land, freshwater and marine environments in many geographic areas. However, the spatial extent of habitats, a key metric of ecosystem structure, has not been mapped in these studies. Marine reserves can provide experimental, before-after and inside-outside (control-impacted), situations for assessing the impact of fishing on ecosystems. We mapped seabed habitats and their associated communities (biotopes) in New Zealand's oldest marine reserve for comparison with pre-reserve maps created about 30 years previously. Areas grazed bare by sea urchins were entirely replaced in the centre of the reserve by kelp, or alga turf, an intermediate biotope between heavily grazed encrusting algae and lightly grazed kelp. Urchins declined following increased abundance and body size of spiny (rock) lobsters and fish (especially snapper) in the reserve but maintained bare rock outside. While this gradient in habitat change matched the gradient of predator abundance, it also matched the extent of reef habitat area. Thus the trophic cascade may be influenced by the effect of habitat on the abundance and behavioural interactions of urchins and their predators. Further ecosystem changes may arise should the abundance of mega-predators, such as seals, cetaceans and large sharks, increase in the region; if parasites become pathogenic; and/or when invasive species reach the reserve. No-take marine reserves provide real-world experiments that show the importance of species in food webs, and the consequences of fishing for ecosystems. Because these changes in ecosystem structure may continue, and will vary with environment, climate and species distributions, reserves need to be permanent and replicated geographically. Habitat maps should be produced for all reserves to enable ecological changes in the ecosystem to be spatially quantified. (C) 2012 Elsevier Ltd. All rights reserved. Biological Conservation (0006-3207) (Elsevier Sci Ltd), 2012-10 , Vol. 155 , P. 193-201 Droits : 2012 Elsevier Ltd. All rights reserved http://archimer.ifremer.fr/doc/00107/21842/20067.pdf DOI:10.1016/j.biocon.2012.05.009 http://archimer.ifremer.fr/doc/00107/21842/ | Partager Voir aussi Kelp forest Ecosystem change Predator release Subtidal mapping Urchin Barren New Zealand Lobster Fish Time-series Télécharger |
Aquaculture de poisson en Martinique : Compte rendu de mission en martinique du 19 au 26 juillet 1990 Auteur(s) : Antona, Martine Résumé : Fish aquafarming is an activity that is starting to take off in Martinique as possible diversification of giant river prawn breeding (Macrobrachium Rosenbergii) which debuted in the middle of the 70s. Two species were involved, one freshwater species (the red tilapia or Saint-Pierre) and a marine species (the redfish or red drum). This mission report presents, in the first section, the local conditions of fish aquafarming development in Martinique the current characteristics of the breeds, the existing production sector and its management. A second section inventories the main operating constraints of this field technical or market constraints. (OCR non controlé) L'aquaculture de poisson est une activité en démarrage en Martinique comme diversification possible de l'élevage de la chevrette (Macrobrachium Rosenbergii) débuté au milieu des années 70. Deux espèces sont concernées, une espèce d'eau douce (le tilapia rouge ou Saint-Pierre pays) et une espèce marine (le redfish ou ombrine tropicale). Ce rapport de mission présente dans une première section, les conditions locales de développement de l'aquaculture de poisson en Martinique - les caractéristiques actuelles des élevages, le secteur de production existant et son encadrement-. Une seconde section recense les principales contraintes de fonctionnement de la filière -contraintes techniques ou de marché. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1990/rapport-2421.pdf http://archimer.ifremer.fr/doc/00000/2421/ | Partager |
5th International Otolith Symposium 2014 - IOS2014 : Book of abstracts Auteur(s) : ICES Résumé : Implementation of ecosystem-based approaches to marine management points to several shared objectives between conservation and fishery management that require better knowledge of the life history of the exploited resources, elucidation of the information encoded in the calcified tissues (otoliths, scales, bones, shells, and corals) of marine and freshwater organisms, and support for knowledge-based, sustainable ocean management and use.
Calcified tissues have been employed since the 19th century to gain knowledge of life traits, population structure, and environmental relationships of fish and molluscs.
Breakthrough advances include the discovery by Pannella (1971) of the daily growth increments and the discovery by Radtke (1984) of otolith tracer approaches, resulting in an exponential growth of publications and four dedicated international symposia.
IOS2014 will be the fifth in a series of independent symposia convened since 1993, to encourage the exchange of information and expertise, and promote the development of new techniques and applications for otolith-based analysis in ecology, management, and conservation. This international forum is the centre for the exchange of information on developments in the field. New techniques of analysis, statistical treatment, and indeed new areas of application are all presented in this forum.
The IOS series started in Hilton Head (USA) in 1993, followed by IOS1998 in Bergen (Norway), IOS2004 Townsville (Australia), and the IOS2009 Symposium held in Monterey (USA). In general, attendance ranged between 250–350 participants. IOS2009 counted 268 registrants from 36 countries, despite the economic crisis. Droits : ICES - All Rights Reserved http://archimer.ifremer.fr/doc/00221/33260/31736.pdf http://archimer.ifremer.fr/doc/00221/33260/ | Partager |
Alternatives to taxonomic-based approaches to assess changes in transitional water communities Auteur(s) : Mouillot, D Spatharis, S Reizopoulou, S Laugier, Thierry Sabetta, L Basset, A Chi, T Éditeur(s) : John Wiley & Sons Résumé : 1. Transitional waters, described as critical transition zones because of their position at terrestrial, freshwater and marine interfaces, provide essential goods and services to the biosphere including human populations. These ecotones face increasing human influence mainly due to population density increase in coastal areas. 2. Transitional water bodies have, to date, received little attention in the development of ecological status indicators, this is a critical deficiency when trying to meet the Water Framework Directive objective of all significant water bodies achieving good ecological status by the year 2015. 3. In order to assess changes in transitional water communities many taxonomic-based indicators have already been proposed but there are a number of concerns for their use such as taxonomic classification difficulties, their unsuitability for multi-site comparisons and their inconsistent relationships with disturbance or stress. 4. Alternative methods based on body size, abundance distribution among functional groups, functional diversity and productivity descriptors are proposed. These methods offer the opportunity to compare sites with different taxonomic compositions and allow derivation of indicators related to ecological status of communities under scrutiny. 5. Finally, the suitability of these taxonomic-free descriptors to provide relevant information for each of the four main biotic compartments in coastal lagoons is discussed. The use of biomass distribution among functional groups for fish, benthos and macrophyte and to use body-size distribution for benthos and plankton is proposed. Copyright (c) 2006 John Wiley and Sons, Ltd. Aquatic Conservation: Marine and Freshwater Ecosystems (1052-7613) (John Wiley & Sons), 2006-07 , Vol. 16 , N. 5 , P. 469-482 Droits : 2006 John Wiley & Sons, Ltd http://archimer.ifremer.fr/doc/2006/publication-1849.pdf DOI:10.1002/aqc.769 http://archimer.ifremer.fr/doc/00000/1849/ | Partager Voir aussi Biotic descriptors Productivity Functional diversity Functional traits Body size Water Framework Directive WFD Télécharger |