The expression “living resources” occurs thirty-eight times in the United Nations Convention on the Law of the Sea (UNCLOS), but the latter does not give any legal definition of the term. The integration of environmental law taxonomy, such as biodiversity, in the evolution of the law of the sea has added to confusion regarding the meaning of “marine living resources.” To clarify the meaning of this expression and its legal scope in the evolution of the law of the sea, it is necessary to analyze the context of its use in UNCLOS and, more broadly, in the legal regime governing marine resources. This article aims to clarify the origins and extent of the confusion regarding the meaning of marine living resources and to analyze how the use of a broader semantic field in different legal instruments and other sources of international law has shaped the legal framework for the conservation and sustainable use of marine living resources.

Introduction.Barberry (Berberis aristata DC.), a small fruit,is found growing in the wild in the temperate region of northernPakistan. Materials and methods. Three different locations ofAzad Jammu and Kashmir, i.e., Topa, Banjosa andNeriyan Sharif, were explored; thirty accessions of barberry wereidentified and characterized on the basis of their growth habit,flowering, fruiting and chemical composition of fruits. Results.The accessions exhibited high diversity in their phenotypical/morphologicaltraits such as growth habit, intensity and time of flowering, fruitsetting, ripening time, productivity, and fruit shape and color.The location had a great impact on quantitative parameters. Accessionscollected from Neriyan Sharif had significantly greater plant height,higher number of branches per plant, extended flowering duration(days), took more time to maturity (days) and had high fruit setting (%),while those from Topa had large-sized leaves and fruits with greateraverage fruit weight. The nutritional composition of fruits indicatedthat the accessions from Topa had higher carbohydrate, ash, total solublesolids and Mn contents, with significantly higher juice pH, andlower acidity; while the accessions from Neriyan Sharif had significantlyhigher moisture, protein, fat, fiber, K, Ca, Na, Fe, Cu, Pb andCr contents and were highly acidic. The accessions collected fromBanjosa were almost intermediate for the quantitative characteristicsstudied. Conclusions. The results suggested that notonly the genotype but its growing location as well are the mainfactors that determine the growing habit, productivity and nutritionalcomposition of barberry fruits, and this ultimately provides importantinformation on how to make the best use of them.

Turkey's 21.8 million head of sheep comprise a rich array of fat-tailed and thin-tailed native breeds and crosses of these with animals of exotic origin. The structure of agriculture is such that most farms are predominantly subsistence oriented, of small size, keep few animals and provide only minimal inputs. Native breeds have evolved to meet these conditions and are generally well adapted to the natural environment, inadequate and unbalanced nutrition and disease stress. In the last 80 years, there have been attempts to modify the natural gene pool and many distinct breed types are in danger of or have already suffered extinction. This paper describes some of the major sheep genetic resources and their conservation status. The government is now aware of the danger of impoverishment or loss of this important aspect of biodiversity and has established programmes for conservation and preservation of several native breeds. Government, research institutions and producers should work together to ensure that the local gene pool is preserved and can thus continue to contribute to biodiversity and sustainable livestock production.

Introduction. Algerian oasesare characterized by a diversification of local fruit species andcultivars. However, this diversity is subject to erosion. To preservethe genetic heritage, we undertook the first work on the inventoryof fruit species crops in the region of Touggourt in south-easternAlgeria. Materials and methods. Our working methodswere based on surveys carried out on farms in the Oued Righ regionaccording to a questionnaire that met our objectives. For this,we divided the study region into three zones and in each zone weselected ten farms for the inventory of fruit species cultivated. Results and discussion. The results of our investigationsallowed us to identify thirteen species, including four specieswith a wide distribution (pomegranate tree, apricot tree, fig treeand vine). The local genetic diversity of these species is littleknown. The varieties or cultivars inventoried have local names givenby the farmers in the region according to certain morphologicalcharacteristics of the fruit. We surveyed five cultivars for thefig tree, two cultivars for the pomegranate tree, two cultivarsfor the vine, and two apricot tree cultivars. The study of the biodiversityof fruit trees in the Oued Righ region showed high richness of thespecies and cultivars; some are local and others are endemic tothe region. Better knowledge of genetic diversity will begin withtests of behavior and characterization of the different genotypes encounteredto dispel the ambiguities and to highlight the actual compositionof populations or varieties of different species.

Goats were first domesticated in Turkey some 10 000–11 000 years ago. The country's population of 5.1 million goats in 2009 (down from 24.6 million in 1960) are still an important livelihood asset for smallholder farmers and nationally are a rich array of farm animal genetic resources of current enormous and future inestimable value. The structure of agriculture is such that most farms are predominantly subsistence oriented, of small size, keep few animals and provide only minimal inputs. Native breeds have evolved to meet these conditions and are generally well adapted to the natural environment, inadequate and unbalanced nutrition and disease stress. In general, there are two classes of goat, the one being the iconic Angora that produces mohair and the other the “common” or “hair” goat. The reduction in numbers is owing to a variety of reasons both internal and external to the country, but the Angora, which now amounts to only 2.5 percent of national goat numbers, has suffered relatively more than the hair types. This paper, based on detailed reviews of the literature and on the authors' own experiences, provides information on 17 breeds or recognized populations of Turkey's goat genetic resources and their conservation status. The government is now aware of the danger of the impoverishment or loss of this important aspect of biodiversity and has established programmes for conservation and preservation of several native breeds. The government, research institutions and producers should work together to ensure that the local gene pool is preserved and can thus continue to contribute to biodiversity and sustainable livestock production.

Backyard poultry is considered as a powerful tool for poverty alleviation. It is further promoted as a way of empowering women in communities where there is gender bias in poultry raising. The low-input systems involved are based on local breeds that are perfectly suited to their environment. However, socio-economic processes put local genetic resources under pressure, leading to the erosion of biodiversity. The present survey addresses this issue in the case of Kabylie, a mountainous coastal region of Algeria, through a survey conducted in 90 households raising poultry, a morpho-biometric description of 315 local chickens, and a performance evaluation of both growth and egg production in experimental semi-intensive conditions. The socio-economic profile of poultry smallholders in Kabylie reveals poor education and high diversification of agricultural assets and confirms gender bias in poultry keeping. The erosion of local genetic resources in chicken is found to be severe despite their cultural importance in Kabylie. From complementary surveys among experienced poultry keepers, the major original local type is postulated to consist of three varieties with black plumage (pure black, mottled and barred). The performance evaluation raised promising results, suggesting that exploiting the local breed could pursue some degree of improvement of low-input backyard systems. Finally, a strategy for a revival of the local breed through the support of the most involved smallholders is outlined in accordance with the information collected in the survey.

Introduction. Xoconostles or acidic cactus pears (Opuntiaspp.) are fruits prized for their fleshy and acidic mesocarp; theyare morphologically different from cactus pears which are sweet, juicyand seedy. Both thrive in semiarid highlands of Central Mexico,tolerate poor soils and scanty rainfall, and have evolved into formalcrops during the last five decades. Wild xoconostles are ubiquitousin Mexican semiarid regions. Domesticated genotypes are found inbackyards and commercial orchards. Folk wisdom attributes xoconostlewith antihypoglycemic effects, cholesterol control and obesity reduction.The peel presents higher antioxidant capacity than strawberry, raspberry,red plum, grapefruit, pear and apple. Our investigation describesthe main cultivars of xoconostles with horticultural value for human consumptionin Central Mexico; it contributes to the elucidation of their morphologicalrelationships. Materials and methods. Twenty-one accessions fromthe Hidalgo and Zacatecas states of Mexico were described using 27 variablesfrom cladodes, flowers and fruits; significant variables were selectedby correlation and PCA, and thereafter a cluster analysis and discriminantcanonical analysis were performed. Results. Thirteen variables werefound to be significant to discriminate accessions: cladode length, numberof rows of areoles, number of areoles in the central row, pericarplength and width, fruit length, fruit diameter, [length / diameter]ratio, areole density, receptacle depth, fruit and peel weight,and pulp acidity. Two canonical roots (Can) explained variability:Can1 (fruit areola density, acidity, number of areole rows, and numberof areoles in the central row) explained 87.55%, and Can2 (peel weight,fruit weight and fruit diameter) explained the remaining 12.45%.Discussion. Can1 was related to plant productivity, while Can2 comprisedmainly fruit quality traits. Both of these traits are of primaryinterest for human utilization and have had a clear effect on domestication. Clustersdid not match the actual taxonomic classification.

Introduction. Un inventaire des espèces de Tephritidae dans des vergers de l’ouest du Burkina Faso a été effectué entre décembre 2007 et décembre 2009. Matériel et méthodes. Un piégeage de détection a été mené dans sept vergers de manguiers en utilisant comme appât de la levure de Torula placée dans des pièges Mac Phail. Résultats et discussion. L’identification et le dénombrement des Tephritidae capturées a permis de recenser 18 espèces : neuf du genre Ceratitis, sept du genre Dacus et deux du genre Bactrocera. Ceratitis cosyra et Bactrocera invadens (respectivement 53,02 % et 36,19 % de l’ensemble des captures) se sont révélées être les espèces dominantes. Nous avons mis en évidence une forte similarité des communautés de Tephritidae au niveau des différents sites étudiés (coefficients de similitude entre 42,86 % et 100 %); cette similarité pourrait être expliquée d’une part par l’homogénéité des conditions climatiques, d’autre part par celle de la végétation de la zone d’étude. La proximité des parcelles de cultures maraîchères et la diversité des fruitiers locaux hôtes des Tephritidae autour des vergers de manguiers pourraient être à l’origine de la richesse spécifique élevée que nous avons constatée. Conclusion. Notre étude a révélé une diversité de Tephritidae dans la zone d’investigation qui présente des communautés d’espèces homogènes. Ces résultats seront complétés par l’identification des espèces associées aux dégâts sur manguier et à l’évaluation de leur importance. Ils suggèrent dès à présent la possibilité de développer, contre ces ravageurs, une stratégie de lutte commune à toutes les localités de la zone d’étude de l’ouest du Burkina Faso.

Introduction. The baobab tree’s potential overexploitation has recently been reinforced by the acceptance of baobab fruit pulp in the EU and US food markets. Despite the number of recent studies on this species, Adansonia digitata, little is known from Malawi, the main exporter of baobab fruit pulp in Africa. Materials and methods. Information on distribution and density of baobab trees present in Malawi was gathered from field surveys. The Maxent software based on the maximum-entropy approach for species habitat modelling was used together with spatial environmental data and geo-referenced records of the baobab tree to analyse its ecological preferences and potential cultivation sites. Farmers were interviewed about who was using and buying baobab fruits in different areas. Fruit and leaf morphological diversity was assessed in eight study sites selected along a latitudinal gradient. Results and discussion. The baobab tree was found to be widely distributed in southern Malawi, with variable densities. Modelling results show that this species could be cultivated in most of the southern region. A large morphological diversity in both fruit and leaf characteristics was observed, which gives the opportunity to select more desirable characters for cultivation. Conclusion. Our study showed that, while some areas of high baobab tree density could be further exploited, its cultivation, however, should be recommended in areas with low density of baobab trees in southern Malawi because there is little natural regeneration. Moreover, this study suggested that there is room for selecting baobab planting material with desirable characteristics for cultivation purposes in Malawi.

Introduction. Les aires protégées représentent un immense réservoir de ressources biologiques dont dépendent fortement les populations riveraines. La non-prise en compte des savoirs locaux constitue souvent un frein aux politiques de conservation et d’utilisation durable de la biodiversité dans ces aires. La réserve de Pama, située en zone soudanienne au sud-est du Burkina Faso, est un bon exemple de la divergence existant entre les besoins d’autosubsistance des populations riveraines et la nécessité de conserver la biodiversité. L’évaluation de l’importance socio-économique de cette réserve pour les populations riveraines pourrait permettre de mieux adapter la stratégie de gestion des ressources naturelles. Matériel et méthodes. Des enquêtes ethnobotaniques ont été menées en se basant sur des interviews individuelles. Les informations obtenues à partir de l’interrogation de 30 personnes ressources ont permis (1) de recenser les différentes utilisations faites de la réserve par les populations locales ainsi que l’impact de ces utilisations sur la flore et (2) d’évaluer la perception des villageois sur la façon de gérer les ressources de leur forêt. Résultats. Un total de 58 espèces végétales de la réserve, soit plus de 15 % de la flore locale, fournissent diverses ressources aux populations riveraines, dont du matériel de construction (90 % de réponses), des plantes médicinales (73,33 %), des plantes alimentaires (73,33 %), etc. Les espèces végétales les plus sollicitées se sont révélées être entre autres Vitellaria paradoxa (80 %), Parkia biglobosa (66,67 %), Diospyros mespiliformis (33,33 %), Gardenia erubescens (33,33 %), Lannea microcarpa (33,33 %), Tamarindus indica (33,33 %), Andropogon gayanus (26,67 %) et A. chinensis (26,67 %) Certaines de ces espèces se sont révélées de plus en plus rares du fait de la dégradation des conditions climatiques, de l’exploitation abusive de bois vert et de l’appauvrissement des sols. Conclusion. L’étude que nous avons menée sur la réserve de Pama nous conduit à préconiser un renforcement des mesures de protection de l’environnement par l’implication des populations riveraines. Par ailleurs, la plantation en champ d’espèces utiles en voie de raréfaction serait une action apte à limiter la pression d’exploitation sur la réserve

Pigs have socio-economic and cultural importance to the livelihood of many Bhutanese rural communities. While there is evidence of increased religious disapproval of pig raising, the consumption of pork, which is mainly met from imports, is increasing every year. Pig development activities are mainly focused on introduction of exotic germplasm. There is an evidence of a slow but steady increase in the population of improved pigs in the country. On the other hand, indigenous pigs still comprise 68 percent of the total pig population but their numbers are rapidly declining. If this trend continues, indigenous pigs will become extinct within the next 10 years. Once lost, this important genetic resource is largely irreplaceable. Therefore, Government of Bhutan must make an effort to protect, promote and utilize indigenous pig resources in a sustainable manner. In addition to the current ex situ conservation programme based on cryopreservation of semen, which needs strengthening, in situ conservation and a nucleus farm is required to combat the enormous decline of the population of indigenous pigs and to ensure a sustainable source of swine genetic resources in the country.

Introduction. Knowledge of tephritid diversity in Senegal was poor before 2004, so PIP-COLEACP and CIRAD, in collaboration with Cérès-DPV, carried out, in 2004, trapping for preliminary detection of fruit flies in six orchards in the Niayes zone. Materials and methods. We selected three mixed mango orchards and three homogeneous mango orchards in this zone. In each orchard, we used three attractants: Terpinyl acetate (Ter), Trimedlure (Tri) and Torula (Tor). Traps were serviced weekly. Results. We captured 77 642 fruit flies in more than 4 months including mango season; they were represented by 18 identified fly species, including ten Ceratitis, six Dacus and two Bactrocera species. Two very serious pests were identified with the confirmation of Bactrocera cucurbitae (Coquillett) for cucurbit crops and the detection of B. invadens Drew Tsuruta & White for fruit crops. The two most abundant species of Ceratitis were C. cosyra and C. silvestrii. Discussion. We captured more fruit fly species in mixed mango orchards than in homogeneous mango orchards. Bactrocera invadens was also more abundant in mixed orchards, probably because of its polyphagous status. This new invasive species, B. invadens, can have many hosts in mixed mango orchards, enhancing its breeding potential. Conclusion. Effective management to deal with this alien species requires: (i) improvement of basic and applied research; (ii) an effective IPM package; (iii) an area-wide management approach; (iv) a sub-regional effort on the part of researchers, extension services, growers, exporters, farming associations and the different actors in fruit value chains (mainly mango).

Introduction. Tamarind (Tamarindus indica L.) belongs to the Fabaceae family; it is a multipurpose tree with slow growth. In order to help improve its growth and development, we assessed mycorrhizal diversity of tamarind parklands in Senegal. Materials and methods. Three sites of tamarind populations were sampled for each agro-ecological zone in Senegal: the Sahelian zone (i), Sahelo-Sudan zone (ii) and Sudan zone (iii). Soil and root samples were collected in each site and used for arbuscular mycorrhizal (AM) spore isolation and root colonization assessment. We identified the mycorrhizal fungi from spore collections and evaluated the root mycorrhization rate, defined as percentage of roots colonized according to agro-ecological zones. Results and discussion. The results did not reveal a specific AM fungal strain associated with tamarind plants. Three arbuscular mycorrhizal fungi (AMF) were identified from spores on the genus level: Glomus, Scutellospora and Acaulospora. Tamarind sites with sandy soil texture (70–90%) and located in dry areas (Sahel and Sudano-Sahel zones) were shown to be rich in mycorrhizal propagules. High densities of soil AM propagules evaluated with the Most Probable Number method (MPN) were found in Niokhoul (1100 propagules per 50 g of soil), Sakal (790 propagules per 50 g of soil) and Mbassis (780 propagules per 50 g of soil). However, higher mycorrhizal colonization (11%) was observed in the Sahel agro-ecological zone compared with the Sudano-Sahelian and Sahelian zones (3%) of Senegal. Conclusion. Our study explored natural AMF diversity as a starting point to develop inocula to be used in commercial nursery production of tamarinds.

Introduction. Fruit and vegetable consumption is now more than ever before understood, along with physical exercise, to be among the factors ensuring well-being. Cross-cultural epidemiological studies reveal a preventive effect of this consumption on certain human pathologies, whence the emergence of preventive nutrition. Changes in biodiversity dietary intake. Industrially-processed products, undergoing a greater or lesser degree of refinement, were developed during the last century; they focused on a few productive species and varieties. The concept of high-calorie foods, an energy source, which has been prevalent in dietetics over the past few decades, had minimised the role of fruit and vegetables in the diet, due to their low calorie content. Plant biodiversity in foodstuffs originating from the American tropics. There are few cultivated major species and varieties in terms of biodiversity. 40% of the edible plant species in the world today originate from the American tropics. Of the planet's 250 000 estimated plant species, 100 000 are believed to be from the Americas. Preserving the beneficial properties of processed products. To improve recovery of the properties of the fresh resource for the consumer, innovation in the processing methods is required, with unit operations ensuring the best possible preservation of the healthy compounds. Conclusion and prospects. Communication on fruit and vegetables has not enjoyed the same research and publicity resources as many processed products. Knowledge of and information on food resources, diet and health have become a major challenge. The relative wealth of the plant biodiversity from the American tropics represents a heritage we need to reharness.

Introduction. Fruit flies (Diptera, Tephritidae) are among the major constraints in commercial horticulture in many African developing countries. Knowledge of the tephritid spectrum in any given area is a prerequisite for the development of an IPM program to alleviate the pest problem. We studied the fruit fly diversity in four main agro-ecological zones which are significant fruit-producing areas in the Morogoro Region, Tanzania. Materials and methods. Fruit fly diversity was investigated for one year (October 2004 – October 2005). Parapheromones, synthetic food attractant and protein-bait traps were used to trap the flies at the different locations in Morogoro region, Tanzania. One mixed orchard was selected at each of four locations representing the different agro-ecological zones of the region. Results. The recently introduced alien species, Bactrocera invadens, and three indigenous pest species, Ceratitis rosa, Dacus bivittatus and D. punctatifrons, were found at all the four sites, while Bactrocera cucurbitae, Ceratitis cosyra, Dacus chiwira and D. humeralis were found in three out of the four sites. The Sokoine University of Agriculture (SUA) Horticulture Unit and Mikese sites had the highest species diversity while the Mkindo and Nyandira sites had the lowest diversity. The between-habitats diversity (Beta diversity) was similar among the SUA, Mkindo and Mikese sites. Only the Nyandira site had a higher dissimilarity in comparison with the other three sites. Discussion. The most abundant species at low- and mid-elevation sites was Bactrocera invadens while, at high elevation, Ceratitis rosa was the dominant species. Protein-baited traps attracted the highest diversity of fruit flies in comparison with the more specific parapheromones. The synthetic food attractant (three-component lure) was less efficient compared with the protein bait. The large dissimilarity at the Nyandira site is probably due to the different types of host fruits found and grown in high altitude areas (mainly temperate fruits). Fruit fly species associated with these types of fruits, e.g., Ceratitis rubivora and Trirhithrum coffeae, were found only at this site.

Introduction. Les produits de l’agro-industrie représentent aujourd’hui une part importante et croissante des aliments consommés par l’homme. La transformation industrielle des productions agricoles réduit la densité nutritionnelle des produits transformés. Productions agricoles majeures. Les productions agricoles mondiales majeures sont pour une bonne part des matières premières pour l’agro-industrie. Ce sont principalement des céréales et les deux plantes sucrières majeures (canne à sucre et betterave). La disponibilité spatio-temporelle des produits transformés permet de répondre aux besoins caloriques et de lutter contre la faim. Or, pour l’entretien de la vie cellulaire et des équilibres physiologiques, il faut aussi consommer des micro-constituants dont les antioxydants, particulièrement communs et abondants dans les fruits et légumes. Fruits, légumes et santé. La consommation des fruits et légumes, sous des formes fraîches ou peu raffinées, est favorable à la protection de la santé du consommateur. Huiles, aromates et santé. Les oléagineux et les aromates contiennent aussi des substances pouvant contribuer à protéger la santé. Des connaissances sont à développer pour une meilleure intégration des huiles et aromates dans les préparations culinaires. Antioxydants et biodiversité. Leur connaissance peut être favorisée par l’essor et la mise en synergie des techniques et outils analytiques, de la physiologie du développement des végétaux, de la nutrition et de la physiologie humaine. La zone intertropicale américaine constitue une aire ressource particulièrement riche. Conclusion et perspectives. Il y a opportunité à rechercher, dans la biodiversité végétale, des espèces d’intérêt pour la protection de la santé du consommateur. Il faut réaliser une démarche intégrative allant de la ressource génétique aux produits transformés.

Studies were conducted in farmer's field, Lambwe School of the Deaf, and Mbita Point Field Station of ICIPE (ICIPE-Mbita) in western Kenya during the long rains of 2001 and 2002 to assess the impact of a diversionary stemborer management strategy on the pest's predators. Treatments consisted of a maize monocrop (control) and an intercrop of maize and desmodium, Desmodium uncinatum Jacq., with Napier grass, Pennisetum purpureum (Schumach), as trap crop around the field (‘push-pull’) in the farmer's field and Lambwe School of the Deaf. Sudan grass, Sorghum vulgare sudanense (Pers.), was used in place of Napier on the station. A combination of sticky traps, direct observation and hand-collection methods were employed. Predator groups encountered included 12 families from 7 insect orders and 4 families from one arachnid order, with most of the foregoing represented in both maize monocrop and ‘push-pull’ plots. A Cheilomenes sp. and Chrysopa sp. were, however, recovered from ‘push-pull’ plots only. Ants, earwigs and spiders were the main predators encountered. Both overall and individual group populations of these predators as well as ant diversity were significantly higher in ‘push-pull’ than monocrop plots in all the sites during the vegetative, flowering and mature maize growth stages (P < 0.05, t-test). The results thus indicate a numerical enhancement of stemborer predators by use of this habitat management system.

We studied the rotifer fauna of one of the most pristine peat-swamps in the Southern Thai province of Narathiwas, To Daengpeat swamp. The samples yielded a total of sixty-seven rotifer species. Of these, three -Keratella mixta (Oparina-Charitonova),Lecane enowi Segers & Mertens and Monommata dentata Wulfert- are new to the Oriental region and the Thai fauna, one,Keratella taksinensis n. sp., is new to science. The fauna consists mainly of cosmopolitan (sensu lato) species, complementedby some Paleotropical and endemic taxa, and is dominated by littoral-benthonic taxa, especially Lecane and, to a lesser extent,Lepadella.

In Reunion Island, insect and mite pests are significant limiting factors to the development of market crops. Several studies have been carried out on some families of pests during the last 40 years, but no comprehensive survey has been undertaken on the arthropods of vegetable crops on this island. During 1997/1998, we studied the arthropod complex on eight main families of crops, namely Solanaceae, Cucurbitaceae, Brassicaceae, Fabaceae, Liliaceae, Asteraceae, Apiaceae and Rosaceae. During a complete year of collection, we gathered 123 species of pests, including 114 species of insects and 9 of mites. We also identified a total of 128 species of beneficials, including 51 species of parasitoïds and 77 species of predators and consisting of 101 species of insects, 14 of mites and 13 of arachnids. Our data constitute the first step for the implementation of strategies for pest monitoring and integrated pest management in an important sector for the island's insular economy.

The chironomid populations of a 6th order section (400 m) of the middle Garonne river were studied monthly from September 1996 to October 1997. For the first time the main channel of the river was investigated including two floodplain waters : a side arm and an oxbow. Two sampling techniques were used for drift and benthic collections. A total of 21 766 specimens (pupae and pupal exuviae) were sorted and 137 species were identified. Among these, 12 species are new for the fauna of France : their ecology and biogeography are given. The chironomid population of the backwaters is especially diverse and distinctive since the waterbody is disconnected from the main channel. The studied section appears to be transitional corresponding with the epipotamal-metapotamal zones. The embankment of the watercourse since 1958, which has isolated floodplain waters and increased the current velocity in the main channel, mainly explains the dual typologic status observed. The main channel is colonised by rheophilous Orthocladiinae whereas the backwaters shelter a mixed population of limnophilous Chironominae and potamobiont Orthocladiinae. This study demonstrates the urgency for preserving floodplain waters because of their species richness, their uniqueness and their faunal interaction with the main channel. The strong faunal contribution of floodplain waters highlights the topicality and the value in investigating the less disturbed potamal zones of large rivers to increase our knowledge on biodiversity, ecology and biogeography of chironomid populations.