Caractéristiques physico-chimiques de l’eau des puits dans la commune de Pobè (Bénin, Afrique de l’ouest)

Objectif : L’objectif de cette étude est d’évaluer la qualité de l’eau des puits à partir de ses caractéristiques physico-chimiques dans la commune de Pobè. Méthodologie et résultats : L’étude entreprise entre juin 2012 et mars 2013 a permis de mesurer au niveau de quinze puits les paramètres physiques tels que le pH, la conductivité électrique (CE) et la température (T) de l’eau ainsi que les paramètres chimiques suivants : bicarbonates (HCO3-), chlorures (Cl-), calcium (Ca2+), magnésium (Mg2+), titre hydrotimétrique ou dureté totale (TH), ammonium (NH4+), nitrates (NO3-), nitrites (NO2-), sulfates (SO42-), phosphates (PO43-) et fluorures (F-). Les valeurs moyennes annuelles sont comparées aux normes relatives à la qualité de l’eau de boisson. L’analyse statistique multivariée dont l’Analyse en Composantes Principales (ACP) et la Classification Hiérarchique Ascendante (CHA) a été également appliquée à l’ensemble des paramètres mesurés. L’eau des puits est légèrement acide avec un pH moyen de 5,83 ± 0,6. Elle est faiblement minéralisée et légèrement dure avec une conductivité moyenne de 236,62 ± 135,54 FS/cm et une dureté totale moyenne de 107,8 ± 40,63 mg/L. La pollution azotée est un indicateur majeur de la qualité de l’eau des puits étudiés. Cette pollution se traduit par des taux élevés en nitrates et en ammonium dans plus de 50 % des puits. Une forte corrélation est signalée entre la conductivité électrique et les paramètres suivants : pH, NO3-, NO2-, SO42-, TH, Cl-, HCO3- et Ca2+. La typologie est principalement gouvernée par cette conductivité qui permet de classifier les puits selon leur qualité physico-chimique. Conclusion et applications : L’eau des puits est soumise à une pollution organique dans la commune de Pobè. Cette pollution d’origine anthropique serait liée à l’infiltration des eaux usées et des engrais chimiques. Les fortes teneurs en nitrates et en ammonium montrent que cette eau est chimiquement non appropriée à la consommation humaine et nécessite dans la majorité des puits un traitement préalable.Mots clés : Physico-chimie, eau de puits, pollution, analyses multivariées, Pobè.Physicochemical characteristics of well water in Pobè municipality, Benin, West Africa Objective : The aim of this study is to evaluate the quality of well water for its physical and chemical characteristics in the municipality of Pobè. Methodology and Results: The study conducted from June 2012 to March 2013 measured in fifteen wells the level of physical parameters such as pH, electrical conductivity and water temperature as well as the following chemical parameters: bicarbonate (HCO3-), chloride (Cl-), calcium (Ca2+), magnesium (Mg2+), total hardness (TH), ammonium (NH4+), nitrate (NO3-), nitrite (NO2-), sulphate (SO42-), phosphate (PO43-) and fluoride (F-). The annual mean values are compared to standards for drinking water quality. Statistical multivariate analysis including Principal Component Analysis and hierarchical clustering was also applied to all measured parameters. Well water is slightly acidic with an average pH of 5.83 ± 0.6. It is weakly mineralized and slightly hard with an average of 236.62 ± 135.54 FS/cm electrical conductivity and a total hardness of 107.8 ± 40.63 mg/L. Nitrogen pollution is a major indicator of well water quality. This pollution finds expression in high rates of nitrate and ammonium in more than 50 % of the wells. It was observed that electrical conductivity show good positive correlation with pH, NO3-, NO2-, SO42-, TH, Cl-, HCO3- and Ca2+.The typology is mainly governed by the conductivity for classifying the wells according to their physical and chemical quality. Conclusion and applications: Well water is subjected to organic pollution in the municipality of Pobè. This anthropogenic pollution is linked to the infiltration of sewage and chemical fertilizers. The high levels of ammonium and nitrate indicate that the water is chemically unsuitable for human consumption and requires that water in most wells be pretreated.Keywords : Physicochemical, well water, pollution, multivariate analysis, Pobè

Problématique du contrôle et de la prévention de la coccidiose du poulet

La coccidiose chez le poulet est une pathologie digestive causée par les sept espèces du genre Eimeria dont les plus pathogènes sont: E. tenella, E. acervulina, E. brunetti et E. maxima. Le cycle de vie des coccidies est direct et très court souvent réalisé en sept jours et qui débouche sur laformation des oocystes excrétés à travers les fèces. L’incidence économique de la maladie est estimée à 2,3 milliards d’Euro mondialement avec 70% des pertes attribuables à la coccidiose sub-clinique, difficilement perceptible, qui déprime le gain de poids vif corporel et l’indice de consommation alimentaire du poulet. L’utilisation du PCR (Polymerase Chain Reaction) permet d’identifier les espècesde coccidies par l’analyse du génome. Les mesures de prévention et de contrôle sont basées sur l’utilisation des anticoccidiens et des vaccins. Toutefois, les problèmes de résistance des coccidies aux médicaments, la présence de résidus médicamenteux dans les produits avicoles et la forme sub-clinique de la maladie engendrée par la réplication des coccidies vaccinales dans les entérocytes, constituent de graves menaces pour la filière poulet. D’autres moyens de lutte continuent de faire l’objetd’expérimentation à travers les plantes médicinales, et les vaccins recombinés. L’utilisation de la résistance naturelle aux coccidies de certains génotypes de poulet est une perspective envisageable quipeut définitivement mettre l’aviculture à l’abri des pertes énormes engendrées par les mesures de contrôle actuelles et la forme sub-clinique de la maladie.Mots clés: Eimeria, anticoccidien, vaccin, plante médicinale, résistance naturelle

A Rapid Biodiversity Assessment & Archaeological Survey of the Fiji REDD+ Pilot Site: Emalu Forest, Viti Levu

The land encompassed by the mataqali Emalu in the province of Navosa has been selected as the pilot site for the Fiji REDD+ programme. A survey to assess the biodiversity of the area and document its cultural heritage sites was carried out by a team of specialists from USP’s Institute of Applied Science (the South Pacific Regional Herbarium and the Environment Unit), the Fiji Museum, NatureFijiMareqetiViti and Conservation International. The expedition was implemented in two phases; in July 2012 and March 2013. Flora, Vegetation and Ecology A total of 707 plant taxa were recorded for Emalu, including 286 bryophytes and lichens, 375 angiosperms, nine gymnosperms, and 35 ferns and fern allies. Altogether, the vascular and non-vascular taxa recorded from the Emalu site spanned 182 families and 391 genera. Over a third (39%) of the vascular plant flora recorded are endemic to Fiji, including 160 species of flowering plants, two fern and fern allies, and two gymnosperms. Ten taxa were encountered that are important focal species due to their rarity, botanical significance, very recent discovery in Fiji and inclusion in the IUCN Red List. Five principal vegetation types were identified; lowland rainforest, upland rainforest, cloud forest, dry forest and talasiga. Herpetofauna Six species of herpetofauna: three endemic, two native and one invasive were captured over 22 man-hours of diurnal survey, 63 hours of sticky tape trapping and nine man-hours of nocturnal surveys. This survey has documented the first records of herpetofauna in this area and indicates a similar herpetofauna habitat to those typically observed in other parts of Viti Levu. The endemic Fiji tree frog (Platymantis vitiensis) was encountered in the area and is possibly the western-most record of the occurrence of this species in Fiji. Avifauna A total of 35 species of birds were recorded during the survey, which included 25 endemic species and one exotic species. Two species of bats were also recorded during the surveys. Ten focal species were identified (eight bird species and two bat species). The bird diversity of Emalu is comparable to the four Important Bird Areas on Viti Levu and ranks even higher in terms of bird density. Terrestrial Insects The target taxa Coleoptera (beetles) recorded 26 families in total and there was also a high abundance of the family Formicidae (ants). These taxa provide critical ecosystem services in forests systems such as soil processing, decomposition, herbivory, pollination and seed dispersal. Insects of conservation value recorded from Emalu included: Hypolimnas inopinata (a rare and endemic butterfly), Nysirus spinulosus and Cotylosoma dipneusticum (rare and endemic stick insects) and Raiateana 5 knowlesi (the rare and endemic cicada). These findings suggest that the Emalu area is pristine and an important site for rare insects on Viti Levu. Freshwater Fish A total of ten species of fish from six families were recorded from the study area. Three species of gobies (Awaous guamensis, Sicyopus zosterophorum, Sicyopterus lagocephalus), two species of eels from the family Anguillidae (Anguilla marmorata and Anguilla megastoma), and the freshwater snake eel from the family Opicthidae (Lamnostoma kampeni) were collected in the area. The Mavuvu mid reach had an exceptionally high abundance and biomass of jungle perch Kuhlia rupestris when compared to other streams in Fiji. No endemic species were observed or caught during this survey. Around areas of human habitation there is evidence of the removal of riparian buffer zones as well as unrestricted livestock access to waterways which, coupled with uncontrolled slash and burn activities has exacerbated environmental degradation in these areas. The use of traditional fish poison (Derris roots) is also a common problem seen throughout the survey sites. Freshwater Macroinvertebrates A total of 76 freshwater macroinvertebrate taxa were identified from the 16,370 specimens collected in the three catchments of the Emalu region. The highly diverse freshwater macroinvertebrate community of Emalu included a high proportion of endemic taxa (75%), with insects being the most commonly occurring group. A total of 14 macroinvertebrate taxa were selected as potential bioindicators. The high rate of endemism, as well as the large number of species with large populations, is indicative of the intactness of both the stream system and the surrounding forest. Invasive Species A total of 26 invasive plants and eleven invasive animals were recorded in the study area, thirteen of which are listed in the 100 most invasive species in the world. Generally, the occurrence and abundance of invasive was associated with proximity to human habitation and to disturbed areas such as tracks, temporary campsites and cultivated areas. The invasive plant species were generally low in abundance, with the exception of Piper aduncum which was locally common, and Clidemia hirta and Mikania micrantha which were both widespread. Archaeological Survey The land belonging to the mataqali Emalu is rich in historical and cultural sites that have never been documented until this survey. A total of 77 sites of historical and cultural significance were documented, including old village sites, hill fortifications, pottery sites, agricultural terraces, sacred pools, house mounds and fortification trenches. Generally, the archaeological finds during this survey have considerable cultural value to the local community as well as at national level

Colo-i-Suva Forest Park Wildflife

This book provides a single portfolio of information about a wide range of interesting groups of organisms typically found in a forest system in Fiji. It was written for the general public, students, researchers and visitors to the Colo-i-Suva Forest Park. The chapters provide brief descriptions and photos of the plants and animal species found in the Colo-i-Suva Forest Park, their distribution, abundance, conservation status and local uses. The book intends to provide a visitor to the park with an enriching experience in better knowing and appreciating its wildlife

Can Myxosporean parasites compromise fish and amphibian reproduction?

Research into fish and amphibian reproduction has increased exponentially in recent years owing to the expansion of the aquaculture industry, the need to recover fishery populations, the impact of endocrine disruptors on the aquatic environment and the global decline of amphibian populations. This review focuses on a group of parasites, the Myxozoa, that affect fish and amphibian reproduction. Lists of the myxosporeans that specifically infect gonads are provided. Most of these are parasitic of freshwater hosts, and most amphibian cases are reported from testes. Sex specificity and sex reversal are discussed in relation to gonadal parasitism. The immune response of the fish to the infection is described, and the contribution of the immunoprivilege of gonads to host invasion is emphasized. The pathological effect of these parasites can be significant, especially in aquacultured broodstocks, on some occasions, leading to parasitic castration. Although myxosporean parasites are currently not very frequent in gonads, their impact could increase in the future owing to the transactions in the global market. Their easy release into the aquatic environment with spawning could make their spreading even more feasible. In the absence of commercial drugs or vaccines to treat and prevent these infections, there is an urgent need to develop specific, rapid and reliable diagnostic tools to control and manage animal movements. In addition, much effort is still to be made on deciphering the life cycle of these organisms, their invasion strategies and their immune evasion mechanisms