Objectives: Water, source of life is essential for all living beings. After its use, the water is loaded in various elements modifying its physical, chemical and biological characteristics. One of the most serious environmental problems is the problem of sanitation. Indeed, human activity leads to the production of wastewater discharged daily into the wild. Methodology and results: Twenty-eight waste water samples were collected from eight Yamoussoukro lakes from sterile containers. The method of Bailenger was used for the detection of parasites. The specific recognition and enumeration of the parasites was done using an optical microscope Prevalences observed were compared between lakes and by parasite species. A total of 13 species of parasites: Ankylostoma sp., Strongyloïd sp., Ascaris sp., Nematodirus sp., Trichuris sp., Toxocara sp., Capillaria sp., Ascaridia galli, Enterobius vermicularis,Taenia sp., Hymenolepis diminuta., Entamoeba coli., Entamoeba histolytica et les larves de Strongles were detected in the waters of Yamoussoukro lakes. Helminth eggs are almost present in all investigated lakes with variable parasite loads. Three species gave very high parasite loads: The species Ankylostoma sp was found in all lakes. Strongyloids and Ascaris sp had prevalence rates of 100 % and 87.5 %, respectively. At the level of the parasite load of the lakes, Lake N ° 5 was the most parasitized with a prevalence of 100 % on all the parasites, then the lakes N ° 1, 6 and 8 (69,2 %) then the Lakes G0, 9 and 10 (53.8 %). Conclusion and application of results: Parasitological analysis show that Yamoussoukro lakes are contaminated by parasites of medical importance. The infestation of these waters with pathogens prohibits their use in agriculture, which is not commonly observed in the field.

Les blooms de cyanobactéries surviennent dans les eaux de surface, en particulier dans les eaux où les conditions physiques et les charges en éléments nutritifs sont favorables à leur prolifération. L'objectif de ce travail a été de déterminer les principaux paramètres physico-chimiques favorisant l'efflorescence des cyanobactéries dans le Sud-Est de la Côte d'Ivoire. La distribution des cyanobactéries et le déterminisme de leur développement ont été étudiés de juin à octobre sur la lagune Aghien, les retenues d'Adzopé et d'Agboville. Les paramètres physico-chimiques ont été mesurés et la composition ainsi que la densité des cyanobactéries ont été réalisés. Le niveau de turbidité, la température, la quantité de phosphates, la quantité de nitrite et la quantité de phosphore sur les sites sont les facteurs déterminants l'abondance des cyanobactéries sur les sites. Un maximum de 39,4x10 6 cellules/ml a été rencontré au mois d'octobre. Les genres dominants sont Microcystis (40%), Anabaena (plus de 14%), Aphanocapsa (10%) et Oscillatoria (8%) dans les milieux étudiés. Ce sont en effet des genres potentiellement toxiques. De plus, pendant la période d'échantillonnage des blooms à Microcystis en juin, les associations Microcystis-Planktothrix en juillet et Microcystis-Anabeana en septembre, ont été observés. La prolifération des cyanobactéries dans les plans d'eau étudiés est sous le contrôle de l'hypereutrophisation à travers la concentration en nutriment mais aussi des paramètres physiques. © 2017 International Formulae Group. All rights reserved.Mots clés : Cyanobactéries, lagune Aghien, déterminisme, prolifération, Côte d'Ivoire.Determination of the proliferation of toxic cyanobacteria in Côte d'Ivoire ABSTRACT Cyanobacteria blooms occur in surface waters, especially in waters where physical conditions and nutrient loads are favourable for their proliferation. The aim of this work was to determine the main physicochemical parameters favoring the efflorescence of the cyanobacteria in the South-East of Côte d'Ivoire. The distribution of cyanobacteria and the determinism of their development were studied from June to October on the Aghien lagoon, the Adzopé and Agboville reservoirs. Physico-chemical parameters were measured and also the composition and density of the cyanobacteria. The level of turbidity, temperature, quantity of J. COULIBALY-KALPY et al. / Int. J. Biol. Chem. Sci. 11(1): 266-279, 2017 267 phosphates, amount of nitrite and amount of phosphorus are factors determining the abundance of cyanobacteria at the sites. A maximum of 39.4x10 6 cells / ml was encountered in October. The dominant genera are Microcystis (40%), Anabaena (more than 14%), Aphanocapsa (10%) and Oscillatoria (8%) in the studied area. These are indeed potentially toxic genera. In addition, during sampling period, blooms of Microcystis in June, the Microcystis-Planktothrix associations in July and Microcystis-Anabeana in September were observed. The proliferation of cyanobacteria in the studied water bodies is under the control of h...

This study was aimed at understanding the main abiotic environmental factors controlling the distribution patterns of abundance and composition of phytoplankton (size less than 10 μm) assemblages in the coastal waters of south‐eastern Côte d'Ivoire. Data were collected during two cruises, in January (low‐water period) and October (high‐water period) of 2014. A total of 67 species were identified and assigned to Bacillariophyceae (49%), Cyanophyceae (21%), Chlorophyceae (13%), Euglenophyceae (10%), Dinophyceae (4%) and Chrysophyceae (3%). Three biotic zones (I, IIA and IIB) were distinguishable on a Kohonen self‐organizing map after an unsupervised learning process. The diatom genera Eunotia sp., Navicula sp. and Actinoptychus senarius are significantly associated with I, IIA and IIB biotic zones, respectively. A clear seasonal cum salinity trend was apparent in phytoplankton distribution patterns. Turbidity and nitrate levels were the main abiotic factors controlling phytoplankton distribution in I, the upland tidal regions of the lagoon. In regions along the lagoon–sea continuum, phosphate and turbidity exert the most control during the low‐water season (IIA), while total dissolved solids control phytoplankton distribution during the high‐water season (IIB). These are climate‐sensitive parameters whose concentrations depend on prevailing hydroclimatic processes. Therefore, seasonality can have important consequences on phytoplankton community and inadvertently the productivity of these systems.

Spatio-temporal dynamics of phytoplankton and their relation to abiotic environmental factors in four rivers of south-eastern Ivory Coast (Soumi e, Eholi e, Ehania and No e) was analysed from July 2003 to March 2005. The pelagic zone of each river was sampled upstream and downstream. Phytoplankton abundance was higher in No e River (154.3 10 4 cells l À1 ) and lower in Eholi e river (23.05 10 4 cells l À1 ). Dominant taxa were Microcystis aeruginosa (K€ utz.) Lemmerm. and Aphanocapsa incerta (Lemmerm.) Cronberg & Kom arek. In general, minimum densities of phytoplankton were observed during the rainy season, while maximum were observed in dry season in the whole stations of the rivers studied, such periods corresponding to low and high concentrations of nitrates. Among the rivers surveyed, Eholi e river seems to be the least disturbed because of its higher species diversity. Seasonality fluctuations of algae abundance appear to be influenced by the flow of water and nitrate levels. This work is a useful starting point for future research on micro algae in Ivory Coast.