Ratio of natural isotopes of nitrogen. I. Primary results: soils of Dombes [Translation from: Revue d'Ecologie et de Biologie du Sol 14, 279-287, 1977]

Utilization of the heavy isotope of nitrogen as a tracer has found numerous applications in soil biology. It allows better definition of different stages of the nitrogen cycle, in particular the immobilization-mineralization cycle. In this work, the authors report the results of calculations of natural isotope ratios of nitrogen in samples of water, soil and vegetation prevailing in Dombes and discuss the possibilities of errors and coefficients of fractionation.

Vision 2050: changement climatique, pêche et aquaculture en Afrique de l’Ouest Du 14 au 16 avril 2010, Dakar, Sénégal

Ce rapport présente les activités et les résultats de l’atelier Vision 2050: Changement climatique, pêche et aquaculture en Afrique de l’Ouest. Les objectifs de l’atelier étaient de discuter les questions critiques et les incertitudes auxquelles est confronté le secteur de la pêche et de l’aquaculture au Ghana, au Sénégal et en Mauritanie, d’élaborer des scénarios sectoriels pour 2050 et de discuter de l’implication de ces scénarios dans le contexte du changement climatique pour ces pays et la région ouest africaine.

Ecologie benthique de la Lagune Ebrié. Détermination du rapport de stabilité biocoenotique (RSB)

The 1912 Jaccard index modification led to the formulation of the Biocoenotic Stability Report (BSR). It is another similarity index based on the evaluation of two opposite ecological states affecting both compared biotopes.

Eléments nutritifs et production primaire dans les lagunes du Côte d'Ivoire : cycle annuel

This paper collects most of the information gathered between October 1974 and July 1976 within the framework of a research program concerning the hydrobioclimate of ivorian lagoons and especially the Ebrié lagoon. Monthly surveys concerning the latter were carried out during 1975. The following parameters - and their vertical distribution wherever it had a meaning - were systematically gathered in a system of fifty-five stations: Transparency (Secchi), Temperature, Salinity, Chlorophylla, Dissolved oxygen, phosphate, nitrate, nitrite. These data provide an outline of the annual cycle of nutrients and primary production of the Ivoirian lagoons

Variation saisonniere des structures hydrologique et dynamique du plateau continental ivoirien (VASPI I, II, III)

This data report contains all the meteorological, hydrological and dynamic data gathered during the VASPI cruises (I : from December 8th to December 13th 1982, II : from March 5th to March 9th 1983, and III : from October 6th to October 10th 1983) carried out along the continental shelf of Ivory Coast by the oceanographic ship "Andre NIZERY". These cruises, which represent a part of a coastal programme, are included in the more general scientific program FOCAL, whose main scientific objective is the study of the thermal context of the intertropical atlantic area.

Bibliographie courante des traveaux du centre (1958-1978)

This publication is an up-to-date review of the papers published by the researchers of the Oceanographic Research Center of Abidjan, since its beginnings (1958-1978).

Campagnes Chalci, Chalci 84-01 (du 17 au 25-01-84) et Chalci 84-02 (du 03 au 11-07-84): resultats des chalutages

This publication gives the results of bottom trawlings made during the cruises CHALCI 84-01 and CHALCI 84-02 by the oceanographic research vessel "Andre NIZERY" sur le plateau continental ivoirien.

Observations hydrologique et dynamique le long de deux radiales du plateau continental ivoirien durant l'année focale 1983

In this report, vertical distributions of the temperature and horizontal velocity components of the currents, got from the two sections BELIER (305 1'W) and VRIDI (4°O 5'W), carried out once a week during the 1983 year, on the Continental shelf of Ivory Coast, are shown.

Les acadjas traditionnels dans le sud-est du Bénin

This study mission on acadja, the traditional way of fishing in the lagoons of the South-East part of Benin, permits us to understand how well-established this fishing practice is, in terms of time and spatial extention. The exploitation of acadja has a great profitability but it also represents the source of some problems as deterioration of branches, deforestation and social conflits. However, when acadjas are rationally exploited, they constitute a hope for waters which are in the process of losing their biological richness.

Campagnes Chalci, Chalci 83-01 (du 11 au 19-01-83) et Chalci 83-02 (du 10 au 18-03-83): resultats des chalutages

This publication gives the results of bottom trawlings made during the cruises Chalci 83.01 and Chalci 83.02 by the oceanographic research vessel "André Nizery", on the ivorian continental shelf. The publication content is: - an introduction explaining the form of results; the trawl recording cards with the characteristics of trawl and the detail of catches by species; the length frequency distributions of the measured samples.

Manuel pratique d'identification des poissons du lac d'Ayamé (Rivière Bia, Côte d'Ivoire)

A taxonomic assessment of fish species was carried out in the Lake Ayamé as a preliminary evaluation within the framework of a project to appraise the biodiversity changes occurred in fish after the construction of a dam at Ayamé in 1959.

Bibliographie des lagunes et du littoral de Côte d'Ivoire (Afrique de l'Ouest)

The present bibliography collects references on lagoon and coastal environments in Côte d'Ivoire. It is mainly based on: - the draft bibliography prepared by Charles-Dominique and Durand in 1979, edited in the Archives Scientifiques du Centre de Recherches Océanographiques d'Abidjan (vol. 5 no. 2); - the synthesis on the marine environment, published in 1993 (LeLoeuff, Marchal and Amon-Kothias editors); - and the synthesis on the lagoon environment, published in 1994 (Durand, Dufour, Guiral and Zabi editors). In spite of a careful check of the available documents, it is more than possible that references are lacking or erroneous. That's why this bibliography is still a draft, and the author will be glad to receive complements and/or corrections from lectors. After these contributions, a more comprehensive version will be proposed. Remarks can be sent to this e-mail: arfi@ortsom.orstom.fr or to the postal address.

Ecologie benthique de la Lagune Ebrié. Théorie sur la méthode du DR' pour la mise en évidence de biocoenoses

The theoretical aspect of the DR' method was presented. It suggestes the association of some characteristic transects, the organisms of which will be used to describe the first biocoenoses of the Ebrié lagoon.

Méthodes simples de determination du CO2 total et du carbone organique dissous en eau saumâtre

Total CO2 of brackish water (Ebrié lagoon) is measured with a simple method: degassing and trapping CO2 in NaOh solution, the conductivity of which is a function of the trapped CO2 quantity. A relation CO2 versus salinity is deduced; it is nearly the same as the one deduced from CO2 measurements performed from alkalinity. Dissolved organic C is evaluated with a CHN analyser by evaporating 0.5 ml of acidified sample. Variation coefficient is near 10% for the lagoon values.