Organic and bacterial pollution in the Ebrié lagoon, Côte d'Ivoire

A systematic study of some pollution indicators [ammonia (NH4-N), faecal coliforms counts] has been carried out for three years (1993-95) in the urban area of the Ebrié lagoon, evaluating the impact of a sea outfall project. This project, for collecting and forwarding wastewaters of the city of Abidjan to the Atlantic ocean in order to reduce the pollutant load in the lagoon, was initiated in 1994. It failed a few months after the first operation and there is now an overall increase in pollution due to continuous use of the lagoon for dumping domestic as well as industrial and agricultural wastes as a consequence of the malfunctioning of the outfall, which was poorly designed, probably because of insufficient funding. (Résumé d'auteur

Seasonal Variability of Carbon Dioxide in the Rivers and Lagoons of Ivory Coast (West Africa)

peer reviewedWe report partial pressure of CO2 (pCO2) and ancillary data in three rivers (Bia, Tanoé, and Comoé) and five lagoons (Tendo, Aby, Ebrié, Potou, and Grand-Lahou) in Ivory Coast (West Africa), during four cruises covering the main climatic seasons. The three rivers were oversaturated in CO2 with respect to atmospheric equilibrium, and the seasonal variability of pCO2 was due to dilution during the flooding period. Surface waters of the Potou, Ebrié, and Grand-Lahou lagoons were oversaturated in CO2 during all seasons. These lagoons behaved similarly to the oligohaline regions of macrotidal estuaries that are CO2 sources to the atmosphere due to net ecosystem heterotrophy and inputs of riverine CO2 rich waters. The Aby and Tendo lagoons were undersaturated in CO2 with respect to the atmosphere because of their permanent haline stratification (unlike the other lagoons) that seemed to lead to higher phytoplankton production and export of organic carbon below the pycnocline