Study of Water Quality of the Ebrié Lagoon and Proposal of Toxin Structures in Relation to Algal Efflorescences

Aims: The aim of this work is to know the interrelationships of the physicochemical parameters likely to explain algal blooms and to identify the potential structures of molecules that can be secreted in an Ivorian lagoon environment: the Ebrié lagoon.

Methodology: Nine stations, selected according to natural influences and anthropogenic pressure, were subject to physicochemical monitoring. It consisted of in situ measurements (temperature, salinity, dissolved oxygen, electrical conductivity) and chemical analyses in the laboratory (pH, nitrates, nitrites). In addition to these measurements, observations were noted in the field, namely the climatology of the day, the colour and smell of the water, the presence of algae (micro and / or macroalgae).

Results: Our results showed that the waters of the Ebrié lagoon are warm (T > 25 °C), with a pH between 6 and 9 and variable salinity. Salinity would be a discriminating factor for the presence of macroalgae. The nutrients levels (nitrates and nitrites) remain within the limits of acceptability.

Conclusion: The waters in our study area are favorable for algal blooms. Given the nuisances associated with algal blooms, the study proposes some structures of toxins which can be secreted on the basis of a literature review.