Most major urban centers in Sub-Saharan Africa are located along the shores of estuaries, lakes, or lagoons which, due to their high biodiversity, are often subjected to significant anthropogenic pressures, particularly waste pollution. This study aims to analyze the phytoplankton community structure of the Ebrié Lagoon, an ecosystem heavily impacted by human activities. Phytoplankton samples were collected between February and November 2020 using a 20-µm mesh plankton net, targeting specific areas of the lagoon exposed to intense anthropogenic pressure. A total of 53 taxa belonging to five phyla were identified: Heterokontophyta, Dinophyta, Cyanoprokaryota, Euglenophyta, and Chlorophyta. Among these groups, Heterokontophyta exhibited the highest diversity, accounting for 58% of the total abundance. Furthermore, Cocody Bay emerged as the most biodiverse site, with 45 species recorded, representing 46% of all identified taxa. These findings highlight the ecological importance of the Ébrié Lagoon as a phytoplankton habitat and emphasize the urgent need for management strategies to safeguard this fragile ecosystem against increasing urbanization.

The natural vegetation strip along water bodies acts as a crucial barrier against the influx of nutrients and sediments. Consequently, the progressive degradation of the riparian vegetation around Banco Bay has led to the silting of the bed of this section of the Ebrié Lagoon. The primary objective of this study was to enhance the understanding of the quality of Banco Bay’s shores to identify priority intervention areas for potential re-vegetation efforts. To achieve this, a riparian quality index assessment protocol was applied. This involved delineating 200-meter-long and 10-meter-wide segments along the riparian vegetation strip. Within these sampling areas, a botanical survey was conducted to assign a coverage percentage to the different components of the riparian strip, allowing for the calculation of the riparian quality index. Data analysis revealed low floristic richness with 17 tree species, predominantly microphanerophytes and nanophanerophytes. The low IQBR values indicate a riparian zone in poor condition, with 92% of the segments classified as very low or low IQBR classes. Given the consequences of water silting, it is essential to use the results of this study as an awareness-raising tool for residents and decision-makers, encouraging collective action towards the re-vegetation of Banco Bay’s shores.

Demographic pressure on watercourses in Côte d’Ivoire is causing increasing degradation of water quality. One of the indicators of water quality is the micro-algal population. The aim of this study is to assess the trophic status of the waters of the Comoé River, based on physico-chemical parameters and micro-algal populations. Four sampling campaigns were carried out from February 2020 to January 2021 at ten selected stations on the river. Abiotic variables were measured in situ and in the laboratory. Microalgae were collected using a plankton net and observed under photonic and electron microscopes for identification. Several indices for assessing the trophic status of the waters were calculated. The study revealed that the waters are relatively warm, rich in nutritive salts and not very transparent. A total of 190 taxa in 79 genera, 39 families, 23 orders, 10 classes and 5 phyla were identified. The Euglenophyceae class, with 58 taxa (30.52%), is the most diverse. The calculated A and B indices range from 6.14 to 7.69 and from 1.14 to 2.23 respectively. The C index fluctuates between 0.20 and 1.18. Nutrient concentration, transparency values and the A, B and C indices indicate that the river’s waters are eutrophic, with more pronounced eutrophy in the middle and lower reaches.