Tridax procumbens (L.) commonly known as coat buttons or Tridax daisy, is a species of flowering plants in daisy family. It is best known as a wide spread weed and pest plant. It belongs to family compositae commonly known as 'Ghamra' and have been extens

The present work is focused on the evaluation of Chlorophyll a contained in phytoplankton from some bays of Abidjan district (Ebrie lagoon, Côte d’Ivoire). The sampling campaigns took place on August and October 2016. The study was interested successively in the physicochemical characterization of bays of Ebrie lagoon system, and the quantification of Chlorophyll a in order to evaluate the trophic state of these bays. Physicochemical parameters studies have shown a significant variation of temperature, conductivity and salinity. The determination of chlorophyll a concentration yielded values that vary between 0.26 μg.l-1 and 25.16 μg.l-1. The highest levels of chlorophyll a are observed about Koumassi stations: Koumassi 1 (15.84 μg l-1), Koumassi 2 (17.89 μg.l-1) and Koumassi 3 (25.16 μg.l-1), located in Koumassi Bay. Thus, bays could be reunited into three trophic classes: Cocody, Marcory and Anna bays are apparently ultra-oligotrophic; those of Yopougon, Azito, Bietry and M'badon are mesotrophic, and the others (Banco and Koumassi) are eutrophic.