Biology of Ethmalosa fimbriata (Bowdich) and fish diversity in the Ebrie Lagoon (Ivory Coast), a multipolluted environment

The biology of the clupeid Ethmalosa fimbriata (Bowdich) was studied as a potential bio-indicator of pollution in three bays of the Ebrie Lagoon, an inter-tropical lagoon in the Ivory Coast (western Africa). Bietri Bay was the most impacted by Abidjan's industrial and urban waste, Cocody Bay was characterized by the presence of eutrophic water, and Sud Boulay Bay, located in a rural zone, was least impacted. Sizes at first maturity (fork length) of E. fimbriata were lowest in the most polluted bay (Bietri: 80.8 and 83.5 mm for males and females, respectively), higher in the intermediately polluted bay (Cocody: 125 and 137.5 mm, respectively), and highest in the unpolluted bay (Sud Boulay: 135 and 145 mm, respectively). Owing to its hardiness, E. fimbriata is the dominant species in polluted water, constituting more than 75% of the total number of fish caught. As a consequence, fish diversity decreased and the community was less structured in the polluted environment than in the unpolluted one.