Detecting Environmental Stress of Tropical Lagoon Using Abundance-Biomass Curve of Benthic Macroinvertebrate Assemblages (Ebrié lagoon, Côte d'Ivoire, West Africa)

Abstract

Sectors IV and V of the Ebrié lagoon are increasingly experiencing fish mortality. The abundance biomass comparison (ABC) is graphical method use to assess the level of environmental disturbance in this area. The aim of the study were to detect the environmental changes caused by anthropogenic activities using ABC curve of benthic macroinvertebrate assemblages presented in the studied areas. Results of the ABC analyses indicated that stations L, K and M are less stressed with biomass curve above abundance curve. Stations N and A recorded a stressed environment with abundance curve above biomass curve. The ABC plots showed that N and A stations could be classified as moderately disturbed and polluted. The Clarke's W index to the benthic macroinvertebrates data, confirmed this situation; it ranged from -0,129 (N) to 0,224 (L). The results of the present study can be extrapolated to other tropical wetland systems to predict the levels of disturbance and to identify characteristic organisms to predict the environmental conditions in the wetland health assessment program.