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.

Structure of Benthic Macroinvertebrate Assemblages in Azagny Channel (Côte d’Ivoire)

“…Taxonomic richness was highest in S1 (22 taxa) and diversity indices showed higher values in S1. Indeed, this station is the furthest from Ebrié Lagoon which presents a state of organic pollution in various places [13,14,43], which tends to show that S1 presents optimal sp4 PC 2 PC 1 conditions for the macroinvertebrates development unlike other stations. It should also be mentioned the diversity of habitats of mangrove forest in S1, which may be responsible for a great diversity of species in these environments [44].…”

“…In addition, the PNA water bodies receive a significant amount of runoff from the watershed, and these waters carries a large quantity of organic matter and its accumulation in water bottom can change macroinvertebrate habitats [10]. Several studies have focused on aquatic diversity in Bandama estuary and Ebrié lagoon [13,14]. However, research of macroinvertebrates structure and distribution is rare in Azagny Channel.…”