Ecological Status of a Coastal Stream in the sea Port Area of Kribi, Cameroon: Diversity of Benthic Macroinvertebrates and Relationship to Some Physico-Chemical Parameters of the aquatic ecosystem

A study aimed to assess the ecological status of the water of the Mboro coastal stream, located in the sea port area of Kribi, South Region of Cameroon, through the diversity of benthic macroinvertebrates and some physico-chemical parameters of the water were carried out. Samples were done seasonally using a multi-habitat approach. Physico-chemical analyses revealed a relatively high oxygen saturation level (79.88 ± 4.91%), an average temperature of (27.70°C ± 1.66°C), and a slightly basic average pH of (7.20 ± 0.77 UC). The relatively low values of the Organic Pollution Index (IPO) indicate that the water of the Mboro stream are polluted. The biological results show a taxonomic richness of 78 taxa including 9391 individuals. Divided into 2 phyla (Molluscs and Arthropods), 4 classes, 20 orders, and 52 families. The class Gastropods was predominant with 35% relative abundance, dominated by the family of Neritidae (Nerita senegalensis), followed by the class Bivalves with a relative abundance of 33%, supplanted by the family of Mytilidae (Mytilus edulis, Xenostrobus pulex) and Mutelidae (Mutela rostrata). These organisms are pollutant-tolerant and can survive in degraded environments. Their significant presence downstream reflects the advanced deterioration of the water quality in that section of the stream. Thus, the development upstream of pollutant-sensitive groups such as the Baetidae (Ephemeroptera), Veliidae and Gerridae (Heteroptera), and Aeshnidae (Odonata) indicates a habitat of good ecological quality. The Hilsenhoff Biotic Index also revealed a notable deterioration of water quality downstream of this industrial complex.