TITLE:
Seasonal Variations in the Water Chemistry and Benthic Macroinvertebrates of a North West Region (Bamenda) Cameroon
AUTHORS:
Raoul Polycarpe Tuekam Kayo, Siméon Tchakonté, Oumarou Farikou Pountougnigni, Paul Alain Nana, Mathias Nwaha, Lié Nyamsi Tchatcho
KEYWORDS:
Pollution, Benthic Macroinvertebrates, Bamenda, Indicator Species, Water Quality
JOURNAL NAME:
Open Journal of Ecology,
Vol.16 No.2,
February
10,
2026
ABSTRACT: Freshwater resources are increasingly being subjected to organic pollution because of the escalating growth of human population which is accompanied by urbanization and the increasing demand for food (Agriculture) and habitat. Consequently, freshwater quality and aquatic ecosystem structure and function are severely affected. The Achichem stream drainage, which flows across the city of Bamenda I and III, North West Region of Cameroon is not an exception. This study, seeks to evaluate the biological and physicochemical state of the Achichem stream of Bamenda. Very little data is available on water quality and diversity of benthic macroinvertebrates of these hydrosystems. Moreover, the real impact of dumpsite Bamenda City Council (BCC) on these invertebrates remains to be determined. The specific objectives are: to determine the physico-chemical parameters of the drainage system; the bio-identification of benthic macroinvertebrate communities, indicators of aquatic pollution in Mezam River; to determine the bioindicators of aquatic pollution levels in the savana highlands of the North West Region and to evaluate the relationship between physicochemical and biological community structure and water quality. A total of 06 sampling stations were selected in 3 stations of Achichem streams that flow across the center city of Bamenda I and III. In each of the stations, sampling was carried out each season (dry and rainy seasons). Analysis of abiotic variables showed that, the Achichem streams, prove to be highly polluted according to OPI and reveal higher values of heavy metals, high temperatures, with high mineralization. Regarding the biotic communities, 54 taxa of benthic macroinvertebrates distributed into 3 phyla, 3 classes, 9 orders and 36 families were identified in the two seasons. Considering the relative abundance of benthic macroinvertebrates, it is observed that the two seasons were dominated by Arthropoda. The specific species collected in dry season were Coleoptera (Cybista sp., Peltodytes sp.), Odonata (Limnometra ciliate, Limnometra sp., Ventidius malayensis), Ephimeroptera (Procloeon pennulatum), Trichoptera (Notonecta Linnaeus) and Diptera (Hydropsyche sp., Hexatoma sp.). The specific species collected in the season were Odonata (Nervosa Rambus, Curictini sp.), Ephimeroptera (Procloeon pennulatum, Anabolia sp.), Trichoptera (Brachycentrus sp., Chimarra sp., Hydropsyche sp.) and Gastropoda (Vorticfex sp.). On the ecological point of view, this invertebrate community is mainly constituted by predators and organisms with gills, highlighting an unpolluted medium. Limnometra ciliata (Heteroptera-Gerridae), a species known to be endemic in Northern zones of America, was found in the Achichem stream. The benthic fauna is less diversified and comprises essentially of Dipterans, Molluscs and Annelids, which are, in their majority, tolerant to pollution. These results show a highly polluted urban waterway within the Bamenda I and III.