Kaonodji Solngar*, Enah Dickson, Ajeagah Gideon
Laboratory of Hydrobiology and Environment, Faculty of Science, University of Yaoundé I, Cameroon
*Correspondence: Tel:23563243896; 237575916857
Email: kaonodji@gmail.com; ajeagahg@yahoo.com
Abstract
The study of environmental quality and the diversity of benthic macroinvertebrates in the Doba oil-producing basin in Chad represents a major ecological and public health issue. Doba, a town in southern Chad and the capital of the Logone Oriental region, has played a central role in the oil industry since the 2000s. Since that time, this region of Central Africa has been subjected to intense industrial pressure linked to oil extraction, which directly compromises the viability of surface and groundwater resources used by local populations. These activities alter water quality as well as the integrity of aquatic and riparian habitats, leading to a loss of biodiversity—most notably among aquatic macroinvertebrates. Assessing the status of biological communities provides data that reflect both the chemical quality of the water and the condition of the habitat. Methods based on biological assessment utilize living organisms to offer a comprehensive overview of the environmental conditions and pressures affecting aquatic ecosystems. The families identified include Dytiscidae, Belostomatidae, Nepidae, Atyidae, Gomphidae, Libellulidae, Hydrometridae, Tabanidae, Chironomidae, Coenagrionidae, Corduliidae, Pilidae, Lymnaeidae, and Naucoridae. The Dytiscidae family is represented by 5 species, followed by the Gomphidae and Libellulidae with 3 species each, and the Belostomatidae and Nepidae with 2 species each; the remaining families are represented by a single species. The species *Cylister vulneratus* is among the 14 species found in the aquatic environment at Debeu. *Caridina africana* is represented by 10 individuals, *Libellula* sp. by 8, *Laccotrephes* sp. by 7, and *Lestinogomphus* sp. by 7; the remaining species are sporadic. Various groups of species have been used for such assessments, with benthic macroinvertebrates remaining one of the most useful groups. To ensure the sustainability of water resources utilized in Doba, several biomonitoring measures are necessary: establishing a permanent biomonitoring network—using biological scoring systems adapted for Central Africa to regularly assess the ecological status of rivers—and systematically combining physicochemical monitoring (testing for polycyclic aromatic hydrocarbons—PAHs—and heavy metals) with the inventory of macroinvertebrates. Furthermore, it is essential to protect water abstraction zones, limit unregulated agricultural activity, and regulate the management of industrial effluents around drinking water sources in order to curb ecological risks.
Keywords: Environmental quality, Benthic macroinvertebrate diversity, Oil-producing basin, Doba in Chad