Status and future of fish biodiversity in Lake Fitri in the Sahelian Zone of Chad

A study was carried out from August 2020 to July 2021 on eight islands located in several villages around Lake Fitri. The aim was to inventory the biodiversity of Lake Fitri's ichthyofauna. The quantitative analysis benefited from data collection through catches and measurements, interviews with fishermen, traditional authorities and other stakeholders. Only eight fish species were recorded: Marcusenius senegalensis, Oreochromis niloticus, Synodontis ocellifer, Clarias gariepinus, Schilbe mystus, Schilbe intermedius, Polypterus senegalus and Protopterus annectens. The average size of fish caught at various sites was small 23.7 ± 1.0 cm. Specific abundance was dominated by Oreochromis niloticus L. and by two species, Schilbe mystus L. and Schilbe intermedius R. The average specific diversity index was estimated at 4.17 ± 0.16, while the equitability index was estimated at 0.86 ± 0.84. The survey clearly shows that fishing regulations are not respected, leading to an over-exploitation of ichthyological resources of which the stakeholders are unaware. Key words: Fish, Lake Fitri, livelihood strategies, sustainable exploitation.