open access

Submitted: 2024-11-04
Natural Resources and Forestry
Published: 2024-11-04

First Assessment of Mormyridae diversity and abundance in the Niger River at Niamey, Niger

Universidade Técnica do Atlântico (UTA) - ISECMAR Ribeira de Julião - Mindelo, São Vicente, Cabo Verde
Directorate of Fisheries and Aquaculture, General Directorate of Water and Forests, Niamey, Niger
Directorate of Fisheries and Aquaculture, General Directorate of Water and Forests, Niamey, Niger
4Department of Rural Engineering, Water and Forestry, Faculty of Agronomy and Environmental Sciences, Dan Dicko Dankoulodo University, Maradi, Niger

Abstract

To analyse the assessment of Mormyridae diversity and abundance in the Niamey fisheries on the Niger River, a study was conducted from August to November 2022. Fish data were collected bimonthly from artisanal fishing landings using gillnets, sparrowhawk nets, baited traps, and baited longlines. A total of 1279 individuals from fifteen species across nine genera were inventoried. Numerically, Mormyrus rume dominated the fish assemblages, comprising 29.9% of the mormyrid sub-community, followed by Marcusenius cyprinoides (15.0%), Campylomormyrus tamandua (12.9%), Marcusenius senegalensis (0.08%), Petrocephalus bovei (0.08%), and Hippopotamyrus pictus (0.16%). The Shannon-Weaver index of species diversity was moderate, reaching H' = 2.96. Major threats to the growth and survival of Mormyrids in the Niger River included overexploitation and anthropogenic disturbances such as domestic uses (e.g., ditch cleaning, clothes washing, bathing), invasion of floating plants (Echhornia crassipes), sand dragging, human waste dumping, and the use of chemical fertilizers and pesticides in adjacent agriculture. The results of this study will contribute to the design of a holistic species management scheme that includes habitat protection, species conservation, and valorisation.

Keywords: River Niger, Diversity, Characterization, Niger, Mormyridae