Assessment of catch, diversity and abundance of ichthyofauna in the Tono Reservoir, Northern Ghana

Abstract

Fish catches from the Tono Reservoir have been reported to decline significantly over the past decade. To investigate this problem, monthly fish samples were obtained from artisanal commercial fishermen and the use of experimental gillnets of stretched mesh sizes 5 cm and 7 cm from January 2015 to December 2016. Fish diversity was assessed using Margalef index (D) of species richness and Shannon-Weiner index (H) of evenness. The mean catch per unit effort for the period of study was 3.89 0.48 kg/canoe/day and the mean annual catch was 1,431.7 15.09 kg. Eighteen (18) fish species and 15 genera belonging to eight (8) families were recorded. The study indicated a low species diversity (D = 1.37). Regarding biodiversity, eight (8) fish species were classified as rare species. The fish catch and fish diversity were low, thus proactive management measures are required to conserve the ichthyofauna in the Tono Reservoir.