Biodiversity and abundance of fish and plankton of Dan-Zaria Dam, Niger State, Nigeria

Abstract

An assessment of fish and plankton biodiversity and abundance of Dan-Zaria Dam were carried out over a period of one year. Sampling of fish and plankton was conducted monthly. Five (5) sampling stations were randomly established based on their importance to the dam. Fish sampling was conducted using cast net, fleets of gill nets of various mesh sizes, ranging from one inch to seven inches. Fishes caught were identified, counted, weighed and lengths taken and recorded. Results indicated that five fish species existed in the dam during the study period, about three of the species viz. Oreochromis niloticus, Tilapia zilli and Clarias gariepinus were the most common, while the two other species, Laboe senegalensis and Alestes nurse were less common. A total of 2,010 fishes were caught. Of the three common species, O. niloticus dominated with an estimated total catch of about 1,609 accounting for 80.05%. The total catch for, T. zilli was 178 representing 8.86%, that of, C. gariepinus was 137 representing 6.82%, the others represented about 4%. Water and plankton samples were taken simultaneously with fish samples. Results showed that Four (4) common taxa existed in the water body at the time of study viz. Chlorophyceae, Cyanophyceae, Desmidiaceae and Bacillariophyceae. In all about 28 species of phytoplankton were identified. About forty (40) species belonging to 4 taxa of zooplankton, the protozoa with about 26 species, Cladoceran (3 species); Copepoda (4 species) and Rotifers comprising about 7 species %. It was therefore concluded that the biodiversity of fish species and abundance were of a short range however with a good yield. While for plankton, it was concluded that their biodiversity and abundance were great at the time of this study.


Key word: Biodiversity, Fish, Plankton, Abundance, Dan-Zaria dam


Journal of Aquatic Sciences Vol.18(2) 2003: 141-148