ECOLOGICAL IMPLICATIONS OF FISH AND GEAR DIVERSITY IN SHIRORO DAM RESERVOIR, NIGER STATE, NIGERIA

Abstract

The mapping of phytoplankton composition and abundance of Tagwai reservoir were assessed with the aid of computer-assisted interpretation of Quick Bird Satellite imagery (Geographical Information System) over a period of six months (February-July 2016). Four sampling stations were selected based on provincial activities around the lake and the co-ordinate points of each identified sampling station were taking using Global Positioning System (GIS). Plankton net was used to take plankton samples from the water surface monthly, preserved using with 5% formalin and taken to the laboratory for analysis. A total of fifteen species from four taxonomic group were identified in which chlorophyceae was the most abundant which ranged from 20.00±14.14 (station III) to106.00±61.89 (station II) There was a significant difference (P<0.05) in the mean variation of chlorophyceae observed in all stations followed by Baccillariophyceae, with the mean range of 68.57±65.94 (station II) to 12.00±4.47 (station III), and Cyanophyceae that ranges from 40.00±28.28 (station III) to 70.00±28.28 (station II) The difference was not significant (P>0.05) in the mean variation of Baccillariophyceae and Cyanophyceae distributions in all the stations.While the lowest was Desmidiaceae.The high relativeabundance of Chlorophyceae is an indication that the reservoir will support fish production.