Effects of rainfall on fish community structure in Agaie-Lapai Dam reservoir of Niger State, Nigeria.

Abstract

The effects of rainfall on fish biodiversity in Agaie-lapai dam reservoir were studied by monthly samplings and measurements taken from 2013 to 2014. The reservoir is situated at 9° 39’ N latitudes and 6° 33' E longitudes located near Bakaje at the confluence of the Jatau River. The reservoir was constructed for irrigation. fisheries and tourism purposes. Samples of Fish was collected from the fishermen in two landing sites where catches were done using cast nets, seine nets and hooks and lines in designated stations. Eleven families were identified during the study belonging to Brigridae 2 species, Characidae 2 spccies, Schilbeidae 2 species, Cichlidae 5 species. Clariidae 2 species Cyprinidge 3 species, Chanidae, Hepsetidae, Malapteruridae, Mochokidae and Mormyridae had 1 specie each respectively. The species diversity was at its peak in the wet season, coinciding with favourable conditions such as highwater level and abundance natural food. The reverse was the case in the dry period as a result of 10v» level-of the water in the reservoir, insufficient food items and uncontrolled fishing practices. The highest species richness value (1.08) was recorded for Schilbeidae while the lowest record of (0.56) value for Hepsetidae. Lapai dam reservoir is a small, unpopular, unmanaged and unmonitored. To correct these abnormities, an urgent need to reverse the trend by government is paramount.