Physicochemical Parameters, Microbiological Water Quality and Fish Abundance in Flooded Areas of Lokoja, Nigeria

This study evaluated the physicochemical and microbial water quality as well as abundance of fish fauna in the flooded area of Lokoja Metropolis (Kogi State, Nigeria) resulting from the flooding of the River Niger and River Benue between September and October 2012 due to the release of water from Lagdo Dam in Cameron and Kanji Dam in Nigeria. Physicochemical and microbiological water qualities were determined using standard methods by APHA. Results obtained revealed that water quality deteriorated and fluctuated significantly. Microbial analysis of water from flowing river as well as those from flood plain was moderate in total coliform (0.042x10^5 and 0.45x10^5 respectively), while in residential areas, total coliform levels were critical (3.4x10^5 and 6.8x10^5). The study which recorded 7,518 fishes belonging to 9 families and 13 species indicated relative diversity with the use of various abundance indices. However, Cichlidae dominated (97.79%) the families in the study while Gymnarchidae had the least (0.013%) abundance. Water quality deterioration and lower species diversity in the study area were largely due to the flood.