Environmental impact assessment of fish farm hatcheries management in lower Niger Basin Area of Nigeria
The environmental impact assessment was carried out in different five geographical zones of Kwara Central, Kwara North, Kwara South, Kogi Central and Kogi West in two phases. Phase 1 was investigation by observation through questionnaire administration and phase 2 was observation by experiment (sampling and analysis) of 5 farms in each zone making a total of 25 farms. Water quality parameters were measured from site to site where alkalinity and hardness differed significantly (p< 0.05). Environmental impact assessments were taken to determine the causes of environmental threats to farm lands and the environment in the selected areas. Of significance of impact assessment were activities like air, traffic, noise, had insignificant impact (p > 0.05), while water pollution, insecurity as a result of land exposure and wild life displacement were impacted significantly (p < 0.05). Fish bred and raised were monoculture of family Clariidae of which species of Clarias gariepinus and Heterobranchus longifilis, Heterobranchus bidorsalis and their hybrids were prominent. Poor quality constructions of brood stock ponds, spawning, nursery tanks and fish hatcheries drainage compartments, their effects coupled with uncontrolled discharge of waste water in the hatcheries caused negative residual impacts of pollution, erosion and degradation of farm lands and environment. To prevent the occurrence of these hazards, fish farmers must obtain permits from relevant authorities and contact experts before embarking on pond constructions and fish hatcheries.
Keywords: Fish farm hatcheries, impacts, assessments, Kwara state, Kogi state