AN INVESTIGATION OF THE IMPACT OF MUNICIPAL WASTE WATERS ON THE DIVERSITY AND ABUNDANCE OF THE CICHLID FISHES OF OGBA RIVER IN BENIN CITY, NIGERIA.

The effects of municipal wastewaters on the fish species diversity and abundance of Cichlid
fishes have been investigated in Ogba River in Benin City, Nigeria. The physico-chemical parameters
of the water of the river were also monitored during the investigation. The results showed that the
water chemistry, species diversity and abundance of the fishes of the river, which were all different
at the sample stations, were negatively impacted upon by municipal wastewaters from the city. The
Condition factor computed for each of the Cichlid fish species showed that the fishes were not in
good condition. The results also showed that the effects were temporary, as the river recovered
through self-purification, in the downstream area, further away from the wastewaters discharge
point. It was recommended that the indiscriminate channeling of municipal wastewaters into river
systems be checked, in view of the fact that such negative impacts could surpass the self-purification
ability of the rivers and cause serious declines in fish and fisheries generally.