A study of the limnology and plankton abundance in relation to fish production in the shore, surface and bottom of this Oyan Lake (northwest of Abeokuta, Nigeria) was investigated between January 2001 and August 2002 at three stations along the entire stretch of the lake. Standard methods were used to monitor the physico-chemical and biological parameters. Such parameters are: water temperature, transparency, pH, dissolved oxygen, conductivity, total alkalinity, total nitrate, total phosphate and total dissolved solids, pelagic primary productivity and plankton abundance. A fleet of nine nets of passive graded experimental gill nets (mesh sizes 2.54 to 177.8mm) of equal surface area was used in catching fish from the shore, surface and bottom of the Lake. Fish catch by artisanal fishermen at three selected landing sites on the lake was also monitored simultaneously.