Further observation of the distribution and abundance of fish stocks in Volta Lake, Ghana
The changes in the distribution of fish in the Volta Reservoir were monitored (1) from December 1968 to October 1973 (5 to 9 years after impoundment) using a battery of gillnets with mesh sizes (stretched) ranging from 13 to 203 mm at 13 mm increments and (2) from 1969 to 1970 using the total commercial landings. Earlier work on species changes is discussed. Changes in total abundance followed the usual pattern of a sudden rise, followed by a decline and then fluctuation around a mean value. Ichthyomass was higher in the northern riverine sector than in the southern lacustrine sector. Changes in the distribution of species, families/groups and ecogroups are described.