A comparison of the composition of the juvenile fish catch from the Sokoto–Rima floodplain, Nigeria in years preceding and immediately after upstream dam completion

The species composition of the juvenile fish catch from part of the Sokoto–Rima floodplain was monitored over four seasons. In three of the years, 1981–1984, the flood pattern of the river was normal. During the 1984–1985 season the cycle was disrupted by completion of the Goronyo Dam, approximately 100 km upstream from the sampling area. The composition of the juvenile fish catch was markedly altered during this season and the diversity greatly reduced. Ways in which fish species could be affected by the change in flood regime are discussed.