Food web structure in a sand-dragged man-made lake of Benin, West Africa: Implications for ecosystem management

Abstract

Knowledge on Lake food web is important to assess ecosystem structure, to depict habitat degradation, to evaluate changes in community structure and to implement sound ecosystem management. We investigated food web components, food chains and trophic levels of the man-made lake of Ahozon of Southern Benin in order to document trophic networks and ecosystem functioning. Biological data were sampled bimonthly from August 2014-October 2015, along with dietary analysis of fishes. Food web components recorded comprised detritus, macrophytes, phytoplankton, zooplankton, macroinvertebrates, fishes, frogs, varanids, turtles, snakes and bird fishers. Detrital and grazing food chains were depicted and interlinked to form the food web. Trophic levels comprised detritivores, producers (algae), herbivores, micro carnivores/omnivores, carnivores, top carnivores with fishes foraging on many trophic positions. Some interactions such as detritus-decomposers, detritus-consumers, nutrients-autotrophs and autotrophs-consumers were recorded and valorized the fishes and the lake. This food web study constituted documentation for fisheri