In Nicaragua a relatively unique situation exists in which the freshwater fish resource is being underutilized as a protein source. Exceptional opportunities are present to develop this resource and increase the protein consumption of the rural inland population of Nicaragua. However the recent introduction of African tilapia threatens the entire natural ecosystem where they appear to be spreading and dominating the local cichlid fauna. Their presence could collapse the fisheries valued at over 10 million dollars. This study will examine the expansion of the introduced African tilapia in Lake Nicaragua and continue long-term studies on the ecology, reproductive biology and recruitment of Nicaraguan cichlid fishes. %%% Numerous studies have documented the disappearance of one or more species from bodies of water following exotic introductions. These studies have taken place after the species have been eliminated and the precise mechanisms or causes for elimination remain hypothetical. This study will examine, document, and understand the actual process of fish invasions before native species, many underscribed, disappear. The results will be used to coordinate management of the cichlid fish resource with the goal of maintaining the genetic diversity of the fisheries while at the same time maximizing the sustainable economic return to the people of Nicaragua.
