Is there a future for artisanal fishing in the Amazon? The case of Arapaima gigas

摘要

In the last ten years Araipama gigas, commonly known as pirarucu, expanded itsdistribution upstream into the Madeira River rapids where it is not a native species.The invasion was favored by escapes from Peruvian fish farms upstream in theMadeira River Basin, where they have been raising pirarucu since the 1970s.Although the Madeira River rapids had formerly represented a geographical barrierto this invasion by limiting floodplain habitats, the construction of the SantoAnt?nio and Jirau dams in 2011 flooded the two most important falls, replacing therapids stretch with a lentic or semi-lentic habitat favoring the invasion of A. gigas.Since construction of the dams, fisheries reports have been marked by the decrease oftraditional commercial species, coupled with the presence of invasive populationsof A. gigas. This example highlights a major emergent threat to artisanal fishing inthe Amazonian freshwater system: government policies favoring dam constructionand the consequent spread of native fish species used in aquaculture to new regionsupstream of waterfalls where they are not native.