The giant fish Arapaima cf. gigas was introduced to the northern Amazon of Bolivia more than half a century ago and now contributes significantly to commercial fishing. Little is known about its distribution potential and current invasion. Here, we address this knowledge gap using two complementary methods: interviews with key informants and examination of fishing records in the main collection centers (Riberalta). Both interviews and fishing data revealed that the species represents approximately 50% of the total commercial catches, and that it now occupies approximately 340 km2 of floodplain lakes in the Beni, Orthon and Madre de Dios river basins. The annual yield is estimated at 258 tons, equivalent to 0.76 kg/ha/year. The current geographic distribution represents approximately a quarter (24%) of the floodplain lakes in the lower part of the Bolivian Amazon, suggesting a high potential for fishing the species if it colonizes the Mamoré and Iténez river basins. remaining. The potential for negative environmental impacts from the invasion of A. cf. gigas seems likely, given the large body size, life history and feeding ecology of this species, but has not yet been clearly demonstrated. The factors that could limit the expansion are natural barriers (waterfalls) in the Lesser Mamoré and cold temperature conditions in the Mamoré and Iténez river basins.
Van Damme PA, Coca Méndez C., Zapata M., Carvajal-Vallejos FM, Carolsfeld J., and D. Olden J. – Management of Biological Invasions, Vol. 6, 2015