Recovery of Arapaima sp. populations by community-based management in floodplains of the Purus River, Amazon

In the present study a unique dataset on population abundance in various community-based management (CBM) and non-CBM areas is analysed to address the question of whether CBM can recover overexploited populations of Arapaima sp. in river-floodplain ecosystems. All non-CBM areas possessed depleted Arapaima sp. populations with a mean density of 0·01 individuals ha−1. Arapaima sp. population densities in all CBM areas changed over time from depleted to overexploited or well managed status, with a mean rate of increase of 77% year−1. Rates of Arapaima sp. population recovery in CBM areas differed, probably reflecting differences in ecosystem productivity and compliance with management regulations. These results indicate that CBM schemes can be effective tools for the recovery and conservation of fish populations with non-migratory life cycles in tropical river-floodplain ecosystems.