Movements of a Mega-Fish Across Its Species Range

Globally, freshwater mega-fishes— fishes that can exceed 2 meters in length and 90 kg in mass—have become critically threatened with extinction owing to dams, habitat alteration, and overharvest.  Little is known about the life history and movements of mega-fishes making informed conservation decisions difficult.  We do know that many of these species move large distances (>1000 km) and pass up- and down-stream through dams. However, there remains a poor understanding of the relative frequency of these or other movements through waterways.  To address this need, we present the first-ever depiction of the range-wide movement frequency and distribution of a mega-fish - American paddlefish (Polyodon spathula).  This study provides important information for the conservation and management of mega-fish species as they become increasingly imperiled by rapid dam expansion in the tropics and harvest across the globe.