This book deals with commercial fishing for large catfish species found in the lower Caquetá River. Commercial fishing for large catfish is the most important and consistent economic activity in the region. From an interdisciplinary perspective the book covers 4 chapters on various sociocultural, biological, and economic aspects of fish resource management. It is argued that the impact of some 60 fisherman is considerable because of the use of drift nets allowing high-level extraction techniques. Research shows a reduction of the catch per unit. It is concluded that more realistic models of actual and future patterns of fish populations compared to fishing intensity is needed in order to come to environmentally sound fish resource management.