This is the 4th edition of the book that has become known in the industry as the Yellow book. It addresses the subject of recirculating aquaculture systems (RAS). Thus, this text is designed primarily for recirculating systems, which the authors feel will be the system design of choice for most new aquaculture ventures. Much of the information provided in this text does, however, also apply to open, semi-closed, and closed systems in terms of tank design, hydraulics, fish management, water quality, etc. The objectives of this text are the practical application of aquacultural engineering principles to the design, construction, and management of an aquatic production system. A chapter on aquaponics has also been added with extensive examples.