Conceptual design of a microalgae-based recirculating oyster and shrimp system

• Published in: Aquacultural engineering 2003-06, Vol.28 (1-2), p.37-46
• Main Author: Wang, Jaw-Kai
• Format: Article
• Language: English
• Subjects: Algae; Animal aquaculture; Animal productions; Artemia; Bacillariophyceae; Biological and medical sciences; Bivalvia; Chaetoceros; Decapoda; Fundamental and applied biological sciences. Psychology; Invertebrate aquaculture; Marine; Mollusca; Penaeidae
• ISSN: 0144-8609; 1873-5614
• DOI: 10.1016/S0144-8609(03)00020-7

The need to reduce water consumption in aquaculture has long been recognized and a great deal of research effort has been directed toward the development of recirculating systems. Unfortunately, current research and development in aquaculture water re-use is largely devoted to bacteria-based systems, while microalgae-based water re-use system development has been neglected. That a large body of knowledge is available on bacteria-based wastewater treatment has no doubt contributed to this reality. However, a bacterial component in a water re-use system dedicates itself entirely to excessive nutrient removal and the required capital and operational expenses are cost items that contribute to the scarcity of commercial successes of such systems. In contrast, a microalgae-based water re-use system produces microalgae that can be used to produce a second crop, such as bivalve seed or Artemia, which can be sold to generate income. The main difficulty encountered in the development of a microalgae-based water re-use system has always been the inability to maintain the desired algal species in an open system. The University of Hawaii has solved this problem. The breakthrough in marine diatom production technology allows us to turn our attention to the development of a water re-use system where the ‘effluent’ becomes a valuable resource. An integrated shrimp/algae/oyster production system reduces water consumption and turns effluent ‘waste’ into a profit center while taking advantage of the antibacterial properties of the marine diatom to control bacterial diseases. The reduction of pathogenic bacteria is likely to also reduce the susceptibility of the shrimp to viral disease. This paper describes the design of a microalgae-based recirculating system that produces oyster and shrimp using the marine diatom Chaetoceros as the intermediary media to remove the excessive nutrients from the shrimp production and to serve as feed for the oysters.