Ideally, microalga used with integrated aquaculture systems should have all of the following characteristics: (1) algal cells must be harvested by simple filtration; (2) easy to mass culture; (3) tolerates wide salinity range; and (4) algae are a valuable by product. With our present work, we choose the cyanobacterium Spirulina platensis for nitrogen removal in shrimp culture tanks since it meets all the above requirements. We previously found that S. platensis grew well in seawater (5–30x salinity) and was easily removed by filtration through 60-Am mesh net. This allowed semicontinuous harvest of S. platensis. Although Spirulina is one of the most widely studied microalgae, especially for waste- water treatment, most studies are with algal monoculture in high-rate algal pond system (Tanticharoen et al., 1993; Phang et al., 2000), not with integrated systems containing both algae and an animal crop. Our present research evaluated the efficacy of integrated algae–
B. Chuntapa et al. / Aquaculture 220 (2003) 355–366356
shrimp culture where S. platensis was used for water quality control with semicontinuous algae harvest.