Health management in recirculating aquaculture systems (RAS)

Recirculating aquaculture systems (RAS) have become more numerous and equally sophisticated as land-based aquaculture production has increased. The complexity of the system gives rise to a number of health management issues whereby the water quality of the production system directly impacts the health of the fish. Additionally, the challenges of using RAS in a seawater environment pose unique issues of water chemistry, fish production biology, and health. Fish health management in RAS depends largely upon the quality of the intake water for controlling the known obligate fish pathogens. However, opportunistic pathogen groups including Flavobacteria spp. and Saprolegnia spp. may pose significant challenges since conventional chemotherapy may have negative effects on the biofilter and subsequently disturbing water quality.