MICROBIAL APPROACHES TO AQUATIC NUTRITION WITHIN ENVIRONMENTALLY SOUND AQUACULTURE PRODUCTION SYSTEMS

Cheng-Sheng Lee*, Andrew Brittain

The Oceanic Institute, 41-202 Kalanianaole Hwy., 
Waimanalo, HI 96795 USA 
cslee@oceanicinstitute.org

The influence of microbial metabolism on animal waste products, health, and nutrition are of recognized importance, and these aspects in aquaculture production systems deserve further study. A workshop funded by the National Oceanic and Atmospheric Administration was held in Honolulu, Hawaii, 21-24 August 2000, to discuss the current studies on the roles of microorganisms in nutrition and health of cultured aquatic species, with the goal of advancing the ability to control the microbial "floc" within aquaculture systems. Presentations and discussion focused on three aspects: the role of microorganisms external to the target species in the nutrient and organic matter transformations taking place in the culture system, the role of internal commensal microorganisms on target species, and the effect of these organisms on the health and growth of the cultured animals: marine shrimp, molluscs, and finfish. Up to the present, overall understanding and control of microbes in aquaculture systems has been limited, even in well-controlled hatchery systems, and have been generally lacking under high density growout conditions. Standard methodology and management capabilities to modify the microbial community are not yet available. Applying modern methodologies that have been developed for studying natural microbial ecosystems offers the potential for a greater understanding of aquaculture systems. In the hatchery, specific bacteria may be added to sterilized tanks to influence the system or improve animal health. Whether probiotic microorganisms derived from an outside environment, however, have an effect on a microbially intensive environment, such as a shrimp pond, has not yet been clearly demonstrated. Collaboration with other experts outside the aquaculture community may result in rational management procedures. Traditional microbial ecology methods applied to aquaculture production systems may improve overall production.

This presentation summarizes the reports presented and topics discussed at the workshop, including attempts to identify the microorganisms of interest and to modify the microbial population, either through environmental manipulation or microbial additions, including probiotics. Knowledge gaps that were identified and recommendations made to the industry are also presented.