Recirculating Aquaculture System
Heterotrophic biofilm filter for recirculating water use in shellfish hatcheries
The development a recirculating aquaculture system (RAS) would allow bivalve hatcheries to reuse production water and minimize impact from fluctuating ambient water quality. The pilot system design consists of a 600 L traditional moving bed bioreactor with K1 Kaldnes carrier elements (AnoxKaldnes, Lund, Sweden). Media were conditioned for ammonia reduction and enriched heterotrophic microbial community to reduce organic waste and remove bacteria from larval production waters. A conventional foam fractionator was also used to assist with removal of dissolved organics. A standardized a heterotrophic conditioning protocol was developed.
Organics were rapidly absorbed and treated by the system with very little perturbation of the biomass in the reactor. Cultured Vibrio spp were loaded to the system and eliminated from the planktonic phase. Bay scallop and eastern oyster larvae were successfully used to test reactor water quality. A pilot scale system was then installed in a commercial oyster hatchery with good results. Currently, a full scale commercial system is being constructed at Oyster Seed Holdings. Inc. 
Richard Snyder, Chris Bentley at VIMS ESL
Michael Schwarz, Reza Ovissipour, Setareh Shiroodi, Steve Urick2, Jonathan van Senten at VT
Michael Congrove, and Kasey Bond at Oyster Seed Holdings, Inc.