The use of ozonized seawater to reduce andeliminate bacterial pathogens in mariculture facilities and to extend shelflife of marine food products is demonstrated. Consequent benefits of this treatment are also discussed. Laboratory and pilot experiments were conducted using ozone gas to reduce disease-producing Vibrio sp. bacteria at a shrimp(Litopenaeus vannameii) hatchery in Ecuador, South America. Pacific Ocean seawater was treated in a 1,540 L capacity fiber glass contact tower (5-7 minretention) with an ozone oxidant residual of 0.07 mg/L. Prior to ozone treatment, Vibrio determined by TCBS plating was too numerous to count, causing shrimp to die of disease (30 tanks of 13,000 L each). After treatment, Vibrio countsand shrimp disease were eliminated, ozonized seawater decreased the time required for normal molting of shrimp and the total growth cycle was reduced bythree days versus control water. From June 1991 until September 1992, survivalrates of larval shrimp were robust, routine antibiotic addition was reduced,and one additional growth cycle was realized. Ozonized ice (fresh water) wasprepared in the Milford Laboratory CT, USA; Gloucester Food Tech Lab, MA, USA;and a field station (brine water) for sockeye salmon (Oncorhynchus nerka) in Homer,AK. USA. In these studies, squid (Loligo pealei) and commercially captured salmon demonstrated a reduction in spoilage and extension of shelf life of 3 to5 days’ time using ozonized ice. Bacteria associated with commercial ice-producing machines were reduced by 4 logs using ozone treatment. In addition, no flavor aberration was noted using ozonized ice.