Essential oil blend as a safe and effective disinfectant strategy for shrimp hatcheries

The Vibrio group of bacteria is considered highly pathogenic to shrimp larvae. Shrimp larvae are susceptible to Vibrio. It is difficult to eradicate Vibrio from the hatchery environment completely. Efforts were made to design an effective disinfectant with almost no side effects or residues. A formulation was developed by combining essential oils with antimicrobial properties to fight against pathogenic Vibrios, such as Vibrio harveyi and V. parahaemolyticus, in a hatchery environment. The anti-Vibrio formulation is a blend of Eucalyptus globulus, jasmine, and gardenia oils, designated as essential oil blend formulation (EOBF). The effective dose of EOBF was optimized on bacteria using TSA and on Vibrio using TCBS agar media. The optimized dose of 40 ppm EOBF was sprayed on the tank and culture area dry surfaces. The trial sites selected were the water filter tank, maturation tank, fry reservoir tank, quarantine and maturation tank, hatchery tank, spawning tank, rinsing tank, plankton tank, larvae rearing tank, packing tank, artemia tank, polychaetes (bucket and floor), squid (equipment and table), and freshwater tank of an experimental hatchery. The swab samples were collected after 3 hours, and a significant decrease in Vibrio, mostly green colonies, such as Vibrio harveyi and V. parahaemolyticus, was found after EOBF application. The obtained results showed that EOBF is an effective disinfectant against pathogenic Vibrios in shrimp hatcheries.