Disease Control in Korean Aquaculture

Abstract

As the mariculture technique had been developed, annual production of shallow water cultures exceeded that of adjacent water fisheries in recent years in Korea. For reducing production losses from infectious diseases in fish aquaculture, various strategies were employed including treatment of effective chemotherapeutics, development of herbal immunostimulants and vaccination, etc. For the treatment of bacterial diseases 27 antibacterial agents have been used under government license. Frequent use of these drugs was accompanied with occurrence of drug-resistant bacteria. Recently, new bacterial diseases have occurred in cultured fishes. As the studying on the control activities of medicinal herbs to bacterial growth, the wormwood Artemisia asiatica, the Galla rhois Rhus javanica and the veiled lady mushroom Dictyophora indusiata were revealed high antibacterial activities to the Gram-positive and negative bacteria. For the enhancement of nonspecific immune response in mariculture fish, medicinal herbs and other several materials were investigated as immunostimulants. Olive flounders Paralichthys olivaceus fed on the diet supplemented with 0.1% extract mixture of the wormwood and the barrenwort Epimedium koreanum showed higher relative percent survival (RPS), when they were challenged with bacterial pathogens. To prevent various infectious diseases, two vaccines were developed and commercially available including vaccines on Edwardsiella tarda and Streptococcus iniae.