We investigated environmental characteristics of the mudflat oyster aquafarms to clarifyeffects of the mudflat environmental factors on growth and mortality of the mudflat oyster Crassostrea gigas by the Net Bag Rack Culture System in two districts in Western Korea. In this study, we have carried out the basic environmental investigation on growth of the single mudflat, water quality and sediments, etc. in Taean and Seosan districts, Choongcheongnam-do, where the single mudflat oyster aquaculture have been performed by the net bag rack culture system. In June 2011 when the final survey carried out at the two districts in western Korea, the mortality in Seosan district was higher than that in Tae-an district. Judging from the results of growth and mortality of the single mudflat oysters investigated at two sites of Jinsan-ri in Taean and Chang-ri in Seosan districts, two results of Taean district showed higher growth and lower mortality than those of Seosan district. It is assumed that the proper acceptable density possible for growth of the mudflat seeds and the secure of economics, in case of plastic cultivate net with the size of 50 x 80 cm, are about 200 individuals. In this study, It was clarified that selection of the suitable sites, the input into the net bag of high quality oyster seeds and selective dispersion in the optimal density of the single mudflat oyster have an effect on growth and mortality of the mudflat oyster.
