Abstract

In this study, we evaluated the effect of inland pollution sources on sea water and oyster (Crassostrea gigas) in JaranmanㆍSaryangdo area after rainfall events. We analyzed the sanitary indicator microorganism such as coliform group, fecal coliform and Escherichia coli (E. coli) in the discharge water of major inland pollutants, sea water and oyster for 3 days after 24.5, 50.0 and 67.5 mm rainfall events. As the rainfall in this area became increased, the range of fecal coliform of 15 contaminants was increased gradually (24.5 mm; 4.5-54,000 MPN/100mL, 50.0 mm; < 1.8-92,000 MPN/100mL, 67.5 mm; 49-240,000 MPN/100mL). However, the range of radius of impacted area of 15 contaminants was decreased and getting better for 3 days. The peak pollution was observed in the Yongho-village domestic waste water. The calculated impact area of inland pollution sources was 0.03 km2 immediately after 24.5 mm rainfall and expanded to 0.2 km2 after 67.5 mm rainfall. These calculations of impacted area matched results from fecal coliform analyses with sea water. According to the evaluation of the influences of inland pollution sources and fecal coliform analyses on sea water and oyster this area, pollutants from inland sources did not reach the boundary line of the oyster growing area after rainfall events. The bacteriological water quality of the oyster growing this area met the Korea standard and US NSSP requirements for approved oyster growing area. And the E. coli level of oyster at 10 station in the designated area was met the EU regulation and the limit of raw oyster in Korea with ranged from < 18 to 230 MPN/100g.