Algae. 2003; 18(2): 169-176.
Algal Growth Potential Test (AGPT) in Streams and Embayment of the Okchon Stream Watershed, Korea
Jae-Ki Shin, Dong-Sup Kim, Hye-Keun Lee, Sung-Jin Maeng, Soon-Jin Hwang
Department of Biological Systems Engineering, Konkuk University, Water Resources Research Institute, Korea
Water Resources Corporation
Algal Growth Potential Test (AGPT) bioassay were conducted to evaluate the stream and reservoir water in the Okchon Stream Watershed during May to September 2002. The water quality of the stream water was clean in the upstream, deteriorating toward the downstream. In particular, SRP and NH₄significantly increased due to treated wastewater. The average AGPT value of the Okchon Stream Watershed was 22.4 mg dw?l〈sup〉-1〈/sup〉, with the range of 0-195.7 mg dw?l〈sup〉-1〈/sup〉. AGPT value was the highest immediately after inflow of treated wastewater, average 91.3 mg dw?l〈sup〉-1〈/sup〉. AGPT was highly correlated with SRP, NH₄ and TIN factors, with P having the greatest effect on the growth of algae. Among N components, NH₄was preferred to NO₃for the growth of algae. Likewise, AGPT was closely linked to meteological and hydrological effects and development of natural phytoplankton. In survey stations, mesotrophic, eutrophic and hypertrophic conditions accounted for 43%, 21% and 36%, respectively. On the other hand, hypertrophic condition focused on the downstream reaches. AGPT was useful in determining not only the limiting nutrients but also the water fertility for the growth of algae. Based on the AGPT results, the management of point sources for water pollution in treated wastewater was important in the protection of aquatic environment in the stream and embayment.
Keywords : algal growth potential test (AGPT), embayment, Microcystis aeruginosa, reservoir, Okchon Stream Watershed, wastewater, water quality