Application of Algal Growth Potential Test (AGPT) on the Water Quality of the Chinyang Reservoir and the Nam River

The algal growth potential test (AGPT) bioassay were conducted to assess the water quality and fertility in the Chinyang Reservoir and the lower part of the Nam River from August 2000 to July 2001, The AGPT value of the Chinyang Reservoir ranged from 0 to 23.4 mg dw $1^{-1}$, while 79% of the algae cultivation have not grown. The AGPT value was in proportion to phosphorus concentration of the water, and it was less when chlorophyll-a was high. This value was higher in the middle and lower layers than in the upper layer, and in the inflow part where the water is shallower than in the lacustrine. The AGPT value has increased in the whole reservoir in August${\sim}$September when the water volume is high. In contrast, the AGPT value in the Nam River varied greatly compared to that of the reservoir, and ranged from 0 to 252.0 mg dw $1^{-1}$ and 65% of the algae cultivation have grown. The value was less than 10 mg dw $1^{-1}$ in the upstream, over the point where the treated wastewater discharged. It was 57 mg dw $1^{-1}$ on the average in the downstream, except in March and July when the discharged water influenced greatly, exceeding the hypertrophic condition. The result of AGPT shows the differences in the time and space on the reservoir and the streams. The AGPT value has increased in July${\sim}$September, and in December in the inflow part of the reservoir; in March and August${\sim}$December in the lower part; and in January, May, and November in the streams. AGPT is useful not only in defining the influence of the limiting nutrients on the algal growth, but also in evaluating the nutrients fertility in the inland water.

진양호와 남강의 수질에 대한 Algal Growth Potential Test (AGPT) 적용

진양호와 남강 수역에서 2000년 8월부터 2001년 7월 까지 남조류 Microcystis aeruginosa에 의한 조류생장잠재력측정 (AGPT)을 수행하였다. 진양호의 AGPT값은0${\sim}$23.4 mg dw $1^{-1}$ 범위이었고, 무생장 처리구가 79%를 차지하였다. AGPT값은 수중 P 농도에 비례하였고, chl-a가 높을 때 낮았다. 또한, 표층보다 중 ${\cdot}$ 저층에서, 하류보다 수심이 얕은 유입부에서 높았다. 계절적으로는 수량이 풍부한 시기인 8월${\sim}$9월에 저수지의 전체를 통해 AGPT값이 증가하였다. 반면에, 남강의 AGPT값은 0${\sim}$252.0 mg dw $1^{-1}$ 범위로써 저수지에 비해 변동 폭이 매우 컸고, 생장이 관찰된 처리구는 65%이었다. 하수처리수가 유입되는 지점을 중심으로 상류는 연중 10 mg dw $1^{-1}$ 이하였으나, 하류 (KUM${\sim}$YOM 구간)는 유량의 영향이 컸던 3월과 7월을 제외한 평균값이 57 mg dw $1^{-1}$로써 과영양 수준을 초과하였다. AGPT 결과는 저수지와 강에서 시공간적인 차이가 관찰되었다. 저수지의 유입부는 7월${\sim}$9월, 12월에, 하류는 3월, 8월${\sim}$12월에, 하천은 1월, 5월 및 11월에 그 값이 증가하였다. AGPT는 조류 생장에 대한 제한영양염 판정뿐만 아니라, 수중 fertility를 평가함에 있어 유용하였다.