Contribution of Primary Production of Phytoplankton to Organic Pollution in a Eutrophic River, the Naktong River

Algae > Volume 11(2); 1996 > Article

Algae 1996;11(2): 231-237.

Bom-Chul Kim, Gil-Son Hwang, Kwang-Soon Choi, Woo-Myung Heo, Won-Kyu Park

Department of Environmental Science, Kangwon National University, Department of Environmental Engineering, Samchok National University, Korea Environmental Technology Research Institute

ABSTRACT

To evaluate the contribution of phytoplankton to organic pollution in the Naktong River, biomass and production of phytoplankton, and COD were measured at 10 sites of the main stream and 6 of tributaries from May to October in 1994. Chlorophyll a concentration and COD ranged 2.7-223.0 mg/l, respectively, at study sites of the main stream. Contribution of algal COD to total COD showed positive correlation with chlorophyll a concentration, and the ratios of algal COD to total COD varied 4-65%(average:24%). Allochthonous organic carbon loading into the Naktong River was contributed by 36.5% from the main stream(Kangjong), 23.0% from the Nam River and 19.5% of the Kumho River. Autochthonous organic carbon loading by production of phytoplankton ranged 24-69%(average:49%) of the total loading. The results indicate that phosphorus, which is a key nutrient of the phytoplankton growth, as well as organic carbon loading must be controlled for improving the water quality of the Naktong River.

Key words: algal COD, eutrophication, Naktong River, organic pollution, phytoplankton, primary production