Limnological Studies in Branch of Han River(Anyang River, Kockneung River) during Spring Season

춘기 한강지류(안양천, 곡릉천)의 육수학적 연구

The persent paper discusses the relation between water pollution and aquatic organisms resulted from the study of the water quality and the kinds of algea and aquatic insects both of the An-yang River from Mt. Kwan-ak to the Han River and of the Kock-neung River from Mt. Puk-han to the Han River during the spring of 1965 and 1966. According to the change of water quality, the An-yang River might be divided into three areas. In the first area, from Mt. Kwan-ak to near An-yang town, water quality is not so polluted that may aquatic organisms such as Anisogamarus ryotoensis, Epeorus, Cambaroides, Zygnem, Batrachospermum moniliform, Draparnaldia glomerata are found. In the second area where water is polluted by the inflow of sewerage water from An-yang town, the concentration of chloride, COD, ammonia-N, nitrate-N, alkali degree increased. Therefore, few aquatic insects and algea are found. In the third area, it is much polluted by the industrial sewerage water frojm Yeong-dong-po; and so the aquatic organisms that indicate strong pollution such as Oscillatoria, Euglena, Tubifex are found in this area. It is also significant that the Nereis japonica that indicates the pollution of brackish water is discorved in the some area. In the case of the Kock-neung River, however, it is not clearly divided into areas, as in the case of the An-yang Riber, according to the pollution of water; but because of villages and towns along the river the gradual pollution of water; but because of villages and towns along the river the gradual pollution of water is observed and accordingly, a considerable change in aquatic organisms is also found in this river. In the area near II-yeung town, for instance, the concentration of the chloride, hardness, nitrite, nitrate is very low, and ammonia-N is not detected; and accordingly the aquatic insects that generally inhabit in mountain stream, such as Anisogamarus ryotoensis, Cambaroides, Epeorus, Thraubs, Hydropsyche are found here. In the down stream of the river, from Kock-chon, the quality of water is considerably polluted and fine sands are found laid on the bottom of the stream; therefore, the aquatic insects are very few, but the algea such as Navicula, Pleusigma, Oscillatoria that indicate water pollution are found in this area.