| Title |
A Study on the Water Quality and the Composition of Aquatic Communities Around the Lake Young - san |
| Authors |
주흥규 ; 박봉헌 ( Heung Kyu Joo ; Bong Heon Park ) |
| Abstract |
The investigation of Physico-chemical water quality and the composition of aquatic organism communities were made from August to September 1988 in the fresh water and seawater areas of Kei-do island, Nabul-do island and Oey-do island around the Young-san Dam. We could get the results as follows ; 1. The consumption of KMnO_4, in the underground water and the criterion of drinking water of general bacillus, and the group of colon bacillus is based on the lack of the hygienic sense for the underground water control of this residents. 2. It is not seemed that the condition of pollution of small river, flowing from the Nabul-do island and Oey-do island to the Young-san Dam, is serious on the physico-chemical point of view, Coliform Group appears high as 4.4×10^3~1.8×10^4 which will affect to the pollution of Young-san dam. 3. The rate of dissolved oxygen in the surface water is rate high as 8.1~9.8ppm, in bottom water as 7.2~9.4ppm. Because the geographical condition of the Young-san dam is different from that of other area in this country there is no higher mountain around it, the dam of Young-san is very wide, affected by the wind, the surface of water runs high, the air contact of water is so wide. 4. BOD and COD make little difference in the surface water and intermediate water, and points of investigating areas. That is ; BOD is 1.5~3.4ppm in surface water, 1.4~3.4ppm in intermediate water, COD is 3.1~5.7ppm in surface water, 3.2~5.2ppm in intermediate water. This result shows that there is no particular outlet source which causes the point source contamination around the Young-san dam. 5. The floating materials show the various distribution at the points of investigation are-as, however that site 2 appears 24~29ppm, the highest rate, is that the widely prevalent fishing net fishery is more source of pollution than the many kinds of shellfish lives in this area. 6. The nutritive salt that is the important materials to decide the nutrition is 0.33~0.61ppm in total nitrate, 0.11 ~0.23ppm in total phoshate with comparatively low. The reason that T-N is 0.58~0.61ppm and T-P is 0.21~0.23ppm with the highest rate of measurement on August in site 1 is because very wide farm land locates in this area and the mixed fertilizer is flowing into this dam during this month. 7. Salinity is not affected by the tied after the construction of the dam, but it is indicating the 78~150ppm in surface water, 83~248ppm in intermediate water by the seawater mixing with freshwater through the outlet gate and gate for shipping and that shows as-pects of water quality of estuary area. 8. District Kwangju city, Naju city, and many small towns are located in upper the Young-san, dam, so that domestic sewage is flowing into the dam without sewage theatment. E. coil indicates the 1.0×10~5.2×10^3 at every points of investigation. Thus this dam is dangerous lake with the pollution of bacillus. 9. A small amount of heavy metal is detected by the clark number because there is no such a big industrial estate around the Young-san dam that will make the water of the Young-san dam be polluted. 10. The quality of seawater around the Young-san dam is comparatively good, but is pol-luted a little by the floating materials, E. coil and n-Hexane. In case of inflow of the tide, the floating material around Mokop harbour will give an in-fluence to the dam. 11. Although the Young-san dam was constructed 7 years ago, this dam has a very different character from the other inland lakes. That is ; this dam is a kind of mixing water with seawater and freshwater everyday with oceanic plankton and fresh water`s plankton living together. The species which are observed 69 species of 40 genera belong to 6 families among which phytoplankton is 54 species, 76% of all species. Especially bacillariophyta among phytoplankton is 46 species that is 85% of all. On the other hand zooplankton among the species is 15 species, among which rotifera is 9 species, that is 60% |