The Water Quality and the Phytoplankton Communities in the Dong River of Kangwon Province, Korea

doi:2004.19.3.217

Algae > Volume 19(3); 2004 > Article

Algae 2004;19(3): 217-226. doi: https://doi.org/10.4490/ALGAE.2004.19.3.217

Jin Hwan Lee^*

Division of Natural Sciences, Sangmyung University, Seoul 110-743, Korea

ABSTRACT

The present study is to examine the water quality and to analyze the plank tonic and benthic phytoplankton communities at 6 stations in the Dong River and its tributary streams of Kangwon Province from November, 2001 to March, 2002. During the studies, water temperature ranged from 3.5 to 12.8℃; pH, 6.5-7.9; DO, 9.29-11.36 mg?l^(-1); BOD_5, 0.20-2.38 mg?l^(-1); TN, 1.2842-3.1871 mg?l^(-1); TP, 0.0052-0.0576 mg?l^(-1); and SS, 0.85-9.62 mg?l^(-1). The standard of water quality according to the Korean Environmental Preservation Law showed the first class except St. 6 through the survey. Six taxa of plank tonic phytoplankton identified were poor flora in November, 2001. The representative species frequently observed were the diatoms Achnanthes lanceolata, Achnanthes minutissima, Cymbella minuta, Cymbella parva, Diatoma vulgare, Fragilaria construens, Gomphonema pervulum, Navicula cryptocephala, Nitzschia palea., Scenedesmus sp. of green algae and Stephanodiscus hantzschii. Monthly dominant species of phytoplankton were Achnanthes lanceolata and A. minutissima in both February and March, 2002, but the blue-green algae, Oscillatoria sp. and the diatom, Stephan discus hantzschii were predominant at some stations in March. Phytoplankton standing crops ranged from 9.84 ⅹ10^3 to 3.56ⅹ 10^4 cell?l-1 in November and 1.68-2.99 ⅹ10^5 cell?l-1 in February, while it changed 4.52-8.01 ⅹ10^5 cell?l-1 at St. 1, 2, 3 and 1.03-1.71 ⅹ10^6 cell?l-1 at St. 4, 5, 6 in March. Benthic phytoplankton communities was composed of 38 taxa in November, 31 taxa in February and 23 taxa in March. It showed a contrary tendency to planktonic phytoplankton diversity. Benthic diatoms which were more than 25% of the total populations were Cymbella turgida, Diatoma vulgare, Cocconeis placentula, Navicula cryptocephala var. intermedia in November; Achnanthe lanceolata, Cocconeis placentula, Achnanthes minutissima in February; and Achnanthes lanceolata and Cyclotella meneghiniana in March.

Key words: benthic diatoms; Dong River; phytoplankton; water quality