Effect of Nutrient Inputs on Water Quality Change and Phytoplankton Growth in Atsumi Bay

Mahlil, Teuku ( Universitas Pertamina, Department of Environmental Engineering, Jalan Teuku Nyak Arief, Simprug, Jakarta Selatan, Jakarta 12220,)
Inoue, Takanobu ( Toyohashi University of Technology, Departments of Architecture and Civil Engineering, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, Aichi 441-8580,)
Matsumoto, Yoshitaka ( Toyota National College of Technology, Departments of Civil Engineering, 2-1 Eisei-cho, Toyota, Aichi 471-8525,)
Aoki, Shinichi ( Graduate School of Engineering Osaka University, Departments of Civil Engineering, 2-1 Yamadaoka, Suita, Osaka 565-0871)
Kato, Shigeru ( Toyohashi University of Technology, Departments of Architecture and Civil Engineering, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, Aichi 441-8580,)
Yokota, Kuriko ( Toyohashi University of Technology, Departments of Architecture and Civil Engineering, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, Aichi 441-8580,)
Rasul, Ernawaty ( Ministry of Health Republic of Indonesia, Environmental Health Engineering and Disease Control Office Makassar, Jalan Wijaya Kusuma Raya No. 29-31, Makassar, South Sulawesi 90224,)
Saga, Makoto ( Toyohashi University of Technology, Departments of Architecture and Civil Engineering, 1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, Aichi 441-8580,)

Journal of Engineering and Technological Sciences
Vol 50, No 4 (2018)

Eutrophication in an estuary occurs as an effect of the enrichment of nutrient inputs from rivers. This condition has become one of the most common environmental issues experienced around the globe and especially in Japan. Atsumi Bay is a eutrophic coastal area in Japan. The objective of this research was to analyze the influences of nutrient inputs from the Umeda River into Atsumi Bay on pre- and post-rainfall water quality conditions. This study was conducted from July to October 2010. The results showed a decrease of surface salinity after rainfall indicating that huge freshwater inputs had overlaid the surface layer of Atsumi Bay rather than the bottom layer. Moreover, post-rainfall conditions showed an increase of chlorophyll a as an effect of phytoplankton growth, followed by an increase of particulate nutrients. On the other hand, dissolved nutrients decreased due to uptake by phytoplankton and dilution by freshwater.