Investigation of pH effects on the growth of Ditylum brightwellii, Asterionella japonica, and Biddulphia mobiliensis

• Main Authors: Ya-Wen Cheng, 鄭雅文
• Other Authors: Saou-Lien Wong
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/36953583420843347443

碩士 === 國立屏東科技大學 === 水產養殖系所 === 101 === Abstract Student ID：M9913002 Title of Thesis：Investigation of pH effects on the growth of Ditylum brightwellii, Asterionella japonica, and Biddulphia mobiliensis Total Page：68 Name of Institute：Department of Aquaculture, National Pingtung University of Science and Technology Graduate Date：January, 2013 Degree conferred：Master Name of Student：Ya-Wen Cheng Adviser：Saou-Lien Wong The Contents of Abstract in This Thesis: In recent years, Mailiao Power Plant flue gas desulphurization system discharged low pH seawater resulted in acidification impact on marine ecology. Over the past few years, phytoplankton abundance clearly greatly reduced, however Ditylum brightwellii seemed to dominate in some sampling periods. The photometric gradient（50 μEm-2s-1、100 μEm-2s-1、150 μEm-2s-1、200 μEm-2s-1）growth experiments, results show that both of the optimum growth and cell number was highest at 100 μEm-2s-1, the cell number up to 273693±4704 cells/mL, the growth rate was 0.25±0.002 day-1 . Temperatures gradient (15℃、20℃、25℃、30℃、32℃）growth experiments, results show that both of the optimum growth and cell number was best at 20℃, but the number of cells decreased while the temperatures was increased. The optimum pH of D. brightwellii cells for growth was around pH7.0, and also reaching the highest number of growth cells, on day 15, up to 191880±2213 cells/mL, the growth rate was 0.15±0.01 day-1. In addition to comparing the coastal dominant species, Biddulphia mobiliensis and Asterionella japonica was also determined and the pH range for the best growth was around pH7.5. Mixed culture further observes D. brightwellii and B. mobiliensis, D. brightwellii and A. japonica growth situation and the relative advantages of different pH environment. In mixed culture experiments, D. brightwellii than the rapid growth of B. mobiliensis and A. japonica, algal populations higher than the other two algae, showing a distinct advantage in interspecific competition. Therefore, the speculate wild Mailiao power plant flue gas desulfurization system discharge water adjacent waters with low pH cause D. brightwellii blooms main factors. Key words: pH, phytoplankton, Ditylum brightwellii, interspecific competition