| 英文摘要 |
This study aimed to investigate the seasonal changes of the primary production, chlorophyll a and nutrients surrounding Taiwan. There were four survey voyages at winter, spring, summer and autumn in 2009. Both temperature and salinity in eastern water of Taiwan were higher than western. Average temperature at 5 m depth in winter, spring, summer and autumn were 22.83, 25.80, 29.35 and 26.95 ℃, respectively. Average salinity at 5 m depth in above seasons were 34.27, 34.14, 33.55 and 33.67 psu, respectively. The primary production calculated from depth 0 to 50 m’s data. The primary production in winter, spring, summer and autumn were 3.158, 5.230, 4.697 and 9.284 ton C/km2/day. The highest primary production appeared at autumn, and in the order were spring, summer and winter. The Chl a in season’s in above season were 0.188, 0.420, 0.298 and 0.352 mg/m3 at depth 5 m water. The concentration of Chl a in spring and autumn were higher than summer and winter. The nutrients also had same tendency with primary production and Chl a. The Nitrate concentrations were 0.402, 1.001, 0.657 and 1.615 uM, the phosphate concentration were 0.181, 0.309, 0.636 and 0.531 uM, the silicate concentration were 11.120, 7.183, 5.909 and 7.005 uM in 5 m depth water at above season.
Calculating and transferring water color data from satellite during 1998-2008 to Chl a and primary production. The average of primary production at spring, summer, autumn and winter in ten years were 2.729, 2.134, 5.070 and 1.831 ton C/km2/day, repectively. The highest primary production appeared at autumn and the lowest appear at winter. The surrounding water of northeastern and Pan-Hoo had the highest primary production. The water temperature of surrounding Taiwan was not significant changed with El Nino and La Nina, but was significant changed with season’s changes.
Primary production of surrounding Taiwan was also not significant change with El Nino and La Nina. Comparing the relationship between temperature and primary production, there are position correlation in summer (the slope was 0.2112), and negative correlation in autumn (the slope was -0.4197).
Nutrients, including nitrate, phosphate and silicate changed with season. All the nutrients in western water were higher than eastern water. There were typhoons pass through this area that caused cold dome upwelling and bring high nutrients. This result caused photoplankton growth and high primary production. The nutrients and season changes were major reasons that affected the primary production of surrounding Taiwan, that inferences were higher than El Nino and La Nina. |