This study investigates the seasonal change and the influence of freshwater input on distributions of transparent exopolymer particles (TEP) in the Gaoping Canyon. The study also aims to understand the variability of TEP and its controlling mechanism. In addition, the distributions and controlling factors of TEP are compared between the Gaoping coastal zone and the northern South China Sea (NSCS).
During the study, concentrations of TEP decreased with depth and seaward distance in the Gaoping Canyon. The concentration was generally the highest around the canyon head, resulted obviously from the influence of nutrient inputs during both wet and dry seasons. Except for the canyon head, the highest water-column inventory of TEP occurred in the period between winter and spring at Station B2 (1719 mg Xeq. m-2). The ratio of TEP-C/POC in the euphotic layer was about 27% in August 2005, 29% in January 2006, 36% in March 2006, and 28% (Gaoping Canyon) and 35% (Fangliao Canyon) in January 2007. The correlation was poor between TEP and POC/PN, due to the significant influence of terrestrial POC inputs. Positive correlations were significant between TEP and Chl. a, arisen largely from the feature of subsurface maximum, suggesting that the distribution of TEP in the euphotic layer of Gaoping Canyon was mainly controlled by phytoplankton productivity. The ratio of TEP in particulate and dissolved organic matter increased with the increase of Chl. a concentration, implying that the high productivity may enhance the transformation of DOC into TEP and POC. Because there was no subsurface chlorophyll maximum occurring in the station during diurnal observations, negative correlations were significant between TEP, salinity and density, but the correlations were positive between TEP and Chl. a.
Concentrations of TEP also decreased with depth in the NSCS and Bashi Channel. The water-column inventory of TEP in the different water mass showed a decreasing trend from the SCS Water (1225 mg Xeq. m-2) to the Kurshio Water (758 mg Xeq. m-2). The ratio of TEP-C/POC in the euphotic layer ranged from 22.4% in Station F, 20.3% in Station M1, 21.5% in Station S4 to 20% in Station S5. TEP correlated well with Chl. a, indicating that TEP were also mainly controlled by phytoplankton productivity in the euphotic layer of SCS and Bashi Channel. The ratio of POC/PN increased with the increase of TEP, showing that the fate of TEP played an important role on carbon cycle in the upper ocean. Bacterial productivity increased with TEP concentrations, implying that TEP may be an important carbon source for bacteria in the studied area.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0909108-191309 |
| Date | 09 September 2008 |
| Creators | Shen, Yu-chun |
| Contributors | Chung yu-chia, Lee chon-lin, Hung jia-jang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0909108-191309 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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