Three oceanographic investigations from 1994 to 1995 in the Taiwan Strait show that the dissolved organic carbon (DOC) in the euphotic layer has a large-scale diurnal variation [2 ~ 4 mg/dm3], and its amplitude range ...Three oceanographic investigations from 1994 to 1995 in the Taiwan Strait show that the dissolved organic carbon (DOC) in the euphotic layer has a large-scale diurnal variation [2 ~ 4 mg/dm3], and its amplitude range has spatial and seasonal changes. Generally, the DOC in the euphotic layer is higher at day than that at night. According to the diurnal variations, DOC can be divided into two parts: new DOC and old DOC. The content of new DOC varies rapidly every day but the content of old DOC does not. Though there is still not a good explanation for this diurnal variation of DOC, it may call attention to the study of organic carbon dynamics, especially the DOC primary production of phytoplankton, the DOC utilization of bacteria, and the flux of DOC in coastal sea water.展开更多
The concentration, distribution, size-fraction structure and diurnal variation of phyto-plankton biomass ( chl α) in the Taiwan Strait were investigated during four cruises conducted in the summer (August) of 1997, 1...The concentration, distribution, size-fraction structure and diurnal variation of phyto-plankton biomass ( chl α) in the Taiwan Strait were investigated during four cruises conducted in the summer (August) of 1997, 1998, 1999 and winter (February-March) of 1998, respectively. The results showed that phytoplankton biomass in the Taiwan Strait was largely influenced by water masses and up-welling, high biomass mainly occurred at the frontal zones. Nano-and pico-phytoplankton dominated the phytoplankton biomass and primary productivity in the Taiwan Strait, they contributed 60% - 80% to biomass and 80% to primary productivity. But size-fractionated phytoplankton biomass was quite different in the northern Taiwan Strait (NTS) and southern Taiwan Strait (STS), and varied significantly annually. Diurnal variation of chl α concentration in the water column and water layers indicated that phytoplankton biomass at most stations had one-day variation cycle, with some difference, which coincide with the tidal rhythm. The diurnal variation of the size-fractionated structure of phytoplankton biomass was strongly influenced by the hydrodynamics and grazing pressure of zooplankton. This study also showed that unusual phenomena observed in phytoplankton biomass during the investigating periods might be the biological response to ENSO events.展开更多
文摘Three oceanographic investigations from 1994 to 1995 in the Taiwan Strait show that the dissolved organic carbon (DOC) in the euphotic layer has a large-scale diurnal variation [2 ~ 4 mg/dm3], and its amplitude range has spatial and seasonal changes. Generally, the DOC in the euphotic layer is higher at day than that at night. According to the diurnal variations, DOC can be divided into two parts: new DOC and old DOC. The content of new DOC varies rapidly every day but the content of old DOC does not. Though there is still not a good explanation for this diurnal variation of DOC, it may call attention to the study of organic carbon dynamics, especially the DOC primary production of phytoplankton, the DOC utilization of bacteria, and the flux of DOC in coastal sea water.
基金This work was supported by a grant from NSFC(No.49636220,49776308)a grant from the Fujian Commission of Science and Thechnology(98-Z-179)
文摘The concentration, distribution, size-fraction structure and diurnal variation of phyto-plankton biomass ( chl α) in the Taiwan Strait were investigated during four cruises conducted in the summer (August) of 1997, 1998, 1999 and winter (February-March) of 1998, respectively. The results showed that phytoplankton biomass in the Taiwan Strait was largely influenced by water masses and up-welling, high biomass mainly occurred at the frontal zones. Nano-and pico-phytoplankton dominated the phytoplankton biomass and primary productivity in the Taiwan Strait, they contributed 60% - 80% to biomass and 80% to primary productivity. But size-fractionated phytoplankton biomass was quite different in the northern Taiwan Strait (NTS) and southern Taiwan Strait (STS), and varied significantly annually. Diurnal variation of chl α concentration in the water column and water layers indicated that phytoplankton biomass at most stations had one-day variation cycle, with some difference, which coincide with the tidal rhythm. The diurnal variation of the size-fractionated structure of phytoplankton biomass was strongly influenced by the hydrodynamics and grazing pressure of zooplankton. This study also showed that unusual phenomena observed in phytoplankton biomass during the investigating periods might be the biological response to ENSO events.
