Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea
were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results
showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration
ranged from 0.22 to 0.35 mg/m
3 and 0.93–1.09 mg/m
3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers
were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed
in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy
area, chl-a concentration maximized at 31.743 mg/m
3, and averaged 1.143 mg/m
3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m
3, the average was 1.168 mg/m
3. The primary productivity reached 1418.76 mgC/(m
2·d) in summer and 1360.69 mgC/(m
2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m
2·d) in summer and 159.04 mgC/(m
2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.
Contribution NO. 4183 from the Institute of Oceanology, Chinese Academy of Sciences.
Project No. 49636210 supported by NSFC.
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