Spring Phytoplankton Bloom in the Fronts of the East China Sea

  • Published : 2006.09.30

Abstract

Frontal areas between warm and saline waters of the Kuroshio currents and colder and diluted waters of the East China Sea (ECS) influenced by the Changjiang River were identified from the satellite thermal imagery and hydrological data obtained from the Coastal Ocean Process Experiment (COPEX) cruise during the period between March $1^{st}$ and $10^{th}$, 1997. High chlorophyll concentrations appeared in the fronts of the East China Seas with the highest chlorophyll-a concentration in the southwestern area of Jeju Island (${\sim}2.9\;mg/m^3$) and the eastern area of the Changjiang River Mouth (${\sim}2.8\;mg/m^3$). Vertical structures of temperature, salinity and density were similar, showing the fronts between ECS and Kuroshio waters. The water column was well mixed in the shelf waters and was stratified around the fronts. It is inferred that the optimal condition for light utilization and nutrients induced both from the coastal and deep waters enhances the high phytoplankton productivity in the fronts of the ECS. In addition, the high chlorophyll-a in the fronts seems to have been associated with the water column stability as well.

Keywords

References

  1. Agusti, S. and C. Duarte. 1999. Phytoplankton chlorophyll a distribution and water column stability in the central Atlantic Ocean. Oceanologia Acta, 22(2), 193-203 https://doi.org/10.1016/S0399-1784(99)80045-0
  2. Beardsley, R.C., R. Limeburner, H. Yu, and G.A. Cannon. 1985. Discharge of the Changjiang (Yangtze) in to the East China Sea. Cont. Shelf. Res., 4, 57-76 https://doi.org/10.1016/0278-4343(85)90022-6
  3. Chen, C., R. Beardsley, and R. Limeburner. 1994. Comparison of winter and summer hydrographic observations in the Yellow and East China Seas and adjacent Kuroshio during 1986. Cont. Shelf Res., 14, 909-929 https://doi.org/10.1016/0278-4343(94)90079-5
  4. Choi, J.-K., J.-H. Noh, K.-S. Shin, and K.-H. Hong. 1995. The early autumn distribution of chlorophyll-a and primary productivity in the Yellow Sea, 1992. The Yellow Sea, 1, 68-80
  5. Fei, Z. 1991. An analysis on the formation mechanism of the distribution of high content of chlorophyll-a in the continental shelf edge waters of East China Sea. Acta Oceanologica Sinica, 11(1), 97-107
  6. Fournier, R.O., M. Van Det, N.B. Hargreaves, J.S. Wilson, T.A. Clair, and R. Ernst. 1984. Physical factors controlling summer distribution of chlorophyll a off southwestern Nova Scotia. Limnol. Oceanogr., 29(3), 517-526
  7. Hickox, R., I. Belkin, P. Conillon, and Z. Shan. 2000. Climatology and seasonal variability of ocean fronts in the East China, Yellow and Bohai Seas from satellite SST data. Geophys. Res. Lett., 27(18), 2945-2948 https://doi.org/10.1029/1999GL011223
  8. Jones, K. J. and R. J. Gowen. 1990. Influence of stratification and irradiance regime on summer phytoplankton composition in coastal water and shelf of the British Isles. Estuar. Coast Shelf. Sci., 30,557-567 https://doi.org/10.1016/0272-7714(90)90092-6
  9. Kirk, J.T.O. 1994. Light and photosynthesis in aquatic ecosystems, 2nd Cambridge University Press. p. 119-120
  10. KORDI, 1998. Ocean Circulation in the Western and Middle Part of East China Sea. KORDI, BSPE97603-00-1042-1. 278 p
  11. Molion, M. 1998. Photoadaptive response during the development of a coastal Antarctic diatom bloom and relationship to water column stability. Limnol. Oceanogr., 43(1),146-153 https://doi.org/10.4319/lo.1998.43.1.0146
  12. Pingree, R.D., P.M. Holligan, G.T. Mardell, and R.N. Head. 1976. The influence of physical stability on, spring summer and autumn phytoplankton blooms in the Celtic Sea. J. Mar. Biol. Assoc. U.K., 56, 845-874 https://doi.org/10.1017/S0025315400020919
  13. Smetacek, V. and U. Passow, 1990. Spring bloom initiation and Sverdrup's critical-depth model. Limnol. Oceanogr., 35, 228-234 https://doi.org/10.4319/lo.1990.35.1.0228
  14. Sverdrup, H.U. 1953. On conditions for the vernal blooming of phytoplankton, J. Cons. Int. Explor. Mer., 18, 287-29 https://doi.org/10.1093/icesjms/18.3.287
  15. Takeoka, H., S. Matsuda, and T. Yamamoto. 1993. Processes causing the chlorophyll a maximum in the tidal front in IyoNada, Japan. J. Oceanogr., 49, 57-70 https://doi.org/10.1007/BF02234009
  16. Wu, Y.-L., Y.-J. Guo, and Y.-S. Zhang. 1995. Distributional characteristics of chlorophyll-a and primary productivity in the Yellow Sea. The Yellow Sea, 1, 81092
  17. Yang, S., Q. Zhao, and LM. Belkin. 2002. Temporal variation in the sediment load of the Yangtze river and the influences of human activities. J. Hydrology, 26, 56-71
  18. Zeng, Q. and V. Klemas. 1982. Determination of winter temperature patterns, fronts, and surface currents in the Yellow Sea and East China Sea from satellite imagery. Remote Sens. Environ., 12, 201-218 https://doi.org/10.1016/0034-4257(82)90053-0