The East China Sea

The East China Sea (ECS) is known for its broad continental shelf, rich natural resources, and tremendous river rimoff from China, which is surrounded by several countries and has a comphcated status, such as topography, chemical environment, hydrography, sediment pattern, riverine input, and biological characteristics. 

Okinawa Trough, the Ryukyu island arc, and the Rjmkyu trench, it makes up another Trench-Arc-Basin system in the West Pacific Ocean, which links northwards with the Japanese island arc and connects southwards with the Taiwan-Philippine island arc. The northwest shelf cormects with the Yellow Sea and between them is the Changjiang River delta, with a water depth of about 50 100 m. 

The SST of ECS ranges from 27 to 29 °C in summer, but some cold eddies were found off northeast Taiwan and to the south of the mouth of the Changjiang River. SST anomalies at the center of these eddies were about 2 5 °C. The strongest front usually occurs in May each year and its temperature gradient is about 5 6 °C over a cross-shelf distance of 30 nautical miles. The Yellow Sea mixed with cold water also provides a contrast from China Coastal waters shoreward of the 50 m isobath, the cross-shore temperature gradient is about 6 8 °C over 30 nautical miles. 

The seasonal variation of the evaporation minus precipitation (E-P) had a secondary effect on the SSS distribution (Fig. 1.29). 

The silicate (SiOs-Si), phosphate (PO4-P), and inorganic nitrogen (DIN) are the nutrients of planktons. In winter, the SiOs-Si, PO4-P, and DIN concentrations in surface waters are 3 40, 0.1 1.6, and l 25 pmol/L, respectively. In summer, the SiOs-Si, PO4-P, and DIN concentrations in surface waters are 5 50, 0.2 1.0, and I SO pmol/L, respectively. 

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For DDE predicted surface ocean concentrations are overestimated in the Gulf of Alaska, the Bering Sea, the Chukchi Sea, and the North Atlantic. In all of these regions also the atmospheric concentration was overestimated. This indicates that the strong overestimation in these regions is caused by enhanced deposition from the atmosphere, and amplified by low volatilisation due to low mean surface temperatures. Also in the East China Sea and in the Gulf of Mexico modelled surface... 

K. Furuya, M. Hayashi, Y. Tabushita and A. Ishikawa, Phytoplankton dynamics in the East China Sea in spring and summer as revealed by HPLC-derived pigment signatures. Deep Sea Res. 11 (2003) 367-387. 

Locations of disseminated (nonphosphorite) authigenic CFA occurrence, as well as locations of phosphorites. Areas with substantial phosphorite deposits include the East China Sea between Korea and Japan, Ceara Rise, Saanich Inlet, eastern and western equatorial Pacific, California Borderland Basins, Gulf of St. Lawrence, Labrador Sea, Long Island Sound, Gulf of Mexico, North Atlantic continental platform, and Iberian margin in the northeastern Atlantic. Source From Ruttenberg, K. C. (2003). Treatise on Geochemistry, Elsevier Ltd. pp. 585-643. 

Hashimoto S, Wakimoto T, Tatsukawa R (1995) Possible Natural Formation of Polychlorinated Dibenzo-p-Dioxins as Evidenced by Sediment Analysis from the Yellow Sea, the East China Sea and the Pacific Ocean. Mar Pollut Bull 30 341... 

Portugese traders with routes to the East China Sea smoked opium with tobacco in long-stemmed pipes. They reintroduced the practice to the Chinese who had frowned on its use. The British East India Company... 

DeMaster, D.J., McKee, B.A., Nittrouer, C.A., Jiangchu, Q., and Quodong, C. (1985) Rates of sediment accumulation and particle reworking based on radiochemical measurements from the continental shelf deposits in the East China Sea. Cont. Shelf Res. 4, 143-158. 

DeMaster, D. J. and C. A. Nittrouer. 1983. "Uptake, dissolution, and accumulation of silica near the mouth of the Changjiang River." In Sedimentation on the Continental Shelf with Special Reference to the East China Sea, eds. Q. Jin, and J. D. Milliman (China Ocean Press, Beijing), pp. 215-219. 

Chen, Y.-L., and Chen, H.-Y. (2003). Nitrate-based new production and its relationship to primary production and chemical hydrography in spring and faU in the East China Sea. Deep Sea Res. II50, 1249-1264. 

Chen, Y.-L., Lu, H.-B., Shiah, F.-K., Gong, G. C., Liu, K.-K., andKanda,. (1999). New production and f-ratio on the continental shelf of the East China Sea Comparisons between nitrate inputs from the subsurface Kuroshio Current and the Changjiang River. Estuar. Coast. Shelf Sd. 48, 59—IS. 

Inland seas make up only a small percentage of the surface and volume of the oceans (2.9% and 0.8%, respectively). Ketchum (1983) includes in his review of enclosed seas the Mediterranean Sea, the Black Sea, the Red Sea, the Baltic Sea, the Bering Sea, the Okhotsk Sea, the Japan Sea, the East China Sea, the Gulf of St. Lawrence and the Gulf of California. The Baltic Sea is the second largest brackish-water system in the world (after the Black Sea), but it is among the smallest of the inland seas (Table 15.1). 

Mackin J. E. and Aller R. C. (1984) Dissolved A1 in sediments and waters of the East China Sea implications for authigenic mineral formation. Geochim. Cosmochim. Acta 48, 281-297. 

The Republic of Korea lies south of the 38th parallel on the Korean peninsula with North Korea as its immediate neighbour. On the mainland, Korea is dwarfed by the enormous countries of the People s Republic of China and the Russian Federation. Across the East China Sea lies the island nation of Japan, which occupied all of Korea for much of this century. 

The Yellow Sea is a typical epicontinental sea surrounded by the continent of China and the Korean peninsula and connected with the East China Sea to the south and with Bohai Sea in the north (Figure 12). 

Figure 12. Bathymetry and geographic system including the east China Sea, the Yellow Sea and Bohai Sea sy.stem.

Denitrification is tbe main output items (37%) with similar values of sedimentation and water exchange with the East China Sea (7 and 8% from total input) and with negligible values of losses as N2O (< 1%). So, annual accumulation of nitrogen in the Yellow sea was 1,229 kt/yr. (447% from input) and the residence time of nitrogen was 1.5 year doubling the N content in marine water every 3 years during 1994-1997. It leads to excessive eutrophication and pollution of the Yellow Sea. 

Chen CTA (2000) The Three Gorges Dam reducing the upwelling and thus productivity in the East China Sea. Geophysics Research Letters 27 381-383. 

In the northern area (the Bohai Sea and the Yellow Sea), the seasonal variations of sea surface temperature (SST) are large and vary from 0 to 28 °C. In the East China Sea, the SST averages about 21 °C and ranges from 7 to 28 °C. In the southern area (north of the South China Sea), the... 

The Yellow Sea is commonly considered to be among the broadest marginal seas in the world (Fig. 1.20, Yang et al., 2003). It is a semi-enclosed sea of the northwest Pacific Ocean with a surface area of 380x10 m and average depth of 44 m, surrounded by the west coast of the Korean Peninsula and the east coast of China and connected to the East China Sea in the south and to the Bohai Sea in the north. The size is about 870 km from north to south and 556 km from east to west. It is quite shallow, with depths ranging from 90 m in the central trough to less than 20 m within 50 km of the coast. The deepest... 

Fig. 1.28. The East China Sea showing the water depth (Valle-Levinson and Mat-suno, 2003) (With permission from Springer)...

Tides can also locally affect surface sediment distribution. Tides are particularly dominant in the East China Sea of the mouth of the Changjiang River and off southwestern Korea. In both instances tidal cmrents are sufficiently strong (l 2 knot(s)) to erode and transport sediments. The intrusion of the Taiwan Warm Water (TWW) between the Changjiang Coastal Water (CJCW) and the Jiangsu Coastal Water (JCW) results in a seaward transition from turbid (CJCW) to clear (TWW) to turbid (JCW) waters east of the Changjiang River Estuary. As a result, Changjiang River sediments tend to be transported to the south by the CJCW, while the sediments to the east of the TWW are predominantly Huanghe River sediments transported south by the JCW. 

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