Affiliations: Institute of Zoology, Chinese Academy of Sciences,
Beijing 100080, China | Center of Marine Environment Science, Xiamen
University, Xiamen 361005, China | Marine Science and Technology College, Zhejiang Ocean
University, Zhoushan 316004, China | Institute of Oceanography, Chinese Academy of
Sciences, Qingdao 266071, China
Abstract: The inventories of nutrients in the surface water and large
phytoplankton (≥ 69 μm) were analyzed from the data set of JERS
ecological database about a typical coastal waters, the Jiaozhou Bay, China,
from 1960s for N, P and from 1980s for Si. By examining long-term changes of
nutrient concentration, calculating stoichiometric balance, and comparing
diatom composition, Si limitation of diatom production was found to be more
possible. The possibility of Si limitation was from 37% in 1980s to 50% in
1990s. Jiaozhou Bay ecosystem is becoming serious eutrophication, with notable
increase of NO_2-N, NO_3-N and
NH_4-N from 0.1417 μmol/L, 0.5414 μmol/L,1.7222
μmol/L in 1960s to 0.9551 μmol/L, 3.001 μmol/L, 8.0359 μmol/L in
late 1990s respectively and prominent decrease of Si from 4.2614 μmol/L in
1980s to 1.5861 μmol/L in late 1990s; the nutrient structure is controlled
by nitrogen; the main limiting nutrient is probably silicon;because of the Si
limitation the phytoplankton community structure has changed drastically.
Keywords: nutrients, Si-limitation, stoichiometric ratios, species composition, Jiaozhou Bay
