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Dissolution kinetics of biogenic silica and tentative silicon balance in the Yellow Sea
Author(s) -
Wu Bin,
Liu Su Mei,
Ren Jing Ling
Publication year - 2017
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.1002/lno.10514
Subject(s) - biogenic silica , dissolution , dissolved silica , sediment , geology , oceanography , flux (metallurgy) , estuary , productivity , seawater , shore , diatom , mineralogy , silicon , geomorphology , chemistry , organic chemistry , economics , macroeconomics
The dissolution of biogenic silica (bSiO 2 ) in coastal environments is important for marine productivity and essential to the global silicon cycle. BSiO 2 dissolution experiments were performed using sediments from the Yellow Sea (YS) to explore the factors that influence bSiO 2 dissolution and to better understand the silicon cycle in the YS. The results showed that the bSiO 2 content in surface sediments varied from 0.40% to 3.7% (average 2.2% ± 0.79%, SiO 2 %). Additionally, the bSiO 2 content was higher in the central areas of the northern and southern YS and lower in the near‐shore area of the northern Changjiang Estuary. The burial flux of bSiO 2 in surface sediments ranged from 0.12 mol m −2 yr −1 to 2.3 mol m −2 yr −1 and gradually decreased eastward from near shore to offshore. Continuous flow experiments showed that the solubilities of bSiO 2 in the YS sediments varied from 91.0 to 303 μ M‐Si. Further, the dissolution rate constant of bSiO 2 was 9.3–41 nmol g −1 h −1 , which is 2–3 orders of magnitude lower than that of other marginal seas such as the Arabian Sea and Scotia Sea. The structural incorporation of aluminum in bSiO 2 and the content of lithogenic minerals in sediments hindered bSiO 2 dissolution. The silica budget of the YS was established. The burial efficiency of bSiO 2 in the surface sediment was calculated to be 73%, which accounts for 4% of the global balance and is much higher than that of the global ocean average. Because of its high sediment accumulation rate and much lower dissolution rate constant, bSiO 2 was well preserved in the YS, highlighting the important role of the YS in the global silicon cycle.