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The annual cycle of plankton diatom growth and silica production in the inner Oslofjord 1
Author(s) -
E. Paasche,
I. Ostergren
Publication year - 1980
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 - 10.4319/lo.1980.25.3.0481
Subject(s) - diatom , biogenic silica , bloom , plankton , dissolved silica , amorphous silica , oceanography , silicon dioxide , phytoplankton , environmental chemistry , environmental science , chemistry , mineralogy , geology , nutrient , chemical engineering , materials science , biology , ecology , metallurgy , engineering , dissolution
Concentrations of amorphous particulate silica (biogenic silica) in the uppermost layer of the inner Oslofjord, Norway, varied between 2 and 324 µ g Si·liter −1 over a 1‐year period in 1977–1978. Most of the silica was present in frustules of living or dead diatoms but there was always a certain amount (up to about 50 µ g Si·liter −1 ) in a form that could not be recognized under the microscope. Silica was produced mainly during three large blooms of Skeletonema costatum in February–March, May, and June. At the peak of the June bloom, there was up to 20 times more Si present as diatom silica than as dissolved orthosilicic acid. Uptake experiments in June indicated depletion times of dissolved Si as short as 3 h. Although the S. costatum cells were less heavily silicified in May and June than in February–March, they showed no morphological signs of a drastic Si shortage.