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Limitation of phytoplankton species in the ocean off western Africa 1
Author(s) -
Hulburt Edward M.
Publication year - 1976
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.1976.21.2.0193
Subject(s) - upwelling , phytoplankton , nutrient , oceanography , nitrogen , diatom , abundance (ecology) , saturation (graph theory) , range (aeronautics) , dinoflagellate , environmental science , ecology , algae , biology , chemistry , geology , materials science , mathematics , organic chemistry , combinatorics , composite material
The growth rate of phytoplankton off the west coast of Africa appeared not to be nutrient limited for two reasons. First, most of the species characteristic of nonupwelling regions did not show increased abundance in upwelling or productive regions where nutrient or other species were abundant. Second, in an upwelling region, where diatoms dominated, nutrients exceeded the half‐saturation values characteristic of diatoms. A deductive model of the nutrient cycle, covering a complete range of nutrient concentrations, is used to interpret the field data. Since most species in the nonupwelling region were not limited, i.e. were not prevented from being abundant, by the small excess of nitrogen there, the compound statement ‘cells in the nonupwelling region were prevented from being abundant and cells in the upwelling region were not prevented from being abundant’ is false. Instead, the statement that ‘co‐occurrence of cells and excess nitrogen, with small and large amounts in the respective regions, was harmonious’ is true.