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Biogeochemical control of phosphorus cycling and primary production in Lake Michigan
Author(s) -
Brooks Arthur S.,
Edgington David N.
Publication year - 1994
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.1994.39.4.0961
Subject(s) - biogeochemical cycle , phosphorus , phosphate , cycling , environmental chemistry , sediment , algae , flux (metallurgy) , spring (device) , nutrient , environmental science , chlorophyll a , nitrate , sediment–water interface , geochemical cycle , chemistry , oceanography , ecology , geology , biology , mechanical engineering , paleontology , biochemistry , archaeology , organic chemistry , engineering , history
A 3‐yr study in Lake Michigan has shown a 27 mmol P m −2 increase in the mass of total P (TP) in the water during spring when the lake is mixed from surface to sediment. This value is an order of magnitude greater than the annual P input from external sources. TP changed in concert with increases in chlorophyll a and organic N and decreases in nitrate and soluble Si. The concentration of soluble reactive PO 4 3− (SRP) remained relatively constant throughout the study. We hypothesize that the SRP concentration is maintained by a chemical equilibrium with calcium‐phosphate species. The increased mass of TP arises from the sequestering of P by algae which displaces the chemical equilibrium and allows more P to be released to the water from the sediments. Solar irradiance and the duration of mixing determine the magnitude of the spring bloom and the demand for P that must be supplied through the flux of P from the sediments to the overlying water.