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CARBON, NITROGEN, AND PHOSPHORUS AND THE EUTROPHICATION OF FRESHWATER LAKES 1
Author(s) -
Schindler D. W.
Publication year - 1971
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.1971.tb01527.x
Subject(s) - phytoplankton , standing crop , eutrophication , seston , epilimnion , nutrient , phosphorus , environmental chemistry , environmental science , nitrogen , redfield ratio , water column , ecology , biology , chemistry , biomass (ecology) , hypolimnion , organic chemistry
SUMMARY The question of nutrients responsible for eutrophication of freshwater lakes is reviewed, and recent additions to the literature on nutrient limitation are discussed. The paper by Lange is criticized on several grounds, including the facts that utilization of HCO 3 − by phytoplankton and the invasion of lake waters by atmospheric CO 2 are ignored as sources of photosynthetic carbon. The phosphorus and nitrogen concentrations used in Lange's experiments are far higher than values published by others for Lakes Erie and Ontario. Preliminary results of fertilizing a small oligotrophic lake with nitrogen and phosphorus are described. The standing crop of phytoplankton increased by 30–50 ×, while the P:N:C ratio in seston did not change from ratios found in unfertilized lakes. Other experiments done in water columns isolated with polyethylene film showed that addition of carbon did not increase the phytoplankton standing crop. Since the fertilized lake was initially lower in total CO 2 than any other recorded in the literature, it is concluded that carbon is unlikely to limit the standing crop of phytoplankton in almost any situation. Measurements of invasion of atmospheric gases to the fertilized lake by the Rn 222 technique were compared with phytoplankton production measurements, revealing that atmospheric invasion of CO 2 is sufficient to support the high phytoplankton standing crop in the epilimnion of the lake. Possible errors in interpretation of culture and bottle‐bioassay experiments with respect to eutrophication are discussed.