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Pelagic responses to changes in dissolved organic carbon following division of a seepage lake
Author(s) -
Christensen David L.,
Carpenter Stephen R.,
Cottingham Kathryn L.,
Knight Susan E.,
LeBouton Joseph P.,
Schindler Daniel E.,
Voichick Nicholas,
Cole Jonathan J.,
Pace Michael L.
Publication year - 1996
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.1996.41.3.0553
Subject(s) - phytoplankton , dissolved organic carbon , pelagic zone , environmental science , structural basin , chlorophyll a , surface water , groundwater , hydrology (agriculture) , oceanography , total organic carbon , nutrient , geology , environmental chemistry , ecology , chemistry , biology , geomorphology , biochemistry , geotechnical engineering , environmental engineering
Within 2 yr of dividing a multibasin lake into discrete lakes for experimentation, dissolved organic carbon (DOC) concentrations and water color (absorption coefficient g at 440 nm, g 440 ) increased in the east basin and decreased slightly in the west basin. These changes were not explainable by watershed vegetation or groundwater chemical composition. However, g 440 increased from 0.7 to 4.2 m −1 for water moving through the sediment‐water interface in the east basin. In the west basin, g 440 of groundwater (0.6 m −1 ), in‐seeping water (0.7 m −1 ), and lake water (0.7 m −1 ) were all similar. Patterns of DOC distribution matched time trends in the surface waters. In the east basin, DOC concentration doubled and g 440 increased 3‐fold from 1990 to 1993. Trends in the west basin were more complex, but in general, there was a decrease in DOC and g 440 over the same period. Changes in the light regime affected phytoplankton vertical distribution, but total areal chlorophyll and epilimnetic chlorophyll concentrations were not altered. The depth of oxygenation was changed by altered mixing characteristics and phytoplankton distribution. Changes in light‐attenuating DOC affected pelagic responses to nutrient inputs.