Premium
Nutrient chemistry of the water column of Lake Tanganyika
Author(s) -
Edmond J. M.,
Stallard R. F.,
Craig H.,
Craig V.,
Weiss R. F.,
Coulter G. W.
Publication year - 1993
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.1993.38.4.0725
Subject(s) - anoxic waters , sink (geography) , nutrient , environmental science , water column , detritus , hydrology (agriculture) , oceanography , geology , environmental chemistry , chemistry , ecology , biology , paleontology , cartography , geotechnical engineering , geography
Lake Tanganyika shows permanent thermal stratification with deep‐water temperatures that have been stable over the period of observation (since 1939). The lake is anoxic below ∼150‐m depth. In general the nutrients show Redfield behavior save in the deep waters of the northern basin where large excesses of phosphate and ammonia are present. Bacterial disproportionation of organic material probably plays an important role in producing these excesses. Inorganic desorption from fluvial detritus is also a possible source of excess phosphate in deep waters. The oxic‐anoxic boundary at ∼150 m is a sink for all forms of fixed nitrogen. Thus the nutrient budget of the lake probably involves fixation of nitrogen in the surface layer in addition to substantial inputs from rainfall and runoff, with the phosphate supplied by vertical mixing. Because these processes are in approximate balance under present conditions, the productivity of the lake must be very sensitive to changes in climatic forcing.