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Ecological stoichiometry and microbial biodiversity effects on water quality in Minnesota lakes

Cultural eutrophication is one of the most important issues facing   water quality managers in Minnesota. Most regulations of nutrient   loading into Minnesota waterways are focused on limiting phosphorus   (P) availability because large quantities of this potentially   limiting nutrient contribute to excessive plant growth and low   (hypoxic) or anoxic conditions and fish kills. Heterotrophic   bacteria are important competitors with plants for P in north   temperate lakes. Furthermore, they typically have low growth   efficiencies leading to high rates of carbon decomposition. When   these high rates of decomposition occur in the surface waters rather   than the hypolimnion, the high rates of oxygen consumption can be   replenished through photosynthesis and mixing with atmospheric   oxygen.    Bacterial strains will be isolated from several lakes and   characterized with respect to their stoichiometry under conditions   of varying nutrients, resource ratios, and growth rates. Bacterial   diversity will be ascertained using denaturing gradient gel   electrophoresis of PCR-amplified 16S rRNA gene fragments (detects   ~99% of the bacterial community without cultivation). It is expected   that higher diversity increases the potential for a given system to   respond to various resource ratios. More diverse communities are   likely to demonstrate a low degree of community homeostasis, whereas   less diverse communities should show more apparent homeostasis,   i.e., little change in biomass stoichiometry with large changes in   substrate stoichiometry.    (eutrophication); (algal bloom); (algal blooms); (nutrient loading);   (phosphorous); (nitrogen); (phosphorous loading); (nitrogen   loading); (anoxic); (anoxia); (anoxic condition); (anoxic   conditions); (N:P ratio); (ratio); (ratios)

In progress
Start Date
End Date
Scope of Study
Field Investigation
Scale of Phenomena
Impact of Pollutants
Nutrients, Including Phosphorus
State Province
Annex Numbers
Control of Phosphorus
Research & Development
Annex 17
Cause-effect inter-relationships of productivity and ecotoxicity

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