SPATIO-TEMPORAL VARIATION IN SESTON AND ITS RELATIONSHIP WITH DISCHARGE IN LTRMP 
KEY POOLS OF THE UPPER MISSISSIPPI RIVER SYSTEM.

Robert M. Burdis
Minnesota Department of Natural Resources, Mississippi River Monitoring Station, 
1801 South Oak Street, Lake City, MN 55041.

Suspended material or seston in aquatic systems is a natural and important part 
of the ecosystem. However, excessive amounts of seston, whether organic or 
inorganic, can have deleterious effects on the biota of an aquatic system. 
Measures of seston, including total suspended solids, volatile suspended solids, 
turbidity, and chlorophyll a were analyzed from Long Term Resource Monitoring 
Program data. Analysis of stratified random sampling data revealed distinct 
spatial and temporal differences in seston both among the pools and among 
strata. The results illustrate the efficiency of Lake Pepin at retaining seston 
and the significant impact the lake has on water quality on the Upper 
Mississippi River. Seasonality was apparent in all water quality parameters and 
varied among some pools. The effects of discharge on water quality parameters 
varied between strata. Water quality variability within strata was also 
examined.

 
Keywords: seston, Upper Mississippi River, water quality, Lake Pepin, discharge