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River Monitoring

Biological Monitoring

Biological monitoring assesses the integrated effects of water pollution on aquatic organisms.

Biological monitoring provides information on the presence and abundance of four groups of aquatic organisms:

• attached algae (periphyton),
• immature insects, worms and clams (macroinvertebrates),
• floating algae (phytoplankton), and
• floating microcrustaceans (zooplankton).

Biological monitoring is conducted annually during the summer months at 16 sites located on the Mississippi, Minnesota, St. Croix, and Vermillion Rivers.

Biological Monitoring Sites

Mississippi River

(Measured from the intersection of the Ohio and Mississippi Rivers near Cairo, IL)

• Near Anoka (river mile 871.6)
• Near Fridley (river mile 862.8)
• Above Lock and Dam No. 1 (river mile 848.0)
• Near St. Paul (river mile 839.4)
• Near Newport (river mile 831.0)
• Near Grey Cloud Island (river mile 826.7)
• Near Government Light (river mile 820.4)
• Above Lock and Dam No. 2 (river mile 815.6)
• Near Diamond Bluff (river mile 800.4)

Minnesota River

(Measured from the downstream end or mouth of the river)

• Near Judson (river mile 120.0)
• Near St. Peter (river mile 89.7)
• Near Jordan (river mile 39.4)
• Near Fort Snelling (river mile 3.5)

St. Croix River

(Measured from the downstream end or mouth of the river)

• Near Stillwater (river mile 24.0)
• Near Prescott (river mile 1.7)

Vermillion River

(Measured from the railroad bridge farthest downstream of Hastings)

• Near Empire (river mile 15.6)

Biological Monitoring Field Equipment & Variables