1998 Annual Status Report Submersed and Floating-leaf Vegetation in Pools 4, 8, 13, and 26 and La Grange Pool of the Upper Mississippi River System
Dates
Publication Date
2001-05
Summary
Aquatic vegetation was investigated in five navigation pools in the Upper Mississippi River System using a new protocol named “stratified random sampling” or SRS protocol for the first time in 1998. The five pools were Pools 4, 8, 13, and 26 of the Upper Mississippi River and La Grange Pool of the Illinois River. The results on submersed aquatic vegetation and rooted floating–leaf aquatic vegetation were summarized in this report. The percent frequencies of submersed aquatic vegetation in shallow water areas (≤ 3 m deep at flat-pool condition) in the five pools were 36.6%, 47.6%, 42%, 6.1%, and 0%, respectively. The aquatic area strata that were directly influenced by the flow in the main channel, such as the main channel borders and [...]
Summary
Aquatic vegetation was investigated in five navigation pools in the Upper Mississippi River System
using a new protocol named “stratified random sampling” or SRS protocol for the first time in 1998. The five
pools were Pools 4, 8, 13, and 26 of the Upper Mississippi River and La Grange Pool of the Illinois River. The
results on submersed aquatic vegetation and rooted floating–leaf aquatic vegetation were summarized in this
report. The percent frequencies of submersed aquatic vegetation in shallow water areas (≤ 3 m deep at flat-pool
condition) in the five pools were 36.6%, 47.6%, 42%, 6.1%, and 0%, respectively. The aquatic area strata that
were directly influenced by the flow in the main channel, such as the main channel borders and secondary
channels, had lower percent frequencies of submersed aquatic vegetation than the aquatic area strata that were
less directly influenced by the flow in the main channel, such as the contiguous and isolated backwaters. The
percent covers of rooted floating–leaf vegetation were 4.1%, 7.5%, 6.5%, 0.9%, and 0%. The majority of
aquatic vegetation that was recorded in Pool 26 was from one isolated backwater area. Aquatic vegetation was
not recorded at any of the sampling sites in La Grange Pool.
