Multiyear synthesis of macroinvertebrate component from 1992 to 2002 for LTRMP

Sauer, J. 2004. Multiyear synthesis of the macroinvertebrate component from 1992 to
2002 for the Long Term Resource Monitoring Program. 2004. Final report submitted  to
U.S. Army Corps of Engineers from the U.S. Geological Survey, Upper Midwest
Environment Sciences Center, La Crosse, Wisconsin, December 2004. Technical Report
LTRMP 2004-T005. 31 pp. + Appendixes A–C.

ABSTRACT

In 1992, macroinvertebrate sampling was begun in Pools 4, 8, 13, and 26; the Open River
Reach of the Mississippi River; and La Grange Pool of the Illinois River as part of the
Long Term Resource Monitoring Program. Long-term monitoring is needed to detect
population trends and local changes in aquatic ecosystems. We selected mayflies
(Ephemeroptera), fingernail clams (Pisidiidae), and the exotic Corbicula species for
monitoring. Midges (Chironomidae) were added to the sampling design in 1993 and zebra
mussels (Dreissena polymorpha) were added in 1995. Sampling was based on a stratified
random design and conducted at approximately 125 sites per study area. Mean densities of
taxa were weighted by strata for extrapolation. The poolwide estimated mean densities of
mayflies, fingernail clams, and midges were all within the range of variation observed
historically. Over the last 11 years of sampling, the northern study areas supported the
highest densities of the target organisms. 

KEYWORDS

Benthic aquatic macroinvertebrates, Corbicula, fingernail clams (Pisidiidae), Illinois
River,Long Term Resource Monitoring Program, mayflies (Ephemeroptera), midges
(Chironomidae), Mississippi River, zebra mussels (Dreissena polymorpha)