LONG-TERM TRENDS IN ILLINOIS RIVER WATER QUALITY:  REFLECTIVE OF GLOBAL 
CHANGES?

Thad R. Cook, Kevin S. Irons, Michael A. McClelland, Greg G. Sass, T. Matthew 
O’Hara, Nerissa N Michaels and Matt R. Stroub.
Illinois River Biological Station, Illinois Natural History Survey, 704 North 
Schrader Avenue, Havana, Illinois 62644

Climate change and invasive species introductions are among the most widely 
publicized and debated topics concerning our environment today.  
Nevertheless, understanding the impacts of these changes are often difficult.  
River monitoring programs, such as the Long Term Resource Monitoring Program 
(LTRMP, 1989-present) and the Long Term Illinois River Fish Monitoring 
program (LTEF, 1957-present) have proven useful for detecting spatial and 
temporal changes within the Illinois River.  We used two water quality 
metrics (temperature and chlorophyll a) and fisheries data from the LTRMP and 
LTEF data sets to test for trends in and potential impacts of global climate 
change on a regional scale.  We also tested for the influences of invasive 
species on water quality.  Preliminary analysis of bi-weekly, LTRMP fixed 
site sampling data indicates an increase in average water temperature of 1.5 
?C within the Illinois River at Havana between 1992 and 2006.  Results from 
the LTEF water temperature data show similar trends from 1979 to 2006.  Our 
preliminary results also suggest no correlation among invasive carps catches 
and chlorophyll a concentrations  Continued collection and analysis of 
regional long-term data sets may play a pivotal role in documenting and 
understanding the global impacts of climate change.     


Keywords:  Illinois River, invasive species, Long Term Illinois River Fish 
Monitoring Program, Long Term Resource Monitoring Program, water quality

Thad R. Cook 
Illinois River Biological Station 
Illinois Natural History Survey 
704 North Schrader Avenue 
Havana, IL  62644 
Phone: 309 543-6000 
FAX: 309 543-2105    
email: t-cook2@uiuc.edu

Poster presentation