Iowa DNR
River & Stream Biological Monitoring
Fish and Benthic Macroinvertebrate Surveys
Physical Habitat Assessments

Invertebrate Program Statistics and Summary

Since the bioassessment program began in 1994, benthic macroinvertebrate surveys have been a critical component of the assessment process.

Total Invertebrates Collected
Unique Taxa
Total Surveys
BMIBI Assessments

Top 5 Most Collected Taxa

Taxa # Collected
Chironomidae 205,239
Cheumatopsyche 95,912
Baetis intercalaris 31,282
Simulium 30,727
Tricorythodes 29,709

Top 5 Most Common Taxa

Taxa % of all sites
Chironomidae 77.68%
Cheumatopsyche 66.22%
Hydropsychidae 59.09%
Oligochaeta 58.01%
Stenacron interpunctatum 51.95%

Valid Assessments

Assessment Type Count
Warm Water 1818
Cold Water 200
Rapid Assessment 188

BMIBI - Warm Water Scores

Stream Sample Date Score

BMIBI - Cold Water Scores

Stream Sample Date Score