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 204,770
Cheumatopsyche 95,766
Baetis intercalaris 31,214
Simulium 30,718
Tricorythodes 29,708

Top 5 Most Common Taxa

Taxa % of all sites
Chironomidae 79.3%
Cheumatopsyche 67.51%
Hydropsychidae 60.22%
Oligochaeta 59.2%
Stenacron interpunctatum 53.1%

Valid Assessments

Assessment Type Count
Warm Water 1816
Cold Water 200
Rapid Assessment 188

BMIBI - Warm Water Scores

Stream Sample Date Score

BMIBI - Cold Water Scores

Stream Sample Date Score