Macroinvertebrate populations provide additional perspective on aquatic life conditions in the river. ORSANCO uses these small water-dwelling organisms as indicators of water quality; some require good, clean water to survive and reproduce. Because many species are highly sensitive to pollution, and because they are relatively immobile, the assessment of macroinvertebrate populations can bring valuable insights on water quality. ORSANCO has conducted macroinvertebrate sampling each year since 1990, including site-specific studies, pool-wide studies, and river-wide surveys. For more information about ORSANCO’s Macroinvertebrate Sampling, contact Bridget Borrowdale.

Macroinvertebrate Data

ORSANCO Biological Indices and Assessment Methodology Download
Macroinvertebrate Data 1964-2023 Download