Macroinvertebrate sampling on the Upper Missouri River

Science · Bug study

Macroinvertebrate Studies

A decade of bug-life sampling — the most reliable indicator we have of cold-water river health.

Over a Decade of Scientific Research

UMOWA has conducted over a decade of scientific investigations (2015–2025) examining the health, diversity, and abundance of macroinvertebrate populations from Holter Dam to Cascade, plus four years of sampling on specific Smith River sites between Fort Logan and Eden Bridge (2016, 2017, 2018, and 2024).

David Stagliano conducted these studies using scientifically rigorous methodology, enabling UMOWA to present findings to state and federal agencies demonstrating the significance of river flushing flows for maintaining healthy aquatic ecosystems.

Bug Health Index

EPT richness, 2015–2024

Mayflies, caddisflies, and stoneflies are the gold standard for clean cold-water rivers. The more distinct taxa we find, the healthier the river. UMOWA's sampling has tracked steady or improving richness across the Holter-to-Cascade reach.

Distinct EPT taxa per sampling year

Higher bars = more diverse insect community. Stacked by order.

Visual summary derived from UMOWA's published Macroinvertebrate Studies (linked below). The full methodology, including kick-net protocols and site-specific values, is documented in each report.