What did Mitchell Davis and Ryan Sargeant find in Idaho fish?

Mitchell Davis and Ryan Sargeant found microplastics in nearly every fish sampled from Idaho's Upper Snake River watershed.

Where do the microplastics in Idaho fish come from?

The microplastics found in Idaho fish primarily originate from synthetic clothing fibers and plastic bags or wraps.

Are microplastics in fish a threat to human health?

Yes, scientists are concerned that microplastics could migrate into fish muscle tissue, entering the human food supply and potentially causing long-term health problems.

Home / Environment / Fish Guts Reveal Shocking Microplastic Scourge

Fish Guts Reveal Shocking Microplastic Scourge

19 Nov, 2025

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Summary

Microplastics found in 40 out of 48 fish sampled.
Particles originated from textiles and plastic bags.
Older fish showed higher plastic concentration.

Fish Guts Reveal Shocking Microplastic Scourge

Microscopic plastic particles have been detected in a significant number of fish from Idaho's Upper Snake River watershed, according to recent research. Undergraduate researcher Mitchell Davis and his advisor Ryan Sargeant analyzed 48 fish from various sites, including the Teton River and Island Park.

Their findings revealed that 40 fish contained microplastics, primarily within their gastrointestinal tracts and, alarmingly, in their livers and eggs. The particles, largely from textiles and plastic bags, suggest a widespread contamination issue. Older fish exhibited higher plastic loads, indicating accumulation over time.