Aquatic Invertebrate Community Monitoring at Effigy Mounds National Monument

Photo of Dousman Creek at Effigy Mounds National Monument
Dousman Creek at Effigy Mounds National Monument.


Scientists use established methods to track aquatic invertebrates and assess stream water quality conditions. Aquatic invertebrates can include insect larvae, worms, crayfish, snails, and other animals without backbones. Many invertebrates live in a stream for several months, which exposes them to changing water quality conditions over time.

When scientists monitor aquatic invertebrates, they can find out what species are present and their tolerance level to pollution and disturbances. Some species can live in poor water quality conditions, while others need cleaner conditions. Aquatic invertebrate communities can serve as the "canary in the coal mine" for water quality of a stream.

Graph depicting water quality assessment of Dousman Creek at Effigy Mounds National Monument
Water quality measurements in Dousman Creek compared to values for the 50th percentile (50% of streams are at or below value) from reference reaches in Iowa. Desirable conditions for Dousman Creek include cool water (<50th percentile), high dissolved oxygen (>50th percentile), pH near 7 and low turbidity.

Since 2008, NPS scientists have monitored invertebrates of Dousman Creek. Initial sampling of invertebrate communities shows Dousman Creek is largely unimpaired. Scientists found that the most common species was one that cannot live in poor conditions. Several uncommon species were also collected. Dousman Creek will continue to be monitored to assess long-term trends. Promoting conservation management practices in the watershed helps to improve and maintain good water quality and stream habitat conditions.

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Learn more at the Heartland Inventory & Monitoring Network.

Data in this report were collected and analyzed using methods based on established, peer-reviewed protocols and were analyzed and interpreted within the guidelines of the protocols.

Last updated: March 16, 2018