Science Stuff

In 2014, Minnesota passed a riparian buffer law, requiring perennial vegetative buffers of up to 50 feet along lakes, rivers, and streams and buffers of 16.5 feet along ditches.   The objective of this law was to reduce sedimentation and nutrient loading in order to improve aquatic ecosystem health.  
Is the law working?
That is the question that the TCTU Streamkeepers set out to answer last year, by doing macroinvertebrate sampling at two sites on the South Branch of the Whitewater River, following up on research that had been conducted in 2018, shortly after the law's implementation.  A team of amateur entomologists including Mitch Abbett, Carl Nelson, Mark Peerenboom, Jim Sauter and Dave Sauter (aka Jim's brother) collected samples of insects that were analyzed by MNTU Habitat Director Dr. Jennifer Biederman and Winona State PhD Candidate Will Varela.  Doug Moran provided angling support.

The results
The analysis used the Benthic Index of Biotic Integrity (B-IBI), a tool that was designed to evaluate stream heath based on macroinvertebrate sampling.  The B-IBI showed a large improvement at one site (Cty 37) where MNTU had also conducted a habitat project.  The B-IBI showed no change at the other site (Cty 26).  Neither of the results was statistically significant, which was not surprising given the limited sampling that the team was able to accomplish, but the Cty 37 results are encouraging and may indicate the value of combining habitat projects with vegetative buffers. The complete report can be found below the photos.  It is succinct and written in (mostly!) plain English.  We encourage you to read it if you are interested in the health of our streams.  Thanks to all of our volunteers, and special thanks to Jenny and Will!

Thanks to Jim Sauter and Jenny Biederman for the photos

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