Macroinvertebrate report out

Mar 11, 2013
Conditions are looking good in Whychus Creek particularly in the restored stretch of Whychus Creek at Camp Polk Meadow Preserve.

Last June volunteers helped our partners at the Upper Deschutes Watershed Council and the Xerces Society monitor macroinvertebrates all along Whychus Creek. The hope was to see how various creek restoration projects have affected conditions in the creek.
The final report just came out and the news was good--particularly at Camp Polk Meadow Preserve:

  • Only seven months after Whychus Creek was diverted into the restored meadow channel at Camp Polk Meadow Preserve, macroinvertebrates indicated better conditions in the restored channel than in the old straightened channel.
  • Not only were macroinvertebrates present in the new channel, demonstrating rapid colonization of a new stream, but the specific macroinvertebrates found there suggest that restoring creek has been effective in improving stream conditions for aquatic life.
  • As Land Trust member and volunteer Herb Blank put it, "we are seeing remarkable and rapid improvements in the macroinvertebrate populations at the Land Trust Preserve, no matter how you measure it."

The macroinvertebrates found from Rimrock Ranch down to Alder Springs show that stream conditions have significantly improved since 2005. Streamflow restoration projects on these stretches of Whychus Creek have helped reduce stream temperatures which in turn creates better habitat for macroinvertebrates.

One sampling site showed mixed results, Sisters City Park. Numbers were good for EPT (Ephemeroptera, Plecoptera, and Trichoptera), bugs that are only found in cold, clean, relatively pristine streams, but with a fair number of the other bugs missing. This could be because conditions are too cold and clean for the missing bugs, or it could indicate problems with other conditions. Monitoring over the next several years will contribute more information that allow us to better understand these results.

To learn more, read the full report.