Water Quality Improvement

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May 30

The Importance of Macros

Posted on May 30, 2018 at 9:52 AM by Allan Warren

macrosBenthic macro-invertebrate samples. Credit: EPA, G. Carter via NOAA/GLER
You might have heard the term macroinvertebrates before, but not sure what it means. If we break down the word to macro – something we can see with our eyes and invertebrates – animal lacking a backbone, we get a clearer picture of what we mean. Aquatic invertebrates that we can see with our eyes include insects, crayfish, clams, snails, and worms. So why do we care about tiny insects in our creeks and streams?

These seemingly insignificant organisms can be an indicator of stream health and water quality. Benthic (bottom of a stream) macroinvertebrates are classified based on their pollution tolerance level. A general classification can be broken down into different categories, such as very intolerant of pollution, moderately intolerant, fairly tolerant, and very tolerant of pollution. For example, mayfly, stone fly, and caddisfly are sensitive to pollution and are classified in the very intolerant category. On the opposite end of the spectrum, black fly larva, leeches, and snails are fairly tolerant or very tolerant of pollution.

A simple sampling of the benthic environment can tell us a lot about stream health. So, check out the creatures below the surface the next time you visit a stream and see what you find! More information about macroinvertebrates can be found at the Puget Sound Stream Benthos website, www.pugetsoundstreambenthos.org/.

Stream Team Habitat Assessment Workshop
The Pierce Conservation District will partner once again with the King Conservation District to host a Habitat Assessment Workshop on Saturday, August 18 from 10 am – 2pm. This assessment is done once a year (August, September, or October) to assess changes in streamside habitat. Topics covered include stream characteristics, bank conditions, and the riparian vegetative zone. This workshop is open to anyone interested in learning more about riparian habitats. For registration and details, please contact Isabel Ragland at isabelr@piercecd.org, call (253) 845-9770 ext. 103 or click here to register.

Summer Stream Monitoring Schedules
  • Quarterly monitors may schedule their summer monitoring between June 21 and September 14. 
  • Bimonthly monitors are scheduled to monitor their streams in July and September.
  • Volunteers are also encouraged to run replicate tests once or twice a year. The replicate testing includes the dissolved oxygen, pH, and nitrate tests. Don’t forget to mention when you email to reserve a kit, that you will need extra sample bottles.