Macroinvertebrate sampling on the Huron River and its creeks

Volunteers set up “picking” stations while trained collectors go into the creeks to pull out macros with a net.

Thanks to our many volunteers, the April 2018 River Roundup was a great success!  It was a tricky spring, as high rains and subsequent high water levels forced us to reschedule the event at the last minute. Changing the date resulted in a drop in volunteer participation, but we were still able to visit many sites and volunteers were able to get into the river and creeks safely. That makes the schedule change worth it! Our volunteers were also able to collect some great samples of benthic macroinvertebrates.

This study is one of the most effective ways that HRWC has to understand how the water quality of the river and creeks may be changing. From the data collected at this semi-annual event, we are able to keep abreast of the health of our waterways. You can see all the results in the April 2018 River Roundup Report.

Case-building caddisflies (Limnephilids) feature prominently in spring collections!

Current watershed health

In a nutshell, the health of the watershed as judged by our macroinvertebrate sampling is holding steady, but there is a lot of variation around this, and the variation does seem to be increasing over time. Recently, we see many locations that have had their best sample ever, but more locations  have been detected as “declining,” generally a very slow decline that is only noticeable with a very long term study like ours. HRWC has held River Roundups since 1994, and we can see these declines in our data.

Four outstanding locations that have had extremely diverse samples of macroinvertebrates lately are Mann Creek (east of Brighton), Huron Creek (in Hudson Mills Metropark), Fleming Creek (headwaters), and the main branch of the Huron River at Zeeb Road. Each of these locations is considered “excellent” in our scoring scheme, and all are significantly improving too (in the statistical interpretation of the word “significant”).

However, for every place that is thriving and improving, it seems that there is one struggling. The streams that I am most concerned about presently are Honey Creek (Washtenaw Co.), Davis Creek (Livingston Co.), and South Ore Creek (Livingston Co.). Honey and Davis are not only significantly declining at the mouth of each creek, but also at sites further upstream in their creeksheds, indicating a wide spread degradation. South Ore Creek is declining at all three locations we sample (though only significantly at one of them). There is no particular source or cause for this degradation, as far as I can tell. All of the declines in these three creeks have happened very slowly, over the course of over fifteen years or more. Generally speaking, it is simply continued development and sprawl that is the primary cause of these creeks’ loss of aquatic life. Development brings more runoff, more erosion, more unstable water flows, and more pollution to the waterways, all of which kill aquatic insects.

One of HRWC’s messages is that maintaining the Huron River watershed’s health in the face of increased population requires changing current patterns of development by encouraging higher density where infrastructure already exists, and holding onto our natural areas so they can continue to provide the ecological services necessary to maintain quality of water, air, and land.

As we see aquatic life declining in the creeks that flow through rapidly developing creeksheds, this message is more important than ever. We initiate programs like Change Makers to educate and inspire residents to become local leaders in their communities.

What’s next?

The next River Roundup is September 29. Put it on your calendar and join us for a day of stewardship!