Mayflies Should Be Normal

by Dan Haug | May 4, 2023

In April, I joined a class of Ames High School seniors to survey benthic macroinvertebrates in Ioway Creek. If you had asked me “what on earth are you doing?” here’s what I would have said:

Hello! I’m Dan and I work on water quality for a local non-profit. And these are environmental science students from Ames High School. Why are we standing in the middle of the creek wearing hip waders and doing what looks like a funny dance? Why, this is a perfectly normal thing to do! We are citizen scientists and we are “science-ing”! The dance is called the benthic shuffle, and is an important part of the protocol for biological monitoring. We are dislodging aquatic insects from the rocks and catching them in our net.

And look at what we have caught from a mere 1 square meter of rocks! 170 mayflies! This too is normal! We are at Brookside Park, and here is a brook babbling over rocks and gravel. It would be strange if we did not find a healthy population of mayflies in such inviting habitat!

No, they don’t look like the mayflies that spatter windshields in Dubuque. But this is indeed Baetis, the blue-winged olive mayfly, imitated with success by many a trout fisherman. In its larval form, we call it the “small minnow mayfly”, for its quick swimming. They live about a year in the creek before they pupate and get their wings, assuming a fish doesn’t eat them first!

benthic macroinvertebrates in Ioway Creek

As I was saying, what you see here is perfectly normal, though maybe not as common as it should be in Iowa streams. If you find a riffle in the stream with no mayflies, well, that would mean something is not right. Perhaps insecticides have washed into the creek from upstream farms and lawns and killed them. Perhaps we’ve inadvertently fertilized the algae in the creek, turned the water a shade greener and the making the water a little less oxygenated at night. There are other insects that can make a living under these conditions. In the creek near the Story County Fairgrounds, you can find plenty of these net-spinning caddisflies, but no mayflies! If all you find are these wriggly little midge flies, well, that’s a sign of more serious pollution.

Nice to meet you! Time to get back to counting bugs!

Results from Ioway Creek (Ames) in 2023

Results from W. Indian Creek (Nevada) in 2022

Think Outside the HUCs

by Dan Haug | Apr 7, 2023

“With the Nutrient Reduction Strategy approaching its 10-year anniversary in 2023, Iowans deserve to see water quality results from the nearly $100 million of public money invested since 2013. Water monitoring is a crucial component to the success of the Nutrient Reduction Strategy and must be designed to assess progress. A strategy without a way to evaluate progress or outcomes is not a real strategy.”
– from Iowa Environmental Council’s 2022 report: “Water Quality Monitoring and the Water Quality Initiative“

fake text message to introduce blog post

Most water monitoring programs are NOT designed to assess progress. Often, people don’t begin monitoring in earnest until the grant funding arrives for an improvement project (or on flip side, until an industry with a reputation for pollution sets up shop in the area). Often, they’re hoping for preliminary results when the grant wraps in 3-5 years. I’ve been down that road, completed a horrifying statistical analysis, and left this conference poster as a warning to others: “Progress tracking is not a realistic use for typical stream monitoring approaches”.

Our local partners in Story County took this warning to heart and made a plan to sustain water monitoring for at least ten years, while shifting our focus. We collected lab samples from more sites (less often, and with less hassle) while ramping up the volunteer program, so we could engage the public and get a baseline understanding of water bodies all around the county. All is well and good. But now and then I come back to the question “how would you monitor water if you were serious about assessing progress?”.

Preliminary results in 3-5 years might be feasible if you already have baseline data for comparison, and account for any big changes in weather. The South Skunk River just upstream of Ames was monitored from 2001-2014 by the Iowa DNR, and we resumed monitoring it in 2020. I have good news and bad news for the newly formed Headwaters of the South Skunk River WMA.

Good news: average nitrate concentrations over the last three years have declined 46% compared to the baseline period. Mission accomplished?
Bad news: the trend goes away if you exclude samples collected during a drought when nitrate levels are at their lowest.

nitrate trend in south skunk river above Ames

Study design is key for progress tracking. In order to be sure that water quality really changed, and to be able to link that change to something that happened in the watershed, scientists approach water monitoring like a medical trial. To do it right, there should be a treatment group (a watershed that receives conservation funding and attention), a control group (a nearby watershed that doesn’t receive funding), a before period, and an after period. There should be a full accounting of land management and conservation practices in both watersheds. If the treatment group improves more than the control group, that’s a good sign the medicine works. At the time we wrote the Story County Monitoring Plan, doing a paired watershed study of the sort that Michelle Soupir did for Black Hawk Lake didn’t make a lot of sense.

It didn’t make sense to invest in progress tracking, because our WQI-funded watershed project had come to a close, further funding was uncertain, and we couldn’t expect much improvement in water quality based on other metrics to date. Our watershed coordinators worked really hard, we had enthusiastic partners in local government and agribusiness, and we organized some well-attended field days where we heard from inspiring early adopters of cover crops and bioreactors. We met some farmers in the watershed who cared enough about soil and water to take a risk and try something new. Unfortunately, at the end of four years, we had a lot of unspent cost share funds and only enough conservation practices to expect or 1 or 2 percent reduction in nitrogen and phosphorus. Ioway Creek is a big watershed (147,000 acres).

However, this year I was reviewing our water monitoring data and had one of those moments like when you squint at an optical illusion and suddenly see a rabbit instead of a duck.

“Hey, that looks a lot like an upstream/downstream study for tracking whether projects in the Ioway Creek watershed and the City of Ames have improved water quality!”

The medicine: A bunch of conservation practices were installed between 2015 and 2019, some of which address nitrogen and some of which address other pollutants. We could include Jean’s no-till fields in Hamilton County, Jeremy’s cover crops in Boone County, Gerold’s bioreactor in Boone County, the UV disinfection system in Gilbert, the permeable parking lot at Ames City Hall, the stream restoration and saturated buffer at the Tedesco Environmental Learning Corridor, and many others.
The treatment group: A downstream site, influenced by all those conservation practices. The South Skunk River at 265th St. has been monitored weekly by the City of Ames since 2003. At this point the river drains 573 square miles, corresponding to the Ioway Creek watershed plus the Headwaters of the South Skunk River watershed.
The control group: An upstream site, not influenced by these practices. At this point, the river drains 316 square miles, corresponding to the Headwaters of the South Skunk River watershed, minus any land within Ames city limits.
A before period: Both sites were monitored between 2003 and 2014.
An after period: Both sites were monitored between 2020 and 2022.

And then I made a boxplot and squinted a little more and said, “Hey, it looks a lot like nitrate has improved at the downstream site!” Same thing for E. coli! Maybe there’s more to this story than just cost-share metrics.

graphs comparing nitrate at upstream and downstream sites

The analysis is described in more detail in our 2022 annual report on water monitoring in Story County. We’ll also have some opportunities this year to talk with other groups around the state that are doing water quality monitoring and swap some tips and tricks.

Here’s one of mine. To see the “rabbit” in this data, you have to be flexible in how you think about watersheds. A watershed is just the land area that drains to a common point. With the right tools, we can delineate a watershed for any point of interest on the river network. I’ve taught several classes of ninth graders how to do this. Neither of these sites are in the Ioway Creek watershed, and they aren’t mentioned in the Watershed Plan, but that doesn’t mean they’re not relevant. The US Geologic Survey’s system for mapping and numbering watersheds is convenient for many purposes. But if you have access to long-term monitoring data, don’t be afraid to think outside the HUCs!

The Great Mussel Rescue of 2022

by Dan Haug | Oct 28, 2022

Updated 2022-11-14 with final count: 53 mussels rescued, 13 of them threatened species!

Three fun facts about freshwater mussels

Mussels keep streams clean. A mature freshwater mussel can filter 10 gallons of water a day, gobbling up algae and other microscopic organisms in the water. As this video shows, mussels can clean up muddy water, but too much silt in the water can bury them alive or clog their gills.
Mussels can hitch-hike long distances. Some mussel mamas have a special lure to flag down passing fish so that the baby mussels (glochidia) can hitch a ride as a parasite on the fish’s gills!
Mussels are in trouble. The United States is a hotspot for freshwater mussel biodiversity but many species were nearly wiped out by over-harvest for the button industry, dams and habitat loss, and too much silt in the water. For more about freshwater mussels, watch this PBS video.

Two state-threatened species of mussels have been found in Ioway Creek–the cylindrical papershell (Anodontoides ferussacianus) and the creek heelsplitter (Lasmigona compressa). An erosion control and stream restoration project is planned at Brookside Park in Ames, so the Department of Natural Resources required that they be relocated before construction begins. Mussel expert Brett Ostby of Daguna Consulting was hired to lead the effort, but finding all the mussels hiding in a patch of streambed is slow work, and there was a kilometer of stream to cover. We needed volunteers…

Volunteers collecting mussels in Ioway Creek

I had been planning volunteer events to monitor water in Ioway Creek and its tributaries and to pick up trash in West Indian Creek, but low water levels forced us to cancel. Low water levels make it easier to find mussels, so Prairie Rivers of Iowa and our partners at the Outdoor Alliance of Story County switched gears and recruited 12 volunteers to help. Five of the volunteers were students at Ames High School, where I’d been talking with earth science classes about runoff and water quality. Teachers Collin Reichert and Kean Roberts were kind enough to lend us some chest waders — essential gear if you’re planning to spend an hour or more in 45-degree water!

Since mussels can be buried in sand, we had to feel around or dislodge them with rakes. The three guys from Daguna Consulting used wet suits and snorkels to tackle some of the deeper pools. Volunteers helped when they were able over a three-day period. It’s slow, tedious work, leaving no stone unturned, but I can hardly complain about spending time in nature on a beautiful day. Ioway Creek has plenty of wildlife to see if you look long enough. I saw birds including a kingfisher, reptiles including a softshell turtle and northern water snake, and invertebrates including a hellgrammite, crayfish, and fingernail clams. For some of the students, being in the creek and seeing these critters was a new experience.

Mussels were fewer and farther between than we expected. We relocated 53 mussels (representing 5 species) to a stretch upstream of the park, where they seem to be more abundant.

8 Cylindrical papershell (Anodontoides ferussacianus)
5 Creek Heelsplitter (Lasmigona compressa)
1 Fragile Papershell (Leptodea fragilis)
37 Lilliput (Toxolasma parvum)
2 Pocketbook (Lampsilis caridum)

Compare that to the results of a DNR mussel survey this year in the Iowa River near Coralville (which found 28 species, and was catching an average of 22 mussels every hour) and it’s clear that the ecosystem in Ioway Creek is out of balance. Hopefully, this project will improve in-stream habitat so the populations grows. Our thorough search ensures that few will be lost during construction.

Volunteers in the Creek All Week

by Dan Haug | May 23, 2022

Trash Cleanup

Ioway Creek recently got some love from the community. On Saturday, May 21, a group of seventeen volunteers (plus another four helping on land) loaded nine canoes with trash as we floated from Brookside Park down to S. 16th Street in Ames. We hauled out 14 tires and 1,560 pounds of other trash including 3 shopping carts, a tent, and two bicycles. Assembling the tools, canoes, food, and people was a collaborative effort involving Prairie Rivers of Iowa, the City of Ames, Story County Conservation, the Skunk River Paddlers, and the Outdoor Alliance of Story County. A few people got wet, everyone got dirty, my muscles are still sore, but we all had a good time on the river!

Citizen Science

On Tuesday May 17, fourteen volunteers tested water quality in Ioway Creek and its tributaries. This is the fifteenth Spring Watershed Snapshot, and the fourth that Prairie Rivers organized. Thanks to the Outdoor Alliance of Story County for help with supplies. This year, some volunteers were already doing regular monitoring of a site for Story County Conservation and adjusted this month’s schedule to coordinate, or picked up a few extra sites. If we include other watersheds and other days tested during the same week, the count is 22 volunteers (and also some Story County Conservation staff) and 47 sites in Story, Boone, and Hamilton counties.

We scheduled the event for a weekday this year to coincide with Polk County’s snapshot, so while the event was less social than it sometimes is (volunteers could pick up a kit any time on Tuesday and test their assigned sites alone or with a friend), they were monitoring as part of a big coordinated effort of the kind that we haven’t seen since before the IOWATER program was cancelled! In Polk County, 75 people covered 115 sites!

A table with our findings are shown below, and a map of the sites can be found here. On Tuesday, the water was clear and phosphorus was low at all our sites. Chloride was highest and nitrate lowest in creeks with more urban watersheds. Dissolved oxygen fell into the “fair” range at several sites in Hamilton County, as well as the south fork of Worrell Creek in Ames. Nitrate was 10 mg/L or higher at most sites, but reached 20 mg/L in the middle sections of Ioway Creek and several rural tributaries. I did some followup testing to make sense of the high nitrate levels at Duff Ave, more on that later.

Thanks to all the volunteers who spent some time in a creek last week!

The Mystery of the Orange Creek

by Dan Haug | Mar 30, 2022

“Is this pollution?” I received this photo, taken at 1PM on March 24, from Ames High School student Oskar Niesen. I met Oskar and other students in Mr. Todd’s environmental science classes for the first time in February, when we talked in the classroom about issues and solutions in Iowa waterways. The class was interested in testing water quality, so I met them again at the creek on March 22 and showed them how.

Later that evening, I visited the site and chatted with Jake Moore and Liz Calhoun with the City’s stormwater program. If someone had let muddy water wash off a construction site, or someone was pouring chemicals down the storm sewer, this would violate city ordinances and they would be the people to check up on it. But the timing wasn’t consistent with construction site runoff. There hadn’t been more than trace rain since Tuesday March 22nd.

Oskar had talked with a geology professor at Iowa State (Dr. Elizabeth Swanner) and suggested another possibility: iron oxide (rust), perhaps formed by naturally occurring bacteria. As Oskar explained “there are generally 3 types of iron oxide formations. One is a stain that we see now, the second is called flocculent iron which is a cloud that I saw then, the third is an iridescent film on the top. Bacteria tend to form all three.” At 5:00 on March 24, when I followed up on Oskar’s tip, the water had cleared up and there was no iridescent film, but there was stain on the rocks and at the water’s edge all the way up to the storm sewer outlet.

Hydrant flushing is done every year with the express purpose of flushing out iron oxide and other mineral deposits that can clog water mains. Liz Calhoun confirmed that crews flushed hydrants in neighborhoods connected to this storm sewer on March 24. A little rust in water can stain laundry but is harmless to people and fish. A release of drinking water can kill fish if it causes a sudden temperature change (this happened last summer when a water main broke) but in this case, we think there’s nothing to worry about. Mystery solved! The only thing more gratifying than working with curious young people and helpful colleagues is a happy ending for water quality!

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