Research project may improve water quality in Dry Run Creek Watershed

March 30, 2012

By Charles Wittman, Iowa State University Extension Service Watershed Projects

Spring has arrived early in northeast Iowa, and the landscape of Dry Run Creek Watershed is coming to life. The creek is flowing, water mostly clear, and a few redwing blackbirds are already staking out their nesting areas in the brush, vocal in their protection of territory.  

The unseasonal sunny, warm and breezy weather is a reminder to Luther College biology department students and faculty that the water monitoring season is again in session. For the past two years, spring has signaled the start point for the Luther team wading into the waters of Dry Run Creek, collecting and analyzing water samples. 

“This year, the focus has shifted — to compiling and analyzing the pages of data and notes into a form that’s more accessible, and then sharing it” says Jodi Enos-Berlage, Ph.D., biology professor who is leader of the bacterial and chemical monitoring portions of the research.

Some of the results have already been shared with a prime audience, the Dry Run Creek Watershed Improvement Association, a group of local landowners interested in improving water quality. Recently, student researchers Andrew Weckwerth of Zumbro Falls, Minn., and Jacob Wittman of Cedar Rapids, also presented a poster detailing their work at the Iowa Water Conference, held at Iowa State University in Ames in early March.  

"Jacob and Andrew did a great job presenting the research results," said Professor Enos-Berlage. 

Their poster, titled "Exploring the Dry Run Creek Watershed: Molecules, Microbes, and Macroinvertebrates," took first place in the poster contest, a significant achievement for the Luther seniors, who were among the few undergraduate presenters at the conference, which featured dozens of project posters.

The poster summarized two years of detailed physical, chemical, and biological monitoring of Dry Run Creek by the Luther research team. 

The 20,000-acre Dry Run Creek Watershed, located just southwest of Decorah, is a mix of farmland and woodland, with some steep slopes and a few limestone outcrops.  The northern portion of the watershed (see map) includes Twin Springs Creek that flows parallel to and north of Highway 9, while Dry Run Creek and its small tributaries fan out to the southwest from Decorah, making up the southern part of the watershed that is defined on two sides by Highways 9 and 52. 

The two creeks meet in the Twin Springs Campground on the west edge of Decorah before entering the Upper Iowa River just inside the city limits.  A portion of Dry Run creek is classified as impaired by the Iowa Department of Natural Resources due to high bacteria levels.  

In 2010 and 2011, Luther researchers collected water and aquatic life samples from April through November to check chemical and biological indicators of creek health.  Red dots on the map mark the specific monitoring sites.   

Parameters included turbidity (amount of sediment suspended in the water), pH (acid or base level), temperature, dissolved oxygen, conductivity, and chloride levels.  Water samples sent to the University Hygienic Lab in Iowa City tested for five other parameters: E. coli bacteria, ammonia, nitrite and nitrate, total nitrogen, and total phosphorus.  Some sites were also analyzed for populations of benthic (bottom-dwelling) invertebrates.   

Here’s a brief look at water quality sampling and research activities conducted last year.

On a typical testing day in the summer of 2011, a small group of Luther biology staff and students left campus by 8 a.m. to beat the heat of day, heading for Twin Springs Campground to prepare for a morning traveling the dusty roads of the watershed—taking water samples and collecting small forms of life – macro invertebrates – from the stony bed of the creek.

The two students who participated in the 2011 monitoring were Weckwerth, a senior majoring in biology and political science, and Wittman, a senior majoring in biology and environmental studies.

Kirk Larsen, Ph.D., professor of biology, traveled with the students, leading the team's search for macro invertebrate life in the creek bed.  He was also instructing the two students in their first hands-on practice collecting the very small animals.

Macro invertebrates, including worms, crayfish, mollusks, water mites and insects, such as mayfly nymphs, living in the stream are indicators of relative stream health. An abundance of different types of critters indicates biodiversity, but the presence or absence of specific individuals or groups can indicate different states of pollution – or lack of it.

The fourth trip of the 2011 season for the students was the first for invertebrate sampling. The normal water sampling schedule was twice monthly at 10 sites in the watershed, April through October, plus a trip after rain events if there was at least one-half inch of precipitation.  

In total, Weckwerth and Wittman made 19 runs through the watershed during 2011.  Invertebrates were sampled once a month during the summer at seven of the ten sites. 

Professor Larsen, wearing hip waders, looked for a section of rocky streambed, walked into the flowing water holding the Surber sampler he uses to collect the small critters.  The sampler is a fine-mesh net attached to a one-foot square black metal frame.  

He selected a section of streambed with a rocky floor, placed the frame on the bottom, the net flowing downstream, and reached in to loosen up the small rocks.  After a few minutes he checked the contents of the net. 

When he was satisfied that he had thoroughly scoured the rocks for macro invertebrates, he lifted the net from the water, turned it inside out and transferred the animals to a plastic zipper bag for identification and counting at the Luther entomology department lab.  

In 2010, the invertebrate sampling schedule was lighter than planned but results revealed some surprisingly good macro invertebrate life in the stream, Larsen said.  He found two indicators of good water quality, Caddisflies and mayflies, in the streams.  

“(However) the abundances of these high quality water indicator organisms are much lower in this watershed than in some of the coldwater trout streams in Northeast Iowa I’ve been sampling over the past few years,” said Larsen. He added with an apparent note of surprise that the water was running remarkably clear this day, another good indicator.

The 2011 macro invertebrate testing was extensive. The students sorted, counted, and identified over 16,000 critters from the three samplings.  Results again showed overall good water quality, but there were significant differences among the sites. 

Macro invertebrate biotic index ratings for water quality, which are based on the presence of diverse groups, pegged 4 of the 7 sites as 'excellent,' 1 as 'very good,' and 2 as 'good.' 

There were also considerable differences in macro invertebrate density (total organisms per square foot) among the sites, another measure of stream health. 

Important changes were made during 2011 in response to 2010 season data; some relatively high bacterial and chemical numbers showed up at one creek site so researchers added three new sampling locations on branches upstream to further dissect contributing sub-watersheds. Three other sites were dropped because they exhibited lower 2010 numbers, said Enos-Berlage. 

There was also a change in the process between years. All samples were analyzed at the University of Iowa Hygienic Lab in 2010, requiring that they be collected early in the week to allow time for mail service and analysis. 

Timing is especially critical for the bacteria E. coli, which must be analyzed within 24 hours of collection. To expand the collection options to any day of the week, Enos-Berlage, along with her students, developed procedures to perform the E. coli analysis at Luther College. Both the Hygienic Lab and Luther College were involved in sample analysis during 2011, depending on when rainfalls occurred. 

Results from the chemical and E.coli analysis in 2011 were consistent with the 2010 season for the most part, with some of the sites carrying heavier bacterial and chemical concentrations than others, particularly in the southwest portion of the watershed. And similar to 2010, numbers usually escalated during heavy rains.  However, the data were interesting in 2011 in that the more prominent sites for bacterial concentration appeared to change when comparing rain versus non-rain events, suggesting different types of contributing sources, according to Enos-Berlage. 

Possible sources of E. coli bacteria, which normally only inhabit the gastrointestinal tract of warm-blooded animals, include fecal matter from livestock, wildlife, or humans. Data obtained during both seasons did not support human septic input as a major contributor to any of the sites.

While the overall goal of the Dry Run Watershed Project is to improve water quality, both Drs. Larsen and Enos-Berlage have also integrated elements into their teaching at Luther. 

Last fall, Jake and another student in Dr. Larsen’s entomology course assisted in analyzing the macro invertebrates from the third summer sampling as a research project in the course.

In addition, 100 students from Dr. Enos-Berlage's microbiology class trekked through the watershed in September and November, stopping at some of the sites to collect samples for analysis back at the lab. Enos-Berlage saw the project as an opportunity for students to learn not only about watersheds, but also agriculture. 

"Fewer young people have rural backgrounds and many have a very limited understanding of farming practices, expenses, impacts, and soil and water conservation mechanisms," said Enos-Berlage. 

Student comments at the end of the course reflected this interest.  One student wrote, "I really enjoyed learning about how farmers use the land, and how their decisions can have such a great effect on the environment. I didn’t have any idea how interconnected those were." 

The two students in the 2011 water sampling/analysis project were funded through a partnership between Luther College and Iowa State Extension. Additional funding from Luther supports other summer activities by the students, including maintaining biology department equipment and labs. 

Andrew and Jake made special efforts to coordinate their fall schedules so that they would both have a three-hour morning block open each day to continue fieldwork.  The data they collected on the project are being used for a required senior project. 

Three months after starting their summer research program (right after Memorial Day) both agreed that it was a good experience, the work both rewarding and enjoyable.

The two "learned the value of preparedness in this type of field research," they said, "and that the more immersed in the project you are (water monitoring pun), the more fun it is to do the actual data analysis. For field research, it's nice to be outside ... most of the time, at least."

"I'm learning a lot more about what it's like to do field work and am really enjoying it. It's helped confirm that field work is something I'd really like to be able to do in my future, especially working with microbes and ecology," added Jake.

Andrew had his own take on the research.

"I'm enjoying the opportunity to connect my interests in biology with the more human issues in a very tangible fashion," he said. "This has been a good way for me to think about land use policy and the value of conservation and the natural environment in our society. I hope to expand on this line of interest in my future studies."

Both also found their experiences expansive.

"I'm learning more and more how much I value working on a project that connects me to my natural environment and allows me to enjoy the outdoors while doing that work," said Andrew.

"It's been a great experience so far working on a project that is so closely connected to the environment and the community, especially a community that I am a part of," said Jake. "I had expected to be bored to death analyzing the data but was pleasantly surprised when I realized I was enjoying it because this is a project that I have a personal interest in.

"I hope to be able to work on similar projects in the future," he said.

Weckwerth and Wittman, along with Professor Enos-Berlage, presented 2011 season findings at a Dry Run watershed landowners’ meeting last September. "The plan now is to try and share the information with more landowners, use the data to enhance grant applications for cost-sharing for land use changes, and ultimately to make improvements in the watershed to reduce the bacterial concentration," said Professor Enos-Berlage.

All Dry Run Watershed landowners are welcome and encouraged to learn about and participate in the study. For more information, landowners can contact Chad Ingels of Iowa State Extension (ingels@iastate.edu) or Paul Hunter of Decorah, who leads the Dry Run Creek Watershed Improvement Association.