How do you restore an impaired stream? In Eastern Iowa, conservationists and farmers are enlisting the appetites of thousands of local mollusks.
Along the rolling hills of eastern Iowa’s farm country, cattle dot the sloping fields among soybean and corn crops. Through the valleys between hillsides, streams meander, home to brown trout and other aquatic life. But when manure or agricultural nutrients such as phosphorus and nitrogen run off and seep in, those streams can become what watershed managers call “impaired.” Add stream bank erosion, and locally disastrous events, including fish kills, can result.
Unlike large animal feeding operations, small farms are not regulated by the federal Clean Water Act. Instead, state and local officials work with landowners on a voluntary basis to help them establish conservation practices. The Jackson County (Iowa) Soil and Water Conservation District has helped local landowners improve the conditions of impaired creeks with both technical assistance and financial incentives.
Michelle Turner, Watershed Coordinator, said that her agency fosters changing land practices to keep streams clean. Installing rocks and trees, for example, can stabilize stream banks, and planting buffer strips of grass between crops can trap rainwater, sediment and nutrients and provide habitat for wildlife, too.
Turner was part of a small group that headed out one chilly fall day to a stretch of Farmers Creek, which twists through 17 miles of Jackson County. About 6,000 head of cattle, vastly outnumbering the people here, watch as the creek’s sediment and nutrient-laden waters flow by, on to the Maquoketa River and into the Mississippi.
Turner, along with Scott Gritters and Jared Brashears of the Iowa Division of Natural Resources based in Bellevue, were on an outing to help the stream restore its ecological balance. They were headed out to don waders and stock freshwater mussels in Farmers Creek.
I was invited to join the group too, and eagerly took them up on the chance. My own waders were conveniently “lost” so I left the mussel stocking to the professionals. I didn’t regret that choice at first, especially when I saw how many mussels would be involved and the method of stocking they would use.
We rendezvoused at Otter Creek, a town of farm residences and a lone gas station. In its parking lot we met up with Nathan Eckert from the US Fish and Wildlife hatchery, located across the Mississippi River from us in Genoa, Wisconsin. When Eckert and a volunteer arrived carrying their cargo of freshwater mussels, I felt as if we were taking receipt of an organ for a transplant operation. In a way, that’s what we were doing.
The enclosed bed of the pickup truck was full of buckets and coolers in which nearly a thousand mussels were piled, shiny and stoic in their rock-like stillness. They are filter feeders, like the sort of critter one might obtain to keep an aquarium clean. Scott Gritters said that mussels were born to eat just the sort of stuff that has been impairing Farmers Creek.
Eckert, a mussel biologist at the hatchery, explained to our group a bit about the process of raising these mussels from captive adults. The collection he brought this day included fat muckets, plain pocketbooks and black sandshells. They did not, however, include zebra mussels. The zebra is an invasive species that has overrun many rivers and lakes, outcompeting native mussels for habitat and food and even anchoring themselves to other native mussels. The invaders have become so pervasive that boaters must clean watercraft and drain water from live wells to ensure they are not transporting the zebra from one body of water to another. Our group wanted to be sure that the mussels we were about to stock into Farmers Creek included no undesireables.
Eckert explained that the mussels he’d raised had been washed, scrubbed and rinsed numerous times, and carefully inspected to be sure they were zebra-free. In addition, many of the mussels had been hand-tagged with identifying numbers so that they could be tracked if a member of the public reported finding one, some day. Wildlife officials could discover how far a mussel had traveled from its point of deposit in Farmers Creek.
We transferred the load of mussels to Gritters’s pickup truck and drove a few miles to Bob Kremer’s farm. Kremer has worked with both Turner and Gritters over the years to establish conservation practices and provide a point for fish stocking. In fact, this wasn’t the first time mussels had been stocked in Kremer’s stretch of the Farmers Creek. Trouble is, these creatures can be very hard to track. They burrow into the mud of the creek bed, mostly never to be seen again.
“Somebody else will know whether or not this works,” Gritters said, easing slowly into his stiff, cold waders. The mussels “have long lifespans,” says said, “and we’ll be retired one day.”
At our first stop, we gathered at the edge of the stream, an especially cold spot due, Gritters explained, to eastern Iowa’s karst topography. Part of the Driftless area, northeast Iowa was never scraped flat by glaciers and is thus ruggedly hilly and underlain by soluble limestone, with lots of sinkholes, caves and underground drainage. Water that flows through rock before forming a stream is much colder than water springing from the ground. That’s what makes it good for cold-loving fish like trout.
For several hours that day, it went like this: Turner, Gritters and Brashears, and I hopped into our respective vehicles. We’d bump along a gravel road, or a dirt lane, or a two-track, to a pre-planned section of Farmers Creek. Gritters and Brashears would determine which species would go into this water. Then they and Turner would grab buckets and wade in, calling dibs on various riffles or pools or tree-lined stretches. Rather than scattering handfuls of mussels in the manner one would throw feed to pigeons, they reached into the water and lowered mussels one by one onto the stream bed. With bare hands. I stood safely but awkwardly on the shore, juggling two sets of cameras and the notepad, documenting their progress, shouting questions.
After thirty or forty minutes the group would emerge from the stream and recap what they’d done. “It is a lot like planting trees,” someone said. “That stretch down there was pure rock,” someone else explained. “Is it just me, or is it getting colder,” I contributed.
Then it was time to load back into our vehicles, splash across a shallow stream crossing and past a herd of cattle gathering for feeding time. Landowner Bob Kremer bounced along his ATV trail in a four-wheeler with a box of elbow-length plastic gloves that he uses for activities such as reaching inside pregnant cows or cleaning recently shot deer. The group took these gloves gratefully as a small measure against the cold.
Another half-hour of hand-sowing, another several hundred mussels had been deposited into the depths, where they’d feed on algae and any other nutrients that passed along. Their destiny was to clean a stretch of stream, returning it to sparkling blue clarity, the condition of these waters before what Gritters called “poor agricultural practices of the past” took their toll.
Agricultural practices today may be better, but they are not perfect. Many local farms have been outfitted with fencing and other measures to keep cattle from trampling the streambeds, but sometimes a few slip through. Rain will fall by the bucket load sometimes, washing soil and sediment into streams, in spite of riprap or new trees. Farmers work to manage manure so that it can be properly applied to fertilize crops and not drift down into the water, but sometimes pumps freeze and waste goes where it should not.
As long as cattle are grazed and crops are grown—in other words, as long as people want to eat and farmers are willing to make that happen—there will be livestock and crops living in these hills and alongside these streams. Voluntary engagement with DNR and watershed management officials can be a good thing for farmers, both for the financial incentives and for the conservation such engagement can foster in land farmers own. In turn, it is a good thing for the public. As Michelle Turner said, “If we want to give our children and grandchildren clean water for drinking, swimming and fishing, we need to act now.” Whether the introduction of mussels will forestall mandatory regulation is not yet known. People in the Farmers Creek watershed certainly hope so.
Native Kansan Julianne Couch now lives in Bellevue, Iowa. Her book Traveling the Power Line: From the Mojave Desert to the Bay of Fundy is forthcoming from University of Nebraska Press later this year.