INHS scientists writing new chapter in long-running story of fishes of Champaign County

INHS Scientists writing new chapter in long-running story of fishes of Champaign County

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Few people see fish the way Josh Sherwood does. Sure, casual observers may notice the minnows that dart away as they look down from a bridge, and anglers learn the habits and haunts of the bass, catfish and other species they hope to catch.

But Sherwood, who’s a fisheries research scientist with the Illinois Natural History Survey (INHS), looks at a different picture. He’s interested in the entire gamut of fish that inhabit Illinois streams, and he’s quick to point out they are much more diverse and striking than you might think.

For an example, he calls attention to the arrestingly colorful, three-inch long rainbow darter, which is common in appropriate habitat throughout the state. During the breeding season, a male rainbow darter’s sides are marked by alternating bars of vibrant blue and orange, colors that also dominate on its fins, too. Below, it may be yellow, green or red, and there’s another splash of orange around its gills.

[Photos: rainbow darter (above), by Lance Merry; striped shiner, by Josh Sherwood.]

Most nonscientists never lay eyes on rainbow darters or the many other nongame fish that dominate our waterways—including myriad other darters, shiners, suckers and sculpins—because we can’t see them where they live, and we don’t have sufficient cause to pull them out of the water for a look.

Of course, pulling fish out of the water for a look constitutes a major part of the job for Josh Sherwood and his colleagues.

Here’s how they survey a reach of stream. Two people stretch a block net across the downstream end, taking care that it connects with the streambed. Then another team approaches them from upstream with a lightly electrified seine, which stuns fish as they approach. Other team members follow close behind and scoop up the fish with dip nets, then deposit them in live wells where they’re held until the collection is finished. The scientists weigh the fish, measure them and record their species, then return them to the stream.

Currently, Sherwood is in charge of fieldwork and sampling for a survey of the fishes of Champaign County, a project with very deep roots. It has been run at intervals of about thirty years going back to the late 1800s, and this is the fifth installment.

As they work on this project, Sherwood and company are building on the legacy of giants in their field. Their predecessors include Stephen A. Forbes, the first director of the INHS and an early definer of ecology as a field, and R. Weldon Larimore and Phillip W. Smith, who pioneered the statewide study of the ecology, distribution and conservation of fishes in the twentieth century.

To date, Sherwood and his team have completed fieldwork at 65 of the 172 sites the survey will encompass, and they anticipate finishing work at the remainder next year. Most of the sites yet to be surveyed are in the Sangamon River watershed, but a few are smaller streams that were too dry for sampling thanks to this year’s drought.

In the watersheds where fieldwork is largely complete—which include portions of the Kaskaskia, Embarras, and Vermilion Rivers—they have found roughly the same mix and numbers of fish that were found in the last survey, with one notable exception.

In the Saline Branch, just downstream of the Urbana-Champaign Sanitary District’s northeast plant, and further downstream, in the Salt Fork of the Vermilion River, fish species diversity has increased dramatically.

In the Saline Branch alone, the number of species collected rose from about 30 in the late 1980s to 45 this past summer.

What accounts for the change? Sherwood hesitates to speculate, since much work on with the data is to be done. But it’s natural to focus on possible changes in the flow emanating from UCSD plant, since it constitutes such a significant portion of the total in the stream.

When we spoke, Sherwood said it was his understanding that shortly after the previous survey, the UCSD began to remove chlorine (which is used as a disinfectant) from its discharge, and that would do a great deal to promote aquatic life.

UCSD open house gives public view of essential processes

UCSD open house gives public view of essential processes

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If you invited friends or family to join you for an open house at a wastewater treatment plant, would they laugh? I’m not naming any names, but I was on my own when I set out for the recent open house at the Urbana-Champaign Sanitary District’s facility on East University Avenue. 

To my delight, however, plenty of other local residents were curious enough about the plant come out for a look around. According to the estimate of UCSD executive director Rick Manner, approximately 200 people stopped by over the course of the day—enough to make him consider holding the event annually.

Manner and his staff were motivated to host an open house because they wanted the people who are served by the plant to see what was accomplished in its just-completed, two-year renovation. Updates to the plant included new buildings to accommodate some of the treatment processes that take place there, as well as new space to accommodate employees as well.

[Photos by author: primary clarifier; control room; water sample; at the outfall.]

Of course, since most visitors to the plant came knowing little of the processes used to treat wastewater, the highlight of the open house was a guided tour that allowed us to see them firsthand.

I was fortunate to fall in with a group that included a Champaign father who had brought along his two young daughters and a friend of theirs. At the outset of our tour, the girls were quick to say they had come only because they hadn’t been given a choice. But their tune soon changed, and their lively interest made the afternoon more enjoyable for everyone involved.

Our tour was led by Dave Hermes, whose regular role is supervisor of maintenance at the plant. He provided concise explanations of what we were seeing at each stop, and answered our questions with the patience of a theme-park tour guide.

 

We started at the building where sewage entering the plant undergoes an initial screening to remove paper and grit. The material taken out in this process is the only byproduct of the plant that goes to a landfill, and the quantity of it is surprisingly small, on the order of a Dumpster or two a week.

We then proceeded through the plant in the same order that wastewater does: to the enormous, circular open-air tanks set deep in the ground where primary clarification takes place; to the concrete weirs where the wastewater churns with bacteria and other microorganisms in a process called “activated sludge”; to secondary clarifiers; to the tallest structures at the plant, nitrification towers, where the water runs down through stacked layers of honeycomb-like plastic, and toxic ammonia is converted to nontoxic nitrates by the action of another group of microorganisms; and finally to the building where water runs through a fabric filter; and back outdoors, where a chlorine-based disinfectant renders the effluent of the plant fit for human contact and capable of supporting aquatic life.

At each stop, a tightly sealed jar of the water from that stage was available for close inspection.

Our tour ended where the discharge from the plant pours into the Saline Branch, one of the most significant tributaries to the Salt Fork of the Vermilion River. As our group dispersed, I overheard the father of the young girls ask for reactions to the tour. “It was more interesting than I thought it would be,” allowed one. “Definitely not boring,” added the other.

One measure of how well the UCSD’s northeast treatment plant does its job is the diversity of aquatic life that thrives downstream from it. Executive director Manner called my attention to the discovery this year of a fish called the big-eyed chub in the Saline Branch. It’s a species that hasn’t been found in Champaign County since 1899.

Tune in next week for a story about the fish survey that prompted that phone call.

U of I Biologists get help from engineers to study river otters

U of I Biologists get help from engineers to study river otters

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Biologists who study North American river otters in the wild face some unique challenges. Otters cannot be fitted with collars, because their heads are smaller than their necks, so their movements can’t be traced with the sort of GPS setup that might be employed to track foxes or coyotes. And it’s rarely possible to distinguish one otter from another in images captured by trail cameras, so there’s a real limit to what can be learned from those.

According to Samantha Carpenter, however, it’s important for scientists to overcome those challenges. Carpenter is a researcher who works in the lab of Nohra Mateus-Pinilla, who studies the ecology of wildlife diseases at the Illinois Natural History Survey.  Because river otters are top predators in many aquatic ecosystems, Carpenter points out, otter management has system-wide impacts, beginning with the many creatures they eat, including fish, mussels, frogs and crayfish.

River otter populations in Illinois have recovered dramatically over the past two decades, from a low of fewer than 100 animals in 1989, when they were listed as endangered in the state, to current numbers, which are estimated to exceed 11,000.  Their recovery is attributable in part to the recovery of aquatic habitats, which have improved so much thanks to the Clean Water Act, and in part to the otters from other states in the mid-1990s, which kick-started the current population boom.

The questions Carpenter and Mateus-Pinilla seek to answer include: How much space does an otter occupy as a home range? Are there seasonal patterns in their use of habitat? What factors affect the size, structure and interactions of their social groups? Answering these questions requires the capacities to trace the movements of individual otters and to distinguish among individuals. Both of these can be facilitated with the use of cutting-edge technology.

Over the past year, Mateus-Pinilla and Carpenter have received help in this regard from people who normally think very little about otters--or wild animals in general--faculty and students from the UI Department of Electrical and Computer Engineering (ECE). Each semester, ECE students enrolled in Senior Design work in teams and select among projects pitched to them by researchers who need real-world assistance.

What have they done for the otter researchers? One team has developed a device that is already deployed at a location near the Salt Fork of the Vermilion River called the “Otter Print Shooter.” It’s a box with a clear acrylic top that contains a digital camera and is buried near a site otters frequent. By means of a sophisticated arrangement of sensors, triggers and lights, the device captures detailed images of otter paw prints. These images enable the researchers to identify individual otters the way fingerprints are used to identify humans.

[Photo, left to right: Nohra Mateus-Pinilla, Yon Chiet Ng, Hui Lin Ng,  Sabrina Yan Ru, Hoong Chin Ng,and Samantha Carpenter deploy the digital tracking plate. Photo Jen Mui.]

Other teams have developed similarly ingenious and useful projects. One has created a system to track individual otters by means of an implantable chip similar the ones used to identify pet dogs and cats. Another is working on an implantable GPS chip, which would enable researchers to trace the movements of individual otters across the landscape via satellite.

Samantha Carpenter describes the fruits of this collaboration between wildlife researchers and engineers with great enthusiasm. And she also looks forward to all that these tools will enable her and others to learn: “Whereas many people view the recovery of river otters in Illinois as a happy ending to their story, we view it as the beginning of an exciting sequel.”