Into the deep

September 24th, 2018

By Tim Harmon for The Journal Gazette

On a recent Friday afternoon, three pontoon boats converged near the middle of Winona Lake, at a spot where the water is deepest. Some of the passengers, all college students or younger siblings who had come along for the afternoon, clasped hands to hold the boats steady as others roped the vessels together. 

At the front of the middle boat, oblivious to a light but steady rain, Nathan Bosch addressed his class. As students pulled up hoods and fastened jackets, Bosch described what they would be doing in the next hour and a half and offered a quick refresher on things they had discussed in his class at Grace College.

Bosch held up a series of gauges and buckets the students would use to probe Winona's waters and record and analyze the results. 

He reminded the students they would likely find the bottom layer of Winona, called the hypolymnion, would be cold water, with much warmer water in the top layer, known as the epilymnion.

 “Are those two separate, or are they mixing together?” he asked the class. “Our hypothesis is that they're separate – that right now Winona Lake is stratified into an upper layer and a bottom layer. So when we take measurements of both layers, we would expect those measurements to be different from each other, right?

“So we're going to measure the two. We're going to measure the biology. We're going to look at if there's any bloodworms” – midge fly larvae – “down at the bottom of the lake. The class yesterday found no bloodworms ...

“We're also going to look at it chemically. We're going to look at some different chemistry tests for the bottom vs. the top. And we're going to look at it physically. We're going to look at things like the pH (the measure of acidity or basicity of a solution). We're going to look at things like temperature and oxygen levels as well.” 

Bosch, who has been teaching this class for 10 years, is director of Grace's Lilly Center for Lakes & Streams, a research and education center aimed at bringing an evidence-based focus to the care of northeast Indiana waters. Housed in the Dr. Dane A. Miller Science Complex, the center has seven full-time and three part-time staffers, and 25 paid student interns. During the summer, it conducts weekly samplings at 14 lakes in Kosciusko County. The center also samples, every two weeks year-round, 14 streams that feed into lakes. 

“These are the best-studied lakes in the state,” said Abby Phinney, the center's communications specialist.

Helping protect lakes and streams in the Warsaw area and training students who hope for a career in such research are two key goals. The center is also part of a growing effort to raise consciousness statewide of the need to protect our water resources.

In a poll taken for the nonprofit Nina Mason Pulliam Charitable Trust last year, 90 percent of those surveyed said they were very concerned or somewhat concerned about pollution in Indiana's rivers, lakes and reservoirs.

A 2014 report by the Indiana Chamber of Commerce noted that the Indiana economy is unusually dependent on water availability. Though it noted the state has been blessed with plentiful water, the report predicted our growing economy could increasingly strain ground and surface water supplies and called for serious commitment to a statewide water resource plan.

A water-quality report last year by IU's Indiana Conservation Law Center noted: “Our waters ... are at risk. Indiana's environmental monitors report that most of the state's streams, rivers and lakes are polluted. At least nine thousand miles of streams and rivers are contaminated by pollutants that wash directly into them from streamside lands. Seven thousand miles of streams and rivers are impaired because we are still piping sewage directly into them. During times of reduced rainfall, Indiana waters are at risk for both quantity and quality, compromising public health as well as economic and ecological values. We need to address these issues.”

Based on the economic worth its lakes bring to Kosciusko County, Bosch said, the center estimates lakes statewide have a $5 billion economic impact. “It's similar to agriculture in northeast Indiana,” Bosch said.

The Lilly Center is doing what Phinney said is a major study on how to control blue-green algae, which produce toxins that can be harmful to pets or humans. (A blue-green algae bloom in Lake Erie left half a million residents in the Toledo area without drinking water for a short period in August 2014.)  The center is also studying the relative effects of sewer and septic systems on lakes.

The center shares the results of its research with residents along the lakes and streams it monitors, Phinney said. The staff makes presentations and offers pieces for lake association newsletters on water quality and conservation, encouraging such strategies as reducing the amount of fertilizers homeowners use on their lawns or reducing runoff pollution by planting natural seawalls. That type of pollution, called “non-point,” is a bigger problem today for the lakes they study than the pollution coming from large single sources such as factories, Phinney said. Keeping lakes clean now involves people paying attention to “a lot of little things,” she said. “Change in a lake takes a long time. We do a lot of education.” 

Two students raised a bucket designed to take samples from sediment at the bottom of the lake, 80 feet below. As the day before, there were no bloodworms.

“It's got me a little bit baffled,” Bosch said. “I'm not sure what that's due to. ... It could be good news if it means there's oxygen down there ... bloodworms do their best when there's low oxygen.” But it could be bad news for the lake if the oxygen level was too low even for bloodworms to survive.  

“That's one of the fun things about doing these sorts of activities with students,” Bosch said. “When you're going out and taking real data, you don't know what you're going to get – and that makes it more interesting. You have to figure it out as you go along. It teaches the students to be critical thinkers and detectives. This is my favorite way to teach.” 

A $5,000 piece of testing equipment Bosch called a Quanta proble might offer some answers by providing readings on temperature and oxygen levels. Bosch assigned four students to shepherd the meter –  “We don't want it to end up on the bottom of the lake,” he said. One student lowered the sensor through 80 feet of water while another held the cable. One held the sensor's display unit, and a fourth student was in charge of writing down the data. 

It was worth the effort. The students found there was only enough oxygen for fish to breathe within the top 15 feet of the water. 

As the session wound to an end, Bosch addressed the whole group again.

“So, all of the fish in Winona Lake are living in the top 15 feet of water, even though the lake is 80 feet deep. So I want to know, why? Why is there no oxygen in the bottom and lots of oxygen at the top?” 

“Phytoplankton?” one of the students offered.  

No, Bosch said, the microscopic algae actually make oxygen.

The oxygen, he explained, likely is being consumed by decomposing vegetation that has grown to be 46 feet deep at the bottom of the lake. “Leaves and weeds and bad algae – all that stuff sticks to the bottom,” Bosch said.  “They are using up oxygen.”  The lake, he said, was once 125 feet deep. Two hundred years ago, before that layer of muck settled at the bottom, sturgeon and other coldwater fish could survive there, he said. But no longer.

So the students this late-summer afternoon got a sense of how lakes evolve and how natural cycles and unnatural pollution could make a lake eventually change – or die. And the class was left to ponder the riddle of where the bloodworms had gone. In an email this week, Bosch said students had since found bloodworms in Cherry Creek near where the creek feeds into the lake, which may only add to the mystery.  

“We have been involved in some research which shows certain fish like walleye can feed on insects living on the bottom of the lake for short periods of time even if there is no oxygen down there,” Bosch wrote. “That may be what is going on in Winona Lake this year.”

The course that had Bosch's class braving the rain is part of an environmental science program the college launched in 2008. Many students take it just because it's interesting.

But Hayden McCloskey, a 20-year-old third-year student from Fishers, was attracted to Grace by the environmental science program and hopes to become a professional researcher. “I might work for a fishery or stick with the nonprofit career with water-monitoring,” McCloskey said. Bosch, who was her adviser when she arrived, told her about the Lilly Center program and urged her to become an intern. 

McCloskey was not one of those aboard the boats that Friday, but she said in an interview the field research was her favorite part of environmental studies. “I always had a passion for water,” she said.

Tim Harmon is an editorial writer for The Journal Gazette.