I’ve always enjoyed Lake Sno-Tip. The views and wildlife make me forget, at least momentarily, that I’m on a suburban college campus. Fish, turtles, frogs, crayfish and all sorts of birds make a home of its water and shores. But for all of Lake Sno-Tip’s charms, it is the bearer of a bad reputation. During my four years at Huntington University, I can’t count the number of times I’ve overheard people joking about how horribly polluted Sno-Tip is. Few students dare to touch its murky water, and silly rumors of three-eyed fish float around the student body. Legend has it there’s a submerged car on the lake floor, along with who knows how many bicycles. I know the latter at least used to be true — my roommate and I pulled an algae-covered, broken bike out of Sno-Tip in 2015.
Sno-Tip may appear unhealthy, but green, murky water does not necessarily indicate cause for concern or imply that Sno-Tip is any more polluted than other lakes of its type. In fact, there have not been any recent studies performed on the lake to confirm or deny public perception regarding its quality. Seeing this lack of data, I conducted a study last semester with the goal of scientifically assessing Lake Sno-Tip’s water quality. For five weeks in October and November 2017, I took weekly measurements of water clarity, dissolved oxygen and phosphorus content. I compared my data to a 1977-78 Sno-Tip study performed by former HU professor James Howald, current Indiana Department of Environmental Management (IDEM) Water Quality Targets, and data from a recent study performed at another Indiana impoundment called Prairie Creek Reservoir. My data is summarized in Table 1. (While the Howald and Prairie Creek Reservoir studies were taken over the course of a year or more, my five-week study is a snapshot of Sno-Tip in the fall and is influenced by seasonal patterns that were averaged out over the longer span of the other studies.)
Water clarity is measured by lowering a disk, called a Secchi disk, into the lake until it can no longer be seen. This depth is how far light is penetrating into the lake, or in other words, how murky the water is. Much of Lake Sno-Tip is only 2 meters deep, and on the brightest days of my study, I could see to the bottom of these sections of the lake. It turns out that the water clarity for Lake Sno-Tip is near where it was in 1977-78, if not a bit clearer, and is comparable to other Indiana man-made lakes.
The dissolved oxygen (DO) content of lake water tells us a bit more about the biology of the lake than Secchi depth does. Aquatic life relies on sufficient oxygen content in the water to survive. If the bottom levels of water ever become anoxic, or entirely lacking in oxygen, microbes cannot break down leaves and other organic material. This causes a buildup of muck and nutrients in the water, which can lead to algae blooms, cloudy green water, and fishkills. Lake Sno-Tip is a fairly shallow lake, so wind does much of the mixing necessary to keep the lake oxygenated, but the fountain also helps pull water up from the lake and expose it to the air. The average DO I measured was slightly lower than those in 1977-78 and Prairie Creek Reservoir, but not yet at troubling, near-anoxic levels according to IDEM. Due to limitations with my equipment, however, I was unable to sample the deepest point of the lake. Doing so will determine whether the lake is anoxic at the bottom and struggling to break down organic matter.
Total phosphorus content was the final parameter I tested and one of the most important for determining lake health. Phosphorus is one of the most influential elements for aquatic systems. Plants and algae require phosphorus for rapid growth, and while a bit of phosphorus is necessary to support life, too much can lead to algae blooms, which crowd out and kill desirable wildlife. Fertilizer runoff, fallen leaves and DC food fed to the fish all contribute to phosphorus levels in the lake. In my study, I measured half as much phosphorus in Sno-Tip’s water than Howald found in the 1970’s, which is an important sign of improvement, but Sno-Tip currently lies just below the IDEM Water Quality Target for maximum phosphorus.
According to the parameters I tested, Lake Sno-Tip appears to be of average health for a lake of its kind. It isn’t especially mucky or loaded with nutrients, and it is home to all sorts of wildlife. Everything we can do to take care of our lake will help keep it healthy. Refrain from feeding the fish, pick up trash if you see it, and enjoy the lake’s views and wildlife! Lake Sno-Tip is truly an asset to this campus – a pretty lovely one – and is a part of our home, too. The more we recognize this, the better it will be for Sno-Tip and campus as a whole.
If you have any questions about my study, don’t hesitate to email me or catch me in person. firstname.lastname@example.org
Adrienne Funderburg is a senior biology major. This opinion reflects the views of the author only.