Dr. Nate Bosch, director of the Lilly Center for Lakes and Streams, answers questions during one of the Lilly Center’s 2020 Eco-tours. Photo Provided.

Staff Report

WINONA LAKE — What’s up with zebra mussels? How does a lake spring work? Does boating stir up the bottom of your lake (or does it have any impact at all?) What’s the temperature at the very bottom of your lake?

The Lily Center for Lakes and Streams answers those questions and many more. All of these questions sourced from people like you around six Kosciusko County lakes (Chapman, Wawasee, Winona and the Tippecanoe chain) during the Lilly Center’s 2020 Ecotours.

How do I keep my shoreline stable without accidentally putting fertilizer in the lake?

Native plants! Native plants are plants that have existed within a certain region for a long period of time and are adapted to that region’s weather, and animal and insect inhabitants. They filter rain and runoff, keep soil from eroding, and provide a healthy habitat for native critters. Native plants also require less fertilizer and water than non-native plants. Although they take a year or two to establish, they’re a lake-focused way to beautify your shoreline and spend less time on yard work.

What’s the difference between watermilfoil and hydrilla?

Eurasian watermilfoil and it’s look-alike, hydrilla, share a few traits. Both grow beneath the surface, are perennials, and have leaves arranged in a similar pattern. The best way to tell them apart is to compare the shape of the leaves. Eurasian watermilfoil is feather-like and very thin; hydrilla is thicker and has serrated edges.

Both are considered invasive species. (You can learn about them on Indiana’s DNR website.) They can grow in dense mats on the surface of the lake, preventing sunlight from reaching native plants and other organisms that rely on photosynthesis. They also clog pipes and offer little food and habitat for native wildlife. After you enjoy a day at the lake, make sure to check your boat and other water recreation equipment for any stray strands.

What’s the temperature of the very bottom of my lake?

It varies slightly, but most lakes in our region sit between 40-60 degrees Fahrenheit in summer. Because Lake Tippecanoe (43 degrees) is deeper than Syracuse Lake (60 degrees), for instance, there is about a 20-degree difference between the two.

After fall turnover, though, the bottom layer of water will actually be warmer than the top. This does two things during the winter months. It causes the top layer to create ice, and it allows fish to find dissolved oxygen.

What can we do to get rid of zebra mussels?

Unfortunately, this doesn’t have a simple solution. Once zebra mussels have entered a lake, they usually stay. Zebra mussels are filter feeders, which means they suck in water and munch on the microscopic organisms (like algae) that enter with the water. If you were to remove all algae from a lake, zebra mussels might die back, but so would lots of other organisms that rely on algae.

The best way to keep invasive species like zebra mussels from entering your lake is to make sure your boat and other water equipment are clean and dry after each use. That way, any zebra mussels that might be trying to hitch a ride are removed before you put your boat into a lake.

Should we reduce goose populations to help the lake?

The short answer: maybe. Goose droppings are definitely a source of nutrients for our lakes, and likely cause more weeds and algae to grow.  However, research needs to be done to understand if the droppings are having a notable impact.

In general, it’s best to avoid feeding geese and giving them a place to eat. One way to do this is to plant native species on your shoreline! Tall grasses and flowering plants act as a natural deterrent, preventing geese from seeing the horizon, which acts as their escape route from predators.

Find the answers to other common questions, including “Do boats stir up the bottom of the lake?” and “How can we support the work of the Lilly Center?” here.