Wall Lake Dissolved Oxygen / Temperature Study
Tom Johnson and Kim Chaney did a Dissolved Oxygen (DO)/ Temperature Study of Wall Lake last week. We try and take the study each summer when the dissolved oxygen levels are at the most stressed levels by warm water temperatures.
Most fish need at least 2 mg/L of DO, but 5 mg/L is recommended for optimal health. Levels below 2 mg/L can distress fish, and levels at prolonged time below 2 mg/L can lead to death. Larger fish are affected by low DO levels before smaller fish.
Also warmer water requires more oxygen because fish feed and digest food more, and fry grow faster. For example, in the hot summer waters, northern pike can thrive at 6 mg/L, largemouth bass at 5.5 mg/L, common sunfish and yellow perch at 4.2 mg/L, and catfish at 3.3 mg/L.
Wall Lake’s Dissolved Oxygen is fairly consistent each summer but we measure and monitor along with the Indiana DNR. These are the recordings from 2023:
Water Quality Monitoring
One of the elements of water quality that is voluntarily measured is Ecoli. Prior to July 2022 the lab which was used by LaGrange County Lakes Council and only had the capability to measure in increments of 50 cfu. CFU stands for colony-forming-unit, which is a unit used to measure the variable bacteria in a sample. The state IDEM quality level for swimming in Indiana is a cfu/ml at and/or below 235 cfu/100 ml in single sample gatherings. Today, we participate with the St Joe River Basin Water Quality Group which gives us a discount in testing as long as we sample once a month based on their directed procedures and frequency. Byron Folsom is a Board member who volunteers to pull these samples and deliver to a collection station under directed procedures and chilled temperature conditions for accuracy.
As the visual shows, our lake is well under any risk limit.
Secchi
What is a Secchi test?
It is a measurement of the transparency of the water in the lake. A Secchi disk is an 8-inch (20 cm) disk with alternating black and white quadrants.
It is lowered into the water of a lake until it can no longer be seen by the observer.
This depth of disappearance, called the Secchi depth.
The Secchi depth can indicate how much light penetrates the water column, which affects where and how well aquatic plants can grow. It can also indirectly indicate the amount of suspended material in the water, such as algae, sediment, and microscopic organisms. High turbidity levels (Turbidity is a measurement of how cloudy or hazy a fluid is, usually water, due to suspended particles) can be caused by stormwater runoff, shore-line erosion, excessive algal blooms, and pollution
The Wall Lake Association would like to thank the volunteers of Richard kelly and John Lovell for taking these recordings along with the participation of the Indiana Clean Lakes Program with which we participate.
Wall Lakes Quality metrics is excellent:
The metrics is measured in feet.
Total Phosphorous
Total phosphorus (TP) is a good way to measure phosphorus in lakes because it includes both ortho-phosphate and the phosphorus in plant and animal fragments suspended in lake water. TP levels are more stable and an annual mean can tell you a lot about the lake’s water quality.
Phosphorus is an essential nutrient for plants and animals in aquatic ecosystems. However, even a small increase in phosphorus can lead to undesirable consequences in water bodies.
What is a Good Level of Phosphorus in Water? To control eutrophication (a process that occurs when there are too many nutrients in a body of water, leading to excessive growth of algae and plants), EPA established a recommended limit of 0.05 mg/L for total phosphates in streams that enter lakes and 0.1 mg/L for total phosphorus in flowing waters.
Wall Lake’s last recorded lab analysis reading was 0.036
The volunteers of Jim and Shelley Sinish do the collection under the instructions and in part with the Indiana Clean Lake Program through Indiana University.