Oliver, Olin, and Martin Lakes are natural glacial lakes located in LaGrange County, Indiana. Davey Resource Group was retained by Oliver and Martin Lakes Conservation Improvement Association to treat invasive aquatic vegetation and provide an Aquatic Vegetation Management Plan update. The project was funded in part by the Indiana Department of Natural Resources Lake and River Enhancement Program.
In early spring 2014, Davey Resource Group biologists identified a total of 2.1 acres of Myriophyllum spicatum (Eurasian watermilfoil), 1.95 acres of Potamogeton crispus (curly-leaf pondweed), and 5.79 acres of both curly-leaf pondweed and Eurasian watermilfoil scattered throughout the lakes.
Invasive aquatic vegetation frequently outcompetes less aggressive native species, degrades aquatic habitat, and interferes with lake recreational activities. Selective herbicides were applied to control invasive species populations without adversely affecting native plant communities. Eurasian watermilfoil was treated with a 2,4-D (liquid and granular) application; curly-leaf pondweed treatments consisted of liquid Aquathol K herbicide. To ensure maximum effectiveness, treatments were targeted for completion when water temperatures were on a warming trend approaching 50°F and not higher than 60°F.
In summer 2014, Davey Resource Group conducted a Tier II aquatic vegetation survey to ensure successful control of invasive species and monitor treatment effects on the native plant community. Diverse native communities are more resistant to invasive species and more stable over time. Based on the survey results, overall plant diversity in Oliver and Olin Lakes is similar to that of other lakes in the area. Additionally, in 2014, both lakes saw a dramatic increase in native vegetation population density, which indicates that native plant communities responded well to lake conditions.
Davey Resource Group’s recommended 2015 treatment strategies for Oliver, Olin, and Martin Lakes were based on 2014 survey results.