Help Fix Kent Park’s Lake
Healthy Aquatic Communities Include Aquatic Plants
by Brad Freidhof – Conservation Program Manager
Restoring a lake and the associated wetlands within the watershed can be difficult and complex. Simply removing sediments, adding structure to the lake bottom, and constructing a few wetland areas above the lake are unlikely to provide the full array of ecological services a healthy aquatic ecosystem can provide. Understanding the diversity, density, and distribution of macrophytes (large aquatic plants), around and within a lake, is essential to understanding the health of a lake community due to the important ecological role aquatic plants play in relation to other aquatic organisms and water quality.
All other life in a lake depends on the plant life. Aquatic vegetation provides food and shelter for fish, wildlife, and the invertebrates that in turn become food for other organisms. Plants improve water quality, protect shorelines, and add to the aesthetic quality of a lake. Studies have shown that nonvegetated lake bottoms support less diverse invertebrate populations and this in turn will support less diverse fish and wildlife populations.
The current lake restoration at F.W. Kent Park has increased the depth of the majority of the lake basin to a depth of 12 feet or greater. At this depth it is less likely that aquatic plants will become established in undesired locations. Three reefs have been constructed at a depth of four feet below the water surface. In these locations native plant communities, including American Eelgrass, Pondweed, and White waterlily, will be established to create aquatic habitat, improve water quality, and add to the aesthetics of the lake. Emergent plants such as Hard-Stemmed Bulrush, American Sweet Flag and Blue Flag Iris, will also be established in several bays and adjacent wetlands to utilize nutrients during the growing season and reduce the availability of these nutrients to non-desirable plants including a variety of algae. The highly productive waters of Iowa have made aquatic plant management a complex and difficulttask, and many of Iowa’s shallow lakes are inundated with aquatic vegetation and invasive aquatic plant species. The intention of adding these native plant communities is to create a competitive plant ecosystem that has the ability to compete with non-desirable plant species and also provide necessary wildlife habitat.
Establishing these macrophyte beds within the lake at F.W. Kent Park will require a lot of manual labor. Staff are preparing for the installation of these plants in mid-June and will be organizing volunteer opportunities to assist with this massive effort. Please contact Brad Freidhof at bfreidhof@ co.johnson.ia.us if you are interested in being added to a contact list for these pop-up volunteer events.
This article originally appeared in Conservation Connection, Johnson County Conservation Newsletter Spring 2019