Department of Natural Resources
The Fort Custer Recreation Area (FCRA) Lakes Enhancement Project kicked off this summer at the 3,000-acre state park located in Augusta, Michigan. The DNR is working with Kieser & Associates (K&A), an environmental science and engineering firm in Kalamazoo, along with the Kalamazoo River Watershed Council (KRWC), Aquest Corporation, Aquatic Services, Inc. and EnviroScience to develop and implement an integrated lake management plan for three lakes in the FCRA (Eagle, Whitford-Lawler and Jackson Hole).
The project is funded through the Natural Resource Damage Assessment as part of the settlement levied against Enbridge Energy in connection with the July 2010 oil release on Line 6B into the Kalamazoo River.
The purpose of the three-year project is to enhance the fish and habitat of FCRA lakes by managing aquatic invasive species (AIS) found in the lakes. The project includes public outreach and education on AIS.
"We did some fish community surveys on Eagle Lake in 2008 and found an abundance of stunted common carp," said Jay Wesley, the DNR's Lake Michigan Basin Coordinator. "We prescribed management actions to introduce a top predator to reduce the carp populations and to manage the dense vegetation in the lake."
Additionally, aquatic plant surveys were conducted in early summer 2018 to assess plant communities in each lake. Invasive species were found in all the lakes at FCRA. Eurasian watermilfoil (Myriophyllum spicatum) was found in more than 50 acres of the main portion of Eagle Lake and over much of its 22-acre lobe and connecting channel. Starry stonewort (Nitellopsis obtusa), purple loosestrife (Lythrum salicaria) and Phragmites (Phragmites australis) were also found in and around the FCRA lakes.
Several treatment options are being used to control AIS in these lakes. Some areas are being treated with traditional chemical herbicides in controlled amounts. Herbicides can be an effective option in controlling large infestations of Eurasian watermilfoil and Phragmites that have been observed in the FCRA lakes.
Another technique being used for managing invasive species is biological control. Biological controls can be used to reduce aquatic invasive plant species by introducing a natural enemy or predator specific to the target species.
For the FCRA project, K&A, with assistance from EnviroScience, reared and released more than 20,000 eggs and larvae of a small aquatic weevil (Euhrychiopsis lecontei) into the smaller 22-acre lobe of Eagle Lake. This weevil is a natural predator of Eurasian watermilfoil. The adult weevils are small aquatic insects, less than 1/8th of an inch in size. The larval and adult stages of the weevil eat the Eurasian watermilfoil stems, weakening the plant and limiting its spread. This can help native plants to re-establish.
"We'll compare the effectiveness of this biological control to the chemical control results to guide future management options," Wesley said.
Another biological control agent used at FCRA is a beetle (Galerucella calmariensis) that feeds exclusively on purple loosestrife, weakening the plant and reducing its spread. Both the adult and the larval stages of this insect damage this invasive plant. K&A reared an estimated 15,000 beetles for the July release at FCRA. Both the weevils and the beetles overwinter along the shorelines and will re-emerge next year.
Both of these biological control efforts pose no risk to any other species found at FCRA.
To assist with the common carp problem, the DNR has stocked about 700 Great Lakes muskellunge averaging 10 inches in length since 2010. We have heard that anglers are starting to catch some of these muskies that are more than 30 inches now. As these muskies get bigger, they will start feeding on the abundant 10 to 12-inch carp and hopefully reduce their population.
The Fort Custer Recreation Area Lakes Enhancement Project is a three-year effort that will continue through 2020. The final product will be a comprehensive lakes management plan the DNR will continue to implement to maintain a balanced plant and fish community, improve the habitat in the lakes and provide increased recreational opportunities for park users.
The lakes in FCRA provide a rustic fishing experience near the cities of Battle Creek and Kalamazoo for bluegill and largemouth bass on all the lakes and a new opportunity to catch muskie on Eagle Lake.