Martens Lake Water Level Drawdown Underway at Sweet Marsh
Posted: 07/13/2011
TRIPOLI, Iowa - Martens Lake in the Sweet Marsh Wildlife Management Area is being drawn down to control the spread of brittle naiad, an exotic invasive aquatic plant discovered in the lake in 2010.
“The drawdown has gone as planned for the first two weeks and if the weather cooperates the lake will be held down for about eight more weeks,” said Dan Kirby, fisheries biologist for the Iowa DNR.
Kirby said brittle naiad is difficult to control once it gets established.  Exposing brittle naiad seeds and plants to air kills plants that have already germinated, and suppresses germination in seeds that are out of the water.
The drawdown plan to control brittle naiad has an added benefit to other plants. The exposed lake bottom will allow desirable plants to grow that will benefit fish and wildlife once the lake level returns to normal.

“If these plants have an opportunity to mature, they will provide excellent fish and waterfowl habitat,” Kirby said. Martens Lake will return to normal pool during September at the latest, to coincide with waterfowl hunting and boat fishing.

The area continues to provide wildlife viewing and fishing while the lake level is down, only not from a boat.  
“Fishing has been good during the drawdown along the south dike and the inlet to Martens,” Kirby said.  Waterfowl and shorebird viewing is excellent along the newly exposed mud flats and shallow water areas.

Since the drawdown began on June 27, the lake is about two feet below summer pool which makes it difficult to access with small boats and virtually impossible to launch a larger motorboat.