Invasive Plants

The two most problematic non-native invasive plants in the watershed are purple loosestrife and Eurasian aquatic milfoil (Myriophyllum spicatum L). The Mona Lake Improvement Association applies herbicides to control weed growth so as to keep the lake open to recreational boating, swimming, and fishing. This strategy, while necessary, is expensive and still does not get at the root of the vegetation problems, which are nutrient enrichment of the lake and the proliferation of non-native invasive plants.

Purple loosestrife has become prolific not just along the edges of the lake but in almost all the drains and creeks that drain into Mona Lake. While chemical and mechanical removal are options, they usually are not very effective. The current strategy to reduce the amount of plants by using the Galerucella calmariensis beetle as a biological control is a good start. Beetles have been released in the Hidden Cove area and the Mona Lake Boat Club area. These efforts should be coupled with property owners physically removing the plants. Residents should however be careful as to the best time of year to remove the plant (pre or post flowering) and how to effectively dispose of the plant (burning). The problem may become even worse by unwittingly spreading the seeds of the plant which can produce up to 2.7 million seeds annually.

An information brochure on purple loosestrife management is available at the Mona Lake Watershed Council office, 143 W. Sherman Blvd., Muskegon Heights.

Invasive Plants