Puslinch Lake located near Cambridge in Southern Ontario is a very shallow (average depth less than 5 feet) recreational lake well known for water skiing, fishing and winter sports. The lake is approximately 400 acres (163 hectares) and surrounded by permanent residences.

In the late 1990s. Eurasian watermilfoil began to dominate the plant community and within a few years became a serious threat to property values and the continued use of the lake for recreational activities. In response to this threat, in 2006 the Puslinch Lake Conservation Association (PLCA) began a three year MiddFoil stocking program. Approximately 12,000 weevils were stocked in both 2006 and 2007, with 6,000 being stocked in 2008.

At the start of the project, average milfoil density was over 400 stems per square meter. Dense, topped-out milfoil dominated more than 70% of the lake's surface area, making this lake one of the most challenging projects ever attempted by EnviroScience and its milfoil weevils.

Although 2006 and 2007 late-summer follow-up surveys revealed that the weevils had become established and were increasing their number, it wasn't until 2008 that dramatic changes to the plant community were noted. By July 2008, dense milfoil beds no longer covered large portions of the lake. In fact, very little milfoil was noted at the surface.

A late-season survey conducted in 2009 revealed that the positive trend was continuing and the below-surface milfoil noted in 2008 was being replaced by desirable native vegetation.

For more information, contact Aaron Jacobs with the Puslinch Lake Conservation Association at aaron.jacobs@motoman.com or use the link provided to the left.