Pine Lake, Forest County Bushy Pondweed Issues

A letter from: Tim Hoyman Ontera LLC

Thursday, August 19, 2010

This morning I met with Dennis Schumacher, Al Vine, and Jerry Wolf at Dennis’ residence on Pine Lake. There has been a great deal of concern caused by uprooted and fragmented plants building up on the southern half of the lake’s east shore. Dennis has been getting many calls relating to this concern and many of those calls blame plant fragmentation from the recent harvesting activities on the west side of the lake. Fragmentation from harvesting is definitely not the issue here. The plants causing the problems on the east side of the lake are bushy pondweed (Najas flexilis), which do not occur to any great degree in the harvested areas.

The first picture attached to this email is one of the many floating mats located a bit north of mid-center of the lake. The remaining two photos are of the east side of the lake where bushy pondweed mats have floated against the shoreline. The substrate on that side of the lake is pretty much sand, but it is shallow at less than 3’ over much of the area. The dock adjacent to the pontoon boat in the last two photos is 36’ long, so you can see that the plants likely go out to about 60’ or more. In this case, I believe it would be nearly impossible to remove the plant mass by hand. Other areas of the east shore have much less or none at all.

I have also included a map indicating where the plant was found during last year’s point-intercept survey. Yellow indicates a rake fullness of 1, orange = 2, and red = 3. As you can see the plant occurs in much of the lake, especially on the west side.

In my conversation with Kyle this morning, he believed that the current harvesting permit held by the district would cover picking up the floating plants. My one worry is that Kyle mentioned that the cutterheads cannot be used while picking up the mats – this may make it impossible as I believe the plants will need to be picked up in sections. Kyle, would you please confirm the specifics here?

I also spoke with Cliff Schmidt this morning. Cliff will not be taking on new work for this summer, but he would be happy to provide an estimate for harvesting next year if the district decides to follow that path. Other contractors exist, but I do not have contact information for them. Cliff also mentioned that removing plants in this situation, whether floating in open water or against the shore may be difficult.

If anyone has any questions, please let me know,

Tim Hoyman, CLM
Aquatic Ecologist
Onterra, LLC
135 South Broadway Suite C
De Pere, WI 54115