Consultant's Report - Minnesota State Legislature

MINNESOTA DEPARTMENT OF NATURAL RESOURCES
Feasibility Study to Limit the Spread of Zebra Mussels from Ossawinnamakee Lake
scenario, the public is encouraged to report suspected locations ofzebra mussels in areas around
the Ossawinnamakee Lake. This scenario allows the public to be an active participant in the
control process.
Objective 2
Ossawinnamakee Lake has one outlet structure that represents the only in-water dispersal point
for zebra mussels from the lake to Pelican Brook. Protection ofthis outlet from the population in
the lake represents the most critical control point for downstream transport. Several treatment
alternatives could be applied to control the movement out of the lake at the outlet structure;
however, the size and anticipated flow rates through the structure present a challenge for
implementation of a control strategy that is feasible to construct and economically responsible to
operate. As an alternative to an aggressive solution at the outlet structure, a more passive system
could be implemented at the exit ofMuskie Bay. Under this scenario, a pelmeable barrier could
be employed that would allow for the movement ofwater but would restrict the movement ofinwater
organisms, including veligers. A barrier similar to the Marine Life Exclusion System
manufactured by Gunderboom, Inc. (discussed in Section V) may be a viable option. A physical
barrier of this type would encompass the entire water column at the exit area of Muskie Bay
(Figure VI-I). The barrier would protrude slightly out of the water and stretch to the bottom of
the lake. The barrier would be moored into place presumably at each shore and also be anchored
along the bottom of the lake to exclude mussels from the outlet area oflake (see Figure V-2 in
Section V).
VI-12 Alternatives Analysis and Recommendations