Plan
In 2009, the MCWD Board of Managers
directed water quality
department staff to create a work plan for a carp removal
and research program. Water quality staff worked closely with the
scientists and researchers from University of Minnesota to develop a carp
removal and research program for selected MCWD Lakes. After further discussion and review, MCWD identified Pierson Lake and Lake Wasserman for the first round of carp removal.
Feasibility
Annual budget for the Carp Removal
and Research Program is $40,000.
Design
The MCWD took two typical approaches to carp removal:
Ice Seining Method:
The commercial fishermen drill holes
in the ice and use fish finding sonar to locate the school of carp. Then, a large hole is sawed in ice and a net is threaded under the ice and set into position
using remote controlled submarines going in opposite
directions. Holes are drilled through the ice approximately every 100
yards. The lead line is snagged at each hole and a winch is used to pull
the net to that point. A large hole is opened at the far shoreline where the
submarines meet. Winches are used to pull the two ends of the seine up
through the ice. The game fish are removed from the seine and released
back into the lake. The carp are kept in a contained area of the
lake until the following day. Fishermen bring in their large trucks
to sort, measure and weigh the carp. The live carp are then transported for
resale to fish markets.
Open Water Seining Method:
The fishermen use fish-finding sonar
to locate the school of carp throughout the lake. A seine with floats
attached to the top of the net and weights attached to the bottom of the net is
trailed behind the boat, encircling the fish. The rope is pulled
using a mechanical pulley through the rings at the bottom of the
seine preventing the fish from escaping the net. The fish are placed in a
contained area in the lake until the following day when hauling trucks are
brought in to sort, measure and weigh the carp. The live carp are then
transported for resale to fish markets.
Narrative
- The Minnesota Department of Natural Resources conducted a Piersons Lake fish survey in 2007
- Blue Water Science conducted a fish survey for Lake
Wassermann in October 2010
- In November 2010, the MCWD Board approved a plan for Lake Wassermann and Piersons Lake to remove and manage the carp population in an effort to reduce internal phosphorus loading
- Staff communicated with lake associations and cities
and lakeshore residents to provided update on the project
- Ice seining of the carp took place mid February
2011on Lake Wassermann
- Carp barriers were installed on Piersons Lake outlet,
Marsh Lake outlet, and Lake Wassermann outlet in April 2011 to prevent
migration of carp to their breeding areas
- Open water seining of the carp took place in mid
May 2011 on Lake Wassermann
Summary
On November 18, 2010, the
MCWD Board of Managers authorized water quality staff to implement the
carp removal and research program and construction of carp barriers at the
outlets of Piersons Lake, Lake Wassermann, and Marsh Lake. The removal and
management of the carp's spawning habits is an effort to help improve
the water quality in Pierson Lake and Lake Wassermann by reducing the internal
loading of phosphorus, as well as improve the water clarity. Carp
can impact a water body by increasing turbidity, releasing nutrients in the
sediment, and destroying aquatic vegetation and aquatic habitats during feeding
activities.
2011
Removal of the carp on Lake
Wassermann was attempted by licensed fishermen in February 2011. The
attempt failed due to the nets getting caught up in debris on the bottom of the
lake when they were being pulled, allowing the carp to escape under the
net. It was again attempted on Lake Wassermann in May 2011. While fishermen caught about 1,000 pounds of carp, nets continued to get caught on the bottom of the lake and several carp managed to escape.
In April 2011, carp barriers were installed at the
outlets of Piersons Lake, Wassermann Lake, and Marsh Lake. The
barriers were used to keep the carp from entering into their spawning area
where they have greater reproductive success. Marsh Lake is a shallow lake located between Piersons and Wassermann that tends to
have a high percentage of fish die during the winter. The fish kill
allows the carp to have less predation on their eggs. By preventing the
carp migration to the breeding area, it forces the fish to spawn in the deeper
lakes allowing a higher percent of the eggs to be eaten by pan fish.
Starting in May, the Area
Partnership for Piersons Lake Enhancement (APPLE) trapped and removed
approximately 36,000 pounds of carp from the Piersons Lake outlet. Vegetation surveys also were completed in both Piersons Lake and Lake
Wassermann to provide information on plant diversity and density.
2012
MCWD staff are
currently working on a partnership with Dr. Peter Sorensen from the University
of Minnesota's Fishery department on a three year study to assess movement,
abundance, and age structure of adult common carp in the Six Mile Creek as part
of a comprehensive diagnostic study to better understand water quality issues
and concerns throughout the Six Mile Creek subwatershed. This information will provide basic
information on carp in this system and allow for recommendations for possible
control, as well as, provide further guidance for identifying and implementing
future projects and initiative to improve the water quality along Six Mile
Creek.
The prevention of carp migration
with the use of fish barriers and removal of carp from the lakes has been
placed on hold at this time. The
partnership between MCWD and Dr. Sorensen and his research team is currently
pending with hopes of beginning a study soon.