Pleasant Lake Carp Removal

Quick Facts:

At a max of 58 ft deep, Pleasant Lake is one of two deep lakes in the VLAWMO watershed. The other is East Vadnais Lake, which has the same max depth.

Pleasant Lake is listed as impaired on the State impaired waters list. It receives water from Deep Lake, Charley Lake (which receives from the Mississippi River), and watershed drainage. Click here for a look at Pleasant Lake's water quality status. 

Common carp are an invasive species in Minnesota, brought to the U.S. from Germany in 1877. They were intentionally introduced through government programs at the request of early settlers who desired fish from their homelands. Common carp were raised in ponds in Washington D.C., and shipped across the country by train to become widely established.

Funding:

VLAWMO capital improvement funds in partnership with the North Oaks Homeowner’s Association.

Reason for the project:

Measures to reduce the Pleasant Lake carp population have already been initiated at Wilkinson Lake. A fish barrier at Wilkinson was put in place by North Oaks Company in the 1990s, to reduce the seasonal spawning migration from Pleasant to Wilkinson. There is evidence that the barrier has been effective at preventing survival of young carp. In a healthy and growing carp population, we would expect to see a spectrum of young, young adult, and adult fish. Initial Pleasant Lake surveys however show that the carp population is composed primarily of large adults. This bodes well for future carp management steps. If the population is primarily composed of large adults and few young are being successfully produced, removal of adults should allow for desired water quality improvements.

Implementation:

There are three steps to understanding carp populations and managing them: 1) Calculating current biomass or amount of carp in the lake. This involves electroshocking surveys with tagging, 2) Understanding movement patterns and especially where carp go for spawning, and 3) Removing enough carp to reach the management threshold. The management threshold for common carp is 100 kg/ha (90 lbs/acre). This is the target biomass level at which we would expect to see measurable improvements in water quality. Biomass in Pleasant Lake prior to removal was 273 kg/ha, which is nearly three times the management threshold.

Telemetry radio tracking was begun in the summer of 2021. Carp were implanted with transmitters to allow VLAWMO staff to track their movements and provide information to inform harvest efforts.

Results:

Staff and project partners accomplished a first harvest in May 2022. Staff continue to monitor the carp population and its impact on lake health and water quality.

Eradication of carp is highly unlikely and not a practical goal. The results of this effort strive for reduced population levels that allow for improved water quality. This pursuit follows with the efforts of Ramsey Washington Metro Watershed District (RWMWD) and Rice Creek Watershed District (RCWD), VLAWMO’s watershed neighbors.

Interim Carp Movement and Biomass Estimate Report: 2020

Carp Movement Report: 2021

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Project Image Gallery

Electroshocking and Tagging:

Removal:

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