Managing Multiple Invasive Species in Lake Minnetonka

Mon, 11 Dec 2023 21:25:03 +0000

Lake Minnetonka is the 9th largest lake in Minnesota and of the most popular among boaters, fishermen and recreationalists. However, the popularity doesn’t come without environmental issues. Invasive species such as curly-leaf pondweed, purple loosestrife, Eurasian watermilfoil and zebra mussels have been discovered as well as dealing with various sources of pollution which has affected water quality.

Lake Minnetonka has been a site for continuous research and management of aquatic invasive species. Many different management techniques are used. Allowing native bluegill populations to flourish may reduce common carp populations as they eat the carp larvae over the winter months, a copper –based pesticide proved positive in managing zebra mussels, flowering rush has been removed by hand pulling, beetles have been successful in controlling purple loosestrife, weed harvesters remove the mats of Eurasian watermilfoil and annual herbicide treatments reduced curly-leaf pondweed.

While northern watermilfoil is native to Minnesota, Eurasian watermilfoil and now hybrid milfoil (a cross between the invasive Eurasian watermilfoil and northern watermilfoil) is an invasive species. Researchers examining the status of this hybrid milfoil in Lake Minnetonka discovered hybrid milfoil are more prevalent in areas treated with herbicides than those areas with little management. This may suggest large scale herbicide treatments to control other aquatic invasive species could promote hybrid watermilfoil growth and some hybrids may show greater tolerance to treatment.

This just goes to show how various control methods may be required in order to maintain a balance between not only the various invasive species in a water body, but native populations as well.

Read More https://www.startribune.com/taking-genetics-to-the-lake-new-study-shows-that-fight-against-invasive-plant-is-more-complicated-th/412469513

Early Spring Triggers Milfoil Growth in Minnesota Lakes

Fri, 08 Dec 2023 22:10:45 +0000

In Minneapolis, the park district’s mechanical harvester has been mowing Eurasian watermilfoil in the Chain of Lakes since before Memorial Day. It began several weeks earlier than usual, said Deb Pilger, director of environmental operations, due to the warm and early-starting spring that caused a healthy crop of invasive aquatic weed growth.

The Lake Minnetonka Conservation District in Minnesota also launched its two aquatic plant harvesters to cut and harvest the milfoil that is already flowering on the surface. The curly leaf pondweed, another aquatic invasive with the ability to grow under winter ice, has died off in the water unusually early this year, releasing phosphorus, which has caused the algae to bloom.

Eurasian watermilfoil Minnesota lakes – Aquarius-Systems

Managing Multiple Invasive Species in Lake Minnetonka

Early Spring Triggers Milfoil Growth in Minnesota Lakes