Invasive Species
2025 Year-End Invasive Species Update
Nowadays we live with the constant threat that invasive species will hitch a ride on a boat, bait bucket or some other means from neighboring lakes and take up residence in Lake Hubert, with all the potentially damaging fallout that could ensue. Already, Middle Cullen Lake has starry stonewort and North Long Lake has Eurasian watermilfoil, both nasty invasives. Spiny water flea also is spreading in the area. These invasives can damage the health of the lake, making it less hospitable for native species and less suitable for boating, swimming, fishing and other recreational activities. They also can be costly to contain. Lakes that already have starry stonewort, for example, have spent in excess of $200,000 to address the problem.
As the lake community’s representative, the LHCA employs a three-pronged approach to help protect Lake Hubert from invasive species: prevention, monitoring and preparedness. Here’s an update on our efforts in the summer of 2025.
Prevention: A key part of prevention is the hiring of county-supplied and -trained inspectors to man the launch during peak times of summer. Invasives spread when water from an infected lake enters ours. Inspectors ensure that boats, bait buckets, ballast tanks and other receptacles are purged of water before entering or leaving the lake, and make sure there are no weeds or other aquatic life on anything entering the lake. The best inspectors treat those encounters as education sessions, showing boaters how they can keep their boats safe for the lake.
In the summer of 2025, inspectors manned our launch a total of 901 hours, the most of any launch in Crow Wing County. Of that total, 399.5 hours were paid for by the county while the other 501.5 hours were paid for by the LHCA. This is one of the primary ways your contributions to the association are used to protect the lake.
Monitoring: Lake Hubert is a public space, and a lot of visitors who don’t live on the lake enter at times when inspectors aren’t working, increasing the risk that someone might introduce an invasive. With the number of threats rising, the LHCA in 2025 contracted with a professional water testing firm to survey the lake regularly for invasive species. If prevention efforts fail, identifying new infestations quickly can significantly lower the mitigation costs and help keep localized problems from becoming bigger, lake-wide issues.
Going forward, Central Minnesota Aquatics - a local company that also periodically treats the lake to control another invasive, curly leaf pondweed - will perform three lake-wide surveys each year to proactively monitor for potential threats. Identifying infestations early can allow us to respond quickly to control and contain any damage that might occur while acting early can minimize the costs. The two surveys performed this summer found no threats beyond the ones we already know about.
Preparedness: Invasive species are tough to remove once they’re in the lake. Treatments can be effective at containing them but also very expensive. If an invasive species is discovered in the lake, speed of response is critical to controlling the spread, minimizing the damage and keeping a lid on expenses. We maintain relationships with the DNR, the county, other lake associations, water quality experts and others who can help with the response, but the costs would be borne by the LHCA.
The experiences of other lake associations have shown the value of maintaining a healthy war chest to enable a strong, rapid response if the presence of an invasive species is confirmed. We’re all here because we love Lake Hubert and want to maintain the things that make it special. Taking care of the lake and preserving its health for future generations is a community endeavor and everyone’s responsibility.
John Engen, LHCA water quality director
The Minnesota Aquatic Invasive Species Research Center (MAISRC) has this useful Identification Guide for AIS.
Watercraft Inspection Program and Watercraft Decontamination Program
The MN DNR manages the Watercraft Inspection Program that inspects our boats at the ramp and provides education to people entering the lake regarding the threat of aquatic invasive species (AIS). They also have launched a Watercraft Decontamination Program, which uses portable, self contained, high pressure, high heat wash units that allows them to decontaminate watercraft at the public water access points without allowing any of the wash water to run off. Use the links below to learn about these programs and to see where there will be a portable unit near you on any given date!
photo courtesy of MN DNR
Starry Stonewort
Starry stonewort was discovered on Middle Cullen Lake in the spring of 2024. It has not yet been detected in Lake Hubert, though we are monitoring for it with help from volunteers. We consider this to be or urgent importance, and we encourage diligence in cleaning, draining and decontaminating any watercraft that has been in any lake other than Lake Hubert.
Curly Leaf Pondweed
The Lake Hubert Conservation Association treated Curly Leaf Pondweed in May of 2021, and again in the spring of 2024. An EPA approved endothall-based herbicide was used for these treatments after obtaining a permit from the DNR.
A delineation survey in the spring of 2025 revealed regrowth of this AIS in the northeast corner of the lake and in the southeast part of Sunset Bay. We will apply for a permit to treat these areas in the spring of 2026.
Curly Leaf Pondweed is an invasive water plant which, if left untreated, can become a problem in our lake. It will likely be treated every 3-5 years in the future.
Zebra Mussels
Photo credit: https://www.dnr.state.mn.us
Zebra mussels were first identified in Lake Hubert in 2015. There may be evidence that zebra mussel populations stabilize and possibly decrease after several years. There is no treatment, but there is much research ongoing at the U of M, and once a treatment is available, we hope to use our saved funds to get rid of this pest!
photo courtesy of MN DNR
Spiny Waterflea
photo credit Minnesota Aquatic Invasive Species Research Center (MAISRC)
Spiny waterflea was introduced to the Great Lakes in the 1980’s from Europe and Asia by cargo ships. It has now been found in some northern Minnesota lakes, including Lake Mille Lacs. It is a tiny predatory zooplankton that feeds on micronutrients in the lake. It is gelatenous and gums up fishing lines. It can be transferred from other lakes by any container of contaminated water, including bait buckets and ballasts. Again, be diligent about transferring any water into our lake, and cleaning, draining and drying all watercraft before bringing it to Lake Hubert from other bodies of water. We are monitoring for it, and have not found any evidence of it in Lake Hubert to date. Thanks to all of the volunteers who are helping to look for this invasive species.