AQUATIC INVASIVE SPECIES (AIS)

Common Names: curly cabbage, crisp pondweed
Growth area: Grows from shore to depths of up to 15 feet
Management: Curlyleaf pondweed is not native to the United States and often causes problems due to excessive growth. When control is necessary, herbicides and harvesting can be effective. In order to reduce mid-summer die-back and phosphorus release, the CLFLWD manages curly-leaf pondweed on lakes within the District that have nuisance levels of growth. Historically, Forest, Bone, and Shields Lakes require annual curly-leaf pondweed treatments.
How to identify Curlyleaf pondweed

The latest reports for Curlyleaf Pondweed (CLP) can be found in the document library below.

Common Names: Eurasian watermilfoil
Growth area: Lakes and streams in depths ranging from shallow to deep
Management: Eurasian watermilfoil can grow rapidly and form thick mats on the water’s surface, which can impede recreation and navigation. When management is necessary, chemical control is one of the most effective methods for reducing abundance and preventing further spread within the waterbody.
How to identify Eurasian watermilfoil

The latest reports for Eurasian watermilfoil (EWM) can be found in the document library below.

Common Names: Flowering Rush
Growth area: Preference for shallow and slow-moving water, where emergent growth can stand one to four feet tall. Flowering rush can also grow out to depths of 20 feet, where the plant is completely submergent.
Management: The CLFLWD has been actively managing Flowering rush on Forest Lake since 2014. The Forest Lake population is currently the only known population to have viable seeds in Minnesota. As such, the District has adopted a management approach that utilizes both herbicide treatments and seed head clippings. This approach has proven to be very effective, as the population has been reduced by 99% since 2014.

How to identify Flowering Rush

To learn more about flowering rush and how you can help manage it along your shoreline, please take a look at our 2024 Forest Lake Property Owner’s Flowering Rush Management Guide

The latest reports for Flowering Rush can be found in the document library below.

Common Names: Purple Loosestrife
Growth area: Perennial plant found rooted in a variety of wet soil habitats, ranging from a couple feet of water to dry shore near the waters edge. Very common in roadside ditches and similar areas with a lot of soil disturbance.
Management: Depending on the size and location of the infestation, management methods can range from hand pulling, herbicide treatments, to biological control with purple loosestrife eating beetles.

How to identify Purple Loosestrife

The latest reports for Purple Loosestrife can be found in the document library below.

Common Names: Zebra Mussels
Growth area: Can tolerate a wide range of environmental conditions. Zebra mussels are more prolific in waterbodies that are not overly nutrient enriched and have a higher calcium content.
Management: Unfortunately, there are currently not many options available for zebra mussel control once their population is established, especially in public waterbodies. However, researchers are investigating possible solutions for the future. In the meantime, the best management approach is still preventing their spread to non-infested waterbodies.
How to identify Zebra Mussels | Latest Zebra Mussel research

The latest reports for Zebra Mussels can be found in the document library below.

• Starry Stonewort
• Hydrilla
• Spiny waterflea