Visitors

Introduction:

Invasive species are non-native plants, animals, or organisms that disrupt the natural balance of an ecosystem.

At Bone Lake, six invasive species have been identified as present: Banded Mystery Snail, Chinese Mystery Snail, Curly-leaf Pondweed, Purple Loosestrife, Rusty Crayfish,
Zebra Mussel.

It is important to clean watercraft and equipment before launching into the lake, and before leaving the landing. Be diligent. Small organisms, plant fragments, roots or seeds can be transported by boats and equipment and introduced to other water bodies.

A Bi-County Ordinance written by Polk County and Burnett County requires you to use a cleaning station when available. Cleaning stations are available at Bone Lake’s north landing and south landing.

Invasives can outcompete native species for resources, alter habitats and reduce biodiversity, creating challenges for conservation efforts. Understanding the species present and their impact is crucial for effective management and preservation of the lake’s natural environment.

Here’s more information on the invasive species that are present in Bone Lake.

Viviparus georgianus Lea

The banded mystery snail shell is up to 1.5 inches tall and 1 to 1.5 inches wide. Horizontal brown bands are visible from outside or inside the shell. A sturdy operculum can seal off the shell when the snail feels threatened making it less susceptible to pesticides than native species. They occupy silt, marl, muck and sand substrates. The snails are native to southeastern U.S. First documented in the Great Lakes basin in 1867. No serious negative impacts have been documented in its introduced range. For more information

Photo: Paul Skawinski

Cipangopaludina chinensis Reeve

Chinese mystery snails are often large, up to 3 inches tall. Shells are typically dark brown and may have dark vertical ridges near the opening. A hardened plate called an operculum can seal the shell against predators or harmful chemicals or pesticides in the water. They are abundant in eastern and central United States. They prefer mucky, organic sediments. Impacts to native species may be insignificant. Turtles and muskrats occasionally feed on Chinese mystery snails.
For more information

Photo: Amy Benson, USGS

Potamogeton crispus L.

Curly-leaf pondweed is a non-native, perennial aquatic plant that grows in shallow water down to 15 feet deep. It prefers cold water and typically dies back in June/July. Small buds called turions produced at the tip of the plant lie dormant through the summer and sprout the following spring. Introduced to North America from Europe in the late 1800s as an aquarium plant.
CLP can form dense matts that impede navigation. Bone Lake Management District managed the lake’s CLP with chemical spraying until 2024. CLP will be managed by plant harvesting on Bone Lake beginning in 2026 due to a Wisconsin DNR policy change that restricts the use of chemical spraying. Learn about CLP management on Bone Lake in our Aquatic Plant Management Plan. 

For more information

Purple Loosestrife

Purple loosestrife is a perennial wetland plant growing to about 8 feet tall, with purple flowers. Many flowering plants have purple flowers, so here are ways to identify this invasive. Stems are woody and four-sided. Leaves are opposite with smooth margins and no leaf stalk. Each flower has six petals and many bloom at the same time.

Purple loosestrife can rapidly colonize new wetland areas displacing native vegetation and reducing nesting habitat and populations of waterfowl and shorebirds. Purple loosestrife can be controlled by manual removal, with Glyphosate or 2,4-D based herbicides. Biological control is widely used and effective: Galerucella beetles feed on the plant without negatively affecting native wetland plants.
For more information

Rusty Crayfish

Rusty crayfish adults can reach six inches in length. Most of the body is tan and each side of the carapace has a rusty brown spot. Claws are large and have brightly colored tips above dark bands. Rustys are larger and more aggressive than most native crayfish and outcompete natives for food. Manual trapping is effective to control rusty crayfish, and smallmouth bass, largemouth bass and yellow perch will consume young rusties. A safe pesticide and biological control have not been found.
For more information

Zebra Mussel

The zebra mussel is a small mollusk that grows to about 1.25 inches long. The shells are flat on the hinged side (D-shaped), light brown to white with brown-black stripes. They have tiny threads that anchor themselves to firm surfaces like rocks, logs, plants, trash and even other animals. Zebra mussels are filter feeders, consuming tiny food particles that are the basis of the aquatic food web, leaving less food available for other aquatic animals. The sharp shells can cut the feet of people and can result in various infections. Manual removal of zebra mussels is easy, but impractical due to their abundance. No chemical control agent is known to kill them without harming other aquatic life or water quality. A 2 percent chlorine bleach solution is effective at killing zebra mussels when cleaning boating equipment or other gear away from waterbodies.
For more information

Photo: Deanne Meyer

Invasives to watch for

These aquatic invasive species are not present in Bone Lake, but they are present in nearby lakes. Watch for them when cleaning your boat or equipment. If you identify any one of these species in Bone Lake, contact any Bone Lake Management District Commissioner.

Eurasian Watermilfoil
Hydrilla
Japanese Knotweed
Common Reed – Phragmites
Starry Stonewort 
Yellow Iris