Silver Lake: Henschke Hillside access temporarily closed

WASHINGTON COUNTY -- The public access to Silver Lake, at Henschke Hillside Lake Access has been temporarily closed due to a recent discovery of an aquatic invasive species called Starry Stonewort (Nitellopsis obtusa).

The County, State, and Silver Lake Protective and Rehabilitation District are in the process of developing a monitoring, control, and eradication plan for Starry Stonewort. Temporarily closing the Silver Lake boat launch to motorized watercraft will minimize chances of spreading the invasive species to other water bodies within the County and State.

Starry Stonewort is a non-native species of algae in the Characeae family that grows from the bottom of the lake up to two meters tall. It is very robust, with whorls of 4-6 branchlets with blunt tips. It grows best in calcium-rich lakes, which are abundant across Washington County. It anchors itself using colorless filaments (rhizoids) that resemble fishing line. These rhizoids contain up to several dozen star-shaped bulbils, which are starch reserves that can grow new individuals.

Starry Stonewort has only been found in a few other lakes in Wisconsin. Fragments and bulbils are easily dispersed between lakes by boats, trailers, and anchors holding sediment. It is native to Europe and Western Asia. It was introduced to the Great Lakes by ballast water, and has been a nuisance in other states for over 10 years. Starry Stonewort forms dense mats of vegetation, reducing diversity of native aquatic plant life in lakes. It can impede passageways for fish and other aquatic animals.

Vegetative mats growing to the surface of the water can prevent recreational activities and reduce water flow. There will be a meeting on Wednesday, August 5th, 2015 in Room 3224 from 5-7pm at the Washington County Public Agency Center in West Bend (333 E. Washington St., West Bend, WI 53095) to discuss Starry Stonewort.

If you have any questions please contact Bradley Steckart, Washington County AIS Coordinator at 262-335-4806 or or visit the DNR website at