An angler holds a clump of quagga mussels snagged on a lure while fishing in the Wisconsin waters of Green Bay. The invasive mussel was found in August 2024 in Geneva Lake in Walworth County, the first finding in a Wisconsin inland lake.
*Courtesy of Paul A. Smith from* *jsonline.com*

Quagga mussels have been detected in Geneva Lake, marking the first time this invasive species has been documented in a Wisconsin inland lake. This finding is especially concerning given Geneva Lake’s reputation for its clear, deep waters and scenic beauty.

Over the years, Geneva Lake has earned the nickname "Newport of the West" due to its luxurious lakeside estates owned by notable families like the Schwinns and Wrigleys. It remains a favorite spot for boating enthusiasts across the state.

However, this popular lake now carries an unfortunate distinction: it’s the first inland lake in Wisconsin to report the presence of quagga mussels, as confirmed by the Geneva Lake Environmental Agency (GLEA) and the Wisconsin Department of Natural Resources (DNR).

A map showing the changes in quagga mussel and zebra mussel population density in Lake Michigan overtime. Zebra mussel populations have declined as quagga mussel populations have outcompeted them.
*Courtesy of NOAA*

"This news is deeply troubling," said Dan Butkus, president of Wisconsin Lakes, a non-profit dedicated to protecting the state’s water bodies. "The spread of any invasive species is concerning, but quagga mussels pose a particularly serious threat."

Native to Europe, quagga mussels likely arrived in the Great Lakes via international shipping, possibly in ballast water. These small, roughly 1-inch-long mussels attach themselves to various surfaces, including the lakebed, and filter plankton from the water. Their presence can clog water pipes, disrupt aquatic ecosystems, and alter food webs.

In Lake Michigan, quagga mussels and their relative, the zebra mussel, have been linked to a decline in yellow perch populations since the mid-1990s due to reduced availability of zooplankton, a key food source for young perch.

Quagga mussels are often referred to as the "bigger and badder" cousin of zebra mussels. They can thrive in deeper, colder waters, on a variety of substrates, and at higher densities than zebra mussels. For example, in Lake Michigan, quagga mussels have all but replaced zebra mussels, dominating the lakebed at densities of up to 7,790 mussels per square meter.

The quagga mussel is an aquatic invasive species found in the Great Lakes and a few inland waters in the Midwest. It was discovered in 2024 in Geneva Lake in Walworth County, the first finding in a Wisconsin inland lake.
*Michael Sears, Milwaukee Journal Sentinel*

Experts worry that quagga mussels could replicate this success in Wisconsin’s inland lakes. Unlike zebra mussels, which typically attach to hard surfaces, quagga mussels can colonize soft, muddy, or sandy lakebeds, which make up the majority of inland lake bottoms, including those in Geneva Lake.

The implications of this spread are still uncertain, as no comprehensive studies have been conducted on quagga mussels in inland lakes. Factors like pH, calcium levels, and other minerals will play a role in determining whether quagga mussels can thrive in these environments.

It’s believed that quagga mussels likely entered Geneva Lake through recreational boating. The spread of aquatic invasive species often occurs when boats aren’t properly cleaned, drained, and dried between uses on different bodies of water. Once established, invasive species like quagga mussels are nearly impossible to eradicate.

The Geneva Lake Environmental Agency has been proactive in combating the spread of aquatic invasive species (AIS). In 2023, the GLEA installed four boat cleaning stations at public launches around the lake, funded by a DNR surface water grant. These CD3 (clean, drain, dry, dispose) units help boaters remove aquatic plants and animals from their boats and trailers, although they don’t address ballast tanks in wake boats, a significant concern for AIS spread.

Increased boating activity on Geneva Lake has been documented, with a 19% year-over-year increase in motorized boats and a doubling of personal watercraft such as jet skis and wave runners. A 2023 survey revealed that 24% of boats at Geneva Lake’s public launches had been on another waterbody within the last five days, increasing the risk of AIS introduction.

The quagga mussels found in Geneva Lake were adults, indicating the species has been present in the lake for two to three years. The GLEA will continue to monitor the situation closely and consider additional measures to prevent further spread.

As this news reaches our community around Lake Beulah, it serves as a critical reminder of the importance of vigilance and proactive measures to protect our lakes. Let’s all do our part to prevent the spread of invasive species and preserve the natural beauty of our waters for generations to come.

Article Source: www.jsonline.com

Alarming Discovery: Invasive Quagga Mussels Found in Geneva Lake – A First for Wisconsin’s Inland Lakes