Aliens Invade the St. Croix Valley

Eurasian Watermilfoil pulled from Long Lake in Stillwater.

Sources report that aliens have invaded the St. Croix Valley. Spotted by fishermen, local residents, out-of-town vacationers and other individuals, both reputable and not, these aliens can apparently take a number of different forms. Some folks describe the aliens as slimy and green, while others insist that they are gray and scaly. Reports of alien sightings are sporadic along the St. Croix River itself, but in other parts of the valley it appears that the aliens have established small colonies, which are rapidly growing and no longer really that small. In recent years, a cadre of highly educated scientists has confirmed the presence of aliens in several area lakes, as well as portions of the St. Croix River, which is troublesome to public officials who had hoped that the reports were all a cruel hoax.

The alien invaders – curly leaf pondweed, Eurasian watermilfoil, zebra mussels, Asian carp and other non-native, aquatic plants and animals – threaten to harm native fish, waterfowl and wildlife, in addition to creating headaches for swimmers, boaters, and lake-lovers who live and play in the St. Croix Valley. In Washington County alone, the statistics are alarming. Nineteen lakes and the St. Croix River are designated as infested by Eurasian watermilfoil, the St. Croix River is infested with zebra mussels downstream of the Boomsite Recreation Area, at  river mile 25.4, and bighead and silver carp have been found in the river south of the Taylors Falls dam. Flowering rush is now invading Forest Lake and curly leaf pondweed is so plentiful in areas lakes that the Minnesota Department of Natural Resources doesn’t even bother naming the lakes affected by it in its Designated Infested Waters List. Common carp is another non-native species that, as the name implies, has become disturbingly common in the St. Croix Valley.

In response to this threat, the Carnelian-Marine-St. Croix Watershed District, Comfort Lake – Forest Lake Watershed District and Chisago County will join forces to host a free workshop on aquatic invasive species (AIS) on Saturday, March 9, 9-11am at the Scandia Community Center. At this workshop, guest speakers Steve McComas and Byron Karns will discuss common invasive plant and animal species found in area lakes and the St. Croix River in addition to highlighting new and emerging threats. People attending the workshop will learn how to identify these aquatic invasives, get the latest updates on where they’ve been found, and find out what’s being done on a local and statewide level to keep aquatic invasive species at bay.

Steve McComas, aquatic scientist and owner of Blue Water Science, occasionally appears on the radio as the Lake Detective on Joe Soucheray’s ESPN 1500 show and writes a Lake Detective newspaper column for Outdoor News. Steve will discuss management options for aquatic invasive plants and common carp.

Byron Karns, who works for the National Park Service, is currently the chair of the St. Croix Aquatic Invasive Species Prevention Task Force. He is a mussel expert and does field monitoring and inventories of invasive and native species on the St. Croix Riverway. Byron will talk about zebra mussels and the threat of Asian carp.

The Carnelian-Marine-St. Croix Watershed District is home to 31 lakes, three designated trout streams, hundreds of acres of wetlands and more than 17 miles of St. Croix River shoreline in Washington County. The Comfort Lake – Forest Lake Watershed District encompasses roughly 47 square miles in northern Washington County and southern Chisago County that ultimately drains to the St. Croix River via the Sunrise River. Both districts oversee a variety of projects and programs to assess and improve the health of local water resources. Workshop planners hope that area residents will learn and be inspired to identify, prevent, manage and destroy invading aliens before they wreak any further havoc on people and places in the St. Croix Valley.

This workshop is free, but please register at The Scandia Community Center is located at 14727 209th St. N. in Scandia.

Extensive information about both aquatic and terrestrial invasive species in Minnesota can be found at