Minn. DNR battles invasive species

Emerald ash borer, asian carp and other species pose a threat to the ecosystem.

by Andrea Schug

The rapid reproduction, growth and spread of invasive species in Minnesota has had a serious impact on the environment, and the Minnesota Department of Natural Resources is more active than ever in its attempts to control the damage. In 1991, the DNR was given the responsibility of creating an invasive species program by the Minnesota Legislature. The long-term plan, completed in 2009, serves to coordinate statewide efforts to manage, prevent and research invasive species. According to the DNR Web site, the three goals of the Invasive Species Program are to prevent introductions of new invasive species, prevent the spread of invasive species and to reduce the impacts that invasive species cause. Chip Welling, coordinator of aquatic invasive species management, has been with the DNR for 18 years. He said the progress in the Invasive Species Program is apparent. âÄúWeâÄôve learned more about what we can achieve and unfortunately sometimes what we canâÄôt achieve,âÄù Welling said. In recent years, the more widely known invasive species across the state, such as emerald ash borer and Asian carp, have helped increase awareness of the problems invasive species pose, Welling said. Here are a few other invasive species that have had a major effect on the ecosystem in recent years: Eurasian watermilfoil Clogging the surface of lakes and interfering with lake recreational activities are not the only problems Eurasian watermilfoil has created for the state. After being transported to a new body of water by boat or water bird, Eurasian watermilfoil causes many problems in the shallow areas of a lake. Milfoil collect near the surface of the water, generating problems for fishermen, swimmers and water skiers. This invasive species also crowds out native plants important to the ecosystem. Current methods used to reduce the watermilfoil population include the use of herbicides and mechanical removal. âÄúThe DNR does rely on members of the public users of the lakes to work with us and to prevent further spread,âÄù Welling said. Zebra mussel The shell of the zebra mussel is covered in yellow and brown stripes, and the shape is similar to that of a clam. Most are less than 1 inch long. They are most abundant in shallow areas of water that contain a lot of algae. Zebra mussels tend to form in colonies and grow in clusters. This species has a rapid reproduction rate of 100,000 to 500,000 eggs per year, allowing them to quickly populate a body of water. Once zebra mussel eggs hatch, the larvae, which are called veligers, attach to any firm surface. The surfaces they often choose are boats, docks, aquatic plants and other mussels. âÄúWe want to help people understand that cleaning off boat trailers and boats can help reduce the spread of many of these invasive species,âÄù said Mike Schommer, communications director for the Minnesota Department of Agriculture. Purple loosestrife The flowers of the purple loosestrife plant are initially hard to see as a threat because of their ornamental value. However, this species has spread to 40 states and has made a home in 68 of 87 Minnesota counties. These plants find homes in marshes and lakeshore areas and have begun to replace plants such as cattails. Because these plants form in dense patches, they have taken over areas where native species such as ducks, muskrats and turtles would have found food or places to nest. This has led to an increase of endangered plant and animal species in these areas. The purple loosestrife spreads through its seeds. The seeds can be blown by wind or carried by water or animals. âÄúItâÄôs always easier to keep invasive species out than to deal with them once they become established,âÄù Welling said. Rusty crayfish The dark orange color of the rusty crayfish, accompanied by a pair of claws, creates a menacing image that matches the manner of this invasive species. This species is aggressive and harms the plant and animal communities that it invades. It eliminates vegetation and consumes eggs and young of the fish in the area. They also mate with native crayfish, eliminating any sign of former inhabitants. âÄúA lot of invasive species put other species in jeopardy of surviving, too,âÄù said forest resource management sophomore Ryan Quinn. âÄúThat can affect the fishing in the area and have an economic impact in the area for tourism and such.âÄù