Preventing the spread of aquatic invasive species in the Brainerd Lakes Area I recently attended the annual Minnesota DNR Roundtable in St. Paul, where the topic of aquatic invasive species was foremost on the agenda. It’s a serious problem, with no easy solutions. And the more you know about it, the more you’ll want to take action. I am happy to say that the Minnesota DNR is tackling the threat to our state’s waters with an aggressive program designed to prevent or minimize the spread of aquatic invasive species. The levels of experience and commitment of the people in charge is second to none, and their battle plans for dealing with the challenges are nothing short of amazing.We are fortunate to have them at the helm. Lindner Media Productions in Baxter is working with the DNR to produce an educational DVD designed to acquaint viewers with the problems caused by aquatic invasive species, and to detail what we as informed citizens can do to take up the fight against their spread. The following feature contains an advanced look at much of the material that will be available for viewing this May. This is one case, however, when it’s perhaps best to read the book in advance, instead of waiting for the movie to come out… EVERY MEMBER OF THE ENVIRONMENT A L C O M M U N I T Y has its own unique place in the
complex natural order that forms our outdoor surroundings. Many of these niches have been established over thousands of years of inter-species competition and interaction, while others have recently been filled by unwanted introductions of invasive species that threaten the ecological balance. In the latter case, the enemy literally is at our doorstep, and has in some cases gained a foothold in some of our local waters. The state of Minnesota, including the Brainerd Lakes Area, is at war with a variety of silent invaders that threaten to upset the delicate natural order of our lakes, rivers and streams. And it’s time for all of us to take that threat seriously, and to begin taking appropriate action to stem the tide of invasion.
Invasive Species—What are They? What do we mean by invasive species? Basically, they are non-native plants and animals—both terrestrial and aquatic— that have been introduced to Minnesota by accident or uninformed intent, often with severe consequences. Let’s look at a couple of familiar examples. Purple loosestrife was transplanted to Minnesota by wellmeaning folks who enjoyed its vivid coloration, little realizing that it would spread like wildfire and displace natural members of the plant community. Fortunately, the Department of Natural Resources has gotten the upper hand on this culprit Photos provided by Dave Csanda
through the carefully researched introduction of leaf-feeding beetles that target purple loosestrife without damaging the surrounding plant community. It’s still present, but largely under control. Score one for the good guys. Sea lamprey, once the scourge of the Great Lakes, virtually brought the population of native lake trout to the brink of extinction. Fortunately, this is another battle that science is winning—or at least keeping at bay—through chemical treatment of lamprey spawning areas in streams flowing into the Great Lakes. With other invaders however, the prospects for chemical or biological control are not good once their populations have been established. Eurasian Milfoil is a good example.Therefore, preventing these invasive species from being introduced into our local waters in the first place is a key part of the strategy for preventing their spread.
Imminent Threats Minnesota faces an invasion of aquatic creatures like zebra and quagga mussels, round gobies and spiny water fleas, which were transported in the late 1980s from the Black and Caspian Seas of Europe and Asia in the ballast tanks of ocean-going ships, and unwittingly disgorged amidst ballast water into the Great Lakes, from where they have relentlessly spread. These are the most insidious of the foes we face in the fight to protect our outdoor heritage. Several species of fish make the list as well. Foremost among these are high-flying Asian carp that literally create headaches both above and above the water’s surface. While these seemingly unrelated species represent a diverse range of plants and animals, they nevertheless share a common and disturbing trait: They were introduced into environments with no natural predators which kept them under control in their homeland, maintaining the delicate natural balance. Once unleashed into new areas, many invasive species are able to spread and multiply at an amazing pace, with potentially severe consequences for natural species that have no defense against them, or that must compete with the onslaught of these foreign invaders for food, habitat and their very existence.
Invasive Invertebrate Species Let’s begin by examining some of the smallest invasive species--invertebrate creatures lacking skeletons. Because they’re comparatively small, you’d think their introduction would be no big deal.Think again. Foremost among these are zebra mussels--small striped mollusks about the size of your thumbnail--that multiply at
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