The Iron County Watersheds are not immune to invasions by aliens. Without proper action these unwelcome species threaten to overtake our lakes and streams.
"Exotic" species—organisms introduced into habitats where they are not native—can have a profound impact on natural plant and animal communities. In a short amount of time, these non-native species can severely alter and degrade native ecosystems and disrupt a biological balance that took centuries to create.
Rusty Crayfish are native to streams in the Ohio, Kentucky, and Tennessee region. Spread by anglers who use them as bait, Rusty Crayfish are prolific and can severely reduce lake and stream vegetation, depriving native fish and their prey of cover and food.
Purple Loosestrife invades marshes and lakeshores, replacing cattails and other wetland plants. The plant can form dense, impenetrable stands which are unsuitable as cover, food, or nesting sites for a wide range of native wetland animals including ducks, geese, bitterns, muskrats, frogs, toads, and turtles. Many rare and endangered wetland plants and animals are also at risk.
Eurasian water-milfoil was accidentally introduced to North America from Europe. It can form thick underwater stands of tangled stems and vast mats of vegetation at the water’s surface. In shallow areas the plant can interfere with water recreation such as boating, fishing, and swimming. The plant’s floating canopy can also crowd out important native water plants. Eurasian water-milfoil can establish quickly by its ability to reproduce through stem fragments and runners. A single segment of stem and leaves can take root and form a new colony. Segments as small as two inches can survive out of water for weeks and can accidentally be transported to different lakes via fragments left on boat propellers or other watercraft apparatus, especially boat trailers.
Zebra mussels have shells that are triangular in shape and can sit flat on the ventral side (unlike quagga mussels which have more rounded shells and cannot sit flat). Their shells rang in color from almost white to tan or brown with darker concentric rings. The average length of a zebra mussel is one inch. Once they are in a waterbody they are their to stay.
Spiny waterfleas are zooplankton (tiny animals) that feed on other zooplankton, decreasing the food supply for native fish. Spiny waterfleas are very small, approximately 1/4 to 1/2 inch in length. Each has a long, straight tail spine that’s twice the length of its body.
Stop the Invasion
INSPECT your boat, trailer, and boating equipment and remove any plants and animals that are visible before leaving any waterbodies.
DRAIN water from the motor, livewell, bilge, and transom wells while on land before leaving any waterbody.
EMPTY your bait bucket on land before leaving the waterbody. Never release live bait into a waterbody or release aquatic animals from one waterbody to another.
WASH and DRY your boat, tackle, trailer, and other boating equipment to kill harmful species that were not visible at the boat launch. This can be done on your way home or once you have returned home.
LEARN what these organisms look like. If you suspect a new infestation of an exotic plant or animal, report it to your natural resource agency