Milfoil, an Unwanted Threat to U.S. Rivers

Eurasian milfoil is a fragile looking flora that was once a everyday plant to find in fresh water fish tanks.

However, It did not stay there. Now it is considered an invasive species that threatens The northern Us fresh water streams, rivers, pools and lakes.

In its domestic Eurasian surroundings it is a comparatively innocent flora (but still a bit of a pest) but here, out of its regular waters, it takes over and demolish ecosystems, clogs water intakes and power plants, and makes them undesirable for recreational purposes.

Several hypotheses are around that explain its foundation. One is that it hitched a ride on the ballast of a ship coming from Europe or Asia. That is a good guess. When they tested boats leaving occupied water, 25 percent carried some milfoil with it. The other main theory is it was introduced by people throwing out aquarium plants or packing material used to ship live worms.

The most hazardous thing about this plant is that it can adapt to live in nearly every kind of marine habitat in North America. It can live in the cold of Washington State or the warmth of Florida. From pristine waters of the Rockies to the salty waters of the salt marshes it can expand. To make its life easier, nothing seems to like eating it.

Once established it spreads rapidly in waters that range from two feet to up to thirty feet, snarling just below the surface and clogging out the native vegetation. Some floras like millet are given little chance to grow, which causes troubles because they are a food source for many and a home for small aquatic animals. This matted growth also causes problems for any mammals or birds that fish for their food. Further more, the vast mats keep the wind from properly oxygenizing the water and suffocating adult fish as well as helping spawn algae blooms which further aggravate the problem.

These plants are problematic to people as well. Not only does milfoil decrease water quality but the mats make shoreline bathing hopeless. Milfoil hinders fish breeding, which means fewer fishermen. Milfoil is also a problem for boatmen because it can become trapped on the engine, cause dangers for water skiers and block navigation hazards from the sailors view.

Communities and companies are also put at a disadvantage because of this small water plant. Water intakes or over flows can get blocked leading to shortages in some places and flooding in others. Dams and electricity output can also be touched if the water plant mats get caught up in the dams.

Milfoil control has been hard. Generally poisonous substances are out of the question as they destroy the very ecosystem they were meant to save. Manual removing the flora isn’t fully successful because the bits that break off can form new plants elsewhere. For that reason the large automatic harvesters are only used in the worst cases and then only as a first step. Milfoil has been more successfully removed by vacuum dredging, which can pick up any broken pieces left behind. A weevil maybe the solution to the milfoil dilemma as it love to eat the water flora and is a natural way to battle the weed.

Milfoil is just one type of unwanted species that has overstayed its welcome; many other invasive aquatic plants are still thriving across the country. When plants or animals are introduced outside their natural environment, you can’t anticipate the implications.