Like zebra mussels, they were first introduced in the Great Lakes, then found a way into the Mississippi. Of an inspection by the U.S. Geological Survey of watercrafts that were traveling on a road, twenty-three percent of the watercrafts had watermilfoil attached to them. The plant can grow higher than other native species, forming a canopy that shades other plants and prevents them from growing. This replaces and reduces the diversity of native aquatic species. Fish rely on plants to eat, and Eurasian watermilfoil provides a smaller abundance of food than native species. Other than destroying other plants, the Eurasian watermilfoil also degrades water quality, reduces oxygen levels in the water, and can restrict recreation such as swimming, boating, and fishing. Just like the zebra mussels, they can also clog water pipes (Nonindigenous Aquatic …show more content…
The snakehead were introduced in small numbers, but can lay eggs that hatch within two to three days, often spawning up to fifteen hundred eggs five times a year. A unique characteristic of the snakehead that allows it to move from pond to pond is its ability to travel on land. Although the snakehead moves slowly on land, they are able to stay out of the water up to two to three days at a time. Snakehead are aggressive feeders, competing with and preying on native fish species. Over ninety-seven percent of the snakehead’s diet is native fish. The other three percent is a mix of insects, crustaceans, and frogs. Snakehead have even been known to attack swimmers if they feel threatened (Nonindigenous Aquatic Species). The common carp, zebra mussel, Eurasian watermilfoil, and northern snakehead are all invasive species that have caused a lot of problems and money to be spent to try a contain them. Their effects on the ecology and on native species are disturbing, and are continuing to get worse. None of the invasive species would have been able to spread if fisherman and boaters followed the state laws of washing a boat when changing lakes, not dumping any unwanted bait into the lakes, and not releasing any non-native species into waters without the consent of regional wildlife