For example, Burmese pythons are becoming a big problem in the Everglades. And some invasive species are intentionally or accidentally released pets. Some ornamental plants can escape into the wild and become invasive.
Insects can get into wood, shipping palettes, and crates that are shipped around the world. Ships can carry aquatic organisms in their ballast water, while smaller boats may carry them on their propellers. People, and the goods we use, travel around the world very quickly, and they often carry uninvited species with them. Invasive species are primarily spread by human activities, often unintentionally. For example, lake trout are native to the Great Lakes, but are considered to be an invasive species in Yellowstone Lake in Wyoming because they compete with native cutthroat trout for habitat. Species that grow and reproduce quickly, and spread aggressively, with potential to cause harm, are given the label “invasive.”Īn invasive species does not have to come from another country.
They can harm the environment, the economy, or even human health. Many of our commercial, agricultural, and recreational activities depend on healthy native ecosystems.Īn invasive species can be any kind of living organism-an amphibian (like the cane toad), plant, insect, fish, fungus, bacteria, or even an organism’s seeds or eggs-that is not native to an ecosystem and causes harm. The impacts of invasive species on our natural ecosystems and economy cost billions of dollars each year. Human health and economies are also at risk from invasive species. Approximately 42 percent of threatened or endangered species are at risk due to invasive species.
Invasive species are among the leading threats to native wildlife. "Invasive species"-they may not sound very threatening, but these invaders, large and small, have devastating effects on wildlife.