Invasive species can be introduced to an area either intentionally or accidentally. Many non-native plants and animals are brought to an area to raise commercially, and many of these species have benign or even beneficial impacts. Citrus trees in Florida are an example of a beneficial plant imported to Florida. Likewise, rainbow trout, striped bass, and largemouth bass have been widely introduced beyond their natural ranges to enhance fishing opportunities, with great success.
However, some non-native species can proliferate unchecked in new environments that lack natural controls that exist in their home range, such as climate restrictions or predators. It is these plants and animals that become invasive, overwhelming native plants and animals, disrupting entire ecosystems and costing millions of dollars to control or eradicate.
Ways in which non-native aquatic species might be introduced in a new area include: