ABOUT AIS

Open your eyes! You don’t have to look far to see plant and animal invaders from another ecosystem. Most lawn grasses and weeds have been transported by humans from Europe and other places. Popular sport fish, like the German brown trout, and common carp, were introduced (purposely released to a new location) in Pennsylvania watersheds by fish and wildlife agencies. The vast majority of Pennsylvania’s introduced species are harmless, but a few, perhaps one in one hundred, are considered INVASIVE SPECIES.

When is an introduced species also an invasive species?

• Introduced
• Non-native
• Exotic
• Alien
• Foreign
• Non indigenous

These are all names for plants, animal, and other organisms that grow and breed outside their native ranges. We identify super successful, harmful species that thrive in wetlands and waterways as AQUATIC INVASIVE SPECIES (AIS).

Why are AIS such a problem?
Invasive species are also know as biological pollution because some invaders can pack the same punch as other kinds of pollution, disrupting ecosystems and reducing biodiversity. AIS can....

• prey on native species, like the flathead catfish, recently introduced to the Delaware River. The Flathead has a huge appetite for a variety of fish;
• compete with native species, like purple loosestrife that can take over a marsh or wetland by crowding out native plants;
• alter ecosystems, like nutria that dig channels that convert productive, green wetlands of the Chesapeake into barren mud flats;
• spread diseases, like the Canada goose that can spread bacteria and viruses and excess nutrients in their waste;
• cause economic damage, like the zebra mussel that is estimated to cost the Great Lakes $100 to $400 million (that’s $400,000,000) each year to control.

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