Native to Eurasia, it arrived in the Great Lakes via ballast water. The round goby is known for competing with and preying on native species.
Native to the Atlantic Ocean, it can now be found in the Great Lakes and many inland waters. The Alewife came to the Great Lakes via the Welland Canal, which connects Lake Ontario and Lake Erie. It was intentionally introduced to inland waters. Alewives are big competitors of native species.
Asian Swamp Eel
Native to Asia, it was imported for the aquarium trade and purposely released from fish markets. It can now be found in the waters of Florida, Georgia, and Hawaii. Asian Swamp Eels compete with native species.
Native to central and eastern United States, is has since invaded the western half of the country. The bullfrog was accidentally introduced to the West via trout stocking. It was also brought to the West for sport and pest control. The bullfrog preys on and competes with native species.
Chinese Mitten Crab
Native to China, this crab arrived via ballast water and can now be found on the West Coast, the Great Lakes, and in Chesapeake Bay. It competes with native species.
Native to Eurasia, it arrived in the Great Lakes via ballast water. It competes with native species.
European Green Crab
Native to Europe, it arrived to the North Atlantic coast and the Pacific coast of the U.S. via ballast water. This crab preys on bivalves and other crustaceans, such as soft-shell clams and scallops.
Native to the central United States and Mississippi River tributaries. It has been intentionally stocked elsewhere by anglers, and is now found in the western U.S. and along the Atlantic coast. The flathead catfish preys on native species.
Native to the Pacific Ocean, it can now be found along the coasts of Florida, Georgia, and North Carolina. It was brought to these new areas via the aquarium trade. Lionfish prey on native species and have extremely venomous spines.
Native to China, Korea, and possibly Russia (the snakehead family is native to Asia and Africa). After being released from fish markets, it can now be found in the eastern U.S. The northern snakehead preys on native species.
Native to South America, this semi-aquatic rodent was introduced to the coasts of the Gulf of Mexico and the Atlantic for its fur. Nutrias damage and destroy vegetation and habitats in wetlands.
Native to the Atlantic Ocean, it was introduced to the Great Lakes after swimming through the Welland Canal, which connects Lake Ontario and Lake Erie. Sea Lampreys prey on native species.
Native to Europe, ballast water and hull fouling brought the sea squirt to the coasts of New England and the Pacific Northwest. Sea squirts are known for forming dense colonies that smother native species.
Veined Rapa Whelk
Native to the Pacific Ocean, ballast water brought it to Chesapeake Bay. The veined rapa whelk preys on bivalves, such as oysters and mussels.