What aquatic invasive species
outside the Basin pose a threat?


The invasive plant hydrilla (found in Cayuga Lake and the Erie Canal), quagga mussels (found in the Great Lakes and the Erie Canal), round goby (found in the Erie Canal and the St. Lawrence and Richelieu rivers), and the Asian clam (found in Lake George and the Champlain Canal) are four of the most threatening invasive species “on the doorstep” of Lake Champlain.

invasive species on the doorstep

Hydrilla, quagga mussel, round goby, and Asian clam (clockwise from top left) are the most threatening invasive species "on the doorstep" of Lake Champlain. Photos: University of Florida, LCBP, Lake George Association, USFWS

aquatic invasive species threats to Lake Champlain graphic

Figure 19 | Non-native and aquatic invasive species threats to Lake Champlain from connected waterways

Invasive plants, animals, and pathogens can move across the landscape and enter Lake Champlain in a number of ways. Primary pathways include aquarium plant and pet dumping, water garden escape (especially during significant tropical storms like Irene), hitchhiking on boats, trailers, and other recreational equipment, live bait release, intentional stocking, and canal passage. Other waterways in the region surrounding Lake Champlain are home to many potential invaders (Figure 19).

Hydrilla is a submerged aquatic invasive plant that grows prolifically in dense mats and is considered more invasive than Eurasian water milfoil, a well-known and established invasive species in Lake Champlain. Hydrilla is believed to be native to Korea, but has now become established in the Cayuga Lake Inlet and Erie Canal in New York, threatening to spread towards Lake Champlain.

Quagga mussels are an aquatic invasive mollusk, first discovered in Lake Erie in 1991, where they are thought to have arrived in ballast water from the Ukraine. The quagga mussel has been referred to as the evil twin of the zebra mussel because it is able to reproduce more prolifically and is adapted to live in deeper water. The species was most likely spread overland by hitchhiking on vessels and equipment. It has caused billions of dollars in damage to aquaducts, hydroelectric dams, and irrigation systems in other parts of the country. Quagga mussels are now present in the Erie Canal and expanding their range eastward, toward Lake Champlain. They have been intercepted by the boat launch steward program on Lake George. If quagga mussels arrive in Lake Champlain, they could threaten the accessibility of deep-water historic shipwrecks that have escaped zebra mussel damage, as well as compete with zebra mussels and native mussels in shallow water.

Round goby are small invasive fish that have spread through the dumping of bait buckets and passage through canals, after their introduction to the Great Lakes from ballast water in the St. Clair River in 1990. Round goby are aggressive eaters that consume the eggs of native fish species and sport fish. The species is presently found both in the Erie Canal and in the Richelieu River.

Asian clams are present in the Champlain Canal and in Lake George, New York, both of which are connected to Lake Champlain. Asian clams are small bivalves with distinctive ridges on their shells. Asian clams are hermaphrodites, so it only takes one clam for reproduction to occur. They are filter feeders that foul water intake pipes and irrigation systems. They reproduce prolifically and displace native species. Asian clams have been successfully overwintering in the cold waters of Lake George. After they die, their shells may persist for years, providing a growing substrate for zebra mussels.

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