Aquatic Invasive Species Part 3: Protecting Lake Champlain from Emerging Threats
While the dozen aquatic invasive species already established in Lake Champlain are being monitored and controlled, the task is challenging. The last thing Lake Champlain needs is new invaders! However, two aquatic species, Hydrilla and round goby, are of growing concern as they get closer to Lake Champlain. If they were to invade, managing them would be extremely difficult.
If you thought managing the dense mats of Eurasian watermilfoil was difficult, think again! Hydrilla verticillata(Hydrilla), an aquatic weed from Asia is one of the most challenging invasive species to control and eradicate in the United States. With just an inch of plant segment, Hydrilla can produce mats of vegetation several feet thick, choking out water bodies and disrupting wildlife habitats.
Studies have found cyanobacteria (blue-green algae) thrive in lakes infested with Hydrilla, particularly due to the mats created on the water's surface. Since 1994, over 170 bald eagles and thousands of American coots have mysteriously died across the Southern U.S. These deaths were traced to a neurological disease caused by a toxin produced by cyanobacteria (blue-green algae), which leads to holes in the white matter of the affected species' brains. Most of these deaths occurred in lakes infested with Hydrilla, where the growth of cyanobacteria can thrive. Fish that ingest the cyanobacteria on Hydrilla are then consumed by waterfowl and apex predators, causing rapid mortality. [AL1] While there have been no reported similar deaths in the Northeast, this remains a potential impact of the invasive.
Hydrilla has not yet been introduced to Lake Champlain, but in 2019, it nearly hitchhiked its way in, wrapped around a boat trailer coming from the Connecticut River where Hydrilla is established! Fortunately, a Lake Champlain Basin Program boat launch steward removed the aquatic plant from the trailer as it was about to enter Lake Champlain. This timely intervention serves as a reminder of the importance of “clean, drain, and dry” prevention methods.
Another species to watch out for is the round goby, a bottom-dwelling fish introduced to North America from Central Eurasia via ship ballast water. The round goby can impact aquatic environments in different ways. They can transfer toxins through the food chain—round goby feed on invasive mollusks, and zebra mussels, which can concentrate toxins from the water. Toxins are passed on to higher-level predators when larger fish or birds feed on round goby, generating diseases like botulism.
Additionally, the round goby plays a significant role in the transmission and persistence of the virus responsible for the viral hemorrhagic septicemia (VHS) disease. This disease poses serious threats to aquatic ecosystems, leading to large-scale die-offs of native fish populations, which reduces biodiversity and overall resilience. The round goby also outcompete native bottom-dwelling species and consumes the eggs and young of sport fish, which can affect economies relying on sport fishing.
This June, eDNA—residual genetic material from the round goby—was found in the Champlain Canal for the first time. Following prevention measures is more critical than ever!
You can help! If you suspect you’ve found Hydrilla or round goby in Lake Champlain, do not put them back in the water. Take pictures and report your findings to the %2C%20to%20isinfo [at] dec.ny.gov%20%2C%20OR." target="_blank">New York State Department of Environmental Conservation or the Vermont Department of Environmental Conservation.
More information on Round Goby
More information on Hydrilla