Lake Champlain: The Issues and Threats



When we understand the issues that threaten the health and safety of Lake Champlain's water and fisheries, we can properly take action to protect the lake and rivers.


The results will be amazing: 
  • beaches that never close during the swimming season
  • fewer algae blooms
  • naturally spawning Atlantic salmon, walleye, and lake sturgeon in our rivers and streams
  • plentiful, healthy, large fish
  • healthier drinking water
  • a better local economy
  • protected property values
Once you get to know the issues, check out ways you can Take Action to reduce these threats ...because a swimmable, drinkable, fishable Lake Champlain is the only option.

Excess Phosphorus
Phosphorus naturally exists in Lake Champlain and is an essential nutrient for plants, wildlife, and humans to live and grow. Lake Champlain runs into problems when too much phosphorus enters the lake from sources such as:
  • fertilizers from lawns, parks, and golf courses
  • farm runoff - manure & synthetic fertilizers and sediment
  • Eroding river banks
  • loose soil (sediment) in driveways and roads
  • wastewater treatment facility overflows & failures
  • failing & failed septic systems
  • Pet waste
  • human waste dumped from boats
Consequences: Too much phosphorus in Lake Champlain often leads to nuisance plant growth and algae blooms, which are large mats of algae in the water that block sunlight from reaching plants at the lake bottom. As algae within the blooms die, the bacteria that break down the dead algae use up large amounts of oxygen in the water. These low oxygen levels can result in dead fish and other aquatic wildlife.
Some types of algae, such as blue-green algae (cyanobacteria), can produce toxins called cyanotoxins. These toxins have been known to kill fish and dogs, and can make a person ill or worse if swam in or swallowed.


Harmful Bacteria
Harmful bacteria and viruses (pathogens) can be carried to Lake Champlain in water pollution runoff, and in some cases, by direct introduction. Sources include:
  • farm runoff (manure)
  • wastewater treatment facility overflows
  • failing & failed septic systems (human waste)
  • pet waste
  • human waste dumped from boats
  • wildlife (mainly waterfowl) droppings
Consequences: Harmful bacteria and viruses can cause people to become sick, or in rare cases, die. The state and some towns regularly test the water quality at public beaches around Lake Champlain during the swimming season for bacteria such as E. coli and other fecal coliform (which inlcudes many kinds of bacteria that comes from animal and human waste). When a certain level of bacteria is found, a beach will be closed until those levels drop to a safe level.


Pharmaceuticals & Personal Care Products
Pharmaceuticals and personal care products enter Lake Champlain through treated water released by a wastewater treatment facility. Many pharmaceuticals and personal care products are not removed by the treatment process and end up in the lake.  Sources include:
  • old medicines flushed down the toilet or drain
  • illegal drug production and disposal
  • laundry detergents
  • perfumes
  • chemicals dumped down the drain
  • Urine and feces from a person taking medicines
Consequences: Since wastewater treatment facilities often cannot filter out the chemicals found in some pharmaceuticals and personal care products, they go straight into the lake. This means that more expensive treatments and processes are needed to clean our drinking water that comes from the lake. Even these treatments and processes cannot clean all the chemicals out 100% of the time. In some cases, pharmaceuticals and personal care products cause problems with fish and other aquatic creatures, such as frogs, by mimicking hormones. This can result in altered reproductive organs in frogs where male frogs mutate into female frogs. This is an emerging issue, and scientists are currently studying possible effects on fish, wildlife, plants, and humans.


Pesticides enter Lake Champlain through urban and farm runoff. Pesticides are used to kill weeds, insects, fungi, and other pests and can cause deformities or death in fish and wildlife. Pesticides also pose a threat to human health when found in swimming and drinking water.  Sources include:
  • farm runoff (primarily atrazine)
  • urban runoff (stormwater) from lawns
  • golf courses
  • public parks
Consequences: Our waters can become unsafe when pesticides enter them. Water pollution runoff containing pesticides from home, commercial, and farm use can irritate peoples' skin and cause illness when swallowed. Fish, salamanders, turtles, birds, and other wildlife can be harmed or die from contact with pesticides. For example, some pesticides mimic hormones and can alter reproductive organs in fish and amphibians.  Pesticides have been linked to human birth defects and in rare cases, death. One report found pesticides in peoples' private wells (read it here).


Toxic chemicals from coal-tar enter Lake Champlain through water runoff from developed areas. Coal-tar is often found in driveway and parking lot sealants, and has been linked to PAH (polyaromatic hydrocarbons) contamination in waters around the nation. Sources include:
  • driveways
  • parking lots
  • tar roofs
Consequences: When waterways and waterbodies are polluted with coal-tar, PAH levels tend to be higher than those in waters without coal-tar sealants surrounding them. Studies have shown that PAHs are toxic to amphibians, and likely other wildife and humans. For example, amphibians frequently die or have their growth stunted when in contact with PAHs (read one study here). Coal-tar has also been linked to PAHs in apartment and house floor dust, where coal-tar flakes are tracked indoors by shoes, bike tires, and pets' feet. Since PAHs are a known human carcinogen (read about it here), PAH in floor dust can be toxic to children, adults, and pets.
The sea lamprey is a parasitic invasive species that feeds on the fluids of fish.  Typically, lamprey are found feeding on cold water fish such as salmon, lake trout, and steelhead trout, however, they can also be found on cool and warm water fish such as northern pike, walleye, bass, and even perch.
Currently the most effective control method is by treating tributaries where lamprey spawn with a chemical lampricide, which is considered safe to humans and mammals. It is also thought that sedimentation (build up of sediment on river bottoms) in the rivers caused by stormwater and erosion create ideal spawning habitat for the parasitic lamprey.  Read more about lampricides here.
Consequences: Lamprey caused significant damage to Lake Champlain's Atlantic salmon and lake trout populations for a number of years.  Since lamprey historically inhabitated larger bodies of water than Lake Champlain, the fisheries in these larger waterbodies can stay healthy with the presence of lamprey.  There has been recent success with lamprey control in Lake Champlain.  Many anglers are seeing larger salmon and lake trout and fewer lamprey wounds on fish.  Sign the lamprey petition here to help ensure lamprey control funding.


Double-crested cormorants are an invasive waterbird on Lake Champlain.  Historically, cormorants have inhabited larger bodies of water than Lake Champlain, however, since they became protected in the Migratory Bird Treaty Act in 1972, the cormorant population has exploded on the Lake.
Recognized as harmful to Lake Champlain's world-class fisheries, annual funding is usually earmarked to help control their populations through shooting, egg oiling, and harassment to discourage egg-laying.
Consequences: Cormorants have a big appetite for Lake Champlain's fish.  The 12,000-20,000 cormorants on Lake Champlain consume about 2-4 million pounds of fish annually.  Left uncontrolled, cormorants could significantly harm the fish populations on Lake Champlain.  Cormorants also displace native waterbirds such as the common tern, while destroying vegetation on nesting islands. Four Brothers Islands, for example, have experienced substantial tree and shrub loss due to cormorant nesting. However, with proper cormorant control, marked habitat improvement has been seen.


Dams & Barriers
Dams are found on many of Lake Champlain's tributaries.  Some still functional and some not, these structures were generally first built to generate electricity.  Older dams were built for mills. 
The non-functional dams around the Basin could be removed without influencing electricity prices or harming property, restoring the natural flow and fish passage that existed before their construction.
Sometimes, sediment can back up behind the dam and must be carefully removed so that it does not rush downstream and clog fish and other aquatic species habitat.
Consequences: Dams prevent native fish like Atlantic salmon, walleye, sturgeon, and American eel from reaching their spawning habitat.  This prevents natural reproduction which causes populations to rely on stocking from our fish hatcheries.  This is neither sustainable nor healthy for fish populations and our tax dollars.  Dams can also create habitat that is more ideal for invasive species like the parasitic sea lamprey.  If the Swanton Dam was removed, for example, several Lake Champlain native fish species would be able to naturally spawn again, including the American eel which feeds on young lamprey.  More lamprey predators and less lamprey habitat means less funding needed for lamprey control.  Fewer funds would be needed for fish hatcheries, as well.  We could even see salmon runs again!  Click here to take action.


Invasive Plants
There are several aquatic nuisance plants in Lake Champlain and along its shores and tributaries.  These include:
Click on each plant name to open an image in a pop-up window.
Consequences: Invasive plants are harmful to Lake Champlain for several reasons: plants that native fish and animals feed on are replaced by these invasives (no animals can feed on the invasives),  invasive plants can spread across large areas suffocating native plants and ecosystems since nothing eats them, and their uncontrolled growth can make recreation difficult by tangling motors, preventing fishing, and taking away swimming opportunities.  
Image credits: Phosphorus/algae bloom - Larry Dupont; Harmful bacteria - Lake Champlain Basin Program; Pharmaceuticals - National Drug Intelligence Center; Pesticides -; Atlantic salmon and lamprey - Kevin Favreau; cormorants - Michigan Dept. of Natural Resources; Dams & Barriers - Lake Champlain International; Water chestnut - US Fish & Wildlife; Eurasian watermilfoil - Alison Fox, University of Florida; variable-leaved watermilfoil - Vermont Dept. of Environmental Conservation; Japanese knotweed - US Fish & Wildlife; purple loosestrife - Paul Champion, NIWA; didymo - PA Fish & Game Department