Threats to Champlain

Invasive Plants

There are several aquatic nuisance plants in Lake Champlain and along its shores and tributaries.

These include:

Water chestnut

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.

Swanton Dam


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.



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 pe

Lamprey wounds on Lake trout


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. 

Driveway sealing


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. 

Pesticides are bad

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.

Fish made of pills

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:

No Swimming Sign

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:

Algae Lake Bloom