Healthy ecosystems provide habitat for native species, retain nutrients and sediment, and store floodwaters. Efforts to protect critical habitat in the Lake Champlain Basin, such as riparian and wetland areas, include improving habitat connectivity and wildlife passage, reducing nutrient runoff into rivers and streams, supporting restoration measures for species of concern, and reducing the risk of new invasions of non-native species.


Several pressures pose threats to the Basin’s biodiversity but efforts to protect habitat are helping to improve the health of the ecosystem.

The Lake Champlain ecosystem includes both the plants, animals, and microorganisms and the habitats that support them. The watershed’s biodiversity refers to the large number and variety of life forms in a broad range of habitats within the Basin’s ecosystem. The Basin’s biodiversity is threatened primarily by loss of habitat, the changing climate, and the introduction of invasive species.

Certain types of habitat are critically important to protecting water quality and ecosystem functions. Wetland and riparian areas provide flood water storage, nutrient retention, erosion control, and food and nursery habitat for fish and other wildlife. These areas also are especially vulnerable to development, pollution, and climate change. Protection and restoration of wetland and riparian habitats is a focus of federal, provincial, and local partners. Projects such as culvert replacements to accommodate passage of aquatic organisms can improve connectivity of ecosystems and provide flood protection measures.

Scientists are documenting the effects of the changing climate throughout Lake Champlain and its watershed. Seasonal temperatures and precipitation patterns are changing toward warmer and wetter conditions. Average surface water temperatures in Lake Champlain have increased in recent decades, and the Lake has frozen over less frequently in the last 50 years than in the previous half century (Figure 9).

Figure 9 - Freeze-over of Lake Champlain

Figure 9 | Freeze-over of Lake Champlain, 1906-2018

These changes in climate affect both aquatic and terrestrial habitat. Across New England, milder winters and increased precipitation in the form of rain negatively impact many economically important tree and forest species, according to a new assessment led by the U.S. Department of Agriculture (USDA) Forest Service Northern Research Station. Forests in the upper reaches of the Lake Champlain Basin are important to the Lake’s water quality, as they store and filter water that eventually travels to the Lake. If the composition or extent of these forests are degraded, the impact on the Lake’s water quality could be significant.

melting snowpack and spring runoff

Changing snowpack and timing of spring melt affects habitat from mountain streams to Lake Champlain. Photo: LCBP.

In response to the biodiversity challenges, various efforts have been undertaken. In 2016, the USDA Natural Resources Conservation Service worked with local landowners to conserve additional wetland parcels in the Otter Creek Swamp, increasing the total amount of conserved wetlands in this system to 2,148 acres. The Nature Conservancy considers Otter Creek Swamp to be the largest and most biologically diverse swamp complex in New England. It is a haven for bird species, a foraging area for endangered Indiana bats, and a home to large mammals such as moose and bear. Otter Creek Swamp also provides flood protection to the downstream town of Middlebury. During Tropical Storm Irene, the wetlands and floodplains reduced flood damage to the town by as much as $1.8 million. This flood protection likely will become more valuable if the frequency of extreme events in the watershed increases as predicted by climate models.

In 2016, Vermont approved the reclassification of the 1,359-acre Sandbar wetlands, the large delta wetland complex between the Lamoille River and Lake Champlain, as Class 1, the highest level of protection. The designation more than doubled the state’s total acreage of Class 1 wetlands. The Sandbar complex is home to 29 rare, threatened, and endangered species and provides water storage, nutrient retention, and erosion control.

Early in 2018, New York’s Adirondack Park Agency classified the 20,543-acre Boreas Ponds Tract as a mix of limited use wild forest and wilderness. This area is home to rare plant and animal habitat and will provide low-impact recreation opportunities for residents and visitors. The tract’s namesake ponds account for 320 acres of water themselves, but the tract also includes the Boreas River and various streams; all the water ultimately ends up in either Lake Champlain or the Hudson River. The classification of the Boreas Ponds Tract increases the size of the Adirondack Park’s High Peaks Wilderness Area to more than 250,000 acres.

Work continues on the restoration of some critical native species in Lake Champlain. New technology is allowing researchers to acoustically track tagged lake sturgeon, which will help fisheries biologists better understand the movement, habitat use, and migratory patterns of the fish. The bald eagle has made a remarkable comeback from years of decline after the use in the mid-20th century of DDT, a pesticide that caused the eagles to produce eggs with thin, unviable shells. The number of nesting pairs of bald eagles in Vermont has grown from one in 2003 to twenty-one in 2017. Audubon Vermont and the Vermont Fish and Wildlife Department are considering upgrading the state status of the bald eagle from endangered to threatened.

The removal of the Willsboro Dam on the Boquet River opened up miles of habitat for Atlantic salmon and other key fish species. Photos: Vic Putman.