Silvio O. Conte National Wildlife Refuge, CT, MA, VT, NH

By the mid-20th century, the Connecticut River was so degraded some called it "the nation's best-landscaped sewer." Species that once thrived on the banks or in the flow of the river were gone, others were going. In 1972, the Clean Water Act set the Connecticut on a path to recovery. In 1991, the U.S. Fish and Wildlife Service committed to helping to restore the watershed by establishing Silvio O. Conte National Wildlife Refuge, 7.2 million acres spanning four populous northeast states.

Today the refuge supports many rare and endangered species, including the shortnose sturgeon, bald eagle, American black duck, seaside sparrow, cerulean warbler, black rail and New England cottontail rabbit. Of the land acquired by the Conte refuge, one of the largest and most unusual parcels is Nulhegan Basin, 26,000 acres of bogs and freshwater wetlands, spruce-fir forest and northern hardwood forest. The cold micro-climate and peat soils are more typical of ecosystems 200 miles north, and the remote landscape is home to moose, black bear, loons, hooded mergansers, wood ducks and spruce grouse.

The Threat

The Connecticut River flows through the heart of New England, known the world over for that moment in autumn when hardwood forests of sugar maple, red maple and birch blaze bright. Projected rises in global temperature of 2 to 10 degrees Fahrenheit may change the very nature of the Conte refuge and the New England countryside. According to the U.S. Environmental Protection Agency, tree species are likely to migrate north by about 200 miles. Some wildlife species may be able to adapt or migrate with the forest habitat, some will not. Alpine species such as the Bicknell's thrush may be the first affected because they depend so heavily on cooler habitats. Aquatic animals will also feel the heat, particularly the imperiled shortnose sturgeon, an estuarine dweller that swims upstream to spawn in cold, fresh waters.

Once plentiful in eastern coastal rivers, the shortnose sturgeon is now found in just 16 of them, thanks to overfishing, dredging, water pollution and the dams that impede its upstream migration. Although the Connecticut River population of this slow-to reproduce bottom feeder is currently stable, a changing seasonal stream flow pattern linked to early melting of the mountain snowpack that feeds the river could change that. Earlier snow melt means that by late summer, stream flows are significantly reduced and dissolved oxygen levels are low, a condition to which juvenile sturgeon new to life in the river are especially susceptible.