Scientists recognize that fish assemblages in developed watersheds are affected primarily by nonpoint source anthropogenic stressors that result from land use development, in particular alteration of physical habitat. Over half of the streams in the Mid-Atlantic Highlands (MAH) have fish communities that are in fair or poor condition, and the USEPA concluded that physical habitat alteration represents the greatest potential stressor across this region. Habitat alteration can occur both in terms of habitat quantity and quality. Loss or destruction of habitat quantity reduces the total amount of habitat available to aquatic species, and can isolate patches of suitable habitat within a stream, which reduces species' survival and alters natural fish movement and migration patterns. Loss of habitat quantity is often associated with significant hydrologic alterations, such as impoundments, whereas loss of habitat quality can be due to factors such as landscape development and alteration of flow patterns on the landscape. The mission of the Canaan Valley Institute (CVI) is to address the environmental problems in the Mid-Atlantic Highlands through a program of environmental stewardship that considers and integrates natural, economic, and human concerns in the management of natural resources.