Thousands of dams, culverts, water diversions and other artificial barriers were constructed during the Industrial Revolution in the Northeast for irrigation, flood control, electricity, drinking water and transportation. Most of these structures still exist in Maine's rivers and can be major barriers to the natural migrations between feeding and spawning areas of fish and other organisms.

In 1999, the U.S. Fish and Wildlife Service started the National Fish Passage Program to raise awareness of these issues and identify projects where native fish populations could be reconnected with historic habitats. In keeping with these goals, the Service's Maine Fisheries Resource Office has teamed with the Atlantic Salmon Commission and the Sheepscot River Watershed Council to begin a study of fish passage, habitat connectivity and non-point source pollution in Maine's rivers. Staff biologists began surveys in August 2003 on Kenduskeag Stream and the West Branch of the Sheepscot River to evaluate bridges and culverts in terms of overall river health and passage of Atlantic salmon and other fish.

Each site is inventoried for design, condition and function. Data is collected on habitat conditions upstream, within and downstream of each structure to determine its effect on flow, passage and connectivity of habitat. Information gathered from this project will be used to make maintenance and design recommendations. Most sites will require only minor work such as removal of debris from beavers, muskrats or storm events. Complete renovation may be required at some sites where restricted or unnatural flow of water through the structure results in major changes to the streambed and its banks or the movement of fish. Next, the resulting data will be combined with other data from rivers across the U.S. to build the Fish Passage Decision Support System. This map and database system will help the Service and partners plan and prioritize fish passage projects. Information on the system is available online at the Service's Fish Passage Decision Support System Web site.

NORTHEAST REGION, U.S. FISH AND WILDLIFE SERVICE -- Conserving the Nature of the Northeast