The Chesapeake Bay Program is the unique regional partnership that's been directing and conducting the restoration of the Chesapeake Bay since the signing of the historic Chesapeake Bay Agreement of 1983. The Bay Program partners include the states of Maryland, Pennsylvania and Virginia; the District of Columbia; the Chesapeake Bay Commission, a tri-state legislative body; and the U.S. Environmental Protection Agency (EPA), representing the federal government. The partnership recently welcomed Delaware, New York and West Virginia as headwater partners to better coordinate efforts in all parts of the watershed. As the largest estuary in the United States and one of the most productive in the world, the Chesapeake Bay was this nation's first estuary targeted for restoration and protection. Scientific and estuarine research on the Bay in the late 1970s and early 1980s pinpointed three areas requiring immediate attention: nutrient over-enrichment, dwindling underwater bay grasses and toxic pollution. Once the initial research was completed, the Bay Program evolved as the means to restore this exceptionally valuable resource. Since its inception in 1983, the Bay Program's highest priority has been the restoration of the Bay's living resources - its finfish, shellfish, underwater bay grasses and other aquatic life and wildlife. Improvements include fisheries and habitat restoration, increases of underwater bay grasses, nutrient and toxic reductions, and significant advances in estuarine science.