The Chesapeake Bay is an estuary a place of transition between the land and the sea, where incoming fresh water mixes with salty ocean water. The Chesapeake Bay is a productive ecosystem and is the largest estuary in North America, home to more than 3,700 species of plants and animals. A healthy Bay requires balancing the needs of the regions people and economy with the needs of the Bay for clean waters and ample habitat for aquatic life. The goal of Bay restoration is to restore this balance by reducing pollution, protecting critical habitat and ensuring sustainable populations of fish and shellfish. The Chesapeake Bay 2006 Health and Restoration Assessment is presented this year in two parts. Part One: Ecosystem Health draws on the most up-to-date monitoring data gathered by Bay Program partners to assess the overall health of the Bay ecosystem last year. Progress toward a restored Bay is tracked with 13 indicators grouped in three priority areas that represent major components of the Bay ecosystem. Quantitative restoration goals have been set for most of these indicators. For each indicator, a chart shows, as a percent of the goal, current status and a history of progress toward achieving the goal. A summary bar chart shows the current status of each indicator with respect to its restoration goal.