There are many types and sources of chemicals - both natural and manmade - in our environment. For example, chemicals such as metals and pesticides are released into the environment from natural processes and/or human activities. Although many chemicals do not pose a threat, certain types and levels of chemicals found in waterbodies have the ability to affect the reproduction, development and, ultimately, the survival of living resources. By living resources we mean the fish, shellfish, crabs, worms, grasses and other creatures. These chemicals are called toxics or chemical contaminants. Chemical contamination in water, sediment and/or in animal tissue is an important issue for people everywhere. In the Chesapeake Bay region, scientists and managers have been carrying out a multi-step effort to assess the Bays tidal rivers and identify, or characterize, areas that are either free of chemical contamination or show early warning signs of chemical contamination. The result of that effort is this report: Targeting Toxics: A Characterization Report - A Tool for Directing Management & Monitoring Actions in the Chesapeake Bays Tidal Rivers. At the same time, scientists have been working to identify the sources of chemical contamination in the Bays tidal rivers. That study resulted in a related report: the 1999 Chesapeake Bay Basinwide Toxics Loading and Release Inventory (TLRI). The information in these reports will help Chesapeake Bay Program decision makers target specific tidal rivers for management and monitoring efforts.