The Seabird Ecological Assessment Network (SEANET) is a citizen science program that brings together interdisciplinary researchers and members of the public in a long-term collaborative effort to identify and mitigate threats to marine birds. SEANET was initiated by the Tufts Center for Conservation Medicine, in collaboration with the Lloyd Center for Environmental Studies in Massachusetts, during Autumn 2002. Since this time, the project has expanded to beaches throughout New England, New York and New Jersey and more recently, to the southeastern US, with beaches in South Carolina, Georgia and Florida. SEANET volunteers conduct year-round beached bird surveys in order to identify and record information about bird mortality along the east coast of the United States. Data collected by hundreds of SEANET volunteers are used to examine the spatial pattern of bird carcass deposition and how it varies across time. These surveys provide baseline information about bird mortality and can help to detect mass mortality events due to oil spills, algal toxins, and disease outbreaks. Marine birds can serve as indicators of ecosystem and human health; monitoring the threats they face and their mortality patterns can teach us about the health of the marine environment.