Seasonal movements and pelagic habitat use of murres and puffins determined by satellite telemetry. Common murres (Uria aalge) were the bird species most seriously injured by the Exxon Valdez oil spill. After the spill, fewer breeding mures were found at the Barren Islands compared to historical data, and annual censuses have not detected any recovery. One hypothesis to explain the failure of common murres to recover is that low food availability is limiting the birds ability to breed successfully or to survive in sufficient numbers during the nonbreeding season. As part of the restoration effort, tufted puffins (Fratercula cirrhata) are being evaluated as samplers of the forage fish community and as indicators of changes that may be affecting murres and other injured resources. Information on the foraging areas and seasonal movements of murres and puffins is needed to test hypotheses concerning recovery potential and to validate techniques currently being employed in the restoration program for seabirds. Because of the potential for oil and gas development in the Chukchi Sea, murre populations of that area are an important element of the recent and ongoing seabird monitoring program sponsored by the Minerals Management Service and U.S. Fish and Wildlife Service. To date, seabird monitoring has emphasized measures of population numbers and breeding productivity. On an annual basis, however, seabirds spend the majority of their time at sea, and even in the breeding season they are most vulnerable to a potential pollution event while they are resting or feeding in marine habitats. Risk assessment for murres requires information on the foraging ranges, specific feeding areas while breeding, and wintering grounds of local populations. Satellite telemetry offers a more cost-effective approach for determining foraging patterns and habitat use by seabirds than conventional survey methods. This study uses implanted satellite transmitters to assess the movements of common murres and tufted puffins from colonies on the Barren Islands and of common murres and thick-billed murres (Uria lomvia) from two colonies in the Chukchi Sea.