Cormorant Oceanography Project: Biologging Data from Great Cormorants (Phalacrocorax carbo), Lithuania, 2023

Oceanographic sampling of the coastal ocean is often sparse in space and time and in situ observations are needed to understand the complex physical processes in this zone. This dataset is provided by the Cormorant Oceanography Project (https://www.osudashcams.com/), an interdisciplinary collaboration between oceanographers and seabird ecologists based at Oregon State University, and in partnership with collaborators globally. We are advancing biologging tag technologies for use with cormorant species to measure in situ oceanographic conditions. This also offers a unique opportunity to study the distribution and behaviors of cormorants relative to environmental conditions along their daily foraging paths. Our biologging tags include combinations of fast-response sensors to measure water temperature, conductivity, and pressure. Each tag contains an inertial measurement unit (IMU) to monitor acceleration and orientation. A GPS unit, triggered when a bird surfaces, provides locations for georeferencing measurements. The sensors collect large volumes of data that are transmitted and retrieved using two-way cellular communications. This dataset consists of GPS tracks and dive profiles from Great Cormorants (Phalacrocorax carbo) tagged at costal colonies in Lithuania, during the 2023 breeding season. Cormorants were fitted with GPS-GSM tags integrated with conductivity, temperature, depth and IMU sensors and were tracked through their post-breeding migration.