This project is an international, interdisciplinary effort to address the rapid environmental changes occurring in the Antarctic Peninsula region as a consequence of the abrupt collapse of the Larsen B Ice Shelf in the fall of 2002. As a result of this collapse, a profound transformation in ecosystem structure and function has been seen in the coastal waters of the western Weddell Sea. This transformation appears to be redistributing the flow of energy between organisms, and to be causing a rapid change in the ecosystem beneath the ice shelf. For instance, the previously dark waters of the Larsen B embayment now support a thriving phototrophic community, with production rates and phytoplankton composition similar to other productive areas of the Weddell Sea.