Abstract: The research will investigate the individual and combined effects of rising ocean acidification and sea surface temperatures on shallow-water calcified benthic organisms in western Antarctic Peninsular (WAP) marine communities. The Southern Ocean is predicted to become undersaturated in terms of both aragonite and calcite within 50 and 100 years, respectively, challenging calcification processes. Adding to the problem, antarctic calcified benthic marine organisms are more vulnerable to ocean acidification than temperate and tropical species because they are generally weakly calcified. Many antarctic organisms are essentially stenothermal, and those in the West Antarctic Peninsula are being subjected to rising seawater temperatures. The project employs both single-species and multi-species level approaches to evaluating the impacts of rising ocean acidification and seawater temperature on representative calcified and non-calcified macroalgae, on calcified and non-calcified mesograzers, and on a calcified macro-grazer, all of which are important ecological players in the rich benthic communities. Multi-species analysis will focus on the diverse assemblage of amphipods and mesogastropods that are associated with dominant macroalgae that collectively play a key role in community dynamics along the WAP. The project will support undergraduate research, both through NSF programs, as well as home university-based programs, some designed to enhance the representation of minorities in the sciences. The principal investigators also will support and foster graduate education through mentoring of graduate students. Through their highly successful UAB IN ANTARCTICA interactive web program, they will continue to involve large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica.