CeDAMar is a seven-year field project (2004-2010) within the Sloan Foundations Census of Marine designed to evaluate patterns of causes of species diversity in the abyssal deep sea (ocean depths of 3000 – 6000 m). CeDAMar’s goal is to document the levels of species diversity of abyssal plains throughout the oceans to provide a baseline for global-change research and a better understanding of historical causes and ecological factors regulating biodiversity. Specific questions addressed include the following:

• How many species are there in the abyssal deep sea?

• Are cosmopolitan species the abyssal norm?

• Are there latitudinal gradients in species richness?

• Are there biodiversity hotspots in the abyss?

• How do diversity and species ranges vary with organism size?

• What environmental factors, including overlying primary productivity, are correlated with biodiversity at the abyssal seafloor?

• Are there biogeographic barriers to the distribution of abyssal fauna?

• What role has geological history played in determining diversity levels of specific basins?

These questions are being addressed through major international collaborative research efforts. Thus, CeDAMar consists of an internationally integrated series of field projects, focusing on six themes: (1) Latitudinal gradients in the Atlantic Ocean, (2) Diversity and biogeography of Antarctic deep-sea fauna, (3) Biodiversity and biogeography of the abyssal Pacific, (4) Diversity patterns in the warm abyss of the Mediterranean Sea, (5) Diversity versus food availability in the Indian Ocean, (6) Time-series analyses of abyssal fauna, (7) Evolution in the North American Basin. These field projects have included sampling expeditions to abyssal regions of most of the major ocean basins, with research cruises having begun in 2002 and continuing through 2009.