In support of the "Microbiology and Carbon Flux" component of the Palmer LTER program (D. Karl, P.I., Project S-046) a special-focus microbiology process cruise was designed and organized to focus on the trophic coupling among various microbial assemblages including heterotrophic bacteria, archaeobacteria, phytoplankton, protozoans and viruses. This cruise was termed Project SANTA CLAµS (Studies in ANTarcticA: Coupled Linkages Among micro(µ)organismS).