Antarctic krill, Euphausia superba, comprise the foundation of the food-web in the Southern Ocean and are the target of a large fishery. Recently, the total abundance of krill in the Scotia Sea was estimated from an international echosounder and net survey (CCAMLR 2000) to be 44.3 million tons (CV 11.4%). The new biomass estimate prompted the Antarctic Treaty's Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) to revise the precautionary catch level for krill in the area from 1.5 to 4 million tons (SC-CAMLR, 2000). These survey results are based on the total echo energy attributed to krill, scaled by the Greene et al. model of krill acoustical reflectivity or target strength (TS). Presented here is a re-analysis of the CCAMLR 2000 data incorporating recent improvements in the characterization of krill TS. Results indicate that the estimated krill biomass in the Scotia Sea may be as high as 192.4 Mt (CV=11.7%), or as low as 109.4 Mt (CV=10.4%), depending solely on the expected distribution of krill orientations. As the lower krill biomass estimate is nearly 2.5 times the previous estimate, the standard krill TS model should be updated and a revision of the precautionary catch level for krill in the Scotia Sea may be warranted.