Supplement to: Chown, Steven L; Huiskes, Ad H L; Gremmen, Niek J M; Lee, Jennifer E; Terauds, Aleks; Crosbie, Kim; Frenot, Yves; Hughes, Kevin A; Imura, Satoshi; Kiefer, K; Lebouvier, Marc; Raymond, Ben; Tsujimoto, Megumu; Ware, Chris; Van de Vijver, Bart; Bergstrom, Dana Michelle (2012): Continent-wide risk assessment for the establishment of nonindigenous species in Antarctica. Proceedings of the National Academy of Sciences, 109(13), 4938-4943, https://doi.org/10.1073/pnas.1119787109