Subantarctic hitchhikers: expeditioners as vectors for the introduction of alien organisms

Equipment identified as high risk vectors included equipment cases, day packs and the cuffs and Velcro® closures of outer clothing. Many expeditioners had travelled overseas in the six months prior to embarkation and had recently visited alpine or high latitude environments. A total of 981 propagules and five moss shoots were collected from clothing and equipment of 64 expeditioners. Ninety species from 15 families were identified, most of which were grass caryopses. Asteraceae and Poaceae contained the greatest diversity of propagules. In germination trials a total of 163 plants (24 species) were identified. A risk assessment was prepared to determine issues posing a threat to subantarctic quarantine and assess possible logistic and management changes to minimise these threats. Many changes suggested have since been implemented resulting in a reduction in the number of alien species recorded in subsequent inspections.