Quantification of intra-regional propagule movements in the Antarctic

Management of non-native species introductions is a conservation priority in the Antarctic region. However, despite the recognised importance of intra-regional propagule transfer, the majority of studies have focused on inter-regional pathways (i.e. from outside of the Antarctic region). Here we quantify the number of seeds carried by expeditioners who have visited sub-Antarctic Marion Island. We recorded 420 seeds from 225 items of clothing, with seeds found on 52% of the items and soil on 45% of them. The median number of seeds for field-based and station-based personnel was 20.5 and 3 per person, respectively. Waterproof trousers and socks, particularly those of field workers, carry the greatest number of propagules (for field workers, medians of 5 and 6.5, respectively) and therefore should be the focus of intra-regional management interventions. Amongst the seeds found entrained within clothing several were from species which are widespread aliens in the Antarctic region including Agrostis stolonifera, Poa annua and Sagina procumbens, and indigenous zoochorous species (Acaena magellanica, Uncinia compacta) were also well represented. The present data provide quantitative evidence in support of previous, largely hypothetical concerns about the risks of intra-regional propagule transfer in the Antarctic