Maritime traffic connects Antarctica’s fragile coasts to global ecosystems


Vessel movements related to fishing, tourism, research and supply expose the Antarctic continent to human impacts. Until now, only rough estimates or industry-specific information have been available to inform evidence-based policies aimed at mitigating the introduction of non-native marine species. The Southern Ocean of Antarctica is home to unique biota and represents the only global marine region without any known biological invasions. However, climate change is removing physiological barriers to potential invasive non-native species and increased vessel activity is increasing propagule pressure. The successful conservation of iconic Antarctic species and environments relies on addressing climate change and direct and localized human impact. We have identified high risk areas for introduced species and provided essential data that will underpin better evidence-based management in the region.


Antarctica, a remote wilderness and long considered pristine, is increasingly exposed to the negative effects of human activity transported by ships, and in particular the introduction of invasive species. Here we provide a comprehensive quantitative analysis of vessel movements in Antarctic waters and a spatially explicit assessment of the risk of introduction of marine non-native species to all Antarctic waters. We show that ships pass through Antarctica’s isolating natural barriers, connecting it directly via an extensive network of maritime activity to all parts of the world, especially South Atlantic and European ports. Ship visits are more than seven times higher in the Antarctic Peninsula (particularly east of Anvers Island) and the South Shetland Islands than elsewhere around Antarctica, together accounting for 88% of visits in the Southern Ocean ecoregions. Contrary to expectations, we show that while the five recognized “Gateway Cities to Antarctica” are important last ports of call, especially for research and tourist vessels, 53 additional ports have had ships leaving directly for Antarctica from 2014 to 2018. We identify ports outside Antarctica. where biosecurity interventions could be implemented most effectively and the most vulnerable Antarctic sites where monitoring programs for high-risk invaders should be established.


    • Accepted November 1, 2021.
  • Author contributions: research designed by AHM, LSP and DCA; AHM has done research; AHM analyzed the data; and AHM, LSP and DCA authored the article.

  • The authors declare no competing interests.

  • This article is a direct PNAS submission.

  • This article contains additional information online at

Data availability

The data supporting the conclusions of this study are available from LLI, but restrictions apply. The data was used under license for this study and is therefore not publicly available. Processed and summarized data may be made available from the authors upon reasonable request and with permission from LLI. The code used to analyze the data for this study is kept in a GitHub repository; access and code are available on request.

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