Assessing the vulnerability of Antarctic marine ecosystems to invasive non-native species
Invasive non-native species are a major threat to global biodiversity. For at least 15 million years coastal Antarctica has been poorly connected to nearby temperate ecosystems due to physical and physiological barriers. Yet, Antarctica is experiencing significant environmental change and becoming i...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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University of Cambridge
2022
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| Online Access: | https://www.repository.cam.ac.uk/handle/1810/334093 https://doi.org/10.17863/CAM.81503 |
| Summary: | Invasive non-native species are a major threat to global biodiversity. For at least 15 million years coastal Antarctica has been poorly connected to nearby temperate ecosystems due to physical and physiological barriers. Yet, Antarctica is experiencing significant environmental change and becoming increasingly exposed to ship-borne human activity that crosses the physical barriers. These factors may facilitate the establishment of non-native marine species. This doctoral research adds insight into the risk of non-native marine species being transported to Antarctica via ships’ hulls and internal seawater systems, with particular focus on pathways of introduction and species found within those pathways. To begin my research, I assessed the current knowledge of non-native marine species in the Antarctic region: the physical and physiological factors that resist establishment of non-native marine species; changes to resistance under climate change; the role of legislation in limiting marine introductions; and the effect of increasing human activity on vectors and pathways of introduction. Evidence of non-native marine species was limited: up to 2019 just four marine non-native and one cryptogenic species that were likely introduced anthropogenically had been reported free-living in Antarctica or in the sub-Antarctica islands, but no established populations have been reported. An additional six species had been observed in pathways to Antarctica that are potentially at risk of becoming invasive. I estimated there may be approximately 180 vessels and 500+ voyages in Antarctic waters annually. However, these estimates are necessarily speculative because relevant data are not recorded comprehensively. In response to the scarcity of data on ship movements into the Southern Ocean, I obtained data on ship activity in the Southern Ocean from 2014-2018 inclusive and developed a ship traffic network for Antarctic-going vessels. I analysed the ship movements and conducted a spatially-explicit assessment of introduction risk ... |
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