Patterns in the distribution and abundance of sea anemones off Dumont d'Urville Station, Antarctica

Knowledge of ecological interactions is integral for informed management, especially in the rapidly changing Antarctic marine ecosystem. Nonetheless, even basic ecological relationships are unknown for most benthic species, including conspicuous predatory species such as sea anemones. The aim of this study is to understand the ecology of sea anemones in the Terre Adélie region. Using video footage collected by remote operated vehicle (ROV), we examined sea anemone distribution and abundance in relation to predator and prey abundance, presence of other taxa and habitat structure. The ROV was deployed over ten diferent transects with depths ranging from 32 to 251 m. A total of 332 sea anemones were observed across 6.6 km2 of seabed surveyed. We compared sea anemone abundance with habitat type and substrate attachment. Multivariate analysis in PRIMER was used to examine community composition. Sea anemone density was not signifcantly associated with habitat types. However, sea anemones were associated with the biogenic substrates, ascidians and bryozoans. This association suggests a potential future vulnerability for Antarctic sea anemones if bryozoan and ascidian distributions are impacted by climate change-associated ecosystem disturbances