1 °C warming increases spatial competition frequency and complexity in Antarctic marine macrofauna

• Published in: Communications Biology
• Main Authors: Barnes, David K. A., Ashton, Gail V., Morley, Simon A., Peck, Lloyd S.
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2021
• Subjects: Article; Antarctic; Southern Ocean; Antarc*; Antarctica
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886862/; http://www.ncbi.nlm.nih.gov/pubmed/33594210; https://doi.org/10.1038/s42003-021-01742-w

Environmental conditions of the Southern Ocean around Antarctica have varied little for >5 million years but are now changing. Here, we investigated how warming affects competition for space. Little considered in the polar regions, this is a critical component of biodiversity response. Change in competition in response to environment forcing might be detectable earlier than individual species presence/absence or performance measures (e.g. growth). Examination of fauna on artificial substrata in Antarctica’s shallows at ambient or warmed temperature found that, mid-century predicted 1°C warming (throughout the year or just summer-only), increased the probability of individuals encountering spatial competition, as well as density and complexity of such interactions. 2°C, late century predicted warming, increased variance in the probability and density of competition, but overall, competition did not significantly differ from ambient (control) levels. In summary only 1°C warming increased probability, density and complexity of spatial competition, which seems to be summer-only driven.