Climate change is predicted to have substantial impacts on benthic communities at high latitudes through changes in ocean physical and chemical properties, retreat of sea ice, changing disturbance regimes and resulting impacts on habitats. In this study we analyse benthic photographs taken over three voyages in the region of Casey Station in East Antarctica over 18 years from 1996 to 2014. We describe algal and invertebrate communities, their functional traits, and their relationships with sea ice cover and habitat complexity.
We find that low sea ice cover and habitat complexity correlate with higher algal cover and diversity at the expense of benthic invertebrates. Sea ice cover and habitat complexity vary in their impact on different invertebrate classes however, with some invertebrates having highest abundance at intermediate sea ice levels, and a small number of invertebrate species benefitting from low habitat complexity. Low sea ice cover correlates with reduced functional richness, evenness and dispersion of benthic communities, and reduction in some ecological services such as bioturbation.
This research highlights the importance of preserving and maximizing the scientific use of historic data sets, and the value of photogrammetry in understanding ecological relationships in marine benthic communities.