Researchers have uncovered a vast ecosystem on an Antarctica ice cap. The communities, largely made up of photosynthetic algae, are likely to host new species to science, and have been shown to add to melting of the ice caps in the region.
Communities of colourful algae cover vast areas of the Robert Island ice cap. Photo: Andrew Gray/NINA
A research team led by Dr Matthew Davey at the Scottish Association for Marine Science (SAMS) spent two months studying algal and plant communities on the Robert Island ice cap, a remote part of the northern tip of the Antarctic Peninsula.
Microorganisms unique to Antarctica
Their survey, published in Nature Communications, found that photosynthetic algae grew across up to 20% of the ice in the area mapped - an area equal to nearly 6% of known photosynthetic-life in Antarctica.
Using microscopy and DNA analysis, the team identified a diverse array of species, including snow and glacier algae. Many of these microorganisms appear to be unique to Antarctica, highlighting the continent’s biological richness even in its harshest environments.
Communities of microscopic algae living on the Robert Island ice cap. The colourful cells absorb solar radiation, transferring that energy to heat, and melting the surrounding ice. Photo: Alex Thomson, Andrew Gray
Algae add to the melting of the ice caps
The survey also highlighted the contribution of the algae to surface melting on the ice. Vibrant red and purple pigments, produced by the algae, act as solar absorbers, transferring heat and melting the surrounding snow and ice. Satellite imagery and ground-based measurements by the team showed that these algal blooms could contribute to as much as 2.4% of the ice cap’s surface melt on certain days.
“This is the first time these ice-cap communities in Antarctica have been mapped and studied in detail,” said Dr. Alex Thomson, the study’s lead author from SAMS. “We know that ice-free areas in Antarctica serve as oases for life, but discovering this extent and diversity of life on the ice itself was like finding forests in a desert.”
The expedition, funded by UKRI NERC and supported by the RRS Sir David Attenborough on its maiden Antarctic voyage in late 2022, included scientists and support from the University of Edinburgh, the Norwegian Institute for Nature Research, the University of Cambridge, the British Antarctic Survey, and Chile’s Instituto Antártico Chileno (INACH).
While the study focused on a single location, researchers suspect that similar algal ecosystems may exist elsewhere on the continent’s ice sheets.
“Now that we know there are large glacial algal communities in Antarctica, the goal is to see how extensive they are, how they contribute to Antarctica’s wider biodiversity and what role they play in influencing glacial melt rates there” said Dr Andrew Gray, a researcher on the project at the Norwegian Institute for Nature Research.
Beyond offering fresh insights into Antarctic biodiversity, the authors hope that the findings could improve climate models by refining our understanding of melting processes in the region.
Read article: Thomson, A.I., Gray, A., Colesie, C. et al. Surface darkening by abundant and diverse algae on an Antarctic ice cap. Nature Commun 16, 2647 (2025).
Contact: Andrew Gray
Related: Antarctic-wide survey of plant life to aid conservation efforts
Scientists worked on foot to survey and sample the ice cap on Robert Island. Photo: Alex Thomson