Hidden Life on Ice: Antarctic Algal Ecosystem Unveiled, Accelerating Glacial Melt

Dr Matthew Davey led the expedition to Robert Island, Antarctica

(IN BRIEF) A team of scientists, led by Dr. Matthew Davey of SAMS, has discovered an expansive ecosystem on the Robert Island ice cap in Antarctica, dominated by photosynthetic algae. This ecosystem, which covers up to 20% of the mapped area, potentially represents nearly 6% of the continent’s known photosynthetic life. Using advanced microscopy and DNA analysis, the researchers identified a variety of snow and glacier algae, many of which appear to be unique to Antarctica. The study also revealed that the algae’s red and purple pigments significantly contribute to the ice cap’s melting by absorbing solar energy, with algal blooms potentially causing up to 2.4% surface melt on some days. Funded by UKRI NERC and supported by the RRS Sir David Attenborough on its maiden Antarctic voyage, the expedition brought together experts from multiple leading institutions. The findings, published in Nature Communications, promise to enhance climate models by providing deeper insights into the role of algae in glacial melt and Antarctic biodiversity.

(PRESS RELEASE) OBAN, 24-Mar-2025 — /EuropaWire/ — Scientists have uncovered a remarkable and extensive ecosystem thriving on an ice cap in Antarctica, a discovery that could reshape our understanding of life in extreme environments. This vibrant ecosystem is dominated by photosynthetic algae, which not only harbor the potential to include species new to science but also contribute to the accelerated melting of the ice through their dark, heat-absorbing pigments.

The breakthrough came from a dedicated research team led by Dr. Matthew Davey of SAMS, in partnership with UHI. Over a two-month expedition, the team meticulously studied the algal and plant communities inhabiting the remote Robert Island ice cap, located at the northern tip of the Antarctic Peninsula. Their findings, published in Nature Communications, revealed that photosynthetic algae cover up to 20% of the mapped ice area – a striking figure that equates to nearly 6% of all known photosynthetic life in Antarctica.

Employing advanced microscopy and DNA analysis, the researchers identified a diverse range of species, including several varieties of snow and glacier algae. Many of these microorganisms appear to be endemic to Antarctica, underscoring the continent’s hidden biological richness. Intriguingly, the study also demonstrated that the vivid red and purple pigments produced by these algae act as powerful solar absorbers, facilitating localized melting. Satellite imagery and on-site measurements indicated that on certain days, these algal blooms could contribute as much as 2.4% of the ice cap’s surface melt.

Dr. Alex Thomson, the study’s lead author from SAMS, remarked, “This is the first time these ice-cap communities in Antarctica have been mapped and studied in detail. Discovering such a diverse and extensive array of life on the ice is akin to finding forests in a barren desert.” The expedition, which received funding from UKRI NERC and was supported on its maiden Antarctic voyage by the RRS Sir David Attenborough in late 2022, brought together experts 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 survey focused on one location, the researchers suspect that similar algal ecosystems might be widespread across the Antarctic ice sheets. Dr. Andrew Gray of the Norwegian Institute for Nature Research added, “Now that we know there are large glacial algal communities in Antarctica, our next goal is to determine their full extent, understand how they enhance Antarctica’s biodiversity, and quantify their role in glacial melt processes.” The team hopes that these insights will ultimately refine climate models by deepening our understanding of the melting dynamics in this critical region.

Live samples of the snow and ice algae are now under examination by co-author Naomi Thomas at SAMS’ Culture Collection of Algae and Protozoa (CCAP) to ascertain whether new species are present and to further elucidate their unique physiological adaptations to the extreme Antarctic environment.

The complete study can be accessed in Nature Communications: 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). https://doi.org/10.1038/s41467-025-57725-6

Media Contact:

Euan Paterson
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Euan.Paterson@sams.ac.uk
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SOURCE: Scottish Association for Marine Science