Penguin waste on the western Antarctic Peninsula speeds up snowmelt by turning white surfaces a vibrant shade of green.
Phosphate Fertilizes Snow Algae
Researchers from the University of Colorado Boulder discovered that phosphate inside guano acts like a fertilizer for microscopic snow algae. When nutrient availability is limited, algae produce a red pigment to protect themselves from sunlight while slowing their growth.
“Kotoran penguin bekerja sebagai pupuk yang memicu mekarnya alga salju hijau yang lebat,” said Alia Khan, a cryospheric biogeochemist at the University of Colorado Boulder, in a release from the American Geophysical Union reported by AFU.id.
Sampling Across Drake Passage
During the 2024–2025 summer season, the scientific team sailed across the Drake Passage to gather 111 snow samples from nine coastal locations. These sites stretched across roughly five degrees of latitude, covering areas both with and without penguin colonies. Researchers used ceramic spoons to collect the material near guano deposits so large they were visible in satellite imagery.
Working near the colonies presented distinct physical challenges for the field team. Khan told Harapan Rakyat that the environment smelled intensely because the birds walk directly over their waste and spread it across the surrounding snowpack.
Contrasting Solar Energy Absorption
Laboratory analysis divided the collected samples into green snow, red snow, and clean snow. Green snow samples contained a median phosphate concentration of 114 micromoles per liter. That level measured roughly 10 times higher than red snow and about 70 times higher than clean snow.
Darker surfaces absorb more solar heat and reflect less light than pristine white snow. Clean snow reflects most sunlight, whereas red snow absorbs about 20 percent more energy. Green snow absorbs approximately 40 percent more energy than clean snow, doubling the heat retention seen in red snow areas, according to Media Indonesia.
Green snow on the western Antarctic Peninsula can absorb about 40 percent more solar energy than clean white snow. The absorbed energy subsequently increases surface heat and increases the chances of snow melting.
Researchers Need More Data to Link Guano to Melting
While a study published on Oct. 7 in the Journal of Geophysical Research: Biogeosciences established that guano nutrients support snow algae growth along the peninsula, researchers have not yet directly measured total melt attributable solely to the waste.
Khan said that the direct link between guano and the multi-stage life cycle of snow algae still requires additional field data before it can be integrated into broader melting projections, CNN Indonesia reported. On the other hand, a 2020 study in Nature Communications said that green algae in that region covered about 1.9 square kilometers with a minimum biomass of 1,300 tons, and is viewed as an important carbon sink in Antarctica.
Did you know? In 2011, a research team found data indicating that melting caused by algae on the Antarctic Peninsula was comparable to melting caused by dust in the snow regions of the Rocky Mountains in the United States. In 2021, Khan published research showing that algal-driven snowmelt on the Antarctic Peninsula matched the melting impact caused by windblown dust on snowpack in the Rocky Mountains of the United States.
Common Questions About Antarctic Snow Algae
How do researchers collect samples near penguin colonies?
Scientists sail across the Drake Passage to the western peninsula and collect samples using ceramic spoons from locations spanning five degrees of latitude.
Why does green snow melt faster than red snow?
Green snow contains higher levels of chlorophyll driven by abundant guano phosphates, allowing it to absorb about 40 percent more solar energy compared to clean snow.
Are guano nutrients the sole cause of green snow blooms?
Researchers emphasize that further study is needed to prove guano is the exclusive trigger for green algae blooms and to incorporate these biological darkening effects into predictive melting models.
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