Penguin Guano Accelerates Melting of Antarctic Snow

A recent study published in the Journal of Geophysical Research Biogeosciences indicates that penguin guano accelerates the melting of Antarctic snow. The research analyzed 111 snow samples collected from nine coastal sites along the West Antarctic Peninsula during the 2024–2025 austral summer, focusing on the relationship between dissolved nutrients and algal cell density, pigment concentration, and pigment composition across different snow types.

The findings show that in green snow, median phosphate (PO₄³⁻) concentrations were tenfold higher (114 μM) compared to red snow (11.4 μM) and approximately 70-fold higher than clean snow (1.54 μM). High-phosphate samples, primarily composed of green snow, exhibited greater cell densities and per-cell pigment concentrations, indicating enhanced biomass and pigment accumulation under phosphate-rich conditions. This suggests that green snow is a bloom state closely associated with elevated phosphate availability.

Additionally, green snow was characterized by lower ratios of nitrogen to phosphate and increased photoprotective carotenoids compared to red snow. This indicates that dense green blooms rapidly utilize bioavailable nitrogen relative to excess phosphate, creating a distinct nutrient signature influenced by wildlife. The study found a positive correlation between phosphate concentrations and wildlife influence (Spearman's r = 0.54, p < 0.001), highlighting ornithogenic inputs as a significant phosphorus source. Overall, these results link phosphate availability to snow algal biomass and pigment composition, suggesting that wildlife-mediated nutrient inputs may intensify algal-driven surface darkening, further contributing to snow melting.