How penguin droppings could be changing Antarctica’s snowy landscape, study finds

Antarctica’s snow-covered landscape is increasingly showing patches of green and red algae. A study published in the Journal of Geophysical Research: Biogeosciences suggests that nutrients deposited by penguins and other seabirds may help these microscopic organisms grow, potentially accelerating local snowmelt.

The findings highlight how wildlife can influence snow conditions in a region already affected by climate change. Although algae do not drive Antarctic melting on their own, their growth can alter the properties of the snow surface and affect how much sunlight it absorbs.

How penguin droppings support algae growth

Penguins feed on fish and other marine animals, and their droppings carry nutrients from the ocean onto land and snow. These nutrients can act as a natural fertiliser for snow-dwelling algae.

Researchers collected samples of snow containing red and green algae from different locations along the western Antarctic Peninsula. They examined the samples’ colour, nutrient content and abundance of algae to investigate the relationship between wildlife-derived nutrients and algal growth.

The study found significantly higher phosphate concentrations in snow samples containing green algae than in samples containing red algae. Phosphate is an important nutrient for biological growth, and its availability may influence the abundance and colour of snow algae.

Penguins are not the only source of these nutrients. Other seabirds, including skuas, also deposit droppings that transfer nutrients from marine ecosystems to Antarctic land and snow.

Coloured snow absorbs more sunlight

Clean white snow reflects much of the sunlight that reaches it. When algae spread across the surface, their pigments make the snow darker or more colourful, reducing its reflectivity and allowing it to absorb more solar energy.

According to the findings, snow covered with red algae can absorb about 20 per cent more solar energy than clean white snow. Snow covered with green algae can absorb about 40 per cent more.

The additional energy may increase melting in areas where algae are present. However, the figures describe differences in solar energy absorption, not the percentage increase in snowmelt itself.

The researchers suggest that the effects of snow algae should be considered when scientists model changes in Antarctic snow and ice. If these biological processes are overlooked, estimates of future melting and the extent of ice-free land along the coast could be less accurate.

Climate change remains the bigger driver

The relationship between seabirds, algae and snowmelt is one part of a much larger environmental system. Rising temperatures and climate change remain major drivers of ice loss in Antarctica, and the study does not establish penguin droppings as a primary cause of the continent’s melting.

The extent of the algae’s future influence is also uncertain. As environmental conditions change, some penguin populations could expand into new areas, potentially transporting nutrients to places where snow algae are less established. Whether this would significantly change melting patterns will require further research.

The findings show that Antarctic snow is shaped not only by temperature and weather but also by biological activity. Understanding these interactions could help scientists develop more complete assessments of how the continent’s snow-covered areas may respond to a warming climate.