Penguin droppings accelerate snowmelt in Antarctica: scientists uncover the mechanism

Phosphate from guano 'fertilizes' the snow

Penguin droppings may accelerate snowmelt in some parts of Antarctica: guano contains phosphate, a nutrient that stimulates the growth of snow algae. This is reported by Gazeta.Ru citing a study by scientists from Western Washington University, published in the Journal of Geophysical Research: Biogeosciences.

What the measurements showed

The researchers worked on the western Antarctic Peninsula, studying how seabirds affect the growth of snow algae. They collected snow samples near penguin colonies and far from them, and then compared the phosphate content in snow of different colors in the laboratory. Green snow turned out to contain roughly ten times more phosphate than snow with red algae, and 70 times more than ordinary white snow.

A chain of processes

Algae multiply on the snow surface and change its color, and colored snow absorbs more solar energy than clean white snow. According to previous measurements, red algae increase sunlight absorption by about 20%, and green algae by about 40%. As a result, the snow heats up more strongly and may melt faster: penguin droppings set off a chain of processes — enrichment of the snow with nutrients, algal growth, and increased heat absorption.

What remains unclear

The researchers warn that climate warming may expand the areas suitable for snow algal growth along the Antarctic coast. At the same time, existing snowmelt projections do not yet take into account the influence of these microorganisms. How strongly seabird guano accelerates melting across the entire continent remains unclear — additional observations are needed to assess the effect. Gazeta.Ru also recalls an earlier publication about a hidden threat accelerating the melting of the Doomsday Glacier.