This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Penguin poop is fertilizing snow algae blooms along the Antarctic Peninsula, feeding dense green algae patches along the coastline, a new study shows. These expanding stretches of green snow melt faster than clean, white snow, potentially speeding up the spread of snow- and ice-free areas of Antarctica.
As temperatures rise across Antarctica, snow algae habitats are expanding along the coasts, darkening the surface and leading to even more warming and snowmelt. By tracking their poop across the snow, penguins are inadvertently supplying the algae with vital nutrients that keep the blooms green and make the melting effect even stronger. "The link between wildlife, nutrients, and snow algae is a critical missing component in projections of expansion of ice-free areas in Antarctica," said Alia Khan, a cryosphere biogeochemist at the University of Colorado Boulder and senior author of the study who began this research while at Western Washington University.
"Without accounting for these biological darkening effects, we are likely underestimating how rapidly coastal snowpacks are melting and how fast ice-free terrain will expand across Antarctica." The study appears in Journal of Geophysical Research: Biogeosciences. Khan and her team focused on color-changing Antarctic snow algae, which grow densely enough in some areas to make the snow itself look red or green. When nutrients are abundant, the algae can stay active, packing their cells with green pigments like chlorophyll to ramp up photosynthesis as the algae race to grow as much as possible during the short Antarctic summer.
When nutrients are scarce or conditions are harsh, the algae hunker down, producing sunscreen-like red pigments to protect themselves from the sun while putting growth on hold. Red snow absorbs about 20% more energy from sunlight than clean, white snow. This extra energy heats up the snow, leading to more snowmelt.
Where nutrients fuel more green pigment and more algae cells overall, green snow absorbs 40% more energy than clean snow—twice the increase seen in red snow—amping up the melt rate even further. Traveling by boat across the rough seas of the Drake Passage, the team gathered samples of both red and green snow algae along the coast of the West Antarctic Peninsula, covering five degrees of latitude and areas with and without penguin colonies. Taking samples near penguin colonies is not a glamorous job, requiring the team to get close to smelly bird droppings to gather algae-tinted snow in bags with ceramic spoons.
"[Penguin] poop can visually look similar to the red snow algae," Khan said. "It's very stinky working near penguins. They're just waddling around in their poop and tracking it all over the snow." Fortunately, the difference between poop, known as guano, and snow algae is clearer in the lab.
Extract — continue reading at the source.
