- In Antarctica, where colonies of penguins and elephant seals aggregate, their droppings, rich in nitrogen, enrich the soil and support thriving communities of mosses, lichens and invertebrates, a new study has found.
- Ammonia released from penguin and elephant seal feces can influence an area up to 240 times the size of the animal colony, the researchers found.
- These findings can be used to create maps of Antarctica’s biodiversity hotspots, the researchers say.
In the extremely cold, seemingly barren Antarctic continent, poop powers life. Literally.
Where colonies of penguins and elephant seals aggregate, their droppings, rich in nitrogen, enrich the soil and support thriving communities of mosses, lichens and invertebrates, a new study has found. It’s not just areas immediately around the borders of the colonies that are rich in biodiversity. The influence of the animals’ excrement seems to spread more than 1,000 meters (0.62 miles) away, researchers have found.
“What we see is that the poo produced by seals and penguins partly evaporates as ammonia,” Stef Bokhorst, a researcher at Vrije Universiteit Amsterdam, Netherlands, and lead author of the study, said in a statement. “Then, the ammonia gets picked up by the wind and is blown inland, and this makes its way into the soil and provides the nitrogen that primary producers need in order to survive in this landscape.”
Bokhorst and his colleagues found this by tracing the flow of nitrogen, an element that has isotopes that can be tracked, right from colonies of Adélie penguins (Pygoscelis adeliae), chinstrap penguins (P. antarctica), gentoo penguins (P. papua) and elephant seals (Mirounga leonina) to mosses, lichens and tiny invertebrates. They trekked through the landscape, collecting samples of soil and vegetation, and set up sensors to detect airborne ammonia, a compound made of nitrogen and hydrogen. They also spent months in the lab analyzing the samples, as well as counting and identifying the invertebrates they had collected.
Their analysis showed that ammonia released from penguin and elephant seal feces could influence an area that was up to 240 times the size of the animal colony. Moreover, the nitrogen footprint, or area of influence of a colony, seemed to be linked to the number of individuals in the colony.
The ammonia in turn prompted the growth of mosses and lichens, which then supported a huge community of small creatures like springtails and mites, numbering millions per square meter. By contrast, there are only about 50,000 to 100,000 invertebrates per square meter in the grasslands of the U.S. or Europe, Bokhorst said.
These findings can be used to create maps of Antarctica’s biodiversity hotspots, the researchers say. “Now we can predict where biodiversity hotspots are, and where our losses are, based on the presence of penguin colonies and how many penguins there are in that colony,” Bokhurst told NPR.
Citation:
Bokhorst, S., Convey, P., & Aerts, R. (2019). Nitrogen Inputs by Marine Vertebrates Drive Abundance and Richness in Antarctic Terrestrial Ecosystems. Current Biology.