Research staff of the Spanish Institute of Oceanography (IEO, CSIC) in collaboration with colleagues from the universities of Santiago de Compostela, Barcelona and Oviedo, in the north of Spainhave documented the presence and origin of various contaminants in the soils of penguin colonies collected on Livingston and Deception Islands, northwest of the Antarctic Peninsula.
The results of the study, published in the journal Geoderma, showed a significant enrichment in nutrients, metals such as copper (Cu) and zinc (Zn) and organic compounds such as polycyclic aromatic hydrocarbons (PAHs).
The scientific team concludes that penguins act as biological vectors capable of transferring contaminants from the marine environment to Antarctic terrestrial ecosystems.
Likewise, they identify multiple origins for these contaminants: the biological activity of the birds themselves, the influence of volcanic activity on Deception Island and, to a lesser extent, human activity linked to scientific bases and tourism.
In some points the levels of these metals exceeded international reference values.
Although the soils seem to withstand them without immediate effects, “if they leak into streams or coastal waters, they could affect extremely sensitive aquatic organisms, such as plankton, the basis of the marine food chain,” Begoña Pérez, first author of the study and researcher at the Vigo Oceanographic Center (Galicia) of the IEO-CSIC, says in a statement.
The study also detected the presence of polycyclic aromatic hydrocarbons (PAHs), polluting compounds that in other parts of the world are usually associated with the burning of fossil fuels or oil. However, in Antarctica the situation is different: on Deception Island the PAHs come, to a large extent, from the intense volcanic activity recorded in recent centuries, while in Livingston they are more linked to bird guano.
“Although the concentrations found do not reach alarm levels and are between 50 and 1,000 times lower than those that generate toxic effects on marine organisms, the research breaks with the idea that Antarctica is an unaltered environment,” says Begoña Pérez.
Furthermore, increased rainfall and thawing of permafrost due to climate change could mobilize metals and pollutants accumulated in soils and guano, moving them to lakes and coastal areas, where they can be harmful to sensitive species and alter polar food chains.
“Penguins are essential for the balance of life in Antarctica, but they can also become a natural source of pollution in an extremely fragile environment,” the teacher points out XL Oteroprofessor at the University of Santiago and researcher at the Center for Interdisciplinary Research in Environmental Technologies of the USC (CRETUS) and coordinator of the study.
Cristina García-Hernández and Jesús Ruiz Fernández, professors at the Department of Geography of the University of Oviedo, who carried out the field work to obtain the soil samples that have made it possible to document the distribution of contaminants, highlight the importance of a finding that underlines “the extreme fragility of Antarctic ecosystems in the face of global climate change, since melting ice could mobilize these accumulated contaminants into the waters.” coastal areas, which would directly affect the base of the marine food chain.”