2023-04-21 12:45:09
Penguins play a key role in recycling iron in Antarctic waters, with chinstrap penguins contributing 521 tonnes of iron a year to the Southern Ocean. This is indicated by the results of a recent study, in which it has also been verified what exactly that role is.
The research has been led by specialists from the Higher Council for Scientific Research (CSIC) of Spain.
Those 521 tons per year of recycled iron contributed to Antarctic surface waters arrive there through guano (substrate resulting from the accumulation of faeces). For the estimation, only chinstrap penguin populations (of the Pygoscelis antarcticus species) have been taken into account.
Traces of metals such as iron are highly relevant to the ecological functioning of the Antarctic Ocean, since it promotes the growth of phytoplankton and the absorption of carbon dioxide from the atmosphere. That is why, in recent years, scientists have worked hard to understand the processes that regulate the amount and distribution of this metal. Until now, studies have shown that other organisms, such as krill or whales, play a crucial role in the biogeochemical cycles of iron, but this research is pioneering in addressing and accrediting the influence that penguins also have on the regeneration of this metal.
“The results of the study not only contribute to a better understanding of the biogeochemical cycle of iron in the Southern Ocean, but also highlight the fundamental role that penguin populations play in it, influencing its environmental concentrations and its ecological functioning,” explains Antonio Tovar-Sánchez, a CSIC researcher at the Institute of Marine Sciences of Andalusia (ICMAN) and principal investigator of the PiMetAn project in the XXXIV Antarctic Campaign.
Penguins play an essential role in the regeneration of iron in the Southern Ocean. (Photo: Michael Van Woert/NOAA/NESDIS)
The researchers also point out that 40 years ago the iron intake figures could be twice the current ones, since, according to recent studies, penguin populations have decreased by around 50% since then. “This decline would have a direct impact on the rates of primary production and carbon sequestration,” says Oleg Belyaev, a CSIC researcher at ICMAN and lead author of the paper.
The study focused on the Collado Vapor chinstrap penguin colony located to the west of Deception Island. The methodology involved three phases: first, guano samples were collected using a collection system that allowed fresh guano to be obtained without interference with the soil for its subsequent chemical characterization. In addition, a census of the penguin colony was carried out through drone images and the use of deep learning software (an artificial intelligence technique), with the aim of estimating the number of specimens of this species. Lastly, coastal water samples were collected using Awa technology, an automatic water collection system operated by drones that made it possible to reach areas that were inaccessible from boats.
This work, developed by four researchers from ICMAN and a researcher from the University of Cádiz in Spain, is the result of the participation of the PiMetAn project in the XXXIV Antarctic Campaign. The team was at the Gabriel de Castilla Spanish Antarctic Base on Deception Island from January 23 to February 26, 2021.
The study is titled “The contribution of penguin guano to the Southern Ocean iron pool”. And it has been published in the academic journal Nature Communications. (Source: CSIC)
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