Key Points
- Using gas chromatography, researchers confirmed the presence of polychlorinated biphenyls (PCBs) in chinstrap penguins and krill from Deception Island, Antarctica. Adult penguins showed the highest PCB accumulation in liver and muscle tissues, while chick brains had the highest concentrations, highlighting significant bioaccumulation even in remote ecosystems.
- Despite Antarctica's isolation, persistent organic pollutants (POPs), including PCBs, were detected—likely transported via long-range atmospheric and oceanic currents. The findings build on decades of evidence that even the most remote regions are impacted by global contamination.
- Due to their ecological characteristics—top trophic status, longevity, and diet—Antarctic penguins serve as strong indicators of environmental contamination. The study found that “others-non-dioxin-like” PCBs were most prevalent, particularly in liver tissues, underlining the need for continued monitoring and regulatory reassessment.
In order to acquire data regarding the presence of polychlorinated biphenyls (PCBs) in Antarctica, a research team made up of members from the University of Murcia (Murcia, Spain), the Carlos III Health Institute (Madrid, Spain), and the University of Siena (Siena, Italy) evaluated the concentration of PCBs in chinstrap penguins (Pygoscelis antarctica) and krill (Euphausia superba) from Deception Island (South Shetland Islands, Antarctica). The relative toxic potential of toxic mono-ortho PCBs congeners in 34 samples of penguin tissues (adult liver and chick brain samples) was analyzed with gas chromatography (GC) and assessed using the Toxic Equivalency Factor (TEF) approach, as well as their Toxic Equivalent (TEQ) concentrations calculated. A paper based on this research was published in Toxics (1).
Long regarded as one of the last pristine regions on Earth, Antarctica has several natural barriers, such as water masses and atmospheric currents, that were thought to protect it from pollution. However, the viewpoint that this continent was totally unpolluted began to be challenged in the 1960s. In 1964, the pesticide dichlorodiphenyltrichloroethane and some of its related compounds were identified in tissue samples of Adelie penguins and a Crabeater seal. This was notable because pesticides had never been used on the continent (2).
Since then, many other persistent organic pollutants (POPs) have been identified in Antarctic samples, which shows that even what was considered one of the most isolated places on the planet is not safe from the global effects of contamination (3–5). Furthermore, POPs might also be transported to these regions through long-range atmospheric transport and oceanic transport. However, the number of transported POPs seems much lower, to a significantly lesser extent, through the involvement of pelagic organisms and migratory birds (6).
Antarctic penguins are potential agents in the monitoring of global environmental pollution, as they possess many characteristics which make them effective sentinels in other regions. Being top predators and long-lived species, they are subject to biomagnification and bioaccumulation. Furthermore, they have wide distribution ranges with ample populations and an adequate body size which facilitates the sampling process. In addition, they can integrate contamination over both time and space (7). In addition, various penguin species typically feed on krill (as well as fish and squid), so the monitoring of their diet can also provide researchers with insights into the bioaccumulation of contaminants (8).
A total of 34 penguin tissue samples were collected during the Antarctic campaigns from 2007 to 2010 and preserved frozen at −20 °C in individual polyethylene bags until they were analyzed with GC. The team studied liver, kidney, muscle, heart, and brain tissue from four adult and six chick specimens. Due to the low amount of chick samples, some tissues were homogenized to obtain 5 g pools for the analyses. In addition, samples of krill were analyzed and obtained from the stomach contents of the penguin specimens (1).
The researchers state in their paper that their results confirm the presence of PCBs in chinstrap penguins and krill from Deception Island, with the adult of the species primarily accumulating PCBs in the liver and muscle, and the chicks exhibiting the highest levels in their brains, and the PCB levels in the krill were lower than those found in krill from King George Island (another island in the Antarctic [9]) and the Ross Sea (a deep bay of the Southern Ocean in Antarctica, and the southernmost sea on Earth [10]).
