Punta Arenas, March 1, 2023.- Nearly 60% of the world population of chinstrap penguins (Pygoscelis antarcticus) reproduce in the Antarctic Peninsula and its northernmost maritime islands (South Shetland Islands and Orkney Islands), an emblematic species of the White Continent that has experienced a dramatic decline of about 30% of its population in just three generations.
This categorical data is part of a study carried out by the researcher of the Chilean Antarctic Institute (INACH) and the Millennium Institute BASE, PhD. Lucas Krüger and recently published by the specialized magazine Diversity, where it also reveals that in a period of 40 to 50 years , 62% of the colonies (groups of penguins) suffered declines greater than 50%.
He also warns that these conditions already mentioned (30% decrease in three generations), would place it in the category of vulnerability to extinction, according to the criteria used by the International Union for Conservation of Nature.
To carry out this elaborate analysis, standardized records and counts of penguins in the Antarctic peninsula for six decades (since 1960) were studied. Likewise, since 2017, an international group of scientists has been dedicated to compiling all the existing information and making it available on a free access platform that is updated every year and that is on the website: https://www. .penguinmap.com/
Possible causes of the decrease
The dramatic levels of decline in these populations are added to the fact that the suspected causes are probably not reversible in the short or medium term.
For the rest, there is some controversy in the scientific community regarding the factors that may be leading to the decline in chinstrap penguin populations. Recent evidence suggests that “the most likely reason is the spatiotemporal change in krill abundance in the northern part of the Antarctic Peninsula due to warming and winter sea ice retreat. It is also probable that other factors act together, mainly associated with climate change, affecting the survival of the nestlings in the breeding colonies and of the juveniles in their first year of life”, declares Lucas Krüger.
Other relevant hypotheses are related to the recovery of whale populations, which are also important consumers of Antarctic krill, in addition to the increase in krill fisheries in Antarctica. “These factors could have contributed to population dynamics, although evidence suggests this could only occur when there are years of low krill abundance”, he adds.
The INACH researcher explains that the models that have projected changes in the ecosystem of the Antarctic Peninsula in the face of different environmental scenarios indicate that current decline trends should be followed up.
“But at the same time, it is complex and difficult with the current knowledge that is available, to give an accurate estimate of the future of the species. For now, we can say that in the recent past the populations have declined considerably, and could be put at risk if the trends continue. Better understanding how this species relates to rapid environmental changes in the Antarctic Peninsula is critical,” he says.
The Antarctic Peninsula is one of the areas of the planet that has suffered the most rapidly from the effects of global warming in recent years and these changes are of great concern to scientists around the world.
The INACH is a technical body of the Ministry of Foreign Affairs with full autonomy in everything related to Antarctic matters of a scientific, technological and dissemination nature. INACH complies with the National Antarctic Policy by encouraging the development of excellent research, effectively participating in the Antarctic Treaty System and related forums, strengthening Magallanes as the gateway to the White Continent and carrying out actions to disseminate Antarctic knowledge among citizens. .
Text and images: Chilean Antarctic Institute (INACH)