IUCN warns: Climate change threatens emperor penguins, fur seals and elephant seals in the Southern Ocean

Antarctica and the adjacent subantarctic regions are no longer stable ecosystems. Climate change is causing sea ice to shrink, ocean temperatures to rise and food webs to falter—with direct consequences for the wildlife of the Southern Ocean. New IUCN assessments make it clear that even species adapted to extreme conditions, such as penguins and seals, are coming under increasing pressure.

In a press release published in April 2026, the IUCN announced that three iconic species of the Antarctic and subantarctic region had each been moved significantly into higher threat categories: the emperor penguin, the Antarctic fur seal and the southern elephant seal.

Reclassifications at a glance:

• Emperor penguin
  previously: Near Threatened (NT) – potentially threatened
  now: Endangered (EN) – highly threatened
• Antarctic fur seal
  previously: Least Concern (LC) – not threatened
  now: Endangered (EN) – highly threatened
• Southern elephant seal
  previously: Least Concern (LC) – not threatened
  now: Vulnerable (VU) – threatened

Although these changes have already been officially confirmed scientifically, they will probably only become visible with the next global database update in the IUCN Red List, likely later in 2026.

A shared cause: an ecosystem is losing its balance

Although these are different animal groups—one bird and two marine mammals—they share one important similarity: they are closely adapted to the extreme conditions of the Southern Ocean. Their survival depends on stable environmental conditions—on sea ice as much as on functioning food webs.

It is precisely these foundations that are currently changing at high speed. Climate change is simultaneously affecting several key processes and upsetting the fragile balance of this ecosystem.

Emperor penguin: habitat is collapsing

Penguins are now among the most threatened groups of birds on Earth; the African penguin (Spheniscus demersus), for example, was already classified as Critically Endangered in 2024 because its food supply is shrinking due to climate-related changes.

The emperor penguin (Aptenodytes forsteri) is completely dependent on Antarctic sea ice. Its habitat includes the coastal areas of Antarctica as well as the adjoining sea-ice zones of the Southern Ocean. For breeding and moulting, it depends on so-called “fast ice”—stable ice surfaces connected to the coast or the seabed that must persist for months. These ice surfaces serve not only as breeding grounds, but also as living space for large colonies during sensitive life stages.

Yet this habitat is coming under increasing pressure. Since 2016, Antarctica has repeatedly recorded record lows in sea ice. At the same time, the ice surfaces are breaking up prematurely more often, causing breeding colonies to be destroyed before the chicks are able to swim.

These changes are not without consequences. Satellite data already indicate a population decline of around 10% between 2009 and 2018 (more than 20,000 adult animals)—a severe loss for a long-lived species with a comparatively low reproductive rate. Model calculations suggest that populations could halve by the 2080s unless greenhouse gas emissions are reduced.

Emperor penguins are not just losing individual animals; far more serious is the fact that the conditions to which the species is evolutionarily specialized are changing fundamentally, meaning that its entire habitat is gradually disappearing.

Antarctic fur seal: food is becoming scarce

In the Antarctic fur seal (Arctocephalus gazella), a different but closely climate-linked mechanism is apparent. The species lives mainly on subantarctic islands such as South Georgia, the South Sandwich Islands or the Kerguelen Islands, where it forms dense colonies along rocky coasts. From there, it uses the cold, productive waters of the Southern Ocean as its feeding grounds. Its habitat is divided in two: land areas serve for breeding and rearing young, while the animals travel long distances across the open ocean in search of food.

At first glance, its habitat remains intact, but its food base is changing. Rising water temperatures cause key prey species such as krill to retreat into greater depths or cooler regions. For fur seals, this means that their main food source is becoming harder to reach.

Young animals are especially affected, as they depend on a reliable food supply. If females have to make longer or unsuccessful hunting trips because of the changed conditions, the survival chances of pups decrease. The consequences are already measurable: since 1999, the population has declined by more than 50%, accompanied by sharply falling survival rates in the first year of life.

Southern elephant seal: diseases are increasing

In the southern elephant seal (Mirounga leonina), another dimension comes into play: disease. In recent years, highly pathogenic avian influenza (HPAI) has also spread among marine mammals, causing considerable losses. The disease has already affected four of the five main populations; in some colonies, more than 90% of newborn young have died.

Climate change is indirectly intensifying this development. Changing environmental conditions and rising temperatures promote the spread of pathogens and enable them to penetrate previously isolated regions. According to the IUCN, disease-related mortality in marine mammals is expected to continue increasing with ongoing global warming—especially in polar regions, where animals have so far had little contact with pathogens. Species living in dense colonies are particularly vulnerable.

At the same time, it is clear that this development is not unexpected. Southern elephant seals have long been considered sensitive to environmental change. Their range was once much larger and extended as far as New Zealand or Western Australia; today they are restricted to a few subantarctic regions. This spatial restriction considerably reduces their ability to adapt. While they were once able to compensate for earlier climate fluctuations, several stress factors are now acting at the same time: fragmented habitats, existing pressure from human impacts and, on top of that, new disease risks.

The current uplisting therefore does not reflect a sudden change, but rather confirms a longer-term trend. When new stress factors are added to existing pressures, the balance of a population can quickly tip.

Why are Southern Ocean species particularly affected?

The three examples show that species of the Southern Ocean are particularly sensitive to climate change. The reason lies in their high degree of specialization: they are adapted to extreme, yet long-stable environmental conditions. But that stability is being lost more and more.

Even relatively small changes—for example in sea ice, water temperature or the availability of prey—can affect their survival and reproduction. Many of these species are closely tied to specific habitats or food sources and cannot respond flexibly to change.

In addition, their options for retreat are severely limited. While species in temperate latitudes can shift their range, there is hardly any such room for movement in Antarctica. The habitat literally ends at the edge of the continent—migration into even colder regions is impossible.

The combination of high specialization, limited flexibility and rapidly advancing environmental change therefore makes Antarctic and subantarctic species extremely vulnerable to the consequences of climate change. Emperor penguins, fur seals and elephant seals are certainly not isolated cases, but stand for a development that is likely to affect many more species.

What matters now

The current reassessments once again show how urgent action is. At the center is, above all, consistent climate protection: only a rapid and substantial reduction in greenhouse gas emissions can limit the loss of sea ice and preserve the stability of Antarctic ecosystems.

The IUCN is also calling for more intensive scientific monitoring of the region. In the hard-to-reach Antarctic, long-term data are lacking in many places to identify changes early and respond to them in a targeted way. Yet such information is crucial for making policy decisions—for example under the Antarctic Treaty—on a sound basis.

Developments in recent years show that without coordinated measures against climate change, pressure on many species will continue to intensify. Antarctica is not an isolated system—what happens here is part of a global transformation whose impacts are becoming increasingly visible.

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Source

• IUCN (2026). Emperor penguin and Antarctic fur seal now Endangered due to climate change – IUCN Red List. https://www.iucn.org/press-release/202604/emperor-penguin-and-antarctic-fur-seal-now-endangered-due-climate-change-iucn