Kategorie: News
Up to 90 per cent of pups are dying – IUCN classifies marine mammals as endangered
The International Union for Conservation of Nature (IUCN) has taken an alarming decision: the southern elephant seal (Mirounga leonina), one of the largest seals on our planet, has been downgraded from ‘Least Concern’ to ‘Endangered’.
This dramatic reassessment comes as a direct response to the devastating losses caused by an aggressive form of avian flu amongst the populations of these impressive animals.
Devastating scale of the epidemic
Highly pathogenic avian influenza, or HPAI for short, has proved to be a deadly threat to elephant seals. Four out of five major colonies of these marine mammals have already been affected – with catastrophic consequences: in some breeding areas, fewer than ten per cent of the young survived. It is particularly tragic that adult females, too, are falling victim to the virus at an above-average rate, which further jeopardises the reproductive capacity of the entire population.
From birds to mammals: an unprecedented spread
Originally known as avian influenza, HPAI has spread across every continent at an alarming rate since 2020. What particularly alarms scientists is that the virus has crossed the species barrier and is now increasingly infecting mammals. From seals and sea lions to the massive elephant seals – marine mammals are proving to be particularly vulnerable to this disease.
Climate change as a catalyst
Experts see a direct link between global warming and the rapid spread of pathogens. The polar regions, where elephant seals form their colonies, have for centuries been natural sanctuaries with low levels of pathogens. Rising temperatures, melting ice and changing ecosystems are now allowing diseases to penetrate these once-isolated habitats. Animals that have had virtually no contact with pathogens for generations lack a sufficiently robust immune system to combat these new threats.
A wake-up call for marine conservation
The case of the southern elephant seal exemplifies just how interconnected the ecological crises of our time are. Climate change, species extinction and the spread of disease reinforce one another. What is affecting elephant seals today could threaten other marine mammals or entire ecosystems tomorrow.
The IUCN Red List is regarded as the most important early-warning system for species conservation worldwide. When a species is downgraded directly from ‘Least Concern’ to ‘Endangered’, it skips an entire warning level – a clear sign of how rapidly the situation has deteriorated. In the case of elephant seals, this change did not occur gradually over decades, but within just a few years.
Threatened Giants of the Seas
Southern elephant seals are among the most imposing inhabitants of the oceans. Males can grow to over four metres in length and weigh up to 4,000 kilograms – making them the largest seals on Earth.
They live mainly in sub-Antarctic waters and on remote islands such as South Georgia, the Kerguelen Islands and Macquarie Island. They owe their name to the trunk-like structure, which is particularly pronounced in males.
Complex struggles for survival
A combination of several factors makes the current situation particularly precarious: As well as avian influenza, elephant seals are suffering from dwindling food resources due to overfishing and changes in ocean currents. Their prey – mainly squid and fish – are migrating to other regions as a result of rising water temperatures. At the same time, the ice floes that serve as resting areas between their extended dives are melting.
What can we do?
Marine conservationists are calling for increased monitoring of the colonies to detect disease outbreaks at an earlier stage. There is also a need for larger protected areas in Antarctic and sub-Antarctic waters. However, the most effective protection remains the consistent tackling of the climate crisis – because only intact, cool habitats can prevent pathogens from spreading further in the long term.
The downgrading of the southern elephant seal’s conservation status is more than just a statistical change. It is a stark reminder that our actions – or inaction – on climate change have a direct impact on the most remote corners of our planet.
IUCN Red List: www.iucnredlist.org/