There was a time, about a hundred years ago, when the Antarctic fur seal barely escaped extinction because they were hunted for their pelts in their millions.
Numbers rebounded as the hunting of fur seals declined but now, thanks to climate change, they are threatened with extinction once again. Climate change is having a huge impact upon their main food source, krill, a small shrimp-like crustacean which is the seal’s main food and which depends upon sea ice to survive in the early part of their life-cycle.
Antarctic steel numbers have dropped by 40% in the past 10 years according to research from the British Antarctic Survey (BAS) at Bird Island in South Georgia, which is the most closely studied colony.
The population size at the moment, 2023, is similar to the 1970s. Worryingly, their life spans are falling according to the study which is published in the journal Global Change Biology.
Because of climate change, krill is becoming less abundant during Antarctic winters.
The seal population of Bird Island is representational of the wider and much larger population of Antarctica. The decline there has been mirrored as another breeding site in Maiviken which is about 60 miles to the east.
The lead researcher in the study, Jaume Forcada, is worried by the results.
The research concluded that the seal population in South Georgia peaked in 2009 at 3.5 million individuals which is far fewer than they had thought. Ninety-five percent of this species of seal live on South Georgia.
The hunting of seals declined because humans started to hunt blue whales and humpback whales. The researchers think that seal populations enjoyed 50 years of growth over the past century thanks to this change in human attitudes.
And because whales eat krill as well and because their numbers declined because of they were hunted this allowed a greater abundance of krill for the seals.
We are told by The Times that the collapse in steel numbers began in about 2009. The Bird Island population has declined by about 7% annually since 2009. Forcada said: “Krill can make up to 80% or more of the diet. The number of pups produced and survival of individuals [declines] when environmental conditions remove krill from foraging areas.”
