The primary inhabitants of South Georgia, a jagged little crust of snow and ice plopped nearly 900 miles north of Antarctica, are a small group of British scientists and seals. The scientists live there year-round, but every December, hundreds of thousands of Antarctic fur seals meet on the shoreline, give birth, and a week later, mate again.
That mating holiday determines much of the future of the species. But over the past 30 years, the scientist neighbors of the seals have picked up on a disturbing trend: The female seals are eating less, shacking up later in life, and giving birth to smaller pups.
So why can’t female seals have it all? According to the British Antarctic Survey scientists, who recently published a piece in Nature, the future of the species hinges on how climate change affects krill, the seals’ main food source while in heat.
Krill, tiny little crawfish-like crustaceans, subsist on algae that cling to the undersides of ice floes. But an annual flow of warm breeze, called the Southern Annular Mode (SAM), has been gaining strength over the last three decades, melting the ice, and leaving the krill without a food source. As a result, hungry female seals aren’t reproducing as often. The rate of mating females has been on the decline for the last three decades, but the span between 2003 and 2012 saw the lowest–a 30% decline altogether.
Humans living comfortably above Antarctica aren’t exactly stung by this new development. But it should serve as a lesson: The consequences of climate change are multitudinous and not entirely predictable. When our food sources become scarcer (as they’re predicted to by 2050), will human females be next?SB