Why Are Antarctic Fur Seals Shrinking?

As climate change wipes out their food supply, females are eating less, breeding later in life, and having smaller pups.

Kristina Bravo is Assistant Editor at TakePart.

Seals melt our hearts with their doe-eyed looks, gnarly surfing skills, and not least of all, their lovable blubbery girth. But lately, Antarctic fur seals have been looking a little smaller and slimmer—all because of, you guessed it, climate change.

According to a recent study published in Nature, warmer climate has led to a decline in krill, the tiny shrimplike crustaceans that feed on phytoplankton that grow on sea ice. As the ice disappears, so do the phytoplankton. Krill are a major food source for Antarctic fur seals, whose teeth are especially designed to serve as sieves for the little animals.

“Over 27 years, we see pups being born with 8 percent less body mass,” Jaume Forcada, a scientist from the British Antarctic Survey and one of the study’s authors, wrote in Nature. “We also see the females breeding later in age, at least by one or two years.”

The dwindling krill population affects several Antarctic creatures, making it a bellwether species for climate change. Emperor and other types of penguins feed on the crustaceans, as do birds—including the endangered albatross—that live in the Southern Ocean. A study published in PLOS ONE last year suggests that global warming could reduce krill habitat by 20 percent.

Antarctic fur seals were hunted to near extinction in the 18th and 19th centuries. Though the species has fully recovered, researchers warn that if their food supply continues to decline, we won’t just see smaller and slimmer seals. We might not be able to see any of them at all.

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