Catching Krill

January 29, 2017
By Damond Benningfield


Krill are small shrimp-like creatures. Credit: National Oceanic and Atmospheric Administration, Sophie Webb

If you could measure the total weight of each kind of animal on the planet, the winner wouldn’t be people or elephants or even blue whales. Instead, it probably would be one of the smallest creatures on the planet: Antarctic krill. The shrimp-like critters typically reach about two inches in length and weigh a few grams. Yet there are so many of them that their total weight could add up to 500 million tons.

That could change in the decades ahead, though. Biologists are concerned that climate change and increased fishing could reduce that number. And that could have a big impact on the entire Antarctic food chain, because krill are a basic food source for everything from penguins to whales.

The changing climate could reduce the krill’s food supply, and make it more difficult for krill to develop their external skeletons. The other challenge is fishing. Krill are used as fish food and in some human food supplements. During the 1980s, international fleets took up to half a million tons of krill per year. By 2015, though, the take was less than half of that, thanks mainly to the collapse of the Soviet Union, which was the major player in the krill business.

But China recently announced plans to increase its take dramatically. It’s building bigger ships to do the job — some as big as supertankers.

China says it’ll follow international rules, which limit the annual take to about four million tons. Still, reaching that limit would leave a lot less krill to sustain life in the Antarctic.