By Elissa Leibowitz Poma
World Wildlife Fund

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Pinky-length crustaceans swarm in rosy swirls throughout the Southern Ocean. Unlike their more photogenic Antarctic cohabitants, these are creatures without an Academy Award-winning documentary narrated by a big-time Hollywood actor. They have no line of cuddly toys. They’re probably not eye-pleasing enough to appear in a save-the-world ad.

But, as one World Wildlife Fund partner group describes them, the tiny creatures called krill are the “bread and butter” of the Antarctic. For whales, seals, penguins, albatrosses and a number of other marine mammals and seabirds, the translucent crustacean with the big black eyes is the most vital meal on the Antarctica menu.

"All Antarctica wildlife either eat krill or eat something that eats krill,” says Mark Stevens, a WWF senior program officer specializing in fisheries.

Krill are one of the planet’s most abundant and successful animal species. They have the largest biomass of any multi-cellular species on Earth. And their gatherings are the biggest on the planet—up to 30,000 individuals per cubic meter fill one rhythmic, oceanic swarm.

Despite the strong populations, competition for krill is on the rise. Harvested krill are used to make fishmeal, omega-3 fatty acid supplements, contact lens solutions, even liquids to flush post-surgical wounds. Farmed salmon are fed ground-up krill, which give the fish its highly desired coral pink hue.

And krill are relatively easy to catch: They swim near the ocean’s surface and they swarm in mobs that fishermen can easily see.

Fishing vessels from such nations as Norway, Russia, South Korea and Japan currently trawl for krill; the United States is expected to enter the market later this year or next year, Stevens says.

As a result of increased krill fishing, marine mammals in certain areas of the Antarctic are finding fewer krill to meet their feeding demand. In some spots, the number of krill has plummeted by 70 percent to 80 percent, Steven says.

Penguin populations are already showing the stress,” he explains. “Numbers are dropping, babies aren’t surviving and moms aren’t coming back from fishing at sea."

On top of that, technology is changing the krill fishery world. A new, high-tech trawler out of Norway is now capable of vacuuming up tens of thousands of krill, processing the catch on the ship and flash-freezing it. It can harvest 100,000 tons of krill in one season. That’s nearly equal to the amount fished in all Antarctic waters by all fleets during the 2006-2007 fishing season.

Fortunately, many countries recognize how overfishing krill affects the health of the ocean and its wildlife. An international treaty organization comprised of more than two dozen cfountries has set an interim limit on the amount of krill allowed to be fished at 600,000 tons. Stevens said it eventually could be set at 4 million tons.

"The problem isn’t the numbers,” he explains. "It’s where [the krill] are taken from.”

Too many vessels in one region result in a swift depletion of krill. So does trawling close to the shoreline or in coves, which could be close to rookeries and wildlife feeding spots. Few krill means that, for example, mother penguins must swim longer distances to search for food for their young. They often don’t survive.

But overfishing isn’t krill’s only enemy. They also are susceptible to the effects of climate change.

In lawnmower-like fashion, krill eat algae that grow on the underbelly of sea ice; this is krill’s main food source during the winter. But with less sea ice during Antarctic winters because of rising global temperatures—6 degrees Celsius higher in Antarctica since 1950, according to American Scientist magazine—algae aren’t as available. Krill spawning is thus affected.

Krill populations could be devastated and thus affect the entire Antarctic food chain if warming trends continue, according to WWF-Australia.

Interestingly enough, though, krill may very well be a team player in the fight against climate change. According to the Antarctic Krill Conservation Project, recent research shows that krill gulp down large amounts of carbon dioxide when they rise to the ocean’s surface to gorge on phytoplankton, their summertime food source. When they then descend deep into the ocean, as they often do, they release the CO2, transferring it to the ocean floor.

The amount of CO2 that millions of krill may be transferring to the bottom of the sea, one study suggests, is equal to the emissions of 35 million cars.

Perhaps a Disney-created character and computer-animated film shouldn’t be out of the question after all.