Krill are able to digest and break down microplastics, study reports

Avatar By Joseph Scalise | 2 years ago

Researchers in Australia have found that krill are able to digest microplastics and turn them into much smaller fragments, according to new research published in Nature Communications.

In the study, scientists at Griffith University found that Antarctic krill are able to break down 31.5 micron polyethylene balls into fragments less than one micron in diameter. Such discoveries were found under laboratory conditions, and they believe that microplastics in the ocean — which are already weakened by UV radiation — would be even easier to break down.

The plastics also took five days to leave the krills’ systems, suggesting that any plastics digested by the small creatures would not move up the food chain and harm any larger animals that consume them. In addition, the digested fragments were often 78 percent smaller than the original pieces. In some cases, they were 94 percent smaller.

While this is a surprising discovery, the team is not yet sure if it would be able to cut back on the current plastics scattered throughout the world’s oceans.

“It’s not necessarily helping plastic pollution, it’s just changing it to make it easier for small animals to eat it,” said lead author Amanda Dawson, a researcher at Griffith University, according to The Guardian. “It could be a new source of plastics for the deep ocean.”

Even so, the findings are significant because they suggest many microplastics digested by krill are too small to be detected by oceanic plastic surveys. As a result, there is a chance the amount of microplastics in the oceans could be higher than previously estimated.

To better understand shifting ocean environments, researchers next need to look at how such microplastics interact with the environment. There is a chance other planktonic crustaceans are able to break down plastic, but more studies need to be conducted to prove that claim. In addition, the team hopes they can find out if the tiny animals can digest fibrous microplastics — which are used in fishing line and clothing — as well.

“I would assume that other planktonic crustaceans should be able to do this as well, we just haven’t seen it yet in any laboratory studies,” added Dawson.