Scientists discover surprising impact of billions of animals smaller than grain of rice: 'This has big implications'

When it comes to removing carbon pollution from the atmosphere and locking it away, we often think of trees, which are big and familiar. But an incredible amount of carbon is being stored each year by billions of animals no larger than a grain of rice, Earth.com reported: migrating zooplankton in the Southern Ocean.

Scientists already knew that carbon was being stored in the ocean over time. However, they thought it was a passive process caused by sinking waste from large zooplankton living and eating near the surface of the water.

The reality is much more active and fascinating. According to a study published in Limnology and Oceanography, zooplankton migrate from the surface to the depths, diving below 1,640 feet every fall.

They stay there for months, and by breathing and sometimes dying deep in the ocean, they pump carbon into the dark reaches of the sea. Then they return to the surface with warmer weather and once more begin to absorb carbon from the atmosphere.

With this cycle, zooplankton pump 65 million tons of carbon into the deep ocean each year. That's good, because when it stays in the atmosphere, carbon — in the form of carbon dioxide — is a big driver of Earth's rising temperature, with all the extreme weather and destruction that accompanies it.

Researchers looked at a century of data to discover not only the cycle of migration but also details about which kinds of zooplankton stored the most carbon.

"We find that copepods significantly dominate carbon storage overwinter," Jen Freer said. "This has big implications as the ocean warms and their habitats may shift."

Copepods are small crustaceans similar to shrimp and responsible for about 80% of the pump effect. Krill drove about 14% and salps 6%.

But even as these tiny creatures fight the warming of the planet, the rising temperature affects them. Hotter oceans could change their habitat and migration, potentially damaging this carbon pump — making it that much more important that we address our own carbon pollution before it changes the planet irreversibly.

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