Viruses that infect and kill algae could influence the ocean carbon cycle.

Ilan Koren and Assaf Vardi at the Weizmann Institute of Science in Rehovot, Israel, and their colleagues used satellite imagery to measure the atmospheric carbon absorbed by a roughly 1,000-square-kilometre algal bloom during its 25-day life cycle in the North Atlantic. They found that the algae converted around 22,000 tonnes of atmospheric carbon into organic carbon — about as much as a rainforest of equivalent size — before viruses caused the bloom to collapse.

Two-thirds of this carbon was released back into the atmosphere within a week of the bloom's collapse. The rest could have been transported deep into the ocean, as infected algae sank to the ocean floor, the authors suggest.

Curr. Biol. http://doi.org/vbx (2014)