Phytoplanktons can be our essential allies in our battle against climate change because of their role in carbon pumping (a process that transforms carbon dioxide into organic carbon, which then decomposes in the depths of the sea). However, these photosynthesizing microalgae are not perfect. As they depend on the nutrients found in their environment, parts of the ocean empty of nutrients could be unsuitable for most phytoplanktons. This is where this recently discovered microbe can come in handy.
The single-celled marine microbe called Prorocentrum cf. balticum acquires nutrients similar to how phytoplankton do. However, the microbe has an additional method of getting nutrients, and that is through eating other microbes. As it photosynthesizes, it releases a carbon-rich exopolymer that attracts other microbes. These other microbes are then entrapped and immobilized on the exopolymer. The tiny ocean predator then eats some of this before leaving the exopolymer. Because of its now heavier weight, the carbon-rich exopolymer then sinks. In other words, this newly discovered microbe can sequester carbon naturally.
Dr. Michaela Larrson, a marine biologist, likens this process to "taking a multivitamin," as the other microbes consumed are packed with nutrients. Researchers say this species could sink 0.02-0.15 gigatons of carbon annually.
(Image Credit: Cohen et al. (2022)/Larsson et al. 2022/Dr. Michaela E. Larsson)
(Image Credit: Larsson et al. (2022)/Glynn Gorick)