Climate change may be weeding out the bacteria that form the base of the ocean’s food chain, selecting certain strains for survival, according to a new study.

In climate change, as in everything, there are winners and losers. As atmospheric carbon dioxide levels and temperature rise globally, scientists increasingly want to know which organisms will thrive and which will perish in the environment of tomorrow.
The answer to this question for nitrogen-fixing cyanobacteria (bacteria that obtain energy through photosynthesis, or “blue-green algae”) turns out to have implications for every living thing in the ocean. Nitrogen-fixing is when certain special organisms like cyanobacteria convert inert — and therefore unusable — nitrogen gas from the air into a reactive form that the majority of other living beings need to survive. Without nitrogen fixers, life in the ocean could not survive for long.