Positive microbe interactions reshape climate predictions

Marine microbes, like bacteria and phytoplankton, form the foundation of the ocean’s food web, providing sustenance for a whole host of marine creatures – from tiny zooplankton to ocean giants like blue whales, and even the fisheries that feed billions of people worldwide.

Until now though, ecologists have devoted very little attention to how they behave. 

A new six-year analysis of marine microbes in coastal Californian waters has overturned long-held assumptions about how these organisms interact. 

The study, from researchers at UC San Diego’s Scripps Institution of Oceanography, found that marine microbes have a positive impact on their fellow microbes – for instance where one microbe’s growth promoted another’s. 

In fact, roughly 78% of microbes have a net positive effect on their neighbours. The study didn’t reveal the mechanisms behind these positive interactions, but Ewa Merz, a postdoctoral researcher at Scripps and the study’s lead author, said a potential example could be one organism releasing waste that another species uses as nutrients.

Interestingly, the team also found that levels of positive interactions increased during periods of stress for the microbes, like elevated ocean temperatures.