Every teaspoon of seawater contains more than a million marine bacteria, though it is invisible to us. These tiny microbes play pivotal roles in governing the chemical cycles that control our climate and shape the health of the global ocean. But are they passive drifters or purposeful hunters?
New research suggests that bacteria in the ocean use similar behaviors to many foraging animals. These animals swim through their environment while hunting and selecting their preferred “food” among a soup of chemicals in seawater.
University of Technology Sydney (UTS) scientists used purpose-designed microchips to gain a “bacteria’s-eye view” of the ocean. They showed that microbes in the natural environment use sophisticated behaviors to detect and move towards foods they like.
Scientists stated that they had some idea that microbes could swim around their immediate environment to find and exploit food patches. But the only available evidence came from laboratory experiments are often not very realistic or representative of natural environments. This kind of behavior had never been comprehensively examined in the environment among natural populations of microbes.
Researchers used a technology called microfluidics to design a specialized “bacteria trap”. They used it to measure the feeding preferences of bacteria in coastal waters near Sydney. Scientists said the work demonstrated how processes occurring over very small distances in the ocean can have large-scale impacts.