Deep-sea hydrothermal vents play host to an exciting array of marine life. At the base of these ecosystems are intricate communities of microorganisms. These bacteria and achaea survive at an astonishing range of temperatures, from more than 120°C at the mouth of the vents, to less than 10°C farther away. Characteristic to some genera is the assembly of orange and white “mats,” masses of bacteria turned colorful from the oxidation of sulfur. A recent article focuses on the dynamics of these communities, specifically in their relationships with temperature, at the Guaymas Basin hydrothermal vents in the Gulf of California
Because of the distinct tie between metabolism and microbial diversity, scientists explored the different cellular processes to assess heterogeneity on a community level. The dominant types of organisms were those that could preform nitrification, nitrogen and sulfur reduction, or methanogenesis; almost expected given the nutrients available. Interestingly though, the distribution of nutrients did not align with the water’s temperature gradient, promoting diversity within the psychrophilic, mesophilic, and thermophilic communities. In other words, different genera of microbes that shared preferences for temperature still varied in their metabolisms.
As for overall differences in diversity, the researchers found very few categories of microbes that were unique to the hottest areas. This could be from some kind of disturbance, like a sudden increase in temperature, that temporarily sterilized the area closest the mouth of a vent. However, due to the metapopulation of microorganisms surrounding the damage, a new, more generic community becomes established as neighbors colonize the newly vacated space.