Featuring C-DEBI scientists Julie Huber and Julie Meyer.


Your aquarium water turns green when you overfeed your fish. When limiting nutrients like nitrates and phosphates are introduced into a body of water, microscopic algae multiply so much that the water changes color. For example, in response to fertilizer runoff, a 2011 cyanobacteria bloom changed the clear waters of Lake Erie into a dark-green soup and forced the nearby city of Toledo into a state of water crisis.

We frequently see what eutrophication looks like and understand how microbes respond to excess nutrients in lakes and coastal areas. A similar microbial bloom is observed when excess nutrients from hydrothermal vents are released on the seafloor. During a submarine volcanic eruption, the microbes living inside the oceanic crust spew out into the water column, along with CO2 and H2S in high concentration. One of the consequences of such changes is a transient phenomenon called “snowblower vents,” hydrothermal apertures that release white flocculent materials resembling snow (For an awesome video, click here). These flocs consist of huge clumps of microbes living chemoautotrophically off CO2 and H2S gases. Who is crazy enough to live inside an active hydrothermal vent and thrive on toxic gases? An article published by researchers at Woods Hole Marine Biological Laboratory addressed this very question by performing detailed molecular analyses on samples from an Axial Seamount eruption.