Bubble Stimulation of Dinoflagellate Bioluminescence

Bubbles are known to be high effective in stimulating dinoflagellate bioluminescence and are important in two-phase flows. Our new paper published in the journal Luminescence provides a quantitative study of the stimulation of dinoflagellate bioluminescence by bubbles. Bioluminescence was stimulated by single bubbles as small as 0.3 mm radius. Bubble clouds with low air flow rates produced bioluminescence levels as expected based on the single bubble results. Bubble clouds with high air flow rates stimulated more bioluminescence than predicted, most likely due to buoyancy effects that resulted in additional fluid shear stress. Coupled with a quantitative model of how fluid shear stress stimulates dinoflagellate bioluminescence, this new understanding for bubbles is relevant to two-phase oceanic flows such as in ship wakes and breaking waves, as well as in laboratory conditions such as sparged bioreactors.