Mixing It Up with Krill

摘要

The perspective "Biomixing of the oceans?" By A. W. visser (11 May, p. 838) challenged the suggestion that dense swarms of vertically migrating krill could generate substantial mixing (1-3). Visser asserted that 1- to 2-cm-long krill are too small to generate turbulence at the larger scales needed to mix water efficiently. Our study of intense turbulence associated with vertically migrating krill in Saanich Inlet (3) addresses Visser's objection. Both the range of length scales and the distribution of shear resembled those of shear-driven turbulence, and the density overturns we observed were consistent with our interpretation of turbulent mixing.