Bioluminescence in Chesapeake Bay.

Bioluminescence measurements made by stimulation of the organisms in a jet of water directed at the face of a phototube have increased the sensitivity of data by a factor of 1000 over "spontaneous" luminescence measurements. In light-baffled cells it has been possible to map the surface bioluminescence of large areas continuously in broad daylight. Measurements of intensity versus depth during both day and night do not show any appreciable diurnal variation in maximum intensity, although there does appear to be a vertical migration of intensity.