Note
Submersible-based investigations of bioluminescence were conducted in sound-scattering layers (SSLs) in the Gulf of Maine using intensified video and dual-beam acoustic methods. Stimulated bioluminescence in the SSLs was high (3-41 µ W sr⁻¹ m⁻³), while spontaneous bioluminescence was not detected. The average intensity of individual bioluminescent sources in the SSLs was 20-200 times greater than the intensity of light emitters outside the SSLs. The tow brightest sources of bioluminescence were identified as the euphausiid, Meganyctiphanes norvegica and the cydippid ctenophore, Euplokamis sp.