Laboratory studies are reviewed that showed fishes stopped schooling at particular light intensities. These are related to light intensities expected in natural waters. Two figures illustrate the attenuation of total energy from noon sun, moonlight, starlight and skylight, and so forth, and show the differences in the fraction of total energy which is visible at different depths in (1) clearest natural water and (2) typical coastal water. Energy visible photopically and scotopically are shown in separate curves. Maximum depths for fish schooling are indicated on these curves. This is only possible if several assumptions can be made. Effects of bioluminescence on fish schooling can only be speculated upon, but at times it probably makes it possible for fish to maintain schools visually. Studies are required to test the assumptions that have to be made in relating laboratory studies to natural conditions. Studies of the effects of bioluminescence on fish schooling are required.
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Richard R. Whitney (1969) studied this question.