[jszymborski]

There are a lot of problems with this that have been outlined in all these comments, and 99% are true.

I would instead take advantages of photoautrophic organisms that already are bioluminescent like Dinoflagellate.

https://en.wikipedia.org/wiki/Dinoflagellate

They can have a startling effect in large numbers and feed themselves with daylight.

https://en.wikipedia.org/wiki/Bioluminescence#mediaviewer/Fi...

Some video of their effect

https://www.youtube.com/watch?v=eSROHwGaLCg

[fineline]

I saw this effect off the beach near me a few weeks ago, it was quite captivating as the breakers were lit up as if by an underwater neon (I actually thought it was an artificial light show of some kind at first). But although deeply impressive, it certainly wouldn't have had a meaningful effect on visibility of the neighbouring land. Moonlight is much more effective.