This is caused when a good half of a cubic chunk is replaced from any block (including water) to air. The lighting does not update. It can only be fixed by filling the entire area with glowstone, and then deleting the glowstone again. The bug you see in the image also happens on land.

Light updates are currently largely broken, and it's a known issue. It's also not an easy one to fix and I have way too much stuff to do before I can actually get to that.

A sort of hack fix on that is the "light updates per column per tick" config option, that slowly over the period of hours fixes lighting at random-ish blocks until it eventually fixes it all. But this option is usually left disabled on servers for performance reasons.