I never thought the phases of the moon had a large effect on fishing, but I guess I was wrong. Just before the server crashed just now, it was midnight, and a full moon. I was fishing in lake shallows with a crappy rod and a woodfish, and catching purely Plaice. No Pike whatsoever. Happy days!

Yesterday though, I was fishing at night in the same location, but the moon was in its very early phase, and I was catching mostly Pike. I maybe found 1 or 2 Plaice after half an hour's fishing.
So, I just thought I'd share. I'm sure most people already know all this stuff, but for newer players or those who don't fish much, this should help in the early hunt for decent Perception food.