Soo guys i think that this depends on your server but i see alot of guides about "easy gold" " fast gold" that aren't really that easy, i play archeage the whole day at the moment and by fishing the whole day in it (sport fishing) i make around 1400g a day guaranteed on my server.
What you need is level your fishing by afk "normal fishing" till 10k proficiency after that you can catch normal and medium fish in the sea soo go sport fishing with a clipper you will be making around 300g a day once you got the mats and the design make yourself a fishing boat where you can store 5 fishes and that's some good income!