>>>>Church tradition that started in order to help fishermen. Way back centuries ago in Italy, fish fell out of favor as a dietary staple. Some pope or cardinal made fish an exemption for Fridays.
Bzzt. No. Ever read the Diache? It was written around the year 80 AD. The earliest Christians fasted on Wednesdays and Fridays. The Friday fast is a continuation from the earliest days of the Christianity. Friday is still a day of penance in the Church even now. It's not an order to eat fish, or that eating fish "fell out of favor". That is a silly idea.
The Didache in English - http://www.earlychristianwritings.com/text/didache-lake.html
Silly or not, a very educated priest told me that story. I have no reason to doubt him.