But that law predates the modern fishing "industry". Sure, there were fisherfolk and fishmongers and all that when it was imposed, but they weren't exactly an industry. So if it was done to benefit someone it was some Bishop's uncle Vinny.

And now, on to one of my favorite pieces of medieval logic trivia: There was a fish greatly prized by the English nobility for its fatty flesh and marvelous taste. Any guess what it was?

The beaver.