Other than baking random crappy food, there is exactly one use for fishing that I know of:
http://wiki.project1999.com/Cobalt_Cod. That cod is used to make
http://wiki.project1999.com/Cod_Oil, which in turn is used to make
http://wiki.project1999.com/Arctic_Wyvern_Armor, which is cheap halfway-decent tradeskill-made Shaman armor.
But other than that and player events (and future quests that P99 will never see) I don't think there's anything useful you can do with fishing.