Trout, along with salmon, are the biggest fish you can catch in URW. They can only be caught in deep water or rivers, and fishing in rapids may give a better chance of catching them. 1 lb of trout can fill nearly all of your hunger bar. Each trout is usually 4-5 lbs, and can be caught in nets.
Trout
A pile of 19 6-pound salmons cost one cord to dry or smoke, same as 19 perches or 19 meat cuts. Therefore it's most economical to dry/smoke salmon/trout instead of meat. The drawback is that you need to be a fairly good fisherman: 10+ Nets, 2 fishing's chants, raft or punt, one fireplace, one wall, and one floor/ceiling tile next to the fireplace.