Salmon
From UnReal World Wiki
Salmon are one of the largest fish you can catch, weighing in at 4-6 lbs. 1 pound of salmon will fill almost all of your hunger bar. They are, along with trout, one of the best available foods.
They are quite rare, and can only be caught in rivers and seas. Fish in rapids for a higher chance. Nets will also catch them.
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, though it may take a lot of time and equipment to procure more than just a few.