There's reports of prisoners complaining about the torture of being fed salmon all the time, because it used to be common food. People signal their class and status through everything, also through food.
Salmon not prepared, handled or stored properly or not served fresh can taste pretty bad and smell pretty bad compared to other meats. Seafood in general goes bad fast compared to beef or pork for example.
I used Blue Apron for a while and got an unreasonable amount of salmon for some reason. It's been almost 6 years and I can still barely eat salmon after that. So I can definitely understand where the prisoners were coming from on this one.
Things might have changed since then, but from what I recall while we had some options on what to pick, for example I could eliminate red meat entirely, there was no option to get meat and not get salmon. So pretty much every week at least one of the meals was salmon.
The lumber camp installation inside the Nordic Hertitage Museum (Seattle) shows a sample employee contract: Salmon will not be served more than 3 times per week.
At the time, salmon was the cheapest, most abundant source of protein. Poor people's food.