Canned tuna doesn’t have bones, nor does canned mackerel. Why does most salmon? I like salmon but picking all the little bones out is too much trouble.
Firstly, I find bones all the time in canned tuna. Due to cooking, they have to be pretty good size to be recognizable (but still soft enough to not really be too noticable when chewing).
Your last comment answers your own question. Trouble = $$$ on the canning line. Salmon have a lot of little fragile bones and it’s hard to remove them without wasting meat.
Canned salmon is usually made from either Pink or Sockeye salmon. They are much smaller than tuna, which are more economically filleted for canning, and the bones are much larger and less able to soften during canning. Salmon is just chunked with bones in for canning; filleting would be so expensive, the cost would make the product uncompetitive.
Those bones are good for you, a great source of calcium. The canning process makes them so tender, they are easily eaten without any problems. Don’t be so picky.
<hijack> What do you do with canned * Mackerel *? I’ve only eaten it as a baked/broiled fish.
People at the University of Alaska recently built a salmon deboning machine: Deboner: The Business of Bones
Apparently, it wasn’t a simple task.
Gee, you must have a tough time eating sardines.
I just eat the mackerel as is, its moist enough (packed in sunflower oil). I usually have it with rice.