Chicken is dirt cheap, like $2/kg wholesale. Price of air freight is about the same on large long contracts and twice of that over the counter. Hauling chicken two ways will increase a final product price at least threefold. Sorry, I can't believe it.
BTW, fish are mostly canned right in the sea on board of fishing vessel or on a bigger factory ship nearby.
I'm unfortunately still not able to remember for the keywords of the one good reputable article I know of that details most of what is shipped for processing and back to multiple countries and the margins involved, but it's out there if you ever feel the need to dig into it.
I am aware of the fish being canned on board vessels and factory ships. There are still a large amount that aren't.
Here is one video demonstrating a large amount of people being involved in the simple canning of cheap sardines... It's definitely much better and more orderly than another video based out of a somewhat open-air assembly line in Portugal I believe.
I could however be completely wrong about all of this. There is some information on the internet that is not amazingly easy to find and verify. When you think about the fact there are many countries with large populaces that are still treated as literal slave labour though and also lesser quality standards involved, so more ability to quite literally cram a shipping container to the brim with whatever they want, margins are incredibly slim, but still money is being made.
Thanks for the links! As I scanned them briefly, air freight is never mentioned, and sea transportation is explicitly mentioned couple of times. This is still crazy (frozen containers has to be powered 24/7), but not unbelievable crazy.
BTW, fish are mostly canned right in the sea on board of fishing vessel or on a bigger factory ship nearby.