Canned fish

When I was eating a can with fish, I became interested how cans are made and what procedures are made to achieve the final product. So here is what I found.
The practice of canning in tin cans is relatively new - perhaps some 200 years old. At first food was canned manually and it took up to 6 hours, so cans were very expensive at first. Later, mechanisation helped cheapen the production of cans.
On the board of a fishing ship, the fish are washed and chilled. Sometimes they are also divided according to their species, but this may be difficult, when there are a lot of species in the area.
When the ship lands, the fish are unloaded, thawed and processed.
The processing is necessary because of bacteria. The most dangerous and abundant of these is Clostridium Botulinum. The processing consists of high temperature (cca 120°C) and pressure.
Cans are mostly steel, with tin coating.