This is what happens when a country has loose fishing regulations.
This footage comes from what we think is the Philippines. Obviously they don’t have very strict hunting or fishing regulations there because one clever citizen made a harpoon fishing gun. The device appears to use the propellant charge from a cartridge to launch the harpoon, and as you can see in the video it’s very effective. This clever inventor found a way to feed himself more effectively so we can’t judge too much.
In case you were wondering this method of fishing would be illegal in the United States.