Like most farming, fishing is no longer a family business, passed down father to sons and daughters, with boats owned by the same families generation after generation.
Most fishing is done on a big scale. Big ships troll the oceans and collect thousands and thousands of seafood, sort it, ice it and store it until the cargo is filled to the brim and the ships can return to canneries and sorting pavilions.
The salmon in your supermarket may have come from Alaska, and its color may not be anything more than the color of pellets fed the young in a hatchery before the salmon was released for its trip to the ocean to fatten up.
A great many species are becoming exstinct, and their fishing is prohibited in most countries.
Next time you're in the supermarket, check the labels carefully, train yourself to look for sustainable seafood. The Monterrey Aquarium Seafood Watch lists fish that are sustainable.