[walrus01]

And in some very poor locations people do fish by sail and rowing, but even in some of the lowest income countries on earth, using small petrol engines is increasingly common (source: buying local seafood in Sierra Leone some years back).

[asciiresort]

> using small petrol engines is increasingly common (source: buying local seafood

Right, because the locals have changed from fishing for themselves to fishing for others. This is market economy dynamics of engaging in activity that produces the most money.

[walrus01]

At least where I was buying fish it was all for domestic consumption in the Freetown metro area. Very little or none of it was being caught to be frozen or canned.