Usually everyone in the fishing villages knows who does it. Often it's not the same people all the time: Individuals may need a larger amount of money than they can get from normal fishing, due to illness of a family member, or necessary repairs to a motorbike they rely on, etc. In a closely knit community you would not report your friend, especially knowing he did it out of desperation.

As far as I know these are not usually larger boats with captains and workers, more single famlilies who own small craft.