Trawling is done by dragging nets along the seabed causing massive damage with huge inefficient polluting fuel-guzzling 1000 horsepower diesel engines.

Trolling is as the other guy says where you putter along with minimum effort and a tiny engine pulling a couple of baited lines through the water, seeing if you pass through a patch where anyone bites.

Trawling is far more analogous to the AI scrapers, hammering the absolute shit out of the ecosystem and throwing almost everything they scoop up away with no regard for the consequences.