Trolling is a form of hand line fishing.
In this technique, a baited fishing line is slowly towed behind a moving boat to catch predatory fish such as tuna or pike. Handline fishing techniques such as this one are usually used on a small scale and are relatively selective. Unwanted bycatch can be immediately released, with a high chance of survival. It is more selective and smaller-scale than longline fishing. There is no impact on the seafloor, fuel consumption is often low, and any bycatch is usually released alive back into the water.