Its also the tearing up of the bottom it turns it into a wasteland.A recent Wayne Hand video (at Chesil with Gem) starts off with a trawler relatively close to the shore, and one of the comments mentions that one boat using gill nets at Christchurch (Hengistbury Head is my "local" fishing spot) has "...cleared out most of the fish..." which if true is so messed up
A tip for others here is to understand where can't be trawled so at least it's holding food if it's there.
Its no coincidence that on Chesil there are areas of hard bottom where trawlers cannot work.
I was surprised that trawler was towing where Wayne was if it was later in the year I would have thought he was just off the bottom looking for cuttle.