Supertrawlers...
We've had them a long while, and the current fuss is being tied up with leaving the EU, but I have a feeling that the Tories would be happy if they were "ours" as they are efficient.
It's a bit like wanting to stop the industrial revolution. You might think Ned Ludd was right and machine breaking was the thing to do, but I'm not sure it's capitalist policy to put people before productivity.
For a view largely divorced from Brexit, try an Australian look at it, with a link to a blog on the environmental issues. (Largely divorced because these factory ships can go anywhere, e.g. paying African countries to fish their waters.)
If you are really worried about overfishing, stop eating fish.
"What is a 'super trawler'? The term 'super trawler' generally refers to large trawlers that stay at sea for several weeks.
www.msc.org