Does sustainable fishing exist?

This is one of several questions that Monty Hall - a telegenic marine biologist - tries to answer on the programme The Fisherman's Apprentice. The BBC filmed his attempt to spend 3 months as an inshore fisherman in south Cornwall. Last night's programme saw him spending a week on a deep sea beam trawler out of Newlyn. Although the boats are old and the work unbelievably hard, the sonar and other kit on board means that fishing is very efficient i.e. not much gets away.

I was stunned by the destruction wreaked on the seabed and the amount of bycatch chucked back dead. His conclusion was that small boats are the only sustainable form of fishing (as well as - presumably - fish you catch to eat yourself). It was difficult to find fault with that conclusion.