It's being discussed on Women's Hour atm. It's the title of a book by Charles Clover and has just been made into a documentary film: endoftheline.com/
It does seem fairly self evident that if we continue to over-fish then eventually there will be no fish left. I try to buy sustainably sourced fish but it is immensly hard and I often don't buy if I can't find out how it was caught. I haven't eaten tuna for years. I seem to be in a tiny minority though and most people seem to think I'm barking for being such a fish-hugger.
So, what do you all do about buying fish, do you care about where your fish comes from and if not, why not?