A good book that shows what is being talked about here in terms of being over fished is a book called the catfish connection. Shows the migratory routes of large pimelodid catfish, and the decline in numbers and size of fish over a period of time.
Exciting that we can now see which species we are actually getting. Too bad on the price though. Seems you will only get serious buyers with a price like that. I would def buy one if I had 3-4k laying around lol.