http://www.bbc.co.uk/news/world-europe-21993684
On a large scale, cheap fish is being substituted for expensive fish without the consumer knowing. Moreover, new varieties, never before consumed, are being detected in fish dishes.

Interesting reading. I wonder how many people could look at a fillet of fish and tell what species it is. Or more to the point, what species it isn't!

Perhaps its best to catch our own after all