Because of the problem with cod stocks lots of the cod's cousins are coming into the shops - Pollack and coley for example. Often they where formerly the fish you bought for your cat and sadly underestimated. Coley doesn't look very appetising on the fishmonger's slab (a bit on the grey-ish side) but it cooks up to a nice white opaqueness and tastes good. I always buy it for variations on a fish pie and for fish curries and I also poach or grill it and serve it with a sauce. I'm pretty sure the local fish and chip shop uses it, too.
What makes me laugh is "monk fish" - angler fish to you and me. 30 years ago it was by-catch and you'd see it very occasionally, complete with very ugly head, in the fishmonger's window as a curiosity. I don't think our fishmonger ever sold it until I came along as he had no idea what to charge me for it - on the first occasion he gave it to me free as he thought it was for the cat! Even when he cottoned on to the fact that I was eating it it still only cost pennies. Contrast the situation now. The last time I saw some this year it was £18.99 a kilo (about $30 a kilo or roughly $15 a pound
). The power of the celebrity chef I suppose.
Incidentally, Haddock is apparently going the way of cod due to over-fishing.