The sablefish, or black cod, supply tightens a bit each year due to quota reductions. But buyers shouldn't worry about the health of stocks in the North Pacific, which are considered sustainably harvested and well managed.

Alaska's sablefish (Anopoploma fimbria) fishery earned Marine Stewardship Council certification four years ago. And in late July, British Columbia's much-smaller sablefish fishery followed suit. While Alaska's 2010 quota sits at 24.8 million pounds, Canada's 2010-11 season qu…