Quotas limit the amount of wet fish - such as cod, bass and ray - boats can catch to protect fish stocks.

BBC: Jersey States discussing local fish quotas

For thousands of years, cod and other bottom-feeding fish were the top predators in the system.

ECONOMIST: Lobsters in Maine

Although nearly 50 percent of the grocery stores visited in Boston sold mislabeled fish, the cod-loving city was tied with Seattle where salmon is king, as having the lowest deception rates.

FORBES: Think You Ate Tuna Sushi For Lunch? Study Finds Mislabeled Fish Nationwide Problem

In general, white-fleshed fish, such as cod, tilapia, or flounder, are low in all types of fat, including omega-3s.

CNN: How to buy the best fish

Research reveals that 7% of cod and haddock - the deep-fried staples of British fish and chips - actually turn out to be cheaper fish substituted to cut costs.

BBC: Mislabelled fish slip into Europe's menus

However, if you can't find a whole fish, a 4-pound section of cod or halibut fillet works just as well and tastes just as good.

WSJ: Magic-Carpet-Ride Chermoula

Dr Mozaffarian said the cooking process had either destroyed all of the good omega-3 or the fried fish were lean white fish like cod rather than oily fish.

BBC: NEWS | Health | Fish prevents deadly heart rhythms

Two years ago Kurlansky's Cod: A Biography of the Fish that Changed the World was an out-of-nowhere hit.

FORBES: The wealth of a nation