Sustainable Seafood #12: In Cod We Trust
Sustainable Seafood #12: In Cod We Trust
In which the E@L relates the stories of the worlds most famous fish (Cod) and America's largest fishery (Alaska Pollock)
Cod is probably the most famous fish in the ocean. Cod was the first international commodity, the reason Europeans came to America, and the primary food source of American colonists. American history is tightly bound to the history of cod fisheries.
Cod and their relatives are some of the most abundant and productive fish in the ocean. All cod-like fishes are members of the Family Gadidae. This includes Atlantic and Pacific cod, Atlantic and Pacific pollock, Atlantic and Pacific hake, haddock, and many other species. Cod fishes are demersal, living just above the seafloor on continental shelves from 50 to 250 m depth. Large cod can reach 5-6 ft in length and weights of 60-80 pounds and can live up to 20 years. They are highly productive; a single female can produce 5-9 million eggs each year. They eat primarily zooplankton and small fish, and are prey to larger fish, birds, and sea lions. Cod live in enormous schools comprised of millions of fish. Cape Cod is named for the abundance of cod that lived just offshore on Georges Bank. The defining feature of cod is their abundance, which allowed them to become common food for common people, virtually a marine equivalent to chicken, and unlike salmon or tuna which were high priced rarities until recently. The story of cod is aptly told by Mark Kurlansky in his book called, appropriately, Cod, and by Paul Greenberg, in Four Fish.
A Whopper of a Fish Tale
Atlantic cod, Gadus morhua, was a staple diet for much of Europe during the Middle Ages. Viking explorers who set out to explore the North Atlantic Ocean (after being kicked out of Norway for murder), eventually discovering and settling Iceland, Greenland, and Labrador, lived primarily on dried cod during their voyages. They got as far as Newfoundland, where they were repulsed by the local natives (which must have been very demoralizing to such a vicious lot). In 1497, John Cabot rediscovered Newfoundland and its abundant cod and claimed it for England (even though he was Italian). In the 1530’s Jacques Cartier re-rediscovered it again and claimed it for France, only to find that there were a thousand Basque fishing boats already there. They hadn’t claimed it because they were keeping it their secret. They caught their fish on the Grand Banks of Newfoundland, a large shallow plateau that juts out between the north flowing Gulf stream and the cold, south flowing Labrador Current. The coming together of these two great currents brings a vast richness of nutrients up onto the banks allowing plankton and fish to flourish.
During the 1500s, in the North and Baltic Seas, the Hanseatic League created a hegemony on codfish and beer. Dried cod caught by Scandinavians, called stockfish, could be stored, traded, and bartered like money. All they had to do was soak it in water and cook it. The Basques discovered that they could preserve their dried fish for long ocean crossings by salting it, thus inventing “salt cod”, which became the de facto standard version of cod. Cod became a major food source in England too, though their climate was too moist for drying cod, and they had no source of salt. Rather than buying salt from France, their enemy, they imported it from Portugal until the Portuguese teamed up with the Spanish Armada, and we know how that went (mostly down).
By the 17th Century, England needed a new source of cod, so their fishermen sailed west to Newfoundland and settled it (the Basques hadn’t bothered). There really wasn’t any other reason to go there. Fishermen caught vast quantities of fish, dried them, and shipped them all over the world (for a fictional but mostly accurate account of the early cod fishery read “Captains Courageous” by Rudyard Kipling). They thought that the fish were infinitely abundant and would last forever (sound familiar?).
Settlers also came to New England because of the abundance of cod. The pilgrims claimed fishing as a primary reason for their charter in North America, even though few knew how to fish, and they brought no fishing gear. But they quickly discovered the abundance of cod around Cape Cod, and on Georges Bank off the coast of Massachusetts. Cod became a primary source of income for the burgeoning city of Boston, whose merchants bought and resold most of the fish caught in Newfoundland and Nova Scotia, bringing them enormous commercial power that began to threaten English rule. Many tons of salt cod were packed in barrels and shipped to the Caribbean as food for enslaved Africans working on sugar cane plantations. Cod were engraved on some of the first American coins, and a gilded cod was mounted in the Boston Town Hall (in Cod we trust?). Many family fortunes were made from cod, forming the basis of a “codfish aristocracy”. The first Congress of the United States began a long history of subsidizing fisheries by granting them a relief from import duties on salt, which was necessary for preserving cod.
The Rise and Fall of Atlantic Cod
As cod stocks dwindled, scientists still failed to grasp the idea that fishing could cause them to be depleted. Instead, they clung to the idea that the ocean was inexhaustible. In 1871, the United States Fish Commisson (the predecessor of today’s NOAA) was created to help preserve the fishing industry, rather than the fish that they pursued. As cod declined further, the Commission devoted its efforts to helping fishermen find ways to catch more fish, and by building fish hatcheries that released millions of small fingerling cod into the ocean. The idea of regulating fisheries, or limiting their catch, was not their responsibility, and was heavily discouraged by the fishing industry.
During WWII, most northern nations stopped fishing, creating a six-year reprieve during which cod stocks grew abundantly. After WWII, Russia built hundreds of enormous fishing boats called BMRTs to supply the protein they desperately needed and fished for cod and pollock all over the world. BMRT stands for Bolshoi Morozilnii Ribolovnii Trawler, or large freezing fishing trawler. England, dependent on cod to support a large network of fish and chip shops, also sent large fishing boats out into the Atlantic. Many of these headed for Iceland, where cod was abundant.
But the party didn’t last. In 1944, Iceland declared independence and turned to cod fishing to fund their economy, shedding its medieval subsistence culture and becoming a modern nation virtually overnight. To protect their most abundant resource, which was cod, they excluded foreign fishing boats from a 4-mile zone around the country. Britain and other countries protested and continued trying to fish. This led to three separate “wars” between the Icelandic coast guard and British fishing boats, protected by British Naval vessels. Many skirmishes ensued, vessels collided, and shots were fired, but nobody was ever killed. Iceland, the only country whose economy depended almost entirely on fish, extended its exclusive zone to 50 miles, and eventually 200 miles, setting a precedent that was soon followed by most coastal countries.
In 1976 the United States also declared a 200-mile Exclusive Economic Zone (EEZ). Rather than kick the foreign trawlers out of our zone, we began putting biologists aboard these vessels to find out what they were catching. (As one of my first professional jobs, between semesters of graduate school, I spent two months working aboard Russian BMRTs, which we biologists called Big Motherf---ing Ruskie Trawlers). These boats rapidly depleted the standing stocks of Atlantic cod. Catches peaked at about 2 million tons in 1970, before the population collapsed. By 1994, less than 50,000 tons were being caught, and the United States prohibited cod fishing on Georges Bank.
As it turns out, cod are the original BOFFFFs (Big Old Fat Fecund Female Fish; see Sustainable Seafood #3 for explanation). As they grow, the proportion of body mass devoted to egg production increases disproportionately, so that 1 ten-kg fish produces as many eggs as 21 one-kg fish. The first fish to disappear from the population were the largest females, which left only small females to reproduce. And as fish populations decline in abundance, younger fish become mature at smaller sizes, producing fewer eggs. A cod living 20 years or more could produce over 100 million eggs, but only two need survive to maintain a stable population. The odds of a cod egg surviving past it’s first year (known as “recruitment”) are about one in ten million. In a good year, recruitment can be enough to replace the population many times over, but in a bad year it can be zero. So as the population dwindled, recruitment took a nosedive.
One of the primary prey items of cod is the snow crab (Chionoecetes opilio). In the Bering Sea, Pacific cod probably eat the majority of juvenile snow crab every year. From an ecological perspective, snow crab exist to feed cod. And as the stock of Atlantic cod crashed, snow crab populations boomed. Whether this was due to lack of predation, or changes in the oceanic climate is still up for debate. From a cod fisherman’s perspective, crab fishing is a lower class of work than cod fishing, and some were reluctant to do it. Nonetheless, with encouragement from the Canadian government, out-of-work cod fishermen quickly made the switch to fishing for snow crab, which soon became the pre-eminent fishery in Newfoundland and Nova Scotia (For a humorous but fictional account of those times, read “The Fishing News” by Annie Proulx). Following the recent collapse of Alaskan snow crab (another story for the future), Canada is now the world’s largest supplier of snow crab (but keep your eye on Norway). In Saint Johns, Newfoundland, the oldest city in North America, founded to harvest the richest cod fishery in the world, both cod and cod fishermen are commercially extinct.
Pacific Cod
Since the collapse of Atlantic cod, the fishery for Pacific cod, Gadus macrocephalus, has become the dominant cod fishery in the United States, mostly from Alaska. In the United States, landings of Atlantic cod are less than 500 tons (1 million lbs), and unsustainable due to overfishing, habitat damage by trawls, and possibly climate change, whereas landings of Pacific cod exceed 183,000 tons (400 million lbs). Pacific cod are caught by trawl (with associated bycatch), by longline (much less bycatch), or in modified king crab traps (a proportion of which become derelict ghost pots). Pacific cod is smaller and less flaky than Atlantic cod, so isn’t as popular in Europe, but it is still an excellent fish. If you see cod in a grocery store in the United States, it is most likely Pacific Cod.
Nutritionally, cod have medium to high protein content, and extremely low fat and cholesterol content. It has a mild flavor and flaky texture that is perfect for fillets, and fish and chips.
Alaska (Walleye) Pollock, Gadus chalcogrammus
Alaska Pollock is a close relative to Pacific Cod. It was previously considered a different genus but has recently been reclassified in the genus Gadus. Pollock supports the largest fishery in the United States, with landings of about 1.2 million tons (2.5 billion lbs) annually. Most of it is caught in the Bering Sea by giant midwater trawls. Considering the size of the fishery, it deserves much more attention than I give it here. But you will never see pollock in the grocery store or order it for dinner. That’s because pollock is used primarily for processed fish products such as fish sticks and fish sandwiches. Pollock is the main ingredient in McDonald’s fish sandwiches. Much of it is also turned into surimi, a highly processed fish product used in Japanese food, and to make artificial crab.
Although the pollock trawl fishery is considered to be highly sustainable, it creates a large amount of bycatch and has been blamed for declining numbers of chum and king salmon in the Yukon and Kuskokwim rivers. For a detailed and entertaining account of the Alaskan pollock fishery, read Billion Dollar Fish by Kevin Bailey.
Pacific Hake Merluccius productus are close relatives of cod and pollock. They are the most abundant fish stock off the US Pacific Coast, from California to the Gulf of Alaska. They form great schools that undergo diurnal vertical migrations following plankton and baitfish. They were one of the primary targets of Russian and Polish fishing fleets prior to establishment of the US EEZ. They are similar in size, texture, and flavor to pollock, reaching 2 feet in length and 2 pounds weight. The US fishery lands 262,000 tons (577 million lbs), even more than Pacific Cod, but it is less valuable, worth only US $64 million. They are jointly managed by the US (74%) and Canada (26%). Fishing quotas are assigned to cooperatives that allocate shares among members including vessels, processors, and tribal groups. Hake is also used in processed fish products like pollock, and is commonly marketed as “whiting” or “Pacific whiting”. Several other hake-like fish (red hake, silver hake, and white hake) are also caught in the North Atlantic, but in much smaller quantities (total of about 6200 tons or 13.8 million lbs).
A Taste of History
Cod, pollock, hake (or whiting), and haddock are slow swimmers that live near the seafloor. Thus they lack the firm muscle mass of tuna, as well as the dark, myoglobin rich tissue for storing oxygen, and have virtually no fat. When cooked, they fall apart into light, delicate flakes. The best way to cook cod is by gently steaming or baking, or layering it atop a panful of sauteed vegetables and tomatoes. Cooking fish “en papillote”, i.e. encased in paper or foil, will seal in the moisture, guaranteeing a tender, juicy dish. They are also excellent when breaded and deep fried, which also helps seal in the moisture, and this is probably the way most people eat cod and haddock. They don’t work well on the grill because they tend to fall apart, although they can be pan-fried if you handle them carefully while turning them over. With current flash freezing technology, these fish can be shipped anywhere in the world. If you buy “fresh” fillets from the grocery store, ask the fishmonger if they have been previously frozen, and if so, ask to buy fillets that are still frozen. That way, you have the option to keep them frozen until you need them, and to thaw them under controlled conditions. If they are actually fresh, prepare them within a day or two, or freeze immediately.
For those of you who are paying subscribers, and who love eating fish, I have posted a recipe for delicious, flaky, moist cod as a separate article within my Sustainable Seafood series. You will see it in your email soon.
Whether you eat fresh cod, hake/whiting, or pollock disguised as a McDonald’s fish sandwich, you are eating one of the most abundant fish in the world. Cod and their kin supported the development of civilization in Northern Europe and Eastern North America, provided much needed protein to many countries after a devastating world war, and still support one of the largest fisheries in the world. More than any other fish, cod can be considered as the international standard fish, to which all others are compared. When you eat cod, you partake of a culinary tradition going back centuries, connecting you to ancient Vikings, intrepid Basque fishermen, European explorers, and early American merchants. When you eat cod, you eat history.
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Sources
Kurlansky, M. (1998). Cod: A Biography of the Fish that Changed the World. Penguin Books. New York, NY. 294 pp.
Greenberg, P. Four Fish. The future of the last wild food. Penguin Books. New York, NY. 285 pp.
Bailey, K. (2013) Billion Dollar Fish: The Untold Story of Alaska Pollock. University of Chicago Press. 288 pp.