Atlantic Cod

Quick Take

• Atlantic cod can produce millions of eggs per female, and yet the species is still classified as vulnerable. The reason reveals a critical misunderstanding about how fish populations actually recover. See egg production details →
• Adult Atlantic cod don't just compete with other predators for food. They also turn on members of their own species in a way most people wouldn't expect. See cannibalistic behavior →
• Northern Europeans didn't just eat Atlantic cod. They crossed entire oceans for it, and the reasons go deeper than simple hunger. See the fishing history →
• Most people picture cod as a modest-sized fish, but the largest recorded specimen would surprise almost anyone who's ever ordered it at a restaurant. See the largest recorded size →
• Atlantic cod hunt by a clock that most predators ignore, and that timing shapes everything about how they feed and where they roam. See crepuscular feeding habits →

The Atlantic cod is a historically important fish species that has sustained human populations near the North Atlantic for hundreds, if not thousands, of years. Its flesh is mild and tasty, with ample nutrients and low fat content. As a benthopelagic predator, it remains near the top of its ecosystem, though it falls prey mainly to sharks and marine mammals. Unfortunately, overfishing and habitat concerns have depleted its numbers over the past few decades.

3 Atlantic Cod Facts

• A capable predator: Though this fish has a few predators of its own, it also preys on several other species, including other fish and invertebrates.
• Occasionally cannibalistic: Adults of this species sometimes prey on their own juvenile members.
• Commercially important: Although Atlantic cod is still targeted by commercial fisheries in the North Atlantic, its role has diminished significantly due to low stocks and strict quotas, and it is no longer as commercially vital as it once was.

Classification and Scientific Name

The scientific name for the Atlantic cod is Gadus morhua. The name Gadus derives from the Latin for “fish” or “cod.” Other names for this species include cod or codling.

This species belongs to the class Actinopterygii (ray-finned fishes) and the order Gadiformes (cods and allies). It further falls into the family Gadidae (codfishes) and the genus Gadus, which contains three species of fish. These have traditionally included the Atlantic cod, the Pacific cod (Gadus macrocephalus), and the Greenland cod (Gadus ogac). A fourth species, the walleye pollock (Gadus chalcogrammus), is now officially classified within the genus Gadus.

Appearance

Dorsally, these fish range in color from brownish to greenish to gray. Dorsal spots accompany this coloration, which fades to silver on their bellies. Color changes in individual fish are known to occur. A pale lateral line, curved over the pectoral fin, marks both sides from near the eyes to the tail.

These heavy-bodied fish possess three dorsal fins, two anal fins, and pectoral and pelvic fins. Their large heads feature blunt snouts and barbels on their lower jaws. The typical size range for adults of this species falls between 39 and 51 inches in length, though the largest specimen on record attained a length of 78.7 inches (6.5 feet). Although most do not surpass 77 pounds, exceptional individuals have been known to exceed 200 pounds.

Distribution, Population, and Habitat

Atlantic cod inhabit the Atlantic and Arctic Oceans from Greenland to Cape Hatteras in North Carolina, USA. In North America, they are most common on Georges Bank and the western Gulf of Maine. Their range also includes much of the western coastline of Europe. It may also appear off the coast of China, though this has not been confirmed by experts.

These fish are capable of surviving in both marine and brackish water from the shoreline to the continental shelf. Adults typically prefer deeper and colder waters, unlike juveniles, who seek out hiding places among seagrass and rocks in shallower waters. They swim at depths up to 1,970 feet, though they usually do not exceed depths of 660 feet.

The IUCN currently lists this species as Vulnerable, although its last assessment took place in 1996. Although efforts are underway to increase stocks, their numbers remain low.

Evolution and History

The Gadiformes, or codfishes, date back in the fossil record to the Palaeogene. The most ancient records originate in the Danian (66 to 61.6 million years ago) and Selandian (61.6 to 59.2 million years ago) stages. Scientists discovered these records in Europe and South Australia.

The order diversified quickly sometime after the early Palaeocene or late Cretaceous. Originally, codfish preferred shallow-shelf environments, but they soon adapted to thrive in deeper water. Certain species within this order, including the Atlantic cod, eventually became isolated in the North Atlantic as opposed to further south.

Humans have fished for Atlantic cod for at least a thousand years and potentially much longer. Northern Europeans in countries like Norway and Sweden have relied on this species for centuries, even crossing the Atlantic Ocean in pursuit of cod populations. Indigenous peoples along the eastern coast of North America have also traditionally fished for cod for centuries, if not millennia.

Predators and Prey

Atlantic cod are top predators along the ocean floor, though they are also ready prey for larger marine species. They are crepuscular feeders, hunting their prey in the dim light of dawn and dusk.

What Do Atlantic Cod Eat?

These fish are omnivorous, feeding on both plant and animal matter. Juveniles mainly eat small crustaceans like shrimp, while adults prey on both invertebrates and other fish like herring, capelin, mackerel, and small haddock. They can also be cannibalistic, hunting juveniles of their own species.

What Eats Atlantic Cod?

This species typically falls prey to marine mammals and sharks like the spiny dogfish. As juveniles, these fish may also become the target of larger members of their own species. Humans are among their most avid hunters, which has led to the decline of the species.

Reproduction and Lifespan

Atlantic cod reproduce offshore in winter and early spring. Spawning takes place near or on the ocean floor, typically at depths between 165 and 655 feet. Ideal spawning temperatures for this species lie between 32 and 53.6°F. However, if temperatures near the ocean floor are unfavorable, the fish may move to the water column.

Males and females reach sexual maturity between two and three years of age with a body length of 12 to 16 inches. Females produce between three and nine million eggs, depending on their size. Larger females produce a greater number of eggs. They release the eggs into the water, where the males fertilize them. The embryos develop over about two weeks, though the larval phase lasts up to three months. The larvae are pelagic until they reach about 2.5 months of age, after which they move to the ocean floor. These fish live to be up to 25 years old.

Fishing and Cooking

Atlantic cod is a popular food fish with high economic importance. Both commercial and sport fishers prize this species for its tasty flesh. Recreational fishermen typically use lures or bait to catch these fish. Commercial fisheries use gillnets, trawl nets, longlines, and rod and reel. According to NOAA, commercial landings of this species in 2021 came to 1.3 million pounds with a value of $3 million. Recreational landings in 2021 came to 750,000 pounds.

The raw flesh of this fish is translucent with a pinkish-to-whitish hue. It transitions to an opaque white as it cooks. Its meat is flaky and tender, though less moist and therefore firmer than Pacific cod. Its taste is mild and sweeter than that of its Pacific cousin, making it an ideal complement to herbs like dill and cilantro.

This fish benefits from several cooking methods, including baking, broiling, frying, sautéing, and steaming. Per 100 grams, its lean flesh contains 82 calories, 0.7 grams of fat, 17.8 grams of protein, and 0.2 grams of Omega-3. Discover 37 ways to prepare cod or try this simple baked cod recipe.