Atlantic Cod

The Atlantic Cod (Gadus morhua) is a large, cold-water fish in the family Gadidae, found on both sides of the North Atlantic from the Bay of Biscay to the Barents Sea and along the coasts of Greenland and eastern North America. It is one of the most historically significant fish species in the region, having supported major commercial fisheries for centuries. Populations of Atlantic Cod, particularly off eastern Canada, collapsed dramatically in the early 1990s due to overfishing, leading to long-term fishing moratoriums and listing as a species of conservation concern in some regions. It remains an important indicator species for North Atlantic marine ecosystem health and fisheries management.

Atlantic Cod have a distinctive combination of fin arrangement and markings that separate them from similar gadid species.

• Dorsal fins: three separate, rounded dorsal fins along the back
• Anal fins: two separate anal fins
• Barbel: a single prominent whisker-like barbel under the chin
• Color: olive-green to reddish-brown above with scattered small dark spots, pale lateral line, white belly
• Size: commonly 50-100 cm, historically up to 1.8 m The pale, distinctly curved lateral line and three-part dorsal fin combination distinguish it from Pollock, which lacks the chin barbel and has a more streamlined, silvery body.

Atlantic Cod inhabit cold, temperate continental shelf waters on both sides of the North Atlantic, from the eastern seaboard of North America and Greenland to the coasts of Europe including the North Sea, Baltic, and Barents Sea. They are typically found from nearshore shallows down to depths of around 600 meters, though most commonly encountered between 50 and 200 meters. Cod favor rocky, gravel, or sandy bottoms and show seasonal movements, migrating between deeper offshore wintering and spawning grounds and shallower feeding areas. Preferred water temperatures range from near freezing to around 10°C, and the species tends to avoid the warmest parts of its range during summer months.

Atlantic Cod are opportunistic bottom-oriented predators, feeding on a wide range of fish, crustaceans, and mollusks, with diet shifting toward larger fish prey as individuals grow. They form loose aggregations, particularly around spawning grounds, though they are not tightly schooling like herring or mackerel. Spawning occurs in late winter to spring at specific traditional grounds, where large numbers gather and females release millions of buoyant eggs that drift and hatch in open water. Cod exhibit relatively slow growth and can live over 20 years, making populations vulnerable to overexploitation. As a major mid-level predator, the species plays an important role in structuring North Atlantic shelf ecosystems.