Return to the Wild - Evolving perspectives on Canadian wildlife
North American Atlantic cod populations are found from North Carolina all the way north to Baffin Island.

Did you know?

One of the largest recorded Atlantic cod was 96 kilograms and 180 centimetres long.

Scientific name: Gadus morhua
Average weight: 2 – 3 kg
Average length: 60 – 100 cm long
Average lifespan: 20 years or more (but wide variation)
An Atlantic cod clearly displaying its barbel.

About

Biology

As the species that defined Canada’s fishing industry more than 500 years ago, the Atlantic cod has gone by many other names, including codfish, scrod, northern cod, ovak and uugak. Whatever it was called, it became highly prized for its inner flesh, which is white, firm and not very oily.

The fish has three dorsal (top of the body) fins, two anal fins and a square tail. It also has a piece of flesh hanging from under its lower jaw, called a barbel. In general, this speckled fish is grey or green, but depending on its particular habitat and diet, it can also be brown, red or golden. A lateral line runs from the gills to the tail and small, smooth scales cover the body of the fish.

A streamlined body allows it to swim at moderate speeds over long distances if it needs to, and there is a very small bone in the cod’s head called an otolith. From the rings in this bone, one can ascertain the age of the fish.

Habitat and behaviour

As a groundfish, the Atlantic cod lives in the bottom layers of the ocean. Usually it is found at water depths of 400 metres or less, and different groups will reside in a bay or the open water of the ocean.

Like many fish in the North Atlantic, the cod is sensitive to water temperatures. However, it can survive in water as cold as – 1˚C due to an antifreeze protein in its blood. Generally it is found in water ranging from 2 to 11˚C.

Spawning for the Atlantic cod might well involve mate selection and occurs in water anywhere from 10 to 200 metres deep, with the female laying millions of eggs. With such high numbers, the fish does not build a nest, nor does it provide parental care.

In general, it is a migrating fish but some stocks move more than others, with cases of a stock passing through an entire life cycle in one bay, while another stock can move approximately 800 kilometres in a year.

In the summer, the cod migrates to waters less than 50 metres deep while it is feeding. Typical meals for the highly opportunistic feeder include fellow Atlantic cod (including its own young), clams, squids, mussels, echinoderms, comb jellies, worms and even the odd seabird. The fish is known to swallow stones that its prey is sticking to and discharge the stones after digesting the organism. Species that prey on it include other fish, seals, whales and above all, us.

Range

The Atlantic cod lives on both sides of the North Atlantic Ocean. Of the North American populations, the fish is found from North Carolina all the way north to Baffin Island. The Grand Banks area, off of Newfoundland and Labrador, has historically been home to large numbers of the fish, a key incentive that first brought Europeans to this continent.