The Grand Banks sit in the Atlantic Ocean off the coast of Newfoundland

The Grand Banks are a series of underwater plateaus located roughly 250 miles east of Newfoundland, Canada, in the Atlantic Ocean. They form part of the continental shelf that extends from North America into the sea. The Banks cover an area of about 36,000 square miles — larger than the state of Maine — and sit in relatively shallow water compared to the open ocean, typically between 300 and 600 feet deep.

The most famous section is called the Grand Bank proper, but the region includes several connected plateaus: the Grand Bank, the Northeast Peak, the Southeast Peak, and smaller formations. The entire system slopes gradually from the continental shelf down toward the abyssal plain of the Atlantic. This underwater geography creates conditions that have shaped human history, trade, and international law for centuries.

Key Takeaways

  • The Grand Banks are underwater plateaus 250 miles east of Newfoundland, Canada, in the Atlantic Ocean.
  • The region covers about 36,000 square miles and sits in water 300 to 600 feet deep, making it part of the continental shelf.
  • Cold currents from the Arctic meet the warm Gulf Stream over the Banks, creating fog and rich fishing grounds.
  • The Banks have been a major fishing zone for over 500 years and remain economically important to Canada and other nations.
  • International disputes over fishing rights on the Grand Banks led to modern ocean boundary laws and treaties.

Why the Grand Banks became famous for fishing

The Grand Banks are one of the world's most productive fishing grounds because of their unique ocean conditions. Cold water from the Labrador Current meets the warm Gulf Stream directly over the Banks, creating an upwelling of nutrients from the seafloor. This collision of currents brings plankton and small fish to the surface, which in turn attracts larger fish — particularly cod, which once filled the waters in such abundance that early explorers reported you could walk across the ocean on their backs.

European fishermen discovered the Banks in the late 1400s, within a few decades of Columbus reaching North America. Portuguese, Spanish, French, and English vessels made the dangerous Atlantic crossing specifically to fish there. By the 1600s, the Grand Banks fishery was so valuable that nations fought wars partly over access to it. The cod trade became the economic engine of Newfoundland and shaped the colonial history of the entire region.

How ocean currents create the fishing conditions

Two major ocean currents meet over the Grand Banks, and this meeting is what makes the region so rich in fish. The Labrador Current carries cold water and icebergs south from the Arctic, while the Gulf Stream carries warm water north from the tropics. Where these currents collide, the cold water sinks beneath the warm water, a process called upwelling.

This upwelling brings nutrients from the ocean floor — nitrogen, phosphorus, and other minerals — to the surface where sunlight can reach them. Phytoplankton feed on these nutrients and multiply rapidly. Small fish eat the plankton, and larger fish eat the small fish. The result is a food chain so productive that it supports one of the world's densest concentrations of fish. The same currents also create the famous Grand Banks fog, which forms when warm, moist air from the Gulf Stream passes over the cold water brought by the Labrador Current.

The collapse of the cod fishery and what changed

For nearly 500 years, the Grand Banks seemed inexhaustible. By the 1980s, however, industrial fishing vessels with sonar, nets the size of football fields, and freezing equipment had removed so much cod that the population crashed. In 1992, Canada closed the fishery entirely — a moratorium that was meant to last a few years while the stocks recovered. Thirty years later, the cod population has not returned to levels that support commercial fishing.

The collapse of the cod fishery had enormous consequences. Thousands of fishermen lost their jobs. Entire communities in Newfoundland that had depended on cod for centuries had to reinvent their economies. The event also changed international law: it demonstrated that ocean resources could be depleted, and it accelerated the creation of Exclusive Economic Zones — areas extending 200 miles from a nation's coast where that nation has the right to manage fishing and other resources.

International disputes and the 200-mile limit

The Grand Banks sit at the center of one of the most important maritime disputes in modern history. Because the Banks are on the continental shelf, both Canada and other nations claimed the right to fish there. France still owns two small islands — Saint-Pierre and Miquelon — near Newfoundland, and used them to claim fishing rights. Spain and Portugal also sent vessels to the Banks.

In 1977, Canada declared a 200-mile fishing zone around its coast and began enforcing it with coast guard vessels. This sparked the "Cod Wars" — a series of confrontations between Canadian and European fishing boats. The disputes were eventually settled through international courts and treaties, but they led directly to the United Nations Convention on the Law of the Sea, which established the 200-mile Exclusive Economic Zone as international law. Today, most of the Grand Banks fall within Canada's zone, though some areas remain in international waters where fishing is regulated by treaty.

What the Grand Banks look like today

The Grand Banks remain a working fishing ground, though the species and methods have changed. Cod fishing is still restricted, but other fish — halibut, haddock, and various groundfish — are caught under strict quotas. The region is also home to oil and gas operations: Hibernia, one of the world's largest offshore oil fields, sits on the Grand Banks and has been producing since 1997.

The Banks are also a major shipping lane. Hundreds of vessels pass through the region each year, and the area is known for rough seas, icebergs, and fog. The wreck of the Titanic lies about 400 miles south of the Grand Banks, in water that icebergs from the same region drift through each spring. Today, the Grand Banks represent a balance between resource extraction, environmental protection, and international cooperation — a balance that continues to shift as climate change warms the Atlantic and fish populations move northward.

Frequently Asked Questions

Are the Grand Banks part of Canada?

Most of the Grand Banks fall within Canada's 200-mile Exclusive Economic Zone, which gives Canada the right to manage fishing and other resources there. However, some areas remain in international waters and are governed by international treaties. France also maintains fishing rights near its islands of Saint-Pierre and Miquelon.

Can you still fish on the Grand Banks?

Yes, but under strict regulations. Cod fishing remains closed or severely limited, but other species like halibut and haddock are caught under quotas. Commercial fishing requires licenses and must follow rules set by Canada's Department of Fisheries and Oceans.

Why is it so foggy on the Grand Banks?

Fog forms when warm, moist air from the Gulf Stream passes over the cold water brought by the Labrador Current. The temperature difference causes water vapor in the air to condense into fog. This fog is so common and thick that it has shaped the region's maritime history and remains a hazard for ships today.

What caused the cod to disappear?

Industrial fishing technology — large vessels with sonar, massive nets, and freezing equipment — removed cod faster than the population could reproduce. By the 1980s, the stock had collapsed. Climate change, which has warmed the Atlantic and shifted fish migration patterns, has also slowed recovery.