The Bay of Fundy is a large inlet of the Atlantic Ocean between the Canadian provinces of Nova Scotia and New Brunswick, famous for producing the highest tides on Earth. At Burntcoat Head in Nova Scotia’s Minas Basin, the Canadian Hydrographic Service recorded a tidal range of 16 meters (52.6 feet), a figure listed in the Guinness Book of World Records. Twice a day, roughly 160 billion tonnes of seawater flow in and out of the bay, reshaping its coastline, fueling a rich marine ecosystem, and drawing visitors from around the world.
Where the Bay Is Located
The Bay of Fundy sits on Canada’s eastern coast, wedged between Nova Scotia to the southeast and New Brunswick to the northwest. Its southwestern mouth opens toward the U.S. state of Maine. The bay stretches roughly 270 kilometers inland from the Gulf of Maine and narrows into two upper arms: Chignecto Bay to the north and the Minas Basin to the east. That funnel shape is central to what makes the tides so extreme.
Why the Tides Are So Extreme
The massive tides aren’t caused by any single feature. They result from tidal resonance, a phenomenon NASA describes as a kind of synchronization between the bay’s shape and the rhythm of ocean tides. When a wave enters the bay’s wide mouth, it travels to the far shore and bounces back. The time it takes for that round trip happens to nearly match the roughly 12.4-hour interval between high and low tides. Because those two rhythms align, each incoming tide reinforces the one already sloshing inside the bay, amplifying the water level dramatically.
Think of it like pushing a child on a swing. If you push at random, not much happens. But if your pushes are timed to the swing’s natural rhythm, the arc grows larger and larger. The Bay of Fundy’s long, narrow, gradually shallowing shape creates exactly that timing match with the Atlantic’s tidal pulse. The result is a vertical difference between high and low tide that can exceed 12 meters on a typical day and reached the record 16 meters at Burntcoat Head.
Walking the Ocean Floor
The enormous tidal range creates one of the bay’s most popular experiences. At Hopewell Rocks Provincial Park in New Brunswick, visitors can walk on the ocean floor at low tide, exploring towering sandstone formations carved by centuries of erosion into shapes nicknamed “flowerpot rocks.” Hours later, the same formations are submerged up to their treetops, and the area becomes a kayaking destination. The window for walking the ocean floor shifts daily with the tide schedule and is ultimately at the discretion of park staff for safety reasons, so checking the park’s tide tables before visiting is essential.
The bay also produces tidal bores on several rivers that feed into it. At the Fundy Discovery Site near the mouth of the Salmon River, the incoming tide creates a visible wave front that pushes upstream against the river’s normal flow. The Shubenacadie River in Nova Scotia is another well-known spot, where outfitters run rafting tours that ride the bore wave as it rolls in.
A Feeding Ground for Whales
The same tidal forces that reshape the coastline also drive an extraordinarily productive food web. The churning water mixes nutrients from the deep ocean with sunlight-rich surface layers, supporting dense populations of plankton and small crustaceans. That abundance draws several species of baleen whales into the bay each summer to feed.
Humpback whales are among the most visible, with the majority of sightings occurring between July and September. Fin whales and minke whales also forage in the area during summer months. The bay holds particular importance for North Atlantic right whales, one of the most critically endangered large whale species on Earth. The outer bay and Grand Manan Basin have long served as key feeding and nursery habitat for right whales, with acoustic monitoring confirming their presence through spring, summer, and fall. Sei whales, another endangered species, are regular visitors as well.
Millions of Shorebirds in Transit
The bay’s vast mudflats, exposed twice daily by retreating tides, host one of the largest shorebird migrations in the Western Hemisphere. Over two million semipalmated sandpipers, representing roughly 75 percent of the species’ global population, pass through the upper Bay of Fundy each year. Beginning in early summer, these small birds leave their Arctic breeding grounds in northern Canada and stop in the bay to refuel on mud shrimp and other invertebrates before continuing to wintering areas in northern South America. The tiny crustaceans that thrive in Fundy’s mudflats provide the calorie-dense food the sandpipers need to nearly double their body weight before making their nonstop transatlantic flight south.
300-Million-Year-Old Fossils in the Cliffs
The bay’s powerful tides do more than move water. They continuously erode the shoreline, exposing geological layers that would otherwise remain buried. On the eastern shore of Chignecto Bay, the Joggins Fossil Cliffs contain the most complete known fossil record of land-based life from the Carboniferous period, roughly 300 million years ago. The site is a UNESCO World Heritage location, sometimes called the “Coal Age Galapagos.”
At that time, the region sat near the equator and was covered in tropical wetland forests. The cliffs preserve upright fossil trees at multiple levels, along with approximately 200 species of fossilized animals and plants. Most significantly, Joggins contains the earliest certain fossil evidence of amniotes, the group of vertebrates that first evolved the ability to reproduce on land without returning to water. That group eventually gave rise to reptiles, dinosaurs, birds, and mammals. The ongoing tidal erosion means new fossils are regularly revealed, making the cliffs a site that scientists have studied continuously for over 150 years.
Tidal Energy Potential
With billions of tonnes of water moving through the bay twice daily, the Bay of Fundy represents one of the most promising locations on Earth for tidal energy generation. The Fundy Ocean Research Centre for Energy (FORCE), located in the Minas Passage where tidal currents are strongest, serves as Canada’s leading test site for in-stream tidal turbines. The technology works similarly to underwater wind turbines, with tidal currents spinning rotors to generate electricity. Development has been cautious and incremental, with significant attention paid to environmental monitoring given the bay’s ecological importance for whales, fish, and shorebirds.
The Bay’s Place in Maritime Culture
The Bay of Fundy has shaped human life along its shores for thousands of years. The Mi’kmaq people have deep cultural and spiritual connections to the bay, and their oral traditions include stories explaining its dramatic tides. European settlers, arriving in the 1600s, built an extensive system of dykes to reclaim tidal marshlands for farming, a practice that continued for centuries and left a visible mark on the landscape. Fishing communities have long harvested lobster, scallops, herring, and dulse (an edible seaweed) from the bay’s waters, and these industries remain economically important to the region today.
The combination of record-setting tides, rare fossil sites, endangered whale habitat, and massive shorebird migrations earned the Bay of Fundy recognition as a UNESCO Global Geopark through the Cliffs of Fundy Geopark designation. For visitors, the bay offers everything from sea kayaking at high tide to walking the ocean floor at low tide, all within the span of a single afternoon.